As I understand there's no hum when amp is in stereo and no input connected?
Be sure that the source's safety GND (case earth potential) is on the same reference point as VSSA safety GND (no ground loops between metal chassis). In this case VSSA will be silent as it would be off.
Hi Idefixe, here it's androuski
LC, I've got two questions of first importance :
- About transformer sizing : if I get 2x42v after diode bridge from a 2x30v transformer, what should be the minimum VA rating for a stereo setup, without sacrifying current capabilities ?
- About regulating : is there any benefit to add regulators to a linear PSU ?
I'm thinking about linear vs/ SMPS....
LC, I've got two questions of first importance :
- About transformer sizing : if I get 2x42v after diode bridge from a 2x30v transformer, what should be the minimum VA rating for a stereo setup, without sacrifying current capabilities ?
- About regulating : is there any benefit to add regulators to a linear PSU ?
I'm thinking about linear vs/ SMPS....
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As I understand there's no hum when amp is in stereo and no input connected?
Be sure that the source's safety GND (case earth potential) is on the same reference point as VSSA safety GND (no ground loops between metal chassis). In this case VSSA will be silent as it would be off.
Yes, when not connected there is a complete silence. There is almost undetectable buzz when directly connected to the DAC. I have to listen realy close to the tweeter to hear any buzz but when I connect USB cable to the DAC all hell breaks loose. I think only solution is to galvanicaly isolate USB receiver from the DAC board. I have almost all the components for the Acko boards for Amanero USB.
I've managed to set only one channel properly to 129 mV and almost 0 offset. I'm going to have some I'm afraid I'm loosing concentration and that might lead to big bang. I would really appreciate if you would show me (a picture maybe?) how to terminate three incoming connections on one VSSA GND faston. I have PSU GND and case/earth cribled into one, but speaker connection is approaching. 
Specified capacitors have finally shipped, I hope to have them before the weekend.
Looking forward to the official LC VSSA! Note, I'm not the least bit stressed about minor deviations from the published diagram; I assume those changes were for the best.
Wish I could get my hands on that lovely chassis too, though the shipping is likely prohibitive.
Looking forward to the official LC VSSA! Note, I'm not the least bit stressed about minor deviations from the published diagram; I assume those changes were for the best
.Wish I could get my hands on that lovely chassis too, though the shipping is likely prohibitive.
Ok, removed earth connection from the gnd of both channels on the amp with USB cable connected to the DAC and it looks like that solves it
!Now, from the DAC gnd plane (actually IVY) I have gnd branches going to the left and right input channels of the VSSA modules and connecting independently to the dedicated power supplies. No preamp (digital volume inside es9018 controled by isolated i2c over arduino).
Aaaah 
the sense of completion. It's been playing for an hour and I'm falling in love with what I hear. Many positive things already when compared to my old amp.
I could write and pamper with words like I worked for Stereophile. But I'd better spend some more time, let it break in and then report. OK if one thing is permitted... positive: I've totaly forgot how uncomfy my chair was for an hour Negative: top end is a bit dry. Hey, but that's only a beginning. Thanks a lot for all your help.
P.S. I really want to know what is a clean way to terminate 3 GND connection on one fast on lug
the sense of completion. It's been playing for an hour and I'm falling in love with what I hear. Many positive things already when compared to my old amp. I could write and pamper with words like I worked for Stereophile. But I'd better spend some more time, let it break in and then report. OK if one thing is permitted... positive: I've totaly forgot how uncomfy my chair was for an hour
Negative: top end is a bit dry. Hey, but that's only a beginning. Thanks a lot for all your help.P.S. I really want to know what is a clean way to terminate 3 GND connection on one fast on lug
KSA1381E/KSC3503E Transistor Pair
A bit of direction or educated guess, or even just personal opinion needed ....
The KSC3503-E version is not readily available, so I am wondering if it's worth it to get some of these as spares, and also for my through-hole version of VSSA (as in Shaan's PeeCeeBee thread), especially before I start comparing how the through-hole version stacks up to the "original". It basically involves calling in a favor, plus double shipping charges, plus a bit higher cost compared to the -D version, and probably a minimum quantity beyond what I would normally want to keep in a drawer.
I guess it comes down to this choice:
a) original KSC3503E to make a complementary pair with KSA1381E @ extra cost, and more spares than I am likely to need
b) KSA1381E/KSC3503D pair
c) substitute yet to be determined
Any opinions, suggestions... coin flip???
A bit of direction or educated guess, or even just personal opinion needed ....
The KSC3503-E version is not readily available, so I am wondering if it's worth it to get some of these as spares, and also for my through-hole version of VSSA (as in Shaan's PeeCeeBee thread), especially before I start comparing how the through-hole version stacks up to the "original". It basically involves calling in a favor, plus double shipping charges, plus a bit higher cost compared to the -D version, and probably a minimum quantity beyond what I would normally want to keep in a drawer.
I guess it comes down to this choice:
a) original KSC3503E to make a complementary pair with KSA1381E @ extra cost, and more spares than I am likely to need
b) KSA1381E/KSC3503D pair
c) substitute yet to be determined
Any opinions, suggestions... coin flip???