[Soundsgoodtome]

Most likely the house sound is generated from the film capacitors made by MHDT Labs themselves, it's how they achieve their signature in my guess - along with the other components of course but their signature is very much what film caps sound like. As for the loose bass mentioned, this wasn't as evident until it was plugged into the speakers which I believe magnified the slight boost. It could very well be a dialing-in thing (as Barra mentions) or a synergy thing with non-adjustable rigs. I do understand there is no such thing as a non-adjustable rig as you can play with all sorts of tweaks but I'm more in regards to actual EQ or some type of analog boost/cross-over/etc in the chain. 
 
What I don't understand is how Barra notices the bass boost in comparison to the Havana he owns... he mentions with the Stockholm and his speakers that the bass intrudes into the mids and kills the soundstage along the way. This is not subtle difference even if the speakers are magnifying any 'slight' changes that would've been heard through headphones. Does the larger transformer in the S2 add that extra impact/boost in the lows? This is the reason for including 2 extra tubes in the tour, something I should've done from the get-go as one of the main features of the MHDT Dacs is in fact tube rolling to tweak the DAC to fit a certain chain. I think the AEG and TripleM GE tube should offer enough differences from the Bendix 2C51 to allow listeners to hear differences subtle or apparent. However if you were to just pick one and be done, I'd go for the AEG or Bendix and go from there. Jiun did mention however that the 2C51 tubes usually add some weight to the bass due to the tube design, so if bass becomes overwhelming the AEG or GE 5670 may be a better choice.
 

Spoiler: Quotes

  @Torq ...
 
Really interesting write up on the Stockholm; I find your comments to be very accurate in regards to my own experience with the Stockholm 2 DAC over the past year or more.  In fact, your comments could easily describe the Havana 2 DAC as well ... 
 
Your comments on bass performance echo my own in a couple different reviews I've done of the MHDT DACs ... compared to other DACs I've owned/borrowed, the bass on the MHDT Dacs has always been just a bit loose around the edges ... something I would never notice until direct A/B listening with other gear.  I'm not so sure this is a tube anomaly as much as it is related to some other factor (perhaps capacitors used throughout or some other nuance of the circuit); the Bendix 6385 and 2C51 tubes will certainly do a bit towards tightening up the bass a hair but I wouldn't call it a "transformation" by any means.  Similarly, an AEG tube will do the same (but good luck finding one).  But the slight "bloom" in the bass is by no means anything glaring and is completely offset by the DACs other stellar qualities (musicality, ease, richness, etc.).
 
The Pagoda DAC, an identical circuit as the Stockholm 2 ... with it's PCM1704 DAC chips, creates a markedly different image sonically than the Stockholm 2 ... and while the bass is a tad leaner/tighter ... it still occasionally has that "trademark" MHDT "bloom" here and there ... which is what leads me to believe it has more so to do with the other components in the DAC (capacitors, etc.) more so than the tube or general R2R design scheme employed.
 
As mentioned, the Havana DAC has even more of this quality ... being a significantly "darker" listen than the Stockholm 2 ... but many users in the long standing Havana thread here at Head-fi have *extensively* modified their Havana DACs putting in different power supplies and in some cases completely replacing all of the MHDT Labs produced capacitors with high end, very expensive "boutique" capacitors and in such cases the consensus is that the DAC was completely transformed in to a far and a way more high end listen by said modifications (bass included) ...
 
I'm no DIY guy, though and so I won't be modifying a Stockholm 2 DAC any time soon but perhaps somebody will; and regarding this, if anyone is interested in such mods ... just spend a lot of time in the Havana thread and pretty much anything you see there will apply to the Stockholm as well ...
 
But thanks again for the comments ...
 
Joel

 

 

Overall Impressions:

I found that MHDT’s product had a little bloom to the bass, which was especially noticeable via my WA6 – in fact with this pairing the bass was a bit overpowering, a little too fat and lacking in some control.  The Stockholm was slightly recessed (that might be too strong a word … but it was not as prominent as with the other DACs I used) when it came to deeper female vocals and yet managed to be a little sibilant with some of the brighter female voices (in places I’m not used to said sibilance).
 
Treble detail seems excellent and has a little extra sweetness to it compared to what I’m used to.  There’s a nice sense of space and air and things don’t get muddled when there’s a lot going on.  This never got fatiguing and had me exploring piece after piece that benefits from a delicate, sweet and detailed handling of the upper mid-to-treble range (primarily small ensemble acoustic stuff).
 
I imagine the tube-DAC feeding tube-AMP configuration here is responsible for much of the low-end bloom and the extra treble sweetness.  These elements were still audible, but much less pronounced, when played through my Ragnarok, though the bass prominence and plumpness was still quite apparent with my speaker rig.
 
The soundstage I found to be quite expansive and, when paired with speakers, nicely three dimensional (more on that in a bit).
 
Overall I found the Stockholm v2 to be very musical, possessing a lovely sweet and detailed treble and, paired properly amp-wise, a very satisfying if somewhat warm bottom end.  The mid-range was lucid and engaging and the overall instrumental tone was beguilingly rich.
 
I didn’t get to spend any time rolling tubes but I imagine that doing so would make it relatively easy to adjust the bass suitably, bring out the upper female vocal range a bit and maybe round off the little bit of unexpected sibilance on some (not all) higher pitched vocals.
 
Despite the fat and somewhat less-controlled sounding lower registers with the WA6 pairing, I found myself listening well into the small hours with the Stockholm, WA6 and HD650.  A slightly leaner tube would improve that further and I think it’s a wonderful combination.  Not that I mean to suggest the MHDT product is limited to that end of the gear spectrum, it was a lovely listen through my Ragnarok as well, but I found it to be particularly musical and engaging with the WA6 and HD650.
 
Compared to the Chord Mojo:
 
The Mojo is definitely more neutral, exhibits none of the Stockholm’s slight de-emphasis in the mid-range, has a much more even, taught, detailed and controlled bass, didn’t exhibit the sibilance I found in the Stockholm but also lacked the upper-end sweetness and generally juicy sounding mids.  Also, I’d give the Mojo the upper hand from an imaging perspective both with headphones and, particularly, with speakers.
 
So … while more accurate and more detailed, the Mojo drew me into the music less than the MHDT unit, unless there was a lot of energy in the female vocals or the bass line was particularly deep and driving.
 
Big orchestral pieces favored the Mojo, partly for it’s imaging and partly because it provided better separation between instruments.
 
Compared to the Bifrost “4490”:
 
The Schiit unit is much drier and more controlled, but no less extended, in the lower registers, flatter through the mids and ess interesting (though probably more accurate) in the upper-mid to treble regions.  Feeding the WA6 it was the most neutral presentation excepting the Yggdrasil, but was a bit less engaging for it.
 
I felt the MHDT was letting me experience more of the nuance of voices than the 4490, and then, through the Ragnarok, the 4490 seemed a bit harsher and less forgiving with anything that wasn’t extremely well recorded.  The Stockholm was, also, a more pleasant listen with lossy source material.
 
Texture and timbre of instruments are more natural, to my ears, with the MHDT DAC than with the “4490”, and notably with woodwind and string instruments there’s a little extra richness to the tone than I find with the Schiit component.
 
Compared to Yggdrasil:
 
This is a rather unfair comparison.  The Yggdrasil is the best DAC I’ve yet heard - and that list includes some very much more expensive gear.
 
The MHDT piece doesn’t do badly here at all, but it doesn’t have the detail, neutrality, ability to, somehow, make everything in the mix seem to be the focus all at once (not technically possible, of course, but I don’t know how else to describe it), that Yggdrasil has.
 
Soundstage/imaging out of the Yggy is out of this world.
 
In some places the Stockholm is a bit more “fun”, and it is more forgiving of poor recordings/lossy encodings, and there is some artificial sweetness or lushness in places that make it a cozier listen … and that’s very desirable at times – but it’s not as truthful or, overall, as satisfying as Schiit’s monster.
 
With Speakers:
 
My speaker system projects a very palpable, three dimensional, sound stage.  The Stockholm was able to play to this very nicely and, I think, does a better job there than even the Akurate DSM that is the primary source for that system (at about 10x the MHDT units price).
 
While I think the Mojo just edges out the Stockholm on overall imaging and instrument placement, it’s pretty close.  Only Yggdrasil is convincingly and obviously more capable here, fixing things in solid positions with no drift and no question as to what is where.
 
Another facet of my speaker rig is the active drive with active crossovers and eight independent channels of amplification with an Isobarik bass configuration.  This system doesn’t need subwoofers at all, and with the MHDT and the stock tube it was overpowering and went beyond bloomy into overdone and boomy.
 
Using USB:
 
My use of USB audio is entirely limited to portable scenarios, either with my 12” Retina Mac Book/15” Mac Book Pro or my iPhone/iPad.  As a result, I don’t own/use any USB re-clockers, conditioners or isolators.
 
Driven directly from the 12” Retina Mac Book I found the results with the Stockholm to be a mess; timing seemed way off, brass instruments had an unusually harsh edge, and it was not a pleasant listen at all.  The Mojo had no such issues here, nor did the Yggdrasil.  Using the Mac Book Pro, Mac Pro, iPhone or iPad as USB sources exhibited no such problems, so I’d chalk this up to the Stockholm being more sensitive to the quality of the USB source than some other units.
 
Of note, my Bifrost also suffered when fed with the Mac Book – but not to nearly the same degree.  Whether this is something to do with the CM6631A USB interface (common to the Bifrost and the Stockholm) or the way each device implements it I don’t know.
 
USB cables were all AudioQuest Cinnamon, with terminations appropriate for the target DAC.  I did try the cable included with the unit, but it made no difference that I could hear, so stuck to the ones I generally used.
 
General Notes:
 
The vast majority of my listening was done feeding the Stockholm v2 via TOSLINK (with a Lifatec glass cable), from a Mac Pro running the latest version of Audirvana with a combination of lossless Redbook CD rips and various 16/44.1 to 24/192 KHz HDTracks/Linn Records downloads and TIDAL for other 16/44.1 material.  I used Spotify for some lossy-listening evaluations.
 
My Bifrost is a very early unit, upgraded to the “4490” board and has the USB Gen 1 board in it.  It only had USB in it at all as a “just in case” measure, so I never bothered with the Gen 2 upgrade.  This is the first cause I’ve had to use that interface for any kind of critical listening.
 
I listened using AKG Q701, Sennheiser HD650 and HD800S, LCD-2.2c and Abyss headphones.  My general impressions remained constant across those headphones.  With the AKG Q701 the plummy bass of the stock tube in the MHDT was very welcome, where with the LCD-2.2c and Abyss it was too much.  The LCD-2.2c and HD650 responded particularly well to the sweet and detailed treble of the Stockholm, but the Audeze’s weren’t such a good match, regardless of amplification for the MHDT unit’s slight deeper vocal recess.
 
Amplifiers used were my WA6, original Lyr, Ragnarok and, for speakers, an Akurate Kontrol/1 with dual Akurate 4200 power amplifiers.  All exhibited the same, fundamental, signature with the Stockholm, the the WA6 definitely emphasized the bass bloom and treble sweetness.
 

Personal Conclusions:

 
One of the most interesting aspects of this tour, for me, was the fact that I have been trying to decide upon a DAC to permanently pair with my WA6 – which I bought a) to let me play with a pure-tube amplifier and b) as a dedicated bed-side rig.  For a while I’ve used the Mojo to feed it and that’s been very nice and it was going to come down to that and either a multi-bit Bifrost or I’d repurpose the 4490 for the WA6 and replace it with a multi-bit model.
 
As things stand my intention is to put a Stockholm v2 with my WA6 and find a tube that tightens/lightens up the bass a bit and make it the mainstay of my secondary stack at home.  It fit particularly well there with the HD650 and did a nice job with the HD800S, and it’s sweet but detailed treble and rich tone treat acoustic pieces in a particularly lovely manner.
 
It’s an engaging, detailed and still completely relaxing listen there, while also being able to exhibit drive and pace and solid rhythm with more neutral amplification/headphones.  I would not describe the MHDT as overly euphoric … but it tends more towards euphony than towards being utterly technical.  It doesn’t skimp on detail at all.  A very satisfying middle ground, I would say … most of the best of tubes and solid-state combined.
 
Value seems very good, and the ability to tune the signature with a solid array of alternate tubes makes it particularly interesting and flexible.  Loved the musicality of the thing and I’ll definitely miss it until mine arrives.
 
No doubt I’ll remember things I wanted to mention the moment I post this, but I’ll update if/when that occurs!
 
---
 
Many thanks to @Soundsgoodtome for arranging the tour and letting me participate, and a very nice job from MHDT with a very musical and entertaining product!

 

  Sad day, but the S2 is going away tonight. Torq takes it from here. I am going to miss it.
 
Interesting results on the speakers. Sounded great, but didn't get a chance to dial it in as the frequency response was all out of wack compared to Havana or my normal DAC. The S2 was putting out some serious bass that really needed adjustment. It goes to show how much the additional grunt adds to the signature. However, to adjust for the added bass would have taken away from the music night, a bit to much effort, so we left it as is. The additional bass without adjustment stepped onto the mids and collapsed the size of the sound stage compared to the optimized HP setup. The airiness was gone. Even with all those issues, it was still very enjoyable. 

 

 

[Barra]

  Most likely the house sound is generated from the film capacitors made by MHDT Labs themselves, it's how they achieve their signature in my guess - along with the other components of course but their signature is very much what film caps sound like. As for the loose bass mentioned, this wasn't as evident until it was plugged into the speakers which I believe magnified the slight boost. It could very well be a dialing-in thing (as Barra mentions) or a synergy thing with non-adjustable rigs. I do understand there is no such thing as a non-adjustable rig as you can play with all sorts of tweaks but I'm more in regards to actual EQ or some type of analog boost/cross-over/etc in the chain. 
 
What I don't understand is how Barra notices the bass boost in comparison to the Havana he owns... he mentions with the Stockholm and his speakers that the bass intrudes into the mids and kills the soundstage along the way. This is not subtle difference even if the speakers are magnifying any 'slight' changes that would've been heard through headphones. Does the larger transformer in the S2 add that extra impact/boost in the lows? This is the reason for including 2 extra tubes in the tour, something I should've done from the get-go as one of the main features of the MHDT Dacs is in fact tube rolling to tweak the DAC to fit a certain chain. I think the AEG and TripleM GE tube should offer enough differences from the Bendix 2C51 to allow listeners to hear differences subtle or apparent. However if you were to just pick one and be done, I'd go for the AEG or Bendix and go from there. Jiun did mention however that the 2C51 tubes usually add some weight to the bass due to the tube design, so if bass becomes overwhelming the AEG or GE 5670 may be a better choice.
 

Spoiler: Quotes

  @Torq ...
 
Really interesting write up on the Stockholm; I find your comments to be very accurate in regards to my own experience with the Stockholm 2 DAC over the past year or more.  In fact, your comments could easily describe the Havana 2 DAC as well ... 
 
Your comments on bass performance echo my own in a couple different reviews I've done of the MHDT DACs ... compared to other DACs I've owned/borrowed, the bass on the MHDT Dacs has always been just a bit loose around the edges ... something I would never notice until direct A/B listening with other gear.  I'm not so sure this is a tube anomaly as much as it is related to some other factor (perhaps capacitors used throughout or some other nuance of the circuit); the Bendix 6385 and 2C51 tubes will certainly do a bit towards tightening up the bass a hair but I wouldn't call it a "transformation" by any means.  Similarly, an AEG tube will do the same (but good luck finding one).  But the slight "bloom" in the bass is by no means anything glaring and is completely offset by the DACs other stellar qualities (musicality, ease, richness, etc.).
 
The Pagoda DAC, an identical circuit as the Stockholm 2 ... with it's PCM1704 DAC chips, creates a markedly different image sonically than the Stockholm 2 ... and while the bass is a tad leaner/tighter ... it still occasionally has that "trademark" MHDT "bloom" here and there ... which is what leads me to believe it has more so to do with the other components in the DAC (capacitors, etc.) more so than the tube or general R2R design scheme employed.
 
As mentioned, the Havana DAC has even more of this quality ... being a significantly "darker" listen than the Stockholm 2 ... but many users in the long standing Havana thread here at Head-fi have *extensively* modified their Havana DACs putting in different power supplies and in some cases completely replacing all of the MHDT Labs produced capacitors with high end, very expensive "boutique" capacitors and in such cases the consensus is that the DAC was completely transformed in to a far and a way more high end listen by said modifications (bass included) ...
 
I'm no DIY guy, though and so I won't be modifying a Stockholm 2 DAC any time soon but perhaps somebody will; and regarding this, if anyone is interested in such mods ... just spend a lot of time in the Havana thread and pretty much anything you see there will apply to the Stockholm as well ...
 
But thanks again for the comments ...
 
Joel

 

 

Overall Impressions:

I found that MHDT’s product had a little bloom to the bass, which was especially noticeable via my WA6 – in fact with this pairing the bass was a bit overpowering, a little too fat and lacking in some control.  The Stockholm was slightly recessed (that might be too strong a word … but it was not as prominent as with the other DACs I used) when it came to deeper female vocals and yet managed to be a little sibilant with some of the brighter female voices (in places I’m not used to said sibilance).
 
Treble detail seems excellent and has a little extra sweetness to it compared to what I’m used to.  There’s a nice sense of space and air and things don’t get muddled when there’s a lot going on.  This never got fatiguing and had me exploring piece after piece that benefits from a delicate, sweet and detailed handling of the upper mid-to-treble range (primarily small ensemble acoustic stuff).
 
I imagine the tube-DAC feeding tube-AMP configuration here is responsible for much of the low-end bloom and the extra treble sweetness.  These elements were still audible, but much less pronounced, when played through my Ragnarok, though the bass prominence and plumpness was still quite apparent with my speaker rig.
 
The soundstage I found to be quite expansive and, when paired with speakers, nicely three dimensional (more on that in a bit).
 
Overall I found the Stockholm v2 to be very musical, possessing a lovely sweet and detailed treble and, paired properly amp-wise, a very satisfying if somewhat warm bottom end.  The mid-range was lucid and engaging and the overall instrumental tone was beguilingly rich.
 
I didn’t get to spend any time rolling tubes but I imagine that doing so would make it relatively easy to adjust the bass suitably, bring out the upper female vocal range a bit and maybe round off the little bit of unexpected sibilance on some (not all) higher pitched vocals.
 
Despite the fat and somewhat less-controlled sounding lower registers with the WA6 pairing, I found myself listening well into the small hours with the Stockholm, WA6 and HD650.  A slightly leaner tube would improve that further and I think it’s a wonderful combination.  Not that I mean to suggest the MHDT product is limited to that end of the gear spectrum, it was a lovely listen through my Ragnarok as well, but I found it to be particularly musical and engaging with the WA6 and HD650.
 
Compared to the Chord Mojo:
 
The Mojo is definitely more neutral, exhibits none of the Stockholm’s slight de-emphasis in the mid-range, has a much more even, taught, detailed and controlled bass, didn’t exhibit the sibilance I found in the Stockholm but also lacked the upper-end sweetness and generally juicy sounding mids.  Also, I’d give the Mojo the upper hand from an imaging perspective both with headphones and, particularly, with speakers.
 
So … while more accurate and more detailed, the Mojo drew me into the music less than the MHDT unit, unless there was a lot of energy in the female vocals or the bass line was particularly deep and driving.
 
Big orchestral pieces favored the Mojo, partly for it’s imaging and partly because it provided better separation between instruments.
 
Compared to the Bifrost “4490”:
 
The Schiit unit is much drier and more controlled, but no less extended, in the lower registers, flatter through the mids and ess interesting (though probably more accurate) in the upper-mid to treble regions.  Feeding the WA6 it was the most neutral presentation excepting the Yggdrasil, but was a bit less engaging for it.
 
I felt the MHDT was letting me experience more of the nuance of voices than the 4490, and then, through the Ragnarok, the 4490 seemed a bit harsher and less forgiving with anything that wasn’t extremely well recorded.  The Stockholm was, also, a more pleasant listen with lossy source material.
 
Texture and timbre of instruments are more natural, to my ears, with the MHDT DAC than with the “4490”, and notably with woodwind and string instruments there’s a little extra richness to the tone than I find with the Schiit component.
 
Compared to Yggdrasil:
 
This is a rather unfair comparison.  The Yggdrasil is the best DAC I’ve yet heard - and that list includes some very much more expensive gear.
 
The MHDT piece doesn’t do badly here at all, but it doesn’t have the detail, neutrality, ability to, somehow, make everything in the mix seem to be the focus all at once (not technically possible, of course, but I don’t know how else to describe it), that Yggdrasil has.
 
Soundstage/imaging out of the Yggy is out of this world.
 
In some places the Stockholm is a bit more “fun”, and it is more forgiving of poor recordings/lossy encodings, and there is some artificial sweetness or lushness in places that make it a cozier listen … and that’s very desirable at times – but it’s not as truthful or, overall, as satisfying as Schiit’s monster.
 
With Speakers:
 
My speaker system projects a very palpable, three dimensional, sound stage.  The Stockholm was able to play to this very nicely and, I think, does a better job there than even the Akurate DSM that is the primary source for that system (at about 10x the MHDT units price).
 
While I think the Mojo just edges out the Stockholm on overall imaging and instrument placement, it’s pretty close.  Only Yggdrasil is convincingly and obviously more capable here, fixing things in solid positions with no drift and no question as to what is where.
 
Another facet of my speaker rig is the active drive with active crossovers and eight independent channels of amplification with an Isobarik bass configuration.  This system doesn’t need subwoofers at all, and with the MHDT and the stock tube it was overpowering and went beyond bloomy into overdone and boomy.
 
Using USB:
 
My use of USB audio is entirely limited to portable scenarios, either with my 12” Retina Mac Book/15” Mac Book Pro or my iPhone/iPad.  As a result, I don’t own/use any USB re-clockers, conditioners or isolators.
 
Driven directly from the 12” Retina Mac Book I found the results with the Stockholm to be a mess; timing seemed way off, brass instruments had an unusually harsh edge, and it was not a pleasant listen at all.  The Mojo had no such issues here, nor did the Yggdrasil.  Using the Mac Book Pro, Mac Pro, iPhone or iPad as USB sources exhibited no such problems, so I’d chalk this up to the Stockholm being more sensitive to the quality of the USB source than some other units.
 
Of note, my Bifrost also suffered when fed with the Mac Book – but not to nearly the same degree.  Whether this is something to do with the CM6631A USB interface (common to the Bifrost and the Stockholm) or the way each device implements it I don’t know.
 
USB cables were all AudioQuest Cinnamon, with terminations appropriate for the target DAC.  I did try the cable included with the unit, but it made no difference that I could hear, so stuck to the ones I generally used.
 
General Notes:
 
The vast majority of my listening was done feeding the Stockholm v2 via TOSLINK (with a Lifatec glass cable), from a Mac Pro running the latest version of Audirvana with a combination of lossless Redbook CD rips and various 16/44.1 to 24/192 KHz HDTracks/Linn Records downloads and TIDAL for other 16/44.1 material.  I used Spotify for some lossy-listening evaluations.
 
My Bifrost is a very early unit, upgraded to the “4490” board and has the USB Gen 1 board in it.  It only had USB in it at all as a “just in case” measure, so I never bothered with the Gen 2 upgrade.  This is the first cause I’ve had to use that interface for any kind of critical listening.
 
I listened using AKG Q701, Sennheiser HD650 and HD800S, LCD-2.2c and Abyss headphones.  My general impressions remained constant across those headphones.  With the AKG Q701 the plummy bass of the stock tube in the MHDT was very welcome, where with the LCD-2.2c and Abyss it was too much.  The LCD-2.2c and HD650 responded particularly well to the sweet and detailed treble of the Stockholm, but the Audeze’s weren’t such a good match, regardless of amplification for the MHDT unit’s slight deeper vocal recess.
 
Amplifiers used were my WA6, original Lyr, Ragnarok and, for speakers, an Akurate Kontrol/1 with dual Akurate 4200 power amplifiers.  All exhibited the same, fundamental, signature with the Stockholm, the the WA6 definitely emphasized the bass bloom and treble sweetness.
 

Personal Conclusions:

 
One of the most interesting aspects of this tour, for me, was the fact that I have been trying to decide upon a DAC to permanently pair with my WA6 – which I bought a) to let me play with a pure-tube amplifier and b) as a dedicated bed-side rig.  For a while I’ve used the Mojo to feed it and that’s been very nice and it was going to come down to that and either a multi-bit Bifrost or I’d repurpose the 4490 for the WA6 and replace it with a multi-bit model.
 
As things stand my intention is to put a Stockholm v2 with my WA6 and find a tube that tightens/lightens up the bass a bit and make it the mainstay of my secondary stack at home.  It fit particularly well there with the HD650 and did a nice job with the HD800S, and it’s sweet but detailed treble and rich tone treat acoustic pieces in a particularly lovely manner.
 
It’s an engaging, detailed and still completely relaxing listen there, while also being able to exhibit drive and pace and solid rhythm with more neutral amplification/headphones.  I would not describe the MHDT as overly euphoric … but it tends more towards euphony than towards being utterly technical.  It doesn’t skimp on detail at all.  A very satisfying middle ground, I would say … most of the best of tubes and solid-state combined.
 
Value seems very good, and the ability to tune the signature with a solid array of alternate tubes makes it particularly interesting and flexible.  Loved the musicality of the thing and I’ll definitely miss it until mine arrives.
 
No doubt I’ll remember things I wanted to mention the moment I post this, but I’ll update if/when that occurs!
 
---
 
Many thanks to @Soundsgoodtome for arranging the tour and letting me participate, and a very nice job from MHDT with a very musical and entertaining product!

 

  Sad day, but the S2 is going away tonight. Torq takes it from here. I am going to miss it.
 
Interesting results on the speakers. Sounded great, but didn't get a chance to dial it in as the frequency response was all out of wack compared to Havana or my normal DAC. The S2 was putting out some serious bass that really needed adjustment. It goes to show how much the additional grunt adds to the signature. However, to adjust for the added bass would have taken away from the music night, a bit to much effort, so we left it as is. The additional bass without adjustment stepped onto the mids and collapsed the size of the sound stage compared to the optimized HP setup. The airiness was gone. Even with all those issues, it was still very enjoyable. 

 

Andrew, the additional bass is definitely magnified on my system - S2 vs. H2. However, there are a few points that explain why it is so apparent on my system. First, this is a 5.1 system with magneplaner front speakers (which are known for their lush and detailed mids, and a significant bass roll off). Therefore, the bass is managed by a pair of high end sub woofers that cross at 80hz. The Maggies are seen as full sized full frequency speakers so they are not capped at 80hz allowing a smooth transition downward. The whole system is dialed in automatically by the Marantz receiver sound setup that optimizes the dBs of each channel through a microphone for a neutral tuning. Therefore, the sub woofers are dialed way down not to overwhelm the rest of the system. Since it was last tuned, I upgraded the amplifier (1000 watts) power cable with a super cable that JJ made for me which had a profound effect on the maggies bringing out significant tactile bass impact - in the maggies - that was not there before. I have enjoyed the additional bass and had not re-tuned my system since. So the S2 adding even more bass impact to the system makes it even more apparent and the bass impact in the upper bass is getting doubled. Dragging out the tuning microphone in the middle of a music night and then again at the end to take it back to the original configuration is a PITA so I skipped that. This is what I meant by re-tuning.
 
I should also mention that the sub woofers are awesome and can handle anything thrown at them so it is fun having more bass. It is just not neutral so it only works well with bassy music genres. We can shake the whole house with them and they are the stars of our movie nights.

 

[Soundsgoodtome]

  Andrew, the additional bass is definitely magnified on my system - S2 vs. H2. However, there are a few points that explain why it is so apparent on my system. First, this is a 5.1 system with magneplaner front speakers (which are known for their lush and detailed mids, and a significant bass roll off). Therefore, the bass is managed by a pair of high end sub woofers that cross at 80hz. The Maggies are seen as full sized full frequency speakers so they are not capped at 80hz allowing a smooth transition downward. The whole system is dialed in automatically by the Marantz receiver sound setup that optimizes the dBs of each channel through a microphone for a neutral tuning. Therefore, the sub woofers are dialed way down not to overwhelm the rest of the system. Since it was last tuned, I upgraded the amplifier (1000 watts) power cable with a super cable that JJ made for me which had a profound effect on the maggies bringing out significant tactile bass impact - in the maggies - that was not there before. I have enjoyed the additional bass and had not re-tuned my system since. So the S2 adding even more bass impact to the system makes it even more apparent and the bass impact in the upper bass is getting doubled. Dragging out the tuning microphone in the middle of a music night and then again at the end to take it back to the original configuration is a PITA so I skipped that. This is what I meant by re-tuning.
 
I should also mention that the sub woofers are awesome and can handle anything thrown at them so it is fun having more bass. It is just not neutral so it only works well with bassy music genres. We can shake the whole house with them and they are the stars of our movie nights.

Ah, thanks for the clarifying details! For some reason I was thinking you were running the 2ch setup without subs and that was overwhelming the mids with bass and only the DAC as a difference factor. With that you can see why I was worried the tube may have been defective lol. I can definitely see how that can overwhelm with two subwoofers moving on top of the maggies!! If you're dialed in for great bass already, any slight shift can turn a system from just right with good weight to stud-shaking earthquake bass.

 

[grizzlybeast]

Not hearing a lot of bass boost. My infinity is a bit flat and the s2 is barely more.Dont need extra tubes IMO and so far

 

[grizzlybeast]

Not hearing a lot of bass boost. My infinity is a bit flat and the s2 is barely more.Dont need extra tubes IMO and so far

okay actually I am.... lol... i think it was because I wasn't letting it warm up. But I actually like it better warmed up. and ughbghg dangit Im gonna wanna sell my infinity DAC... Freakin A.... See this is why I didn't want to sign up for this tour. 
 
Do they have a balanced version? Time to do some research...

 

[Soundsgoodtome]

They sure do, an interesting one too with double the components.

In regards to warm-up, these r2r dacs really do like to stay on so unless you'll be gone for days it's just best to leave them on at all times. Not only do the clocks stabilize after a day or two but the components when nice and well heated give a much more pleasant and effortless sound.

okay actually I am.... lol... i think it was because I wasn't letting it warm up. But I actually like it better warmed up. and ughbghg dangit Im gonna wanna sell my infinity DAC... Freakin A.... See this is why I didn't want to sign up for this tour. 

Do they have a balanced version? Time to do some research...

 

[Luckbad]

 
okay actually I am.... lol... i think it was because I wasn't letting it warm up. But I actually like it better warmed up. and ughbghg dangit Im gonna wanna sell my infinity DAC... Freakin A.... See this is why I didn't want to sign up for this tour. 
 
Do they have a balanced version? Time to do some research...

 
Email them and ask. They had a balanced Stockholm v1. Pagoda definitely has a balanced version now.

 

[grizzlybeast]

They sure do, an interesting one too with double the components.

okay actually I am.... lol... i think it was because I wasn't letting it warm up. But I actually like it better warmed up. and ughbghg dangit Im gonna wanna sell my infinity DAC... Freakin A.... See this is why I didn't want to sign up for this tour. 

Do they have a balanced version? Time to do some research...

 
 

 

 
okay actually I am.... lol... i think it was because I wasn't letting it warm up. But I actually like it better warmed up. and ughbghg dangit Im gonna wanna sell my infinity DAC... Freakin A.... See this is why I didn't want to sign up for this tour. 
 
Do they have a balanced version? Time to do some research...

 
Email them and ask. They had a balanced Stockholm v1. Pagoda definitely has a balanced version now.

I will offer solid impressions later on. This is bad timing to want a different DAC I will head it up over the weekend and see if I want to sell my infinity. It seems I loose a little precision when switching to the S2 but gain realism. 

 

 

[Torq]

  @Torq ...
 
Really interesting write up on the Stockholm; I find your comments to be very accurate in regards to my own experience with the Stockholm 2 DAC over the past year or more.  In fact, your comments could easily describe the Havana 2 DAC as well ... 
 
Your comments on bass performance echo my own in a couple different reviews I've done of the MHDT DACs ... compared to other DACs I've owned/borrowed, the bass on the MHDT Dacs has always been just a bit loose around the edges ... something I would never notice until direct A/B listening with other gear.  I'm not so sure this is a tube anomaly as much as it is related to some other factor (perhaps capacitors used throughout or some other nuance of the circuit); the Bendix 6385 and 2C51 tubes will certainly do a bit towards tightening up the bass a hair but I wouldn't call it a "transformation" by any means.  Similarly, an AEG tube will do the same (but good luck finding one).  But the slight "bloom" in the bass is by no means anything glaring and is completely offset by the DACs other stellar qualities (musicality, ease, richness, etc.).
 
The Pagoda DAC, an identical circuit as the Stockholm 2 ... with it's PCM1704 DAC chips, creates a markedly different image sonically than the Stockholm 2 ... and while the bass is a tad leaner/tighter ... it still occasionally has that "trademark" MHDT "bloom" here and there ... which is what leads me to believe it has more so to do with the other components in the DAC (capacitors, etc.) more so than the tube or general R2R design scheme employed.
 
As mentioned, the Havana DAC has even more of this quality ... being a significantly "darker" listen than the Stockholm 2 ... but many users in the long standing Havana thread here at Head-fi have *extensively* modified their Havana DACs putting in different power supplies and in some cases completely replacing all of the MHDT Labs produced capacitors with high end, very expensive "boutique" capacitors and in such cases the consensus is that the DAC was completely transformed in to a far and a way more high end listen by said modifications (bass included) ...
 
I'm no DIY guy, though and so I won't be modifying a Stockholm 2 DAC any time soon but perhaps somebody will; and regarding this, if anyone is interested in such mods ... just spend a lot of time in the Havana thread and pretty much anything you see there will apply to the Stockholm as well ...
 
But thanks again for the comments ...
 
Joel

Interesting .. and glad to know I'm not imagining things!
 
Regardless of the source of the bass "bloom", I should say that, excepting with my speaker system, it wasn't something I found to be intrusive or troublesome at all, and I certainly don't consider it to be a problem.  My primary comparisons are with units that are known to be pretty neutral, perhaps even lean in one case, but the bass here was noticeably fat enough that it was worth calling out.  In many systems I expect it would be a definite plus - for me it was just something I observed and don't really view as negative or positive.
 
Still, it'll be interesting to see what, if any effect, playing with tubes in the thing has when my own unit arrives ... since I have a bunch of tubes here that I snagged from @Luckbad just begging to be explored!

 

[grizzlybeast]

MHDT Labs Stockholm V2 impressions 

 

Build, aesthetics, functionality :
I am kind of partial to the aesthetics. I just don't really like the sun shaped etching on the top plate. Other than that I really like how it looks. I would get a black one when I do. The acrylic faceplate is pretty cool looking and the B.U.R.T kind of represents the builders personality and their care of making things that represent themselves. To swap tubes you just need to unscrew the top plate with an allen wrench and gently pry the tube out to swap it. 
 
The DAC's output seems to be slightly lower in volume compared to my pulse infinity by about 4 db but I don't consider that much. The DAC needs to be warmed up for a long time in order to it to emit its true sound. @Soundsgoodtome told me he left it on for hours or all day practically never turning it off to hear it at its best. My initial impressions were prior to the tube warming up and I was first met with a sound that was a tad strained and a little hard in the presence region later it opened up and impressions began to solidify and become easier to tell. 
 
Even though I had an impression of the Toslink sounding deeper in dimension, I mostly listened in USB because I forgot my infinity had toslink too. USB vs USB is fine and still provided notable differences. 
 
For listening I used my own files of mostly electronic music, some soul, world, and latin stuff as well as some great songs that were sent by Andrew a couple of which I was already very familiar with. I was able to tell most of the differences with my Trafomatic HEAD 2 amp but the NuPrime was able to reveal them as well. Given the fact that the Pulse infinity has an upgraded power cable, LPS, truly balanced configuration, upgraded as far as I could, and better USB cable I figured it would leave the basic plug and play S2 in the dust but umm.....
 
 

I would prefer this to be my set up than what I own and here is why....(unedited and messy... sorry tired now from being up all last night)
SOUND

1. The soundstage sounds deep and round to me but the good macro dynamics make this sound very realistic to my ears. Everything is more raw and slightly pure in tone with better pop from the recording but is slightly less wide in image than the Infinity. This could be because I am used to hearing only width with the infinity though.
2. The infinty sounds more dry than the S2 but a little cleaner and faster at times but only slightly  
3. There is a warm hue to the bass that doesn't seem like it is more in quantity but overall warmer than the infinity. I noticed this more after the amp was warmed up. It never lost any solidity it just gained a bit of bass glow if I can say that. On some songs I don't feel like the bass warmth is being unrealistically cut dry. When I was listening to the bass slams with the Omni(which freakin slams) all of the solidity and textures were there but the bass reverbs and resonances didn't like they were as digitally processed and regulated.  Only a hair more lingering of the note when I listened for it but this was very subtle. This is still quite neutral to me in the bass without ever sounding bloated, recessed, or boosted. 
4. The best part was that the midrange seemed less dry, more realistic and tangible because as Mia Doi Todd was singing in "Paraty" her voice popped out a bit from the recording and had more depth to it. Its like her voice carried through almost to the end without a ceiling. I am having  a hard time describing this but basically more realistic in dynamics and timbre..more full bodied, raw and clear. Before letting the DAC warm up I couldn't tell the difference. After leaving it on it became obvious with her voice and consistent with many others as listening continued. The infinity seemed more flat but just as detailed if not a hair more because the decay was quicker and the resolution was about the same as both are good at details. 
5. I can't tell which had the blacker background with definite certainty, but  If I had to pick I would most likely say the impression is that the infinity is quieter. 
6. The clarity is just a little bit more on the the S2 to me it seems. There is a fullness without any veil to the sound of the DAC and the treble seems balanced yet smooth. 

I really think this DAC is for people who love their music to sound realistic and natural. The infinity DAC is a only slightly more sterile, flat, and dry from the mids up but neither are bright. Maybe if I really tried I would see where the infinity would best the S2 but I kind of don't care. This DAC sounds more true to the source when it comes to midrange realism IMO and allow the music to come through uncompressed. The mids sound full and tangible, the bass sounds taught and solid, the soundstage has good dimension, the highs aren't rolled off and while its a bit more raw sounding than the more behaved Infinity, that is what I like. I appreciate the emotion this captures... I went into this liking my inifinity more at first and had a bias because 1. I didn't want to consider buying a new DAC. 2. the infinity MSRP is more than double 3. I had grown to like my DAC and it is fully balanced.
 
The infinity doesn't sound bad or super dry or anything but the slight differences in decay and realism make me really want to peer into what something like the Pagoda would offer. The tendency to over imagine what I am describing is almost irresistible as most of these required a lot of swapping back and forth in between songs with ears I learned to be a little less discerning than I previously thought.
 
I will climb the latter of DACs to see how high it goes since I already have my end game amps and headphones and that may end with a yggy since my first taste of R2R is positive. I think I want a tad more precision, detail and space (infinity has some of those things) but with the Macro dynamics and wholesome timbre of this DAC. If I am going to buy one I may as well buy one that is a clear upgrade to my infinity. Maybe the Pagoda is for me. The Stockholm doesn't sound like an upgrade but more so better for my tastes. Same way I like the HD800S more than the HD800... for my tastes. 
 
Well thats all I have on this one. But in my opinion this is a great DAC and I have a hard time believing others brands in this price range can be more musical, clear, and true to source. 

 

[Soundsgoodtome]

Excellent stuff Grizz, you brush on what an r2r transitioned audiophile hears very well. This was similar to my experience of going to a non-oversampling R2R for the first time. Even with over-sampling r2r dacs like the Bimby or DAC19 can't put out that sound the S2, Atlantis, or Pagoda is capable of producing. As for you having to shuffle gear now, sorry for your wallet.

 

[grizzlybeast]

yeah.. why i didn't want to  sign up.. And GEEESHSHSH that post needs major editing... lol. Tired now and off to get some groceries. I will have this packed up tonight because I a am a little mad at it. Truth is that I don't like having gear here that I prefer over my own if it is not mine. Hence why I am shipping it earlier... true story. 

 

[Torq]

So ... I mentioned in my impressions that I was buying a Stockholm 2.  I got around to putting in the order very late last Tuesday night (the day after shipping it off for its next spot in the tour) and it arrived midday(ish) on Saturday!  That's incredibly fast ... 4 days total!
 
Since I've been tied up all weekend, I've only had time to unbox it, hook it up, let it sit powered on for an hour and spend about 30 minutes listening to it, so proper pictures of it in its new home will need to wait.  I wound up going with a black unit and, like @grizzlybeast I'm not a fan of the sun motif of the tube opening, so my top plate will be visiting my office lab to have that all cut out - which will also mean I can run fatter tubes and/or swap tubes without having to remove the top plate.
 

 
While this unit has only had 90 minutes of power-on time, I noticed immediately that although it still has a warmish bottom end (with whatever tube is pre-installed in it - haven't had a chance to open it up and take a look yet) it is no longer something I would describe as having bass bloom and is a definitely more controlled in the lower registers than what I heard with the tour unit.
 
Once this has some proper time on it I'll do a full review of it, along with some tube rolling, and see where things sit then!
 
It does sound pretty bloody marvelous already though!

 

[Luckbad]

  So ... I mentioned in my impressions that I was buying a Stockholm 2.  I got around to putting in the order very late last Tuesday night (the day after shipping it off for its next spot in the tour) and it arrived midday(ish) on Saturday!  That's incredibly fast ... 4 days total!
 
Since I've been tied up all weekend, I've only had time to unbox it, hook it up, let it sit powered on for an hour and spend about 30 minutes listening to it, so proper pictures of it in its new home will need to wait.  I wound up going with a black unit and, like @grizzlybeast I'm not a fan of the sun motif of the tube opening, so my top plate will be visiting my office lab to have that all cut out - which will also mean I can run fatter tubes and/or swap tubes without having to remove the top plate.
 

 
While this unit has only had 90 minutes of power-on time, I noticed immediately that although it still has a warmish bottom end (with whatever tube is pre-installed in it - haven't had a chance to open it up and take a look yet) it is no longer something I would describe as having bass bloom and is a definitely more controlled in the lower registers than what I heard with the tour unit.
 
Once this has some proper time on it I'll do a full review of it, along with some tube rolling, and see where things sit then!
 
It does sound pretty bloody marvelous already though!

 
That was fast! It doesn't take much to make you fall in love with an MHDT Labs DAC. I spent a couple weeks reading about MHDT stuff and missed out on a used Paradisea 3, then ultimately ordered an Atlantis.
 
@grizzlybeast I fell in love with the Atlantis almost immediately paired with a Garage1217 Project Sunrise III amplifier. This was intended to be my work setup, so after the first weekend at home, it went to work.
 
I had an Audio-GD Master-11 at home, which is an incredible fully balanced unit with 4x PCM1704U-K chips and a bonkers solid state amplifier in it.
 
After my Atlantis and Garage1217 amp went to work, I kept coming home and missing the tube sweetness. The Master-11 has all of the R/2R goodness, natural timbre, etc. But something about the Atlantis just draws you in.
 
Less than two weeks later, I sold my Audio-GD Master-11 and bought a second MHDT Labs Atlantis and a Garage1217 Project Horizon III w/ Supercharger for home.
 
I then went through the madness of tube rolling to find exactly what tubes I wanted. I eventually settled on GE Triple Mica as my favorite for the Atlantis.
 
I sold @Torq one of my bundles of tubes so he can get a good taste and have a couple more tube samplers to sell yet.
 
Now I'm blissfully living in MHDT land at home and work. I also use the same tubes in both amps after spending a small fortune rolling tubes for those. I settled on 6N6P/6н6п tubes and the close variants (6Н6П-И and 6H30Pi).
 
For now, my focus is just deciding what I can do to improve on what I already have. An UpTone Regen is currently feeding my home Atlantis. I'll also grab a pair of linear power supplies from Garage1217 when Jeremy gets those ready. @Soundsgoodtome is letting me try out his Audio-GD DI-U8 next week, so I'll get some good A/B testing in next weekend there.
 
I'll also check out this Stockholm at the end of the tour. I swapped a Pagoda/Atlantis for two weeks with him and decided I actually prefer the Atlantis. The Stockholm... well, maybe I'll end up with one Atlantis and one Stockholm. We'll see!

 

[grizzlybeast]

 
So ... I mentioned in my impressions that I was buying a Stockholm 2.  I got around to putting in the order very late last Tuesday night (the day after shipping it off for its next spot in the tour) and it arrived midday(ish) on Saturday!  That's incredibly fast ... 4 days total!

Since I've been tied up all weekend, I've only had time to unbox it, hook it up, let it sit powered on for an hour and spend about 30 minutes listening to it, so proper pictures of it in its new home will need to wait.  I wound up going with a black unit and, like @grizzlybeast
 I'm not a fan of the sun motif of the tube opening, so my top plate will be visiting my office lab to have that all cut out - which will also mean I can run fatter tubes and/or swap tubes without having to remove the top plate.




While this unit has only had 90 minutes of power-on time, I noticed immediately that although it still has a warmish bottom end (with whatever tube is pre-installed in it - haven't had a chance to open it up and take a look yet) it is no longer something I would describe as having bass bloom and is a definitely more controlled in the lower registers than what I heard with the tour unit.

Once this has some proper time on it I'll do a full review of it, along with some tube rolling, and see where things sit then!

It does sound pretty bloody marvelous already though!

That was fast! It doesn't take much to make you fall in love with an MHDT Labs DAC. I spent a couple weeks reading about MHDT stuff and missed out on a used Paradisea 3, then ultimately ordered an Atlantis.

@grizzlybeast
 I fell in love with the Atlantis almost immediately paired with a Garage1217 Project Sunrise III amplifier. This was intended to be my work setup, so after the first weekend at home, it went to work.

I had an Audio-GD Master-11 at home, which is an incredible fully balanced unit with 4x PCM1704U-K chips and a bonkers solid state amplifier in it.

After my Atlantis and Garage1217 amp went to work, I kept coming home and missing the tube sweetness. The Master-11 has all of the R/2R goodness, natural timbre, etc. But something about the Atlantis just draws you in.

Less than two weeks later, I sold my Audio-GD Master-11 and bought a second MHDT Labs Atlantis and a Garage1217 Project Horizon III w/ Supercharger for home.

I then went through the madness of tube rolling to find exactly what tubes I wanted. I eventually settled on GE Triple Mica as my favorite for the Atlantis.

I sold @Torq one of my bundles of tubes so he can get a good taste and have a couple more tube samplers to sell yet.

Now I'm blissfully living in MHDT land at home and work. I also use the same tubes in both amps after spending a small fortune rolling tubes for those. I settled on 6N6P/6н6п tubes and the close variants ([COLOR=222222]6Н6П[/COLOR][COLOR=222222]-И and 6H30Pi).[/COLOR]

[COLOR=222222]For now, my focus is just deciding what I can do to improve on what I already have. An UpTone Regen is currently feeding my home Atlantis. I'll also grab a pair of linear power supplies from Garage1217 when Jeremy gets those ready. @Soundsgoodtome
 is letting me try out his Audio-GD DI-U8 next week, so I'll get some good A/B testing in next weekend there.[/COLOR]

[COLOR=222222]I'll also check out this Stockholm at the end of the tour. I swapped a Pagoda/Atlantis for two weeks with him and decided I actually prefer the Atlantis. The Stockholm... well, maybe I'll end up with one Atlantis and one Stockholm. We'll see![/COLOR]

What is it that you prefer about the Atlantis over the Pagoda? My top priority is bass control, midrange realism, and soundstage in that order. My trafomatic had soundstage to spare.