I wouldn't expect a big device such as the THF-51 or the 2SK182ES to be installed on a separate bracket. They are probably best bolted directly onto the main heatsinks.
The 2SK180 devices could use separate heatsinks, but I don't expect the store to supply these. Builders will probably want to gain access to a bench top drill press.
The 2SK180 devices could use separate heatsinks, but I don't expect the store to supply these. Builders will probably want to gain access to a bench top drill press.
Because I first posted about it here, I should now post the link to the swap meet:
2SK60 2SJ18 Sony VFETs
Thanks,
Alex
2SK60 2SJ18 Sony VFETs
Thanks,
Alex
Forelast mod ongoing: additional bypass of the 10 000uF output caps with 220uF quality caps (see past posts).
Yes, the caps are positioned in an odd way, that is on purpose. I may need space under the boards if the last mod (additional SMPS filter) turns out to be benefical, hence the position of these bypass caps.
As for the sonic impact, we will have to wait for next week. It appears that the sound changed over the inital hours, so we better wait until it is settled. The caps do need some burn-in.
As it is not easy to evaluate the changes of this particular mod (long time period due to burn-in, hence not an easy quick before/after comparo this time), it is Gilles who will assess them. Gilles is using the amp since a few months now and all the mods we carried out where performed at his. He knows the amp by heart and has the benefit of comparing it (quick amp switch, all is ready for that) each time to his very own amp that I built with him. The latter is a stable amp reference re sound over time (no more tweaks on this one), enabling the evaluation of the mod regardless the elapsed time. Of course I will give it a listen aswell but then I will rely on auditive memory with far more limitations...
Stay tuned for the verdict
Claude
Yes, the caps are positioned in an odd way, that is on purpose. I may need space under the boards if the last mod (additional SMPS filter) turns out to be benefical, hence the position of these bypass caps.
As for the sonic impact, we will have to wait for next week. It appears that the sound changed over the inital hours, so we better wait until it is settled. The caps do need some burn-in.
As it is not easy to evaluate the changes of this particular mod (long time period due to burn-in, hence not an easy quick before/after comparo this time), it is Gilles who will assess them. Gilles is using the amp since a few months now and all the mods we carried out where performed at his. He knows the amp by heart and has the benefit of comparing it (quick amp switch, all is ready for that) each time to his very own amp that I built with him. The latter is a stable amp reference re sound over time (no more tweaks on this one), enabling the evaluation of the mod regardless the elapsed time. Of course I will give it a listen aswell but then I will rely on auditive memory with far more limitations...
Stay tuned for the verdict
Claude
Attachments
The caps are Nichicon KZ 220uF/50V...
Oh, and Tungstenaudio is not foreign to that mod at all... eventhough the values have are different.
Claude
Oh, and Tungstenaudio is not foreign to that mod at all... eventhough the values have are different.
Claude
I had bypassed the Rubycon output capacitors on my VFET (N version) with 1000 uF / 50 V Nichicon KZ.
I quite like the change, but in my case it needed almost a week to settle in ... 😛
Regards, Claas
I quite like the change, but in my case it needed almost a week to settle in ... 😛
Regards, Claas
Yep, that's why I won't comment before a week.
TBH, I even thought about burning them in, but I quickly realised that to do it properly I would need a, ahem... power amp! That's due to their (unusual location at the output, they do see quite some voltage and amperes...)
Anyway, let's see how that 10000 + 220 + 0.33 combo sounds... baring in mind I don't expect a huge change though, whatever the positive or negative.
bb und Grüsse an Dü
Claude
TBH, I even thought about burning them in, but I quickly realised that to do it properly I would need a, ahem... power amp! That's due to their (unusual location at the output, they do see quite some voltage and amperes...)
Anyway, let's see how that 10000 + 220 + 0.33 combo sounds... baring in mind I don't expect a huge change though, whatever the positive or negative.
bb und Grüsse an Dü
Claude
Hi,
I got 2200µF/63V BlackGate FK...anyone try these bypassing the 10000µF out put cap ?
Damien
I got 2200µF/63V BlackGate FK...anyone try these bypassing the 10000µF out put cap ?
Damien
if you're young enough, then you probably have enough years in front of you, to wait a moment when BG is finally starting to sing
Moi, I'm too old for that
Moi, I'm too old for that
Yeah,
Those BlackGates would probably work well as per channel power bypass on the OS boards.
I would recommend the Nichicon varieties already mentioned (KW, KZ), as well as the Elna Silmic for output coupling cap bypass. Those all take about a week to sound their best, but most of the benefits will show around 100 hours.
Those BlackGates would probably work well as per channel power bypass on the OS boards.
I would recommend the Nichicon varieties already mentioned (KW, KZ), as well as the Elna Silmic for output coupling cap bypass. Those all take about a week to sound their best, but most of the benefits will show around 100 hours.
I guess cap bypass is a widely debated topic. Some say it makes no audible difference (or can't make any), some claim it does, some say (with correct tech background to back it off) you get extra resonance... but omit the word CAN.
What follows is very personal, based on my own experience (bypassing since a few decades):
1) There is no straight rule re bypass, as long as you don't get a silly resonance, take / do...what suits you/your ears best!
2) Caps have evolved, what was true 30y ago isn't necessarly anymore, as I recently found out. ESR on lytics can be very different from what it used to be in the 80s or 90s
3) I tend to apply personnaly a kind of rule of the thumb. As all guessworks, it is based on experience and some tech considerations re resonnance etc.
That rule starts with (for caps in amp's signal path, "digital" is another matter (!), amp's PS aswell nowadays, and what follows applies mostly for lytics) to bypass big caps with another one that is around 500 times smaller. That is what worked best FOR ME. However, ther can be other considerations, as here, so that I may alter the corresponding value range. But I would (HERE) not chose bigger than say 40x smaller and not smaller than 2000x smaller. It can get more complicated when different cap tech are involved, but let's not dig into that.
This value range should with quality caps avoid resonnances / response in most cases, things that can be measured on a scope that are, depending on lytic caps of course, rather of the mentioned magnitude.
Long story short: to help damping, I wouldn't HERE bypass the 10000uF lytic with a 2200uF one. I would either replace the 10000uF with a quality one (if it isn't already), or (some might even say AND, but I found OR worked nearly aswell) bypass it with anything quality between 220uF and 5uF.
BUT THEN...
That was the basic idea, but then HERE we have "a problem": a third bypass could then likely be needed to dampen the second one... and that third bypass exists already in form of the quality PP 0.33uF one (and has a nice final value, so let's keep it). So more thinking is required here to keep things into the right extented ball park, from 50 to 10000x.
I had calculated an accaptable middleway, which would have been in fact calculated 58uF. BUT then as Papa had already done similar in another build chosing a somewhat bigger value, plus I decided that the big lytic cap needed indeed "more help" than the smaller PP so the middleway wasn't perhaps ideal, plus some quality caps were available at 220uF... I decided to go for 220uF. That is still just within the range I wanted, but as you can see there are many possible choices, and TBH I am not sure it makes a bugger difference if chosing 47uF rather than 470uF on the paper... but I felt slightly more confident going 100uF or 220uF, don't ask me why. And 220uF were available, end of (long) story while still being in the acceptable range.
So if the idea is to help response, I am not so sure that bypassing an amp's 10000uF signal cap with a 2200uF is a good idea ". Nor that the latter wouldn't then require a bit more than 0.33 to be bypassed itself. But that's just me.
But I can be wrong, try it for yourself...
Have fun, this is a hobby, so please no sterile debate here, so just expressing my own very humble POV and I am stepping out
Claude
PS: If designing it from scratch, applying my silly theory, I would have here probably chosen 10 000uF + 100uF + 1uF PP. But then I would have had to listen to it, spend time comparing etc., while Papa went 220uF or higher in similar cases, which is not far off anyway so why bother (eventhough the values might have been chosen to adjust sound, but well...)
What follows is very personal, based on my own experience (bypassing since a few decades):
1) There is no straight rule re bypass, as long as you don't get a silly resonance, take / do...what suits you/your ears best!
2) Caps have evolved, what was true 30y ago isn't necessarly anymore, as I recently found out. ESR on lytics can be very different from what it used to be in the 80s or 90s
3) I tend to apply personnaly a kind of rule of the thumb. As all guessworks, it is based on experience and some tech considerations re resonnance etc.
That rule starts with (for caps in amp's signal path, "digital" is another matter (!), amp's PS aswell nowadays, and what follows applies mostly for lytics) to bypass big caps with another one that is around 500 times smaller. That is what worked best FOR ME. However, ther can be other considerations, as here, so that I may alter the corresponding value range. But I would (HERE) not chose bigger than say 40x smaller and not smaller than 2000x smaller. It can get more complicated when different cap tech are involved, but let's not dig into that.
This value range should with quality caps avoid resonnances / response in most cases, things that can be measured on a scope that are, depending on lytic caps of course, rather of the mentioned magnitude.
Long story short: to help damping, I wouldn't HERE bypass the 10000uF lytic with a 2200uF one. I would either replace the 10000uF with a quality one (if it isn't already), or (some might even say AND, but I found OR worked nearly aswell) bypass it with anything quality between 220uF and 5uF.
BUT THEN...
That was the basic idea, but then HERE we have "a problem": a third bypass could then likely be needed to dampen the second one... and that third bypass exists already in form of the quality PP 0.33uF one (and has a nice final value, so let's keep it). So more thinking is required here to keep things into the right extented ball park, from 50 to 10000x.
I had calculated an accaptable middleway, which would have been in fact calculated 58uF. BUT then as Papa had already done similar in another build chosing a somewhat bigger value, plus I decided that the big lytic cap needed indeed "more help" than the smaller PP so the middleway wasn't perhaps ideal, plus some quality caps were available at 220uF... I decided to go for 220uF. That is still just within the range I wanted, but as you can see there are many possible choices, and TBH I am not sure it makes a bugger difference if chosing 47uF rather than 470uF on the paper... but I felt slightly more confident going 100uF or 220uF, don't ask me why. And 220uF were available, end of (long) story while still being in the acceptable range.
So if the idea is to help response, I am not so sure that bypassing an amp's 10000uF signal cap with a 2200uF is a good idea ". Nor that the latter wouldn't then require a bit more than 0.33 to be bypassed itself. But that's just me.
But I can be wrong, try it for yourself...
Have fun, this is a hobby, so please no sterile debate here, so just expressing my own very humble POV and I am stepping out
Claude
PS: If designing it from scratch, applying my silly theory, I would have here probably chosen 10 000uF + 100uF + 1uF PP. But then I would have had to listen to it, spend time comparing etc., while Papa went 220uF or higher in similar cases, which is not far off anyway so why bother (eventhough the values might have been chosen to adjust sound, but well...)
if in doubt, see how's he doing it
there must be something, he made his Flock happy
and, I taught him almost everything I know
there must be something, he made his Flock happy
and, I taught him almost everything I know
Oh, and after all the time spent typing all this... personal guesswork, remains the big question: does it really help the sound HERE, LOL?
No clue, we shall know in a few days, but don't expect any abyssimal change of course... the unit is nice sounding as it is and Papa already thought of an acceptable bypass in form of the 0.33 PP cap, so we are more into "potential very fine tuning to own taste" anyway...
Hobbies are a wonderfull to waste time, and to spread odd theories, aren't they 🙂 ?
Have fun guys
Claude
No clue, we shall know in a few days, but don't expect any abyssimal change of course... the unit is nice sounding as it is and Papa already thought of an acceptable bypass in form of the 0.33 PP cap, so we are more into "potential very fine tuning to own taste" anyway...
Hobbies are a wonderfull to waste time, and to spread odd theories, aren't they 🙂 ?
Have fun guys
Claude
I had these exact elcos (Rubycon USR 10000/63) in a PSU for chip amp, and they gave me *excellent* sonic results. I disassembled that amp, and used those elcos for something else. Ended up pushing them too far and ruining them with overvoltage. So, how much do these cost and what are the sources?
Thanks,
Alex
Thanks,
Alex
The ones in the VFET kits probably came from Nelson's secret stash. I think I've also seen them on Mouser. They are actually quite good. When we are talking about bypassing them, the differences are subtle, but still worth experimenting with..
Cost 6 bucks or so, look at the usual places (Mouser, RS...) the prob being more availability / stock.
Look for ref. 1189-2739-ND
I hope that helps
Claude
Look for ref. 1189-2739-ND
I hope that helps
Claude
