I agree, normally if good results are had, they are subtle.
I did get a very good result from this simple 3 cap smoothing / bypass setup, I use this one for my little tube pre-amp.
I will implement the same setup on my Meanwell 36v / 5.9 amp SMPS, hopefully I get the same good result.
Rob43
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OK, after a little thought I changed my design for adding bypass caps to my OPA1656 Op Amps.
My new design allows for Very Quick install & removal of any bypass cap configuration.
The small cap is a Elna RFS SILMIC II 10 uF 25v, the big cap is a Russian K42Y-2 PIO 0.1 uF 250v, both are considered very good "Audio Grade" caps. (yes, I can make them fit)
These are currently burning-in, I will start my A/B listening tests tomorrow.
Rob43
My new design allows for Very Quick install & removal of any bypass cap configuration.
The small cap is a Elna RFS SILMIC II 10 uF 25v, the big cap is a Russian K42Y-2 PIO 0.1 uF 250v, both are considered very good "Audio Grade" caps. (yes, I can make them fit)
These are currently burning-in, I will start my A/B listening tests tomorrow.
Rob43
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Claude, I'm really look forward to your "A" & "C" results, I hope they sound good !
Rob43
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Following with interest.
Do you have some pics how you have done with the Wurth coils? Does it need drilling to fit ?
I don't have those pics yet because I haven't gotten to that stage yet.
I need to accomplish each mod one by one, this way we as a community will know what works & what doesn't.
I know for certain that I won't be doing any drilling to make them fit. I am certain that I will need to build a 15 to 25mm set of jumpers from my 20 AWG OFC wire, most likely I will use 2 twisted wires for each connection (17 AWG). Once all 4 shielded inductors are connected this way, I will most likely use a drop of clear silicone glue to keep them in place.
Rob43
I will not include the price of the Amp or the PSU, because both are needed regardless if someone is going to mod or not mod.
Bypass caps that are soldered in are not included because most won't bother with adding bypass caps.
I'm not totally sure yet based on variations that have not been tried, but here's a reasonable guess:
1) 4 Wurth Inductors ~$29
2) Caps at C5, C10, C15, & C20 ~$1.60
3) OPA1656 Op Amps ~$15 (DIY) to ~$35 (Pre-made)
4) Caps at C36 & C37 ~$9
5) Caps at C32, C33, C38, & C39 ~$6 to ~$10 depending on what's chosen
6) Smoothing & bypass caps for Meanwell PSU ~$6 (easy, no soldering required)
7) Shipping & miscellaneous parts ~$10
Rough Total = ~$79
Rob43
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Thanks Rob.
Idea is really great. On the other hand if we add the price of the PSU, I remain skeptical about the project because of the final cost.
In any case this project is really great for enthusiasts and DIYer.
You can get top end TPA3255 RTR modules from DrMordor or Jlester with
optimized (PFFB etc) and high end components for less than $150 with a quality LLC PSU.
Idea is really great. On the other hand if we add the price of the PSU, I remain skeptical about the project because of the final cost.
In any case this project is really great for enthusiasts and DIYer.
You can get top end TPA3255 RTR modules from DrMordor or Jlester with
optimized (PFFB etc) and high end components for less than $150 with a quality LLC PSU.
Hi Rob,
Very interesting! It is only now that I understand what you are doing: bypassing the PS of the op amp! I thought initialy you would rather remove the the DC coupling caps to your board and try bypassing these caps!
I went the lazy route, bypassing the Op amps PS caps at under the board, of course not with such fine parts as yours. It is ongoing, I didn't expect that much from this mod as there seem to be already bypassing caps on the board, so I went for small "gobal/ foe all op amps" PP admitely somewhat remote from them. I shall read you with interest, that's another bit to play with.
As of my mod A and C, already posted
Hint in view of the next mod I had no time yet to type: the filter had no downside but its effect where small, I digged somewhere else and found another PS tweak that has better VFM/ It is additional.
Great having so much ideas to play with, excellent idea of yours to open this thread!
Claude
Very interesting! It is only now that I understand what you are doing: bypassing the PS of the op amp! I thought initialy you would rather remove the the DC coupling caps to your board and try bypassing these caps!
I went the lazy route, bypassing the Op amps PS caps at under the board, of course not with such fine parts as yours. It is ongoing, I didn't expect that much from this mod as there seem to be already bypassing caps on the board, so I went for small "gobal/ foe all op amps" PP admitely somewhat remote from them. I shall read you with interest, that's another bit to play with.
As of my mod A and C, already posted
Hint in view of the next mod I had no time yet to type: the filter had no downside but its effect where small, I digged somewhere else and found another PS tweak that has better VFM/ It is additional.
Great having so much ideas to play with, excellent idea of yours to open this thread!
Claude
Hi Daniboun,
I understand your point and it could indeed be more efficient to start from other ready to plug modules. Just a side note, with postage and various accessories and casing and wires my guess is you are more in the 200E bracket, but you to say. In some case you also need an extra stage to feed symmetricaly, something this unit has already. Indeed most parts Dr. Mordor uses seem to be state of the art (why shouldn't he, price is similar and he buys once, plus seems to know what he is doing), but some tweaks here are not implemented elsewhere. At the end, different aims, different products, not too dissimilar prices, question is rather how they compare sonicaly... if pursuing my understanding of your post.
I am though not sure you understand our very own point (as far as I believe Rob and I pursue the same goal). The money we spent is irrelevant as we did it for the community, more as a game to explore possibilities for future tweakers. Speaking for myself, of course I spent too much on this, and given my daily job and what I charge for it I would say far far more... especialy given I don't even own such a unit! But that's not the point, it is a puzzle, something to try for the sake of science (LOL, it is fun, remember) and having some extra fun and time with a good friend (who owns 2 units). Given we can't go to the restaurant, I regard this money and time well spent. And there is of course a more serious reason: by indeed us spending the money and exploring possibilities, we can save many other people -that are cost orientated- money on telling them what mods to go for in priority. Indeed, the filter I built wasn't as cost effective (VFM!) as OPA1656 or the next mod to post, so people can make their choice. At the end, if I consider my mother's unit (on its way) that I am likely to tweak sooner or later so we share more music and fun together, I guess I will spend around 30E on her unit only as going straight to the more reasonable tweaks to achieve an acceptable end result while having super VFM tweaks and some spice to make it balanced. That means that for less than 100$ for a fully working and safe unit, postage included, she gets a replacement amp, either permanent or as of now... just to save the situation as the A/B amp I tuned for her 25y ago just died (or rather needs me to repair it, and I am lockdown for months - yep, won't be weeks, I don't buy it).
Back to my understanding of your preoccupation, an intersting thing to do as you own many Class D units would be for you to wait for us to post all our mods and then:
- to go for the ones that are best VFM, compare then your very efficiently tweaked unit in terms of VFM with other existing units
- then go for the full option, doing all the good mods regardless price, and compare the sonic quality with your reference Class D amps. These use a better layout and parts from day 1, so have the edge, on the other side they may not use all our tweaks, hence interesting to hear how close they get at the end. Or if other Doctors (or you tweaking...) decide to implement them in the future, LOL
Just thinking out loud, important is everyone gets what he wants and let's not forget those who already own the unit and don't want to start from scratch, which wouldn't be cost effective at all
Have fun and please let us know if you want to tweak your unit accordingly, happy to assist, you are welcome...
Claude
I understand your point and it could indeed be more efficient to start from other ready to plug modules. Just a side note, with postage and various accessories and casing and wires my guess is you are more in the 200E bracket, but you to say. In some case you also need an extra stage to feed symmetricaly, something this unit has already. Indeed most parts Dr. Mordor uses seem to be state of the art (why shouldn't he, price is similar and he buys once, plus seems to know what he is doing), but some tweaks here are not implemented elsewhere. At the end, different aims, different products, not too dissimilar prices, question is rather how they compare sonicaly... if pursuing my understanding of your post.
I am though not sure you understand our very own point (as far as I believe Rob and I pursue the same goal). The money we spent is irrelevant as we did it for the community, more as a game to explore possibilities for future tweakers. Speaking for myself, of course I spent too much on this, and given my daily job and what I charge for it I would say far far more... especialy given I don't even own such a unit! But that's not the point, it is a puzzle, something to try for the sake of science (LOL, it is fun, remember) and having some extra fun and time with a good friend (who owns 2 units). Given we can't go to the restaurant, I regard this money and time well spent. And there is of course a more serious reason: by indeed us spending the money and exploring possibilities, we can save many other people -that are cost orientated- money on telling them what mods to go for in priority. Indeed, the filter I built wasn't as cost effective (VFM!) as OPA1656 or the next mod to post, so people can make their choice. At the end, if I consider my mother's unit (on its way) that I am likely to tweak sooner or later so we share more music and fun together, I guess I will spend around 30E on her unit only as going straight to the more reasonable tweaks to achieve an acceptable end result while having super VFM tweaks and some spice to make it balanced. That means that for less than 100$ for a fully working and safe unit, postage included, she gets a replacement amp, either permanent or as of now... just to save the situation as the A/B amp I tuned for her 25y ago just died (or rather needs me to repair it, and I am lockdown for months - yep, won't be weeks, I don't buy it).
Back to my understanding of your preoccupation, an intersting thing to do as you own many Class D units would be for you to wait for us to post all our mods and then:
- to go for the ones that are best VFM, compare then your very efficiently tweaked unit in terms of VFM with other existing units
- then go for the full option, doing all the good mods regardless price, and compare the sonic quality with your reference Class D amps. These use a better layout and parts from day 1, so have the edge, on the other side they may not use all our tweaks, hence interesting to hear how close they get at the end. Or if other Doctors (or you tweaking...) decide to implement them in the future, LOL
Just thinking out loud, important is everyone gets what he wants and let's not forget those who already own the unit and don't want to start from scratch, which wouldn't be cost effective at all
Have fun and please let us know if you want to tweak your unit accordingly, happy to assist, you are welcome...
Claude
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Sure, I understand that it cost a few dollars to play this game and was betting there'd be some slight push back on the price when a question like yours is asked.
BUT...
It has become SO SO routine to order a "box" on ebay or amazon and get it a few days later, actually ordering this way has lost almost all of its excitement.
So instead of ordering someone else's pre-made "box", a project like this is just like cooking, I, you, and probably many others love to cook and create new fun dishes; just like all of the exciting creativity waiting for anyone that wants a fun Class D adventure like this !
Rob43
Thanks for your talkative responses Rob and Claude. I actually think that it is a project of enthusiasts for enthusiasts and in this sense, passion is priceless if it is not the limit of our portfolios) I hope in any case that you will have a maximum of success and I will follow this topic with enthusiasm.
The next tweaks are about bypassing various PS caps. As there are many ways and views around that (and all very respectable!), I thought I might post here my experience and view « for once » before concentring solely on the results of the various bypasses to come, as there will be many.
Now to the idea behind. 30y ago a young me started experimenting with bypassing PS caps for various audio devices for various stages. I was triggered by Infinity and other top brands which also bypassed caps with smaller quality ones on Xovers etc. Back then, my experience was limited, so I just followed blindly the 1/100 rule, bypassing a big electrolytic cap by a 1% more qualitive one, and then that one also bypassed in the same manner etc… and ended up stacking up caps on caps with at the end a 0.01 Wondercap (that’s no joke, it was an expensive make in trend by then).
I did that for all caps (!), still have my integrated amp like that and of course there was no real harm (well, nowadays I realise it could have been bad, introducing oscillations and also having stupidely long connections LOL) to do that for all caps, it just being very expensive and not clever.
30y later, I realise that most -if not "all"- benefits can be had by just bypassing the cap closest to the input /need in case of a bank (and not all caps), that given oscilloscope measurements it is always good to start with a good cap eventhough you bypass it later, and that absorbing an oscillation in the magnitude of far less than 1/1000 covers all acceptable cases or so. Bottom line : bypassing with 1/1000 rule is OK and some even say 1/10000 (I often go for anything between 1/100 and 1/1000, around 1/500 being my baseline), increasing quality caps with different technology works great and is cost efficient, going stupidely low value is not (anything under 0.1uF, there are exceptions of course, but say bypassing a 1uF high quality cap is often useless), having short legs / connections with decreasing capacity is important. Of course, there are still some exceptions, like the absolute need to use 0.01uF caps very close to some PS legs for some delicate HF op amps, and also sometimes not wanting any bypass in some stages of a CRCRC filtering PS or with tubes as useless or even introducing possible problems.
With these experience and findings in mind, let’s tackle our first bypass on the big PS caps… I hope I explained now why I will try to go "clever and simple" instead of "overkill", but also why there are different ways to explore all that at dfferent locations, so that I also read Rob with a lot of personal interest as I consider them very complementary!
Claude
Now to the idea behind. 30y ago a young me started experimenting with bypassing PS caps for various audio devices for various stages. I was triggered by Infinity and other top brands which also bypassed caps with smaller quality ones on Xovers etc. Back then, my experience was limited, so I just followed blindly the 1/100 rule, bypassing a big electrolytic cap by a 1% more qualitive one, and then that one also bypassed in the same manner etc… and ended up stacking up caps on caps with at the end a 0.01 Wondercap (that’s no joke, it was an expensive make in trend by then).
I did that for all caps (!), still have my integrated amp like that and of course there was no real harm (well, nowadays I realise it could have been bad, introducing oscillations and also having stupidely long connections LOL) to do that for all caps, it just being very expensive and not clever.
30y later, I realise that most -if not "all"- benefits can be had by just bypassing the cap closest to the input /need in case of a bank (and not all caps), that given oscilloscope measurements it is always good to start with a good cap eventhough you bypass it later, and that absorbing an oscillation in the magnitude of far less than 1/1000 covers all acceptable cases or so. Bottom line : bypassing with 1/1000 rule is OK and some even say 1/10000 (I often go for anything between 1/100 and 1/1000, around 1/500 being my baseline), increasing quality caps with different technology works great and is cost efficient, going stupidely low value is not (anything under 0.1uF, there are exceptions of course, but say bypassing a 1uF high quality cap is often useless), having short legs / connections with decreasing capacity is important. Of course, there are still some exceptions, like the absolute need to use 0.01uF caps very close to some PS legs for some delicate HF op amps, and also sometimes not wanting any bypass in some stages of a CRCRC filtering PS or with tubes as useless or even introducing possible problems.
With these experience and findings in mind, let’s tackle our first bypass on the big PS caps… I hope I explained now why I will try to go "clever and simple" instead of "overkill", but also why there are different ways to explore all that at dfferent locations, so that I also read Rob with a lot of personal interest as I consider them very complementary!
Claude
Moving on to mod I: bypassing the 2 big PS caps (C37, C38) with quality 2x2.2uF Murata X7R caps each.
This is an easy mod and cost 3$, so worth a try. Interesting point is that Gilles performed this mod alone and he a) never ever had done such a thing before, b) didn’t know at all what it was about nor what to expect « if at all », hence for me a very neutral feedback. I find he did a good job placing the caps cleverly and it is very straight forward given their tiny size. Yes, he didn’t finalise cutting the legs : that is because we are not done so we might need to desolder and solder them back again, hence not finalising / caring about the cosmetic (no danger).
Gilles did it… so what about YOU ?
The aim here is to help the 2 big electrolytic PS caps by having some quality ones bypassing them. It is important to understand that both big caps are in parallel and not in different rails. We chose 4 x 2.2uF because the bypass ratio seemed right to me (see previous post) and it was easy to fit under the board that way (many small, small also meaning we couldn’t use C0G / PPP etc.). Now you can either consider that we bypassed each 3000uF with 4.4uF directly in situ (important not to have long wires there), or alternatively as I like also to view it, that we do bypass the last 3000uF big PS cap (out of a bank of 2) with 4.4uF, half of it being directly located at the cap, the other half admitely « apparently » a bit remote… of the cap. And that applying regardless what big cap you consider, LOL ! But all this is academic as at the end it would even be better if these bypass caps would be located at the amp chip’s legs and not at the caps, so who cares about bypass caps being at one or the other big cap as these are as far away from the destination ! Note also that it is feasible to get them to the amp chip’s legs… but really not very practical for us, hence sticking to the big caps legs as easy and safe soldering points with then a hopefully low R route to the amp chip.
Now to the sound, we found :
- Perceived faster attacks / rising edge when starting a tone, feels like more impulse / faster response time +2, very easy to spot on bass percussion
- Cleanliness on mids and treble, lisibility of multiple tones on complex music with various instruments. They all appear less blured, the amp sounds quicker and much sharper, + 1
- Decays and echo are more realistic and lasting longer, +1
TBH, Gilles surprised me as that is exactly what I do expect from such a mod, but I didn’t know if this amp would be reactive or not. With say an overall +2 perceived sound improvement (a tad more noticeable overall than say the SMPS filter) it works great and is indeed better VFM than my own filter (poor me !)… but then of course both bring something very different to the music and have additional effects in our case. Who knows if this cap bypass wouldn’t have worked even better on an amp without filter… or on the apparently lower grade PS caps Aiyima now fits ? You to tell !
Is it worth going further in that direction with these big PS caps ? IME not. Explanation: tweaks that are correctly performed either work or not IME. If bypassing works, then it works quite well if Ok executed, eventhough you wouldn’t use the best possible quality parts or the ultimate bypass cascade. And if it doesn’t work… well it doesn’t regardless, or very very little. In short, as with most tweaks, I am confident we are now at « at least 80% of what is achievable » around the topic « bypassing these PS caps ». Bypassing further with smaller values, using other caps etc. might one day, after a lot of hassle, perhaps, bring us from +2… to +2.5. Perhaps. Not worth at that magnitude. Perhaps OK when you have a majour tweak like a subplatter on a TT that brings +10 and you are looking for +12 going for another subplatter material.
But we are not done yet. Instead of playing further with these bypasses, we still have some mods in the agenda regarding main PS caps :
1) Replacing the existing big PS caps by better ones (has anyone done it before so we save some time) ?
2) Adding more capacity to the big PS caps
Regarding 1, it is interesting because we don’t know if the bypass caps made a good big cap « near perfect for our limited purpose » and given our schematic/parts, job done… or if starting with a VG quality one might yeld further benefits.
Regarding 2, I don’t expect much there at all, but if we have extra big PS caps lying around it is quickly done adding them on my SMPS filter. Better knowing/trying than guessing, being surprised can be a good thing.
But all that will all have to wait after the lockdown. For now we can still try bypassing… other PS caps : the lower voltage ones for op amps etc.
Stay tuned
Claude... and Gilles (mostly in fact ;-)
This is an easy mod and cost 3$, so worth a try. Interesting point is that Gilles performed this mod alone and he a) never ever had done such a thing before, b) didn’t know at all what it was about nor what to expect « if at all », hence for me a very neutral feedback. I find he did a good job placing the caps cleverly and it is very straight forward given their tiny size. Yes, he didn’t finalise cutting the legs : that is because we are not done so we might need to desolder and solder them back again, hence not finalising / caring about the cosmetic (no danger).
Gilles did it… so what about YOU ?
The aim here is to help the 2 big electrolytic PS caps by having some quality ones bypassing them. It is important to understand that both big caps are in parallel and not in different rails. We chose 4 x 2.2uF because the bypass ratio seemed right to me (see previous post) and it was easy to fit under the board that way (many small, small also meaning we couldn’t use C0G / PPP etc.). Now you can either consider that we bypassed each 3000uF with 4.4uF directly in situ (important not to have long wires there), or alternatively as I like also to view it, that we do bypass the last 3000uF big PS cap (out of a bank of 2) with 4.4uF, half of it being directly located at the cap, the other half admitely « apparently » a bit remote… of the cap. And that applying regardless what big cap you consider, LOL ! But all this is academic as at the end it would even be better if these bypass caps would be located at the amp chip’s legs and not at the caps, so who cares about bypass caps being at one or the other big cap as these are as far away from the destination ! Note also that it is feasible to get them to the amp chip’s legs… but really not very practical for us, hence sticking to the big caps legs as easy and safe soldering points with then a hopefully low R route to the amp chip.
Now to the sound, we found :
- Perceived faster attacks / rising edge when starting a tone, feels like more impulse / faster response time +2, very easy to spot on bass percussion
- Cleanliness on mids and treble, lisibility of multiple tones on complex music with various instruments. They all appear less blured, the amp sounds quicker and much sharper, + 1
- Decays and echo are more realistic and lasting longer, +1
TBH, Gilles surprised me as that is exactly what I do expect from such a mod, but I didn’t know if this amp would be reactive or not. With say an overall +2 perceived sound improvement (a tad more noticeable overall than say the SMPS filter) it works great and is indeed better VFM than my own filter (poor me !)… but then of course both bring something very different to the music and have additional effects in our case. Who knows if this cap bypass wouldn’t have worked even better on an amp without filter… or on the apparently lower grade PS caps Aiyima now fits ? You to tell !
Is it worth going further in that direction with these big PS caps ? IME not. Explanation: tweaks that are correctly performed either work or not IME. If bypassing works, then it works quite well if Ok executed, eventhough you wouldn’t use the best possible quality parts or the ultimate bypass cascade. And if it doesn’t work… well it doesn’t regardless, or very very little. In short, as with most tweaks, I am confident we are now at « at least 80% of what is achievable » around the topic « bypassing these PS caps ». Bypassing further with smaller values, using other caps etc. might one day, after a lot of hassle, perhaps, bring us from +2… to +2.5. Perhaps. Not worth at that magnitude. Perhaps OK when you have a majour tweak like a subplatter on a TT that brings +10 and you are looking for +12 going for another subplatter material.
But we are not done yet. Instead of playing further with these bypasses, we still have some mods in the agenda regarding main PS caps :
1) Replacing the existing big PS caps by better ones (has anyone done it before so we save some time) ?
2) Adding more capacity to the big PS caps
Regarding 1, it is interesting because we don’t know if the bypass caps made a good big cap « near perfect for our limited purpose » and given our schematic/parts, job done… or if starting with a VG quality one might yeld further benefits.
Regarding 2, I don’t expect much there at all, but if we have extra big PS caps lying around it is quickly done adding them on my SMPS filter. Better knowing/trying than guessing, being surprised can be a good thing.
But all that will all have to wait after the lockdown. For now we can still try bypassing… other PS caps : the lower voltage ones for op amps etc.
Stay tuned
Claude... and Gilles (mostly in fact ;-)
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Thanks, Sir
And you indeed do think right: very easy, and you don't even have to care for the correct polarity when fitting these caps... as they fit either way
Trickiest part was to find the right bypass capacitor reference, in terms of value(s), size, technology (ceramic) and quality (C7R). Of course their are other possible makes. You can't sadly fit PPP down there, space is way to small and it would hurt budget, but for some other bypasses we have in mind we will use similar tiny blue blobs... but much smaller value ones, that come in C0G excellent quality.
So the trick with these bypasses is indeed more in finding the right additional parts and the correct locations to try, not really fitting them (it is easy, pretty safe and easily reversible): go for it when you feel it... and let us know
Claude
And you indeed do think right: very easy, and you don't even have to care for the correct polarity when fitting these caps... as they fit either way
Trickiest part was to find the right bypass capacitor reference, in terms of value(s), size, technology (ceramic) and quality (C7R). Of course their are other possible makes. You can't sadly fit PPP down there, space is way to small and it would hurt budget, but for some other bypasses we have in mind we will use similar tiny blue blobs... but much smaller value ones, that come in C0G excellent quality.
So the trick with these bypasses is indeed more in finding the right additional parts and the correct locations to try, not really fitting them (it is easy, pretty safe and easily reversible): go for it when you feel it... and let us know
Claude
Thanks, Sir
And you indeed do think right: very easy, and you don't even have to care for the correct polarity when fitting these caps... as they fit either way
Trickiest part was to find the right bypass capacitor reference, in terms of value(s), size, technology (ceramic) and quality (C7R). Of course their are other possible makes. You can't sadly fit PPP down there, space is way to small and it would hurt budget, but for some other bypasses we have in mind we will use similar tiny blue blobs... but much smaller value ones, that come in C0G excellent quality.
So the trick with these bypasses is indeed more in finding the right additional parts and the correct locations to try, not really fitting them (it is easy, pretty safe and easily reversible): go for it when you feel it... and let us know
Claude
Good job Claude on install those small MLCC caps at location C36 & C37.
I'm going to go a different route and use either PP Film or PIO caps at that location and others.
The reason I'm going to work hard at making the bigger PP Film or Russian PIO caps fit is because of the great sound quality associated with them vs the possible microphonic/ringing properties of the MLCC caps, plus the possible distortion factor that they are cable of. I've personally experienced this ringing sound once before and don't really want to hear it again, hopefully you don't get this microphonic effect.
Rob43
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Thanks Rob
Yep, PPP caps or else are of course better, I even whish I could have found C0G caps that fit there... sadly not with that capacity.
I am quite happy with these Murata FOR PS APPLICATIONS, they seem to work quite well vs other MLCC caps that can display some problems. But I wouldn't fit them in the signal path. Note eventhough happy where they are in the main PS, I could though still try to bypass them with 0.1uF C0G caps, but I am not sure it is worth the hassle TBH... Anyway, they brought a plus and no negative, for less than 3$ all the 4 of them and they are dead easy to fit.
But then your project has indeed more perspectives
It looks hard though to place your caps while keeping connecting distances short. Rob, do you have already something in mind? If not, for whatever it is worth, if it would have been my unit and a pure laboratory as yours, I had an idea whereby (bypassing) PPP caps would be located instead of the current PS caps... and the big electrolytic caps would then end up lying towards the rear of the unit, horizontaly. That way the PPP caps would have been closest to the chip without having to dismantle the heatsink (short connections). It could still just fit while being able to close the lid, admittely fiddling quite a bit... that would then start to look like my own DAC that is full packed everywhere and in every direction with odd routings all over, GLOL!
Great idea of yours Rob, please keep us updated... I wanted anyway to take myself after the lockdown the PS caps (and hence the bypasses) out to replace the main caps with better ones, so "while at it" I could still consider a better option like... perhaps yours indeed
Take care, Rob, and thanks again for this great thread ful of ideas and fun
Claude
Yep, PPP caps or else are of course better, I even whish I could have found C0G caps that fit there... sadly not with that capacity.
I am quite happy with these Murata FOR PS APPLICATIONS, they seem to work quite well vs other MLCC caps that can display some problems. But I wouldn't fit them in the signal path. Note eventhough happy where they are in the main PS, I could though still try to bypass them with 0.1uF C0G caps, but I am not sure it is worth the hassle TBH... Anyway, they brought a plus and no negative, for less than 3$ all the 4 of them and they are dead easy to fit.
But then your project has indeed more perspectives
It looks hard though to place your caps while keeping connecting distances short. Rob, do you have already something in mind? If not, for whatever it is worth, if it would have been my unit and a pure laboratory as yours, I had an idea whereby (bypassing) PPP caps would be located instead of the current PS caps... and the big electrolytic caps would then end up lying towards the rear of the unit, horizontaly. That way the PPP caps would have been closest to the chip without having to dismantle the heatsink (short connections). It could still just fit while being able to close the lid, admittely fiddling quite a bit... that would then start to look like my own DAC that is full packed everywhere and in every direction with odd routings all over, GLOL!
Great idea of yours Rob, please keep us updated... I wanted anyway to take myself after the lockdown the PS caps (and hence the bypasses) out to replace the main caps with better ones, so "while at it" I could still consider a better option like... perhaps yours indeed
Take care, Rob, and thanks again for this great thread ful of ideas and fun
Claude
