It perfectly fine to run 12V rails. And there is no real penalty to do so.
You will want a little smaller value resistor in this case.
Something like 249R should work nicely. Also with that resistor you will only be doing about .3W so your call as to if you want to go 1/4W or 1/2W.
Cheers!
Russ
You will want a little smaller value resistor in this case.
Something like 249R should work nicely. Also with that resistor you will only be doing about .3W so your call as to if you want to go 1/4W or 1/2W.
Cheers!
Russ
Thanks leo,
I was asking as I still consider using the PH 3.3V shunts for Avcc doing it the needsp way (post #163). I will however first test the Russ tweak as it is less invasive and quite a bit cheaper!
Nevertheless, the C1 pads and the right C59 pad look perfect for mounting the PH reg (after removing the op amp).
Nic
I was asking as I still consider using the PH 3.3V shunts for Avcc doing it the needsp way (post #163). I will however first test the Russ tweak as it is less invasive and quite a bit cheaper!
Nevertheless, the C1 pads and the right C59 pad look perfect for mounting the PH reg (after removing the op amp).
Nic
Thanks Russ,
I know that I will need to change the resistor value and thank you for the calculation of what I have to use🙂
Nic
No probs!
BTW thats how I fitted the PH shunts for the AVCC L&R on the Buffalo24 , straight across those ceramics after removing the op-amps, they worked a treat😀
No - you are right to stress this. In fact with your tweak changing VA supplies or voltages retrospectively may be dangerous. Will the total current draw from the VA supplies increase notably with this tweak on or is it almost fully compensated by a lower draw from the buffer?
Thanks,
Nic
Seeing as its gone quiet I thought I'd try Russ's mod, yes the voltage buffer op-amps run a fair bit cooler
Thanks Russ! I give this one a thumbs up😉
Thanks Russ! I give this one a thumbs up😉
So not a tweak for better sound on the 24bit buffalo 🙁 - how have others fared with this <tweak>?
Can't say it made a lot of difference on the Buffalo32s sound wise, certainly worth doing on this version though mainly for long term reliability
I don't think the original Buffalo voltage buffers ran as hot as the Buffalo32s
Maybe time to try PH regs inplace of the op-amp buffers like I did with Buffalo24😀
I don't think the original Buffalo voltage buffers ran as hot as the Buffalo32s
Maybe time to try PH regs inplace of the op-amp buffers like I did with Buffalo24😀
Ok, so this is more of a fix for the overly hot-running op-amps & their long term reliability - some would say the product shouldn't have been sold with this obvious flaw in it's design.
What are the consequences of these op-amps failing during operation?
What are the consequences of these op-amps failing during operation?
jkeny, do you have a buffalo dac or just some idea that it is a flawed design without ever having listened to it? Just curious.
Nic
Nic
NicMac, I've listened to it in a friends - do you disagree with what I said or have you thought about the question I raised - or are you evaluating me rather than the issue?
I know the Buffalo is a good sounding DAC but this is DIYAudio & I think it's about striving for the best sound possible which I don't think was achieved with the Buffalo. This DAC is, in my opinion, capable of a lot more - just read this thread from the beginning & the many other posts re the power supplies (or listen to Dustin's comments on the AVCC supply)
I know we all have an emotional bond with our equipment and want to think it's the best there is but this is not a mature attitude & some objectivity is a good idea!
The whole idea of starting this thread was because there was no central point for all the tweaks that had started to emerge for the Buffalo.
I know the Buffalo is a good sounding DAC but this is DIYAudio & I think it's about striving for the best sound possible which I don't think was achieved with the Buffalo. This DAC is, in my opinion, capable of a lot more - just read this thread from the beginning & the many other posts re the power supplies (or listen to Dustin's comments on the AVCC supply)
I know we all have an emotional bond with our equipment and want to think it's the best there is but this is not a mature attitude & some objectivity is a good idea!
The whole idea of starting this thread was because there was no central point for all the tweaks that had started to emerge for the Buffalo.
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Maybe the op-amp buffers do run a little hotter than we'd like but it could be argued they run within max ratings and would be fine
Regarding the regs, well I think the PH ones made a very worthwhile upgrade, if they didn't I wouldn't be using them on the Buffalo32s as well as the Buffalo24😉
BTW theres designs out there much more expensive than Buffalo32 which uses bog standard regs, for me the regs brought a far bigger difference than faffing about with fancy arsed caps and other passive parts
Regarding the regs, well I think the PH ones made a very worthwhile upgrade, if they didn't I wouldn't be using them on the Buffalo32s as well as the Buffalo24😉
BTW theres designs out there much more expensive than Buffalo32 which uses bog standard regs, for me the regs brought a far bigger difference than faffing about with fancy arsed caps and other passive parts
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This is not a flaw in the design, let alone an obvious one. The buffers will run for many years as they are currently designed.
Well, it should have cropped up during testing & been obvious - it's one of the first things to check on any circuit - any components running hot 
. In the case of op-amps, it usually signifies oscillation which is a flaw.
Just staying within max ratings would not be a desirable design goal, I believe.
. In the case of op-amps, it usually signifies oscillation which is a flaw.Just staying within max ratings would not be a desirable design goal, I believe.
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No - I'm not evaluating you or your question at all. I think that asking if the tweak has an audible benefit is the best and probably the only really important question considering that the unit should run just fine without the tweak and without any smoke for years to come (according to Brians post).
I already did "upgrade" the power for AV with JSR's and replaced the three onboard "VD" regs (as you may see if you read the rest of the thread). I found a definite improvement with the first change, but I'm not sure with the latter (difficult for me to undo and do A/B comparisons unfortunately).
I have a couple of PH 3v3 shunts ready to try for Avcc and feed-back on the simpler and way cheaper Russ tweak therefore obviously interest me a lot.
I was really just curios, sorry if I gave the wrong impression.
Nic
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