The Stax Thread III
Sep 18, 2023 at 2:38 PM Post #24,331 of 26,473
Regarding the bass on electrostats - it just is what is. You're not gonna get ear-flapping slam and impact like with planars or with (some) closed dynamics, though a thoroughly amp'd 007 Mk 1's bass is kind of interesting in its own right. I'm not holding out hope for a tech breakthrough to close that gap, or a new amp to magically fill out more than an OG DIY T2 (which I find slightly stronger in bass fill versus the Kerry T2 I had). I think these are the physics of an ultra thin, ultra light diaphragm of a wearable size, driven by relatively weak electrostatic forces. Magnets, coils, and cone materials are 800 lbs gorillas by comparison. You can push it only so far before you're risking the lifespan of those electrostatic diaphragms, or your needed amp is infeasible.

I've transitioned fully to speakers for the "tactile" feel of lower spectrum energy. So pursuing this in headphones (which cannot equal a good speaker rig here) is not a high priority.

I think serious headphone audiophiles should try electrostats, but they're not gong to be for everyone.
 
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Sep 18, 2023 at 3:45 PM Post #24,332 of 26,473
Hello all,

I don’t post on here often, but just wanted to give people a heads up on two things. This post is about 50% warning of the dangers of picking the wrong builder for your DIY Stax amp and 50% praise for the community and particular members within it.

Firstly – a word of warning – do your research more thoroughly than I did. I bought a KGSSHV via eBay in late 2020 from Felitsa Audio AKA Thuan, who I can now see have a bit of a poor reputation. The sound was good, and certainly a step up from the Stax energizer I’d been using previously, but more on this later. I paid around 1800 euros for the amp, including shipping (which increased between the time of purchase and payment taking place, a warning sign I should’ve taken more notice of perhaps). Upon arrival I took a look and to my uncultured eye all looked fine. However, within 3 months the power LED had died (and consequence of some awful design choices), and within 6 months there was some noticeable discolouration to several resistors due to heat distress. I replaced these, and all was fine for another two years. Until…

All of a sudden around two months ago, I turned the amp on and was greeted with a puff of smoke. Not good. I powered it off, opened the lid and took a look. With nothing obvious I tried turning it on again, only to be greeted with more smoke coming from a small area of the PCB which I now know had carbonised and was burning. Eek.

A local hifi repairer took a look and had a go at fixing the issue, but couldn’t. At this moment in steps our hero of the hour, Head-Fi’s very own Søren Brix. At two children our family is probably complete, but if I had my time again Søren would be a strong contender for the name of our first born.

I contact Søren via PM here, and after a few photos and messages he asked me to give him a call. He very kindly agreed to take a look at the amp, and arranged a shipping label. From this point onwards Søren was extremely generous with both his skillset and his time, talking me through the process carefully and explaining the issues in a way which made sense to me, even with my fairly limited understanding of electronical engineering.

Essentially, the amp was a mess. Sometimes this was due to poor materials (wire which wasn’t specced for the temperature and current, mixed capacitors which should’ve been paired etc) and sometimes it was due to a lack of understanding of the build process and the fundamentals behind it. The power supply was running at a mixture of 450v and 500v, the left channel was wired out of phase, and various other issues (some of which were a fairly significant safety concern). Frustratingly, poor quality solder had been used throughout which made the rest of the repair much more time consuming as cleaning became incredibly difficult.

Søren essentially rebuilt the ENTIRE power supply whilst salvaging some of the parts from the old board. He also changed the board from an A1968 to an IXYS setup (the A1968 on the left board was the cause of the original issue), replaced all of the internal wiring and cleaned up the board, re-doing various poorly soldered joints along the way. I can only imagine how long it must’ve taken. At every stage he talked me through what he’d done/was going to do and why, and I really enjoyed talking to him about the process.

The process was obviously made significantly more complicated due to the state the amp originally arrived in. This meant unpicking some non-standard design choices, undoing rushed workmanship and I’m sure plenty of head scratching.

I received the amp last week, and the difference in the sound is striking. Instruments have more separation, there’s increased clarity and possibly even more pace/precision, but most of all the improvement at the bottom end is phenomenal. The range of bass my headphones are now capable of creating is genuinely incredible, and music feels fuller and warmer as a result. I flit between some L500s and some 007 Mk1s, and both feel like they have been significantly upgraded. It’s also bloody loud when you want it to be! As I started by saying I hadn’t been particularly unhappy with the sound, but after doing some extended listening it’s definitely a case of not missing what you don’t know.

In essence, I would say to anyone out there that when you pick a builder think what there motivations are. Some, like Søren, clearly are working for the enjoyment of the hobby and want the people they’re building for to really enjoy what they end up with. In fact, when he sent me the unbelievably reasonable bill I knew I’d been undercharged, but in his own he ‘considered it as a contribution to the community.’ Others like Felitsa Audio seem to be doing it purely for profit, and I think its pretty obvious which set of motivations lead to a better experience. I don’t wish to slander anyone, but having now seen the thread in which Kevin unpicks, ‘repairs’ and rebuilds another of their creations, I am pretty clear in my understanding of how I’ll approach any future DIY building projects.

(Søren, if I’ve made any mistakes in the above please correct!)
 
Sep 18, 2023 at 5:16 PM Post #24,333 of 26,473
Hello all,

I don’t post on here often, but just wanted to give people a heads up on two things. This post is about 50% warning of the dangers of picking the wrong builder for your DIY Stax amp and 50% praise for the community and particular members within it.

Firstly – a word of warning – do your research more thoroughly than I did. I bought a KGSSHV via eBay in late 2020 from Felitsa Audio AKA Thuan, who I can now see have a bit of a poor reputation. The sound was good, and certainly a step up from the Stax energizer I’d been using previously, but more on this later. I paid around 1800 euros for the amp, including shipping (which increased between the time of purchase and payment taking place, a warning sign I should’ve taken more notice of perhaps). Upon arrival I took a look and to my uncultured eye all looked fine. However, within 3 months the power LED had died (and consequence of some awful design choices), and within 6 months there was some noticeable discolouration to several resistors due to heat distress. I replaced these, and all was fine for another two years. Until…

All of a sudden around two months ago, I turned the amp on and was greeted with a puff of smoke. Not good. I powered it off, opened the lid and took a look. With nothing obvious I tried turning it on again, only to be greeted with more smoke coming from a small area of the PCB which I now know had carbonised and was burning. Eek.

A local hifi repairer took a look and had a go at fixing the issue, but couldn’t. At this moment in steps our hero of the hour, Head-Fi’s very own Søren Brix. At two children our family is probably complete, but if I had my time again Søren would be a strong contender for the name of our first born.

I contact Søren via PM here, and after a few photos and messages he asked me to give him a call. He very kindly agreed to take a look at the amp, and arranged a shipping label. From this point onwards Søren was extremely generous with both his skillset and his time, talking me through the process carefully and explaining the issues in a way which made sense to me, even with my fairly limited understanding of electronical engineering.

Essentially, the amp was a mess. Sometimes this was due to poor materials (wire which wasn’t specced for the temperature and current, mixed capacitors which should’ve been paired etc) and sometimes it was due to a lack of understanding of the build process and the fundamentals behind it. The power supply was running at a mixture of 450v and 500v, the left channel was wired out of phase, and various other issues (some of which were a fairly significant safety concern). Frustratingly, poor quality solder had been used throughout which made the rest of the repair much more time consuming as cleaning became incredibly difficult.

Søren essentially rebuilt the ENTIRE power supply whilst salvaging some of the parts from the old board. He also changed the board from an A1968 to an IXYS setup (the A1968 on the left board was the cause of the original issue), replaced all of the internal wiring and cleaned up the board, re-doing various poorly soldered joints along the way. I can only imagine how long it must’ve taken. At every stage he talked me through what he’d done/was going to do and why, and I really enjoyed talking to him about the process.

The process was obviously made significantly more complicated due to the state the amp originally arrived in. This meant unpicking some non-standard design choices, undoing rushed workmanship and I’m sure plenty of head scratching.

I received the amp last week, and the difference in the sound is striking. Instruments have more separation, there’s increased clarity and possibly even more pace/precision, but most of all the improvement at the bottom end is phenomenal. The range of bass my headphones are now capable of creating is genuinely incredible, and music feels fuller and warmer as a result. I flit between some L500s and some 007 Mk1s, and both feel like they have been significantly upgraded. It’s also bloody loud when you want it to be! As I started by saying I hadn’t been particularly unhappy with the sound, but after doing some extended listening it’s definitely a case of not missing what you don’t know.

In essence, I would say to anyone out there that when you pick a builder think what there motivations are. Some, like Søren, clearly are working for the enjoyment of the hobby and want the people they’re building for to really enjoy what they end up with. In fact, when he sent me the unbelievably reasonable bill I knew I’d been undercharged, but in his own he ‘considered it as a contribution to the community.’ Others like Felitsa Audio seem to be doing it purely for profit, and I think its pretty obvious which set of motivations lead to a better experience. I don’t wish to slander anyone, but having now seen the thread in which Kevin unpicks, ‘repairs’ and rebuilds another of their creations, I am pretty clear in my understanding of how I’ll approach any future DIY building projects.

(Søren, if I’ve made any mistakes in the above please correct!)
Tuan is the sickness of our hobby. Many years ago i had a bad experience with boards never received. I wrote this on head-case when no one yet knew him well and everyone trusted him even Kerry and Kevin Gilmore. Of course alla people misjudged me
 
Sep 18, 2023 at 5:22 PM Post #24,334 of 26,473
Hello all,

I don’t post on here often, but just wanted to give people a heads up on two things. This post is about 50% warning of the dangers of picking the wrong builder for your DIY Stax amp and 50% praise for the community and particular members within it.

Firstly – a word of warning – do your research more thoroughly than I did. I bought a KGSSHV via eBay in late 2020 from Felitsa Audio AKA Thuan, who I can now see have a bit of a poor reputation. The sound was good, and certainly a step up from the Stax energizer I’d been using previously, but more on this later. I paid around 1800 euros for the amp, including shipping (which increased between the time of purchase and payment taking place, a warning sign I should’ve taken more notice of perhaps). Upon arrival I took a look and to my uncultured eye all looked fine. However, within 3 months the power LED had died (and consequence of some awful design choices), and within 6 months there was some noticeable discolouration to several resistors due to heat distress. I replaced these, and all was fine for another two years. Until…

All of a sudden around two months ago, I turned the amp on and was greeted with a puff of smoke. Not good. I powered it off, opened the lid and took a look. With nothing obvious I tried turning it on again, only to be greeted with more smoke coming from a small area of the PCB which I now know had carbonised and was burning. Eek.

A local hifi repairer took a look and had a go at fixing the issue, but couldn’t. At this moment in steps our hero of the hour, Head-Fi’s very own Søren Brix. At two children our family is probably complete, but if I had my time again Søren would be a strong contender for the name of our first born.

I contact Søren via PM here, and after a few photos and messages he asked me to give him a call. He very kindly agreed to take a look at the amp, and arranged a shipping label. From this point onwards Søren was extremely generous with both his skillset and his time, talking me through the process carefully and explaining the issues in a way which made sense to me, even with my fairly limited understanding of electronical engineering.

Essentially, the amp was a mess. Sometimes this was due to poor materials (wire which wasn’t specced for the temperature and current, mixed capacitors which should’ve been paired etc) and sometimes it was due to a lack of understanding of the build process and the fundamentals behind it. The power supply was running at a mixture of 450v and 500v, the left channel was wired out of phase, and various other issues (some of which were a fairly significant safety concern). Frustratingly, poor quality solder had been used throughout which made the rest of the repair much more time consuming as cleaning became incredibly difficult.

Søren essentially rebuilt the ENTIRE power supply whilst salvaging some of the parts from the old board. He also changed the board from an A1968 to an IXYS setup (the A1968 on the left board was the cause of the original issue), replaced all of the internal wiring and cleaned up the board, re-doing various poorly soldered joints along the way. I can only imagine how long it must’ve taken. At every stage he talked me through what he’d done/was going to do and why, and I really enjoyed talking to him about the process.

The process was obviously made significantly more complicated due to the state the amp originally arrived in. This meant unpicking some non-standard design choices, undoing rushed workmanship and I’m sure plenty of head scratching.

I received the amp last week, and the difference in the sound is striking. Instruments have more separation, there’s increased clarity and possibly even more pace/precision, but most of all the improvement at the bottom end is phenomenal. The range of bass my headphones are now capable of creating is genuinely incredible, and music feels fuller and warmer as a result. I flit between some L500s and some 007 Mk1s, and both feel like they have been significantly upgraded. It’s also bloody loud when you want it to be! As I started by saying I hadn’t been particularly unhappy with the sound, but after doing some extended listening it’s definitely a case of not missing what you don’t know.

In essence, I would say to anyone out there that when you pick a builder think what there motivations are. Some, like Søren, clearly are working for the enjoyment of the hobby and want the people they’re building for to really enjoy what they end up with. In fact, when he sent me the unbelievably reasonable bill I knew I’d been undercharged, but in his own he ‘considered it as a contribution to the community.’ Others like Felitsa Audio seem to be doing it purely for profit, and I think its pretty obvious which set of motivations lead to a better experience. I don’t wish to slander anyone, but having now seen the thread in which Kevin unpicks, ‘repairs’ and rebuilds another of their creations, I am pretty clear in my understanding of how I’ll approach any future DIY building projects.

(Søren, if I’ve made any mistakes in the above please correct!)
Awesome! Hero arc by Søren. Yep, anyone here who's not familiar with the names "Felitsa Audio", "Thuan", "LilKnight" needs to remember them and stay far away! Lots of horror stories out there. He seemed like an OK dude at first, but turned out not to be, and just keeps coming back under different labels.

That's cool you've got IXYS parts now. The original version KGSShv at 500V with IXYS parts is my favorite sounding one, of the 5 or 6 I've heard. IIRC the other part's correct label is Sanyo 2SA1968 but what do I know, I'm no builder lol
 
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Sep 18, 2023 at 5:58 PM Post #24,336 of 26,473
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Sep 19, 2023 at 8:34 AM Post #24,337 of 26,473
Few weeks ago there was a headphone exibition in Essen, Germany. While not all big headphone manufacturers were present (e.g. Focal, Abyss), there was enough to explore.
I was there together with a friend (also a Stax owner), and our outcome was very similar and simple. By a big margin we preferred Stax over everything else. The Susvara was a contender, but it was again obvious they need a very capable amp to shine.
It is beyond me how anyone might want any Audeze after listening to a Stax (probably only if that bass presentation is preferred). The asked price for an LCD5 seemed ridicolous in comparison (which really has a small bass if not EQed).

So we concentrated in testing estat systems. I found the Warwick Aperio interesting, mainly because of the technical abilities. It was playing highly energetic, with really good resolution, nice bass and pure speed. But after few songs there was a strong feeling that the presentation is sounding artificial, not "organic" and especilly the treble was overdone (too much emphazied). In total an interesting but mixed bag, which I would not trade with a good Stax setup.
In comparison the smaller Bravura was just lesser in every way.

We spend a lot of time at the booth of Malvalve, a german manufacturer of tube amplifiers, CD-Players etc. It was interesting, as they had both their headphone amps in combination with a lot of estats. These amps drive both conventional and estat phones. The smaller Headamp 3 was not intersting at all, it sounded not powerful, not open and detailed, but the big Headamp 5 was impressing. Very nice timbre, staging and detail with a deep and firm bass. Music choice was limited, but from memory definetely Megatron level I would say. It has the option of increasing the bias voltage, but was set to 580V for Stax.
We tested all current round Stax and all sounded great. The "hybrid" design of the amp might be dicussed controversial though, same as the price of about 19k€.
Beside Stax there was also The Audeze Crbn and Dan Clark Voce plus Corina. We thougt neither of them was holding a candle against the Staxes. And while all the Stax were scaling like hell when changing from Headamp 3 to 5, Voce and Corina seemed to stick with their limitations (they sounded "nice", but definetely no "energetic" experience). Voce and Corina sounded similar, maybe no surprise if they share the same driver (read that somewhere). On the 3 the sound was reminding me of listening with a very average Stax amp, the differences between Stax phones and DCA were not too big in overall performance. Very much in comparison to the 5. The Crbn got only few minutes of listening time, IMO no contest to Stax. It scaled at the 5, but still...
Summing up, we felt that we are very happy with our Stax, and a good amplifier is making the difference. In the end not really a new finding :)
 

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Sep 19, 2023 at 8:52 AM Post #24,338 of 26,473
Few weeks ago there was a headphone exibition in Essen, Germany. While not all big headphone manufacturers were present (e.g. Focal, Abyss), there was enough to explore.
I was there together with a friend (also a Stax owner), and our outcome was very similar and simple. By a big margin we preferred Stax over everything else. The Susvara was a contender, but it was again obvious they need a very capable amp to shine.
It is beyond me how anyone might want any Audeze after listening to a Stax (probably only if that bass presentation is preferred). The asked price for an LCD5 seemed ridicolous in comparison (which really has a small bass if not EQed).

So we concentrated in testing estat systems. I found the Warwick Aperio interesting, mainly because of the technical abilities. It was playing highly energetic, with really good resolution, nice bass and pure speed. But after few songs there was a strong feeling that the presentation is sounding artificial, not "organic" and especilly the treble was overdone (too much emphazied). In total an interesting but mixed bag, which I would not trade with a good Stax setup.
In comparison the smaller Bravura was just lesser in every way.

We spend a lot of time at the booth of Malvalve, a german manufacturer of tube amplifiers, CD-Players etc. It was interesting, as they had both their headphone amps in combination with a lot of estats. These amps drive both conventional and estat phones. The smaller Headamp 3 was not intersting at all, it sounded not powerful, not open and detailed, but the big Headamp 5 was impressing. Very nice timbre, staging and detail with a deep and firm bass. Music choice was limited, but from memory definetely Megatron level I would say. It has the option of increasing the bias voltage, but was set to 580V for Stax.
We tested all current round Stax and all sounded great. The "hybrid" design of the amp might be dicussed controversial though, same as the price of about 19k€.
Beside Stax there was also The Audeze Crbn and Dan Clark Voce plus Corina. We thougt neither of them was holding a candle against the Staxes. And while all the Stax were scaling like hell when changing from Headamp 3 to 5, Voce and Corina seemed to stick with their limitations (they sounded "nice", but definetely no "energetic" experience). Voce and Corina sounded similar, maybe no surprise if they share the same driver (read that somewhere). On the 3 the sound was reminding me of listening with a very average Stax amp, the differences between Stax phones and DCA were not too big in overall performance. Very much in comparison to the 5. The Crbn got only few minutes of listening time, IMO no contest to Stax. It scaled at the 5, but still...
Summing up, we felt that we are very happy with our Stax, and a good amplifier is making the difference. In the end not really a new finding :)
how much tubes on the malvalve? around 20?:ksc75smile:
 
Sep 19, 2023 at 3:05 PM Post #24,339 of 26,473
Few weeks ago there was a headphone exibition in Essen, Germany. While not all big headphone manufacturers were present (e.g. Focal, Abyss), there was enough to explore.
I was there together with a friend (also a Stax owner), and our outcome was very similar and simple. By a big margin we preferred Stax over everything else. The Susvara was a contender, but it was again obvious they need a very capable amp to shine.
It is beyond me how anyone might want any Audeze after listening to a Stax (probably only if that bass presentation is preferred). The asked price for an LCD5 seemed ridicolous in comparison (which really has a small bass if not EQed).

So we concentrated in testing estat systems. I found the Warwick Aperio interesting, mainly because of the technical abilities. It was playing highly energetic, with really good resolution, nice bass and pure speed. But after few songs there was a strong feeling that the presentation is sounding artificial, not "organic" and especilly the treble was overdone (too much emphazied). In total an interesting but mixed bag, which I would not trade with a good Stax setup.
In comparison the smaller Bravura was just lesser in every way.

We spend a lot of time at the booth of Malvalve, a german manufacturer of tube amplifiers, CD-Players etc. It was interesting, as they had both their headphone amps in combination with a lot of estats. These amps drive both conventional and estat phones. The smaller Headamp 3 was not intersting at all, it sounded not powerful, not open and detailed, but the big Headamp 5 was impressing. Very nice timbre, staging and detail with a deep and firm bass. Music choice was limited, but from memory definetely Megatron level I would say. It has the option of increasing the bias voltage, but was set to 580V for Stax.
We tested all current round Stax and all sounded great. The "hybrid" design of the amp might be dicussed controversial though, same as the price of about 19k€.
Beside Stax there was also The Audeze Crbn and Dan Clark Voce plus Corina. We thougt neither of them was holding a candle against the Staxes. And while all the Stax were scaling like hell when changing from Headamp 3 to 5, Voce and Corina seemed to stick with their limitations (they sounded "nice", but definetely no "energetic" experience). Voce and Corina sounded similar, maybe no surprise if they share the same driver (read that somewhere). On the 3 the sound was reminding me of listening with a very average Stax amp, the differences between Stax phones and DCA were not too big in overall performance. Very much in comparison to the 5. The Crbn got only few minutes of listening time, IMO no contest to Stax. It scaled at the 5, but still...
Summing up, we felt that we are very happy with our Stax, and a good amplifier is making the difference. In the end not really a new finding :)
Wild looking amp! Would be curious to see under the hood.

CRBN would have been audeze’s all-time best recommended if:
1) price tag was $2k
2) didn’t have the static and sticking issues day one
3) Audeze licensed and sold the kgssHv as at a “package” pair rate.

It does really well on a strong solid state amp but yeah… 007 is better 🤷‍♂️
 
Sep 19, 2023 at 7:04 PM Post #24,340 of 26,473
Wild looking amp! Would be curious to see under the hood.

CRBN would have been audeze’s all-time best recommended if:
1) price tag was $2k
2) didn’t have the static and sticking issues day one
3) Audeze licensed and sold the kgssHv as at a “package” pair rate.

It does really well on a strong solid state amp but yeah… 007 is better 🤷‍♂️
I found a link to this amplifier with specs and under the hood pics.

https://www.malvalve.de/Headamp5.htm

About the CRBN, I did not want to say it is a terrible headphone, it certainly is not. Just that I liked each of the round Stax significantly better :wink:
 
Sep 20, 2023 at 4:32 AM Post #24,342 of 26,473
And just like that... a new megatron is born into the world :-D. I will be updating with impressions in the next few weeks. @Dukei absolutely nailed it with this build. /Endgame

Megatron.jpgmegatron 2.jpg
PXL_20230918_205542401.jpg
Impressive!!!
 
Sep 20, 2023 at 4:48 AM Post #24,343 of 26,473
And just like that... a new megatron is born into the world :-D. I will be updating with impressions in the next few weeks. @Dukei absolutely nailed it with this build. /Endgame

Megatron.jpgmegatron 2.jpg
PXL_20230918_205542401.jpg
awesome. the psu is regulated with tubes?
 
Sep 20, 2023 at 6:22 AM Post #24,345 of 26,473
And just like that... a new megatron is born into the world :-D. I will be updating with impressions in the next few weeks. @Dukei absolutely nailed it with this build. /Endgame

Megatron.jpgmegatron 2.jpg
PXL_20230918_205542401.jpg

I'm not really a stickler for looks, but DIY build or not, this is just absolutely gorgeous. Congrats! Looking forward to impressions. :)
 

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