labeelen
100+ Head-Fier
You wil probably need one or more dip8 sockets to elevate the pcb. See the tight fit of my soic to dip8 pcb’s which are smaller than ss3602.
REVIEW: Firestone Audio Tobby DAC
- Thread starter project86
- Start date
-
- Tags
- firestone-tobby
Thank you for the input!
Recently I bought this DAC because I needed one, and don't remember hearing a Ti1794 chip, also the review was interesting.
Now that I have it, seems to me that this DAC has lots of potential, just that with stock op-amps it has recessed highs. Also missing some clarity, sounds a bit muddy, but I have hope it can be corrected because of how genuinely good (clean, open, natural) are the mids/voices compared to the rest of the sound. I'm almost sure it's a op-amp limitation.
Sadly I have very little electronical experience, and none with opa rolling, but from what I can understand, the top two ones are the low pass filter (LPF) opas (one for each channel), and the 4pcs before them are I/V opas that I don't know what means. But I'm guessing all 4 (2 on each channel) need to be changed with the same op-amps, at once?
So, I ordered a pair of Burson V5iD for the LPF to see how much can the sound quality change, but I will also want to try the Muses 8920 that from a YouTube video intrigues me compared with the V5iD's. Seems like a cheaper Sparkos alternative. Problem is, that I would like to combine their strengths, the soul from Muses with Burson's extented highs and better overall separation. Do I understand correctly that I would need to buy another pair of V5iD's so I can install 4 of them in the V/I and two Muses 8920 in the LPF? Would the DAC work with this config? I'm only using the XLR output, so the 7th opa does nothing for me. Could I just unplug it, maybe free some 0. amps from the power supply, or get rid of some electrical/magnetic interference? Or with it missing something might brake/burn?
If the DAC proves to up the SQ with this changes, in the future I'll still be very tempted to get the Sparkos. But for now, knowing they could have a fitting problem and the need to use DIP8 spacers plus the higher price, for a still unproven DAC (for me) keeps me away from them.
Recently I bought this DAC because I needed one, and don't remember hearing a Ti1794 chip, also the review was interesting.
Now that I have it, seems to me that this DAC has lots of potential, just that with stock op-amps it has recessed highs. Also missing some clarity, sounds a bit muddy, but I have hope it can be corrected because of how genuinely good (clean, open, natural) are the mids/voices compared to the rest of the sound. I'm almost sure it's a op-amp limitation.
Sadly I have very little electronical experience, and none with opa rolling, but from what I can understand, the top two ones are the low pass filter (LPF) opas (one for each channel), and the 4pcs before them are I/V opas that I don't know what means. But I'm guessing all 4 (2 on each channel) need to be changed with the same op-amps, at once?
So, I ordered a pair of Burson V5iD for the LPF to see how much can the sound quality change, but I will also want to try the Muses 8920 that from a YouTube video intrigues me compared with the V5iD's. Seems like a cheaper Sparkos alternative. Problem is, that I would like to combine their strengths, the soul from Muses with Burson's extented highs and better overall separation. Do I understand correctly that I would need to buy another pair of V5iD's so I can install 4 of them in the V/I and two Muses 8920 in the LPF? Would the DAC work with this config? I'm only using the XLR output, so the 7th opa does nothing for me. Could I just unplug it, maybe free some 0. amps from the power supply, or get rid of some electrical/magnetic interference? Or with it missing something might brake/burn?
If the DAC proves to up the SQ with this changes, in the future I'll still be very tempted to get the Sparkos. But for now, knowing they could have a fitting problem and the need to use DIP8 spacers plus the higher price, for a still unproven DAC (for me) keeps me away from them.
Last edited:
labeelen
100+ Head-Fier
I recently started listening to this DAC again. After numerous opamp swapping I finally settled on 4x muses8920 for I/V conversion and 2x opa627 (on soic to dip8 pcb) for LPF and 1x opa627 (on soic to dip8 pcb) for SE (rca output). (as opa627 is single channel you need to combine 2 for for each balanced operation)
This will fix all the limitations that you might experience with the stock opa2604.
Burson V5i in I/V sounds more detailed and spacious than muses8920 but also less natural and a little metallic, so I still prefer muses8920 for I/V.
You could also substitute the opa627s for the lower cost dual-channel opa2107 (which is dip8 package) for LPF in combination with another muses8920 for SE.
If you only use balanced XLR you can leave the single opa2604 in SE unchanged as it is only used for rca (single ended) output.
If you don’t want to solder yourself you might want to consider (two or three of) these:
https://www.audiophonics.fr/en/opa/burr-brown-opa627-dual-opa-with-support-unit-p-8434.html
Thank you for your input!
I have returned the V5id's because they sounded metallic and unnatural. For the I/V section I was scared to get the 8820 that supposedly are clean and neutral, and got the 8920 that are a bit dark and a little analog colored. For LPF I bought 2x OPA1612 and with all of them I cannot believe how greatly the sound improved. This DAC is a real surprise and it's not at all bright or harsh, I'm actually a bit sorry for going with the safe option (8920) and very curious to try the 8820, I think the this DAC still has more to offer.
With that in mind, I also ordered a pair of Neutrik NC3MD-LX-B XLR's from a local store, and from VBS Audio a good IEC + copper wire to solder the XLR's and IEC (socket) to the electronical board, because the original ones look to me like really cheap options that can only degrade the signal. Will post pics with the mods.
I have returned the V5id's because they sounded metallic and unnatural. For the I/V section I was scared to get the 8820 that supposedly are clean and neutral, and got the 8920 that are a bit dark and a little analog colored. For LPF I bought 2x OPA1612 and with all of them I cannot believe how greatly the sound improved. This DAC is a real surprise and it's not at all bright or harsh, I'm actually a bit sorry for going with the safe option (8920) and very curious to try the 8820, I think the this DAC still has more to offer.
With that in mind, I also ordered a pair of Neutrik NC3MD-LX-B XLR's from a local store, and from VBS Audio a good IEC + copper wire to solder the XLR's and IEC (socket) to the electronical board, because the original ones look to me like really cheap options that can only degrade the signal. Will post pics with the mods.
labeelen
100+ Head-Fier
Hi All,
For all Tobby users that also own the matching Bobby headphone amplifier I would like to share some experiences that might be of interest to you.
Recently I replaced the current Burson V5i opamps with Sparkos ss5290 in my FireStone Audio Bobby headphone amplifier.
I did several listening tests and would like to share my findings with Bobby owners and other readers.
As a reference (and for those interested) I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
Bobby's default opamps are the OPA604 which are ok but are a little veiled and lack some sparkle and detail.
In the past years, after numerous tests, I settled on Burson V5i and OPA627. The V5i giving more tranparancy, detail and better definition in the bass.
OPA627 was also a very nice upgrade option if you like a warmer fuller sound with subtle highs, detail and a little darker atmosphere.
When I swapped the above with the Sparkos ss5290 I was immediately aware that this upgrade elevated and transformed the Bobby to a whole new level.
The sound was smooth, natural and very detailed and music was playing effortless and with great authority against a deadsilent background. It was a real joy to discover new insights in my music and It confirmed that the true potential of the Bobby amplifier was unleashed with this latest upgrade.
Sub-bass
The lowest frequencies are not predominant or in your face but present themselves in the form of a increased sense of the space and more accurate placing of instruments (in accoustic or live recordings). For testing electronic sub bass I often use ‘Doin it Right’ by Daft Punk. With the ss5290 the lowest bass notes can clearly be heard but you won’t feel them in your stomach.
Bass
Bass response may appear lean compared to Opa627 or V5i but you never have the feeling you are missing anything. In the live performance of ‘Inception:Time’ by Hans Zimmer and the Vienna Radio Symphony Orchestra the ss5290 displays the scale of this performance realistical and very convincing and the rumble never overshadows the other instruments.
Mids
Male and female vocals sound very natural and lifelike without any rough edges. Definition and placement of instruments is excellent as can be heard in songs like ‘In Your Eyes’ from Peter Gabriel.
On ‘Man in the long black coat’ the voice of Dylan and his harmonica sound natural and convincing. In my opinion harmonica’s are very challenging instruments to reproduce accurately. (that’s why this is also a good test-track to evaluate the subtle differences in linear power supplies, fuses and power cords)
Accoustic instruments like guitars show a nice and natural attack and decay as in ‘Trouble’s What You’re In’ by Fink. With lesser quality amplification this guitar can sound harsh or even aggressive.
Highs
The high frequency spectrum is well extended and airy but never sharp or piercing. In ‘I love Paris’ from Johnny Frigo this is nicely demonstrated with a highhat that sounds very realistic and convincing, with a decay that goes on forever.
in short:
The ss5290 breathes new life in my Bobby Amplifier and really elevates it to a whole new performance level.
I was also surprised that the Bobby had no problem in combination with my HiFiman HE6se v2 Headphones which have a reputation of being notoriously difficult to drive.
All in all I am very positive about this latest change and I am also very interested if @John90 has had similar experiences with using the smaller dual channel variant ss3602 in his Tobby DAC.
For all Tobby users that also own the matching Bobby headphone amplifier I would like to share some experiences that might be of interest to you.
Recently I replaced the current Burson V5i opamps with Sparkos ss5290 in my FireStone Audio Bobby headphone amplifier.
I did several listening tests and would like to share my findings with Bobby owners and other readers.
As a reference (and for those interested) I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
- Qobuz (Hi-res streaming service)
- Roon (running on Synology NAS)
- HQPlayer (running on Intel Nuc12i5) for upsampling and EQ
- Fibre optic Media Converters
- Gustard R26 R-2R DAC using it's internal (LAN) Network Audio Adapter
- Transparent MusicLink Super (balanced) XLR interconnect
- Firestone Audio Bobby (balanced) Headphone amplifier
- HiFiman HE6se v2 with custom balanced cable by CustomCansUK
Bobby's default opamps are the OPA604 which are ok but are a little veiled and lack some sparkle and detail.
In the past years, after numerous tests, I settled on Burson V5i and OPA627. The V5i giving more tranparancy, detail and better definition in the bass.
OPA627 was also a very nice upgrade option if you like a warmer fuller sound with subtle highs, detail and a little darker atmosphere.
When I swapped the above with the Sparkos ss5290 I was immediately aware that this upgrade elevated and transformed the Bobby to a whole new level.
The sound was smooth, natural and very detailed and music was playing effortless and with great authority against a deadsilent background. It was a real joy to discover new insights in my music and It confirmed that the true potential of the Bobby amplifier was unleashed with this latest upgrade.
Sub-bass
The lowest frequencies are not predominant or in your face but present themselves in the form of a increased sense of the space and more accurate placing of instruments (in accoustic or live recordings). For testing electronic sub bass I often use ‘Doin it Right’ by Daft Punk. With the ss5290 the lowest bass notes can clearly be heard but you won’t feel them in your stomach.
Bass
Bass response may appear lean compared to Opa627 or V5i but you never have the feeling you are missing anything. In the live performance of ‘Inception:Time’ by Hans Zimmer and the Vienna Radio Symphony Orchestra the ss5290 displays the scale of this performance realistical and very convincing and the rumble never overshadows the other instruments.
Mids
Male and female vocals sound very natural and lifelike without any rough edges. Definition and placement of instruments is excellent as can be heard in songs like ‘In Your Eyes’ from Peter Gabriel.
On ‘Man in the long black coat’ the voice of Dylan and his harmonica sound natural and convincing. In my opinion harmonica’s are very challenging instruments to reproduce accurately. (that’s why this is also a good test-track to evaluate the subtle differences in linear power supplies, fuses and power cords)
Accoustic instruments like guitars show a nice and natural attack and decay as in ‘Trouble’s What You’re In’ by Fink. With lesser quality amplification this guitar can sound harsh or even aggressive.
Highs
The high frequency spectrum is well extended and airy but never sharp or piercing. In ‘I love Paris’ from Johnny Frigo this is nicely demonstrated with a highhat that sounds very realistic and convincing, with a decay that goes on forever.
in short:
The ss5290 breathes new life in my Bobby Amplifier and really elevates it to a whole new performance level.
I was also surprised that the Bobby had no problem in combination with my HiFiman HE6se v2 Headphones which have a reputation of being notoriously difficult to drive.
All in all I am very positive about this latest change and I am also very interested if @John90 has had similar experiences with using the smaller dual channel variant ss3602 in his Tobby DAC.
Attachments
Last edited:
labeelen
100+ Head-Fier
Hi All,
To celebrate it's 10th anniversary I recently upgraded Tobby's Opamps.
As a short memory refresh, Tobby was Firestone Audio's PCM1794 based DAC that was introduced in 2013 !
Being a fully balanced design it was standard equiped with 7x OPA2604 dual channel opamps from Burr Brown.
Four of these opamps took care of I/V conversion, another two performed LPF and one was used to combine the balanced circuits into single ended RCA output.
A few years ago I tried all possible opamp variants on the above mentioned functions, finally settling on:
Muses8920 for I/V conversion
OPA627 for LPF
OPA627 for SE conversion (which is optionally if you only use balanced)
Recently I did some testing with the Sparkos opamps in a few of my headphone amplifiers and wanted to also give it a try in the LPF section of my Tobby DAC.
I would like to share my experience with Tobby owners and of course any other reader(s) that are interested.
As a reference I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
In this test I will primarily focus on the impact that the opamps had on the LPF section of the DAC.
The default OPA2604 is a well respected audio amplifier that is good but there was room for improvement.
I had very positive experiences with upgrades to Muses and Burson variants but finally settled on the Opa627 because this was musically the most balanced to my ears with a warm (now and then maybe a little dark) tonality with spacious and detailed highs.
When I swapped them with two Sparkos ss3602 dual channel opamps I immediately noticed that the sound became less colored. In hindsight Opa627 sounded really warm, dark and nasal compared to the ss3602.
ss3602 was more detailed, neutral and controlled. At first it seemed to have less low end but after a while you start to appreciate this because the overall tonal balance is more natural and accurate.
Sub-bass
Low freqencies are better controled by the ss3602. This is demonstrated in Hans Zimmer's 'Inception: Time' where the rumble is very noticable but does not overwhelm all other instruments and details.
Bass
As mentioned earlier at first bass response may appear a little lean compared to Opa627 or V5i but it's the quality that counts, not the quantity.
Mids
A good example of the neutral sound and excellent separation can be heard in 'Summerhead' by Cocteau Twins. On Opa627 this can sometimes sound congested (maybe even chaotic) but not on ss3602 where the sound remains smooth an controlled and you can still hear the individual instruments and melody lines.
As an example for female voices, Olivia Vedder sounds crystal clear on 'My Father's Daughter' and the timing and attack of the percussion is spot on.
Highs
The Tobby/ss3602 combination had an overall very smooth and forgiving presentation which however does not mean it is rolled-off. In the contrary, high frequencies are very articulated but are never piercing or sibilant.
All in all I was very impressed with the potential that our 10 year old DAC design still had to offer. It looks like the Firestone Audio engineers designed a very future proof DAC and I am looking forward to the next 10 years with this recent Sparkos ss3602 'transplantation'.
Would like to hear if there are still any Tobby owners around that want to share there experiences with upgrading to discrete operational amplifiers.
To celebrate it's 10th anniversary I recently upgraded Tobby's Opamps.
As a short memory refresh, Tobby was Firestone Audio's PCM1794 based DAC that was introduced in 2013 !
Being a fully balanced design it was standard equiped with 7x OPA2604 dual channel opamps from Burr Brown.
Four of these opamps took care of I/V conversion, another two performed LPF and one was used to combine the balanced circuits into single ended RCA output.
A few years ago I tried all possible opamp variants on the above mentioned functions, finally settling on:
Muses8920 for I/V conversion
OPA627 for LPF
OPA627 for SE conversion (which is optionally if you only use balanced)
Recently I did some testing with the Sparkos opamps in a few of my headphone amplifiers and wanted to also give it a try in the LPF section of my Tobby DAC.
I would like to share my experience with Tobby owners and of course any other reader(s) that are interested.
As a reference I have included the Custom Headphone Target Curve that I used to EQ my HiFiman HE6se v2 headphone for the listening tests.
My audio-chain consisted of:
- Qobuz (Hi-res streaming service)
- Roon (on Synology NAS)
- HQPlayer (on Intel Nuc12i5) for upsampling and EQ
- Raspberry Pi 4 running RoPieeeXL with HQPlayer's Network Audio Adapter (NAA)
- Glass Optical Fibre connection
- FireStone Audio Tobby 192k D/A Converter
- Longon Silverplated Luxury Series XLR (interconnect)
- Firestone Audio 'Bobby' Professional (fully balanced, Class A) Headphone Amplifier
- HiFiman HE6se v2 with custom balanced cable by CustomCansUK
In this test I will primarily focus on the impact that the opamps had on the LPF section of the DAC.
The default OPA2604 is a well respected audio amplifier that is good but there was room for improvement.
I had very positive experiences with upgrades to Muses and Burson variants but finally settled on the Opa627 because this was musically the most balanced to my ears with a warm (now and then maybe a little dark) tonality with spacious and detailed highs.
When I swapped them with two Sparkos ss3602 dual channel opamps I immediately noticed that the sound became less colored. In hindsight Opa627 sounded really warm, dark and nasal compared to the ss3602.
ss3602 was more detailed, neutral and controlled. At first it seemed to have less low end but after a while you start to appreciate this because the overall tonal balance is more natural and accurate.
Sub-bass
Low freqencies are better controled by the ss3602. This is demonstrated in Hans Zimmer's 'Inception: Time' where the rumble is very noticable but does not overwhelm all other instruments and details.
Bass
As mentioned earlier at first bass response may appear a little lean compared to Opa627 or V5i but it's the quality that counts, not the quantity.
Mids
A good example of the neutral sound and excellent separation can be heard in 'Summerhead' by Cocteau Twins. On Opa627 this can sometimes sound congested (maybe even chaotic) but not on ss3602 where the sound remains smooth an controlled and you can still hear the individual instruments and melody lines.
As an example for female voices, Olivia Vedder sounds crystal clear on 'My Father's Daughter' and the timing and attack of the percussion is spot on.
Highs
The Tobby/ss3602 combination had an overall very smooth and forgiving presentation which however does not mean it is rolled-off. In the contrary, high frequencies are very articulated but are never piercing or sibilant.
All in all I was very impressed with the potential that our 10 year old DAC design still had to offer. It looks like the Firestone Audio engineers designed a very future proof DAC and I am looking forward to the next 10 years with this recent Sparkos ss3602 'transplantation'.
Would like to hear if there are still any Tobby owners around that want to share there experiences with upgrading to discrete operational amplifiers.
Attachments
Last edited:
Good to see you are still upgrading, because it has a lot to offer.
I have installed the IEC connector also bypassing the fuse. It says Furutech on it but it's VBS audio. Also upgraded from 8920 to Muses01 on I/V stage. OPA1612 on LPF will maybe change for Sparkos SS3602.
The Neutrik NC3MD-LX-B XLR's I bought don't fit in the back panel, I either have to modify them (grind them down) or buy something else.
The differences are not small with this upgrades, it has a much more mature sound signature while improving in every way in small to medium amounts. I will keep upgrading, will squeeze every bit of performance it has to give.
I have installed the IEC connector also bypassing the fuse. It says Furutech on it but it's VBS audio. Also upgraded from 8920 to Muses01 on I/V stage. OPA1612 on LPF will maybe change for Sparkos SS3602.
The Neutrik NC3MD-LX-B XLR's I bought don't fit in the back panel, I either have to modify them (grind them down) or buy something else.
The differences are not small with this upgrades, it has a much more mature sound signature while improving in every way in small to medium amounts. I will keep upgrading, will squeeze every bit of performance it has to give.
Attachments
The modding is completed, for now. I've also installed the XLR's and a pair of Sparkos SS2590 Dual (with pro to dual adaptors that were really easy to solder) but also got rid of all the iron I could. Iron is a audioplhile's enemy, the iron I took out was replaced with good copper (from VBS Audio) or in the case of the transformer, I've soldered the wires to the PCB after removing all of the (nasty) connectors.
The "iron delete" has made as much of an improvement as op-amps but in a different way, they are complementary to each other.
In the future I hope I can add more filtration somehow (more capacitors in the PSU section), but I need help from someone who knows where or how to install them, if it's possible to do so.
Great little DAC!
The "iron delete" has made as much of an improvement as op-amps but in a different way, they are complementary to each other.
In the future I hope I can add more filtration somehow (more capacitors in the PSU section), but I need help from someone who knows where or how to install them, if it's possible to do so.
Great little DAC!
Attachments
labeelen
100+ Head-Fier
Wow @John90 , that looks impressive !
I also did some additional finetuning because after my earlier experience with the Sparkos ss3602 I also wanted to try some of my Single Ended Headphone amps with the Firestone Audio Tobby D/A Converter.
As you are aware the Single Ended outputs also require an additional opamp and up til now the balanced outputs of the Tobby DAC where merged into the single ended output via an OPA627 opamps.
Although the OPA627 are very highly regarded I found them a little too dark sounding in this application so I also replaced them with one ss3602.
Immediately the dark veil disappeared and the character of the ss3602 (as described in my previous review above) came back.
It was a deja-vu with the previous swap of the opamps in the balanced output channels, i.e. a less colored sound with more detail, neutral and better control.
The ss3602 improves on the OPA627 in the areas of:
- more neutral (less dark) sound signature
- more space and better soundstage
- higher transparency with more details en more refined highs
- darker back-groud makes it easier to hear the fine details like decays and spacial information
- overall a very smooth, rich, dynamic and enjoyable sound !
Attachments
Last edited:
I think that this is the last mod, I'm more than pleased with it.
@labeelen
You may be interested to find out that the decrease in bass quantity has to do with the DACs inability to power the Sparkos. At least it was the case with mine. SS2590 needs more juice than SS3602, but also SS3602 needs more than a normal opamp, let's say a opa627.
Firstly, to my ears after testing some of the most recommended opamps...
Muses 8920 - clean but kind of simple sound
Muses 01 more audiophile signature but not very clean
opa1642 - focuses on mids/voices
opa2210 - similar to opa1612 but less clean
opa1612 - has everything
Sparkos SS2590 - the best of
... in various combinations I concluded that the best combination is opa1612 on I/V and Sparkos SS2590 (dual) on LPF. I wanted a (neutral) balanced DAC in every aspect, so that it can play well any type of music.
After installing the opa1612 on I/V the DAC lost much of the bass kick (also did with the Sparkos) so, I've asked around and then I took the DAC to my trusted electronics guy. After he inspected the DAC with my choice of opamps installed he said that we need to find more power for the opamps. Also said that the stock power regulators are very good (great news), but because of this, not very powerful.
He looked for power everywhere, the easiest thing was to unplug the SE opamp, leaving only the XLR's operational, it sound best on balanced outputs anyway and I have balanced inputs on my amplifier. Then he said that he enlarged the "power pool" by adding (between the regulators and opamps) more capacitors and of bigger value. The idea is that there is more current for the Sparkos to consume when the bass kicks, and in the short moments when there's no base, there is sufficient time for the capacitors to recharge.
He also did something to better integrate de opa1612, and also changed the capacitors (before the regulators) with bigger and better ones.
After these mods, the DAC stopped playing sounds and started playing music. It's not just the energy in the bass region that improved (better said, came back) but also everything flows better with more precision. and when asked it will bang, the voices will go high, and the highs will sparkle. Without harshness, sibilance and it doesn't lose control.
It is transparent and well balanced with a little sweetness, enough to be pleasant but not warm or boring. The imaging is holographic, precise and everything is naturally woven together. To quote the engineer that did these last (and very important) mods, it sounds like a big DAC now. I don't know or care how it measures, to my ears, in my system and room, it may be the best DAC I've ever owned, right out there with my ex Katalyst level Linn Selekt. With only ~1000 euros (and some manual labor) spent on it and the mods, it has crazy value.
@labeelen
You may be interested to find out that the decrease in bass quantity has to do with the DACs inability to power the Sparkos. At least it was the case with mine. SS2590 needs more juice than SS3602, but also SS3602 needs more than a normal opamp, let's say a opa627.
Firstly, to my ears after testing some of the most recommended opamps...
Muses 8920 - clean but kind of simple sound
Muses 01 more audiophile signature but not very clean
opa1642 - focuses on mids/voices
opa2210 - similar to opa1612 but less clean
opa1612 - has everything
Sparkos SS2590 - the best of
... in various combinations I concluded that the best combination is opa1612 on I/V and Sparkos SS2590 (dual) on LPF. I wanted a (neutral) balanced DAC in every aspect, so that it can play well any type of music.
After installing the opa1612 on I/V the DAC lost much of the bass kick (also did with the Sparkos) so, I've asked around and then I took the DAC to my trusted electronics guy. After he inspected the DAC with my choice of opamps installed he said that we need to find more power for the opamps. Also said that the stock power regulators are very good (great news), but because of this, not very powerful.
He looked for power everywhere, the easiest thing was to unplug the SE opamp, leaving only the XLR's operational, it sound best on balanced outputs anyway and I have balanced inputs on my amplifier. Then he said that he enlarged the "power pool" by adding (between the regulators and opamps) more capacitors and of bigger value. The idea is that there is more current for the Sparkos to consume when the bass kicks, and in the short moments when there's no base, there is sufficient time for the capacitors to recharge.
He also did something to better integrate de opa1612, and also changed the capacitors (before the regulators) with bigger and better ones.
After these mods, the DAC stopped playing sounds and started playing music. It's not just the energy in the bass region that improved (better said, came back) but also everything flows better with more precision. and when asked it will bang, the voices will go high, and the highs will sparkle. Without harshness, sibilance and it doesn't lose control.
It is transparent and well balanced with a little sweetness, enough to be pleasant but not warm or boring. The imaging is holographic, precise and everything is naturally woven together. To quote the engineer that did these last (and very important) mods, it sounds like a big DAC now. I don't know or care how it measures, to my ears, in my system and room, it may be the best DAC I've ever owned, right out there with my ex Katalyst level Linn Selekt. With only ~1000 euros (and some manual labor) spent on it and the mods, it has crazy value.
Attachments
Last edited:
Users who are viewing this thread
