Not built according BOM and no picture means comparison and advice is hard if not impossible. Using what you have (oh how many emails I get with such questions) is not why a BOM was created. The system GaryB uses for modifications is more efficient I think. Till now his mods were the most convincing and I adapted 2 of his mods in my own V3 DACs.
Believing should be done in church, Pana FC performs fine in many devices. They're better than the standard stuff that is found in devices. Lelon is known for its exploding character ! Do a google search on that please.
Believing should be done in church, Pana FC performs fine in many devices. They're better than the standard stuff that is found in devices. Lelon is known for its exploding character ! Do a google search on that please.
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Yes agree. Here just talking aboout Lelon LL just right after the rectifier because gave good results elsewhere. BC, Philips caps with small ESR are IMHO not good here, maybe it's different for PS used with digital stuffs, after all I'm not a pro and don't use scope but just my ears and long two cents swaps caps hobby because just able of that and no more.
Advices of gary are good but not always agree with some.
I use many Pana FC in many Tweaked cd players, sometimes it's not the good choices because a harchness in highs can be heard (sometimes)... most of th etimes it's a good and not expensive caps for digital environment.
And all our hifi environment are so different... it's a trap and advices for one can't be good for others.
Let exchange...with conscience of these limits.
Advices of gary are good but not always agree with some.
I use many Pana FC in many Tweaked cd players, sometimes it's not the good choices because a harchness in highs can be heard (sometimes)... most of th etimes it's a good and not expensive caps for digital environment.
And all our hifi environment are so different... it's a trap and advices for one can't be good for others.
Let exchange...with conscience of these limits.
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The SB Duet doesn't have an SPDIF transformer but it does have a blocking cap. As I discussed in Eldam's thread on the SB Duet tweaks, I did add an SPDIF transformer to my Duet but that's not required for good sound. It can help the Duet with some DACs but I don't think it makes a big difference with the V3 DAC.
I still use Chinch to switch between differents sources and DACS and try diferent on shelves wire like DIY ones. I always use on shelves wires for that from different sources like eg aeronautics tripled shelded... or hifi brands
Both JP and I have commented in the V3 build thread that one gets best results using 75ohm BNC connectors on the source (SB Duet in your case) and on the V3 DAC and then using 75ohm coax cable for the digital cable. It's OK if you don't want to do that - this is DIY and you should have fun doing whatever you want. But it's possible that when you tweak your DAC to get the best sound in your system that you might be compensating for less than ideal effects in places like the SPDIF connection. The end result could still be very good, but it might not be universally good for other people since it's adjusted just for your particular set up. I think that's the point that JP was making.
Have fun.
---Gary
Thanks JP - you are known as a tough (but fair) critic, so I appreciate the vote of confidence. ---Gary
So maybe low esr polymer are not good before these smd regs ?! Red Panasonic FP are warmer than others...and have no harchness.
@ Gary : didn't understand SB Duet have a blocking caps, believed it was an added cap in your special shematic).... So I will test with a strap in the Subbu instead of the MKC caps !
Don't want at the moment change ten BNC in my equipments... and more for the wires ! i ALWAYS use short wires and good 75 ohms ones. sometimes directly on the pcb with no connector... I can't heard the difference with the same wire with or without chinch connector. Impedance adaptation experiment told me it's not always important with spidf (many experiences with my duets and some DAC). So we have to be carefull sometimes with the concept of 'universel' and i alway write with a IMHO in mind.
@ Gary : didn't understand SB Duet have a blocking caps, believed it was an added cap in your special shematic).... So I will test with a strap in the Subbu instead of the MKC caps !
Don't want at the moment change ten BNC in my equipments... and more for the wires ! i ALWAYS use short wires and good 75 ohms ones. sometimes directly on the pcb with no connector... I can't heard the difference with the same wire with or without chinch connector. Impedance adaptation experiment told me it's not always important with spidf (many experiences with my duets and some DAC). So we have to be carefull sometimes with the concept of 'universel' and i alway write with a IMHO in mind.
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I don't think that will work. The blocking cap in the Duet blocks the DC from the SPDIF driver IC. But the IC used as the receiver in the V3 DAC, the Wolfson WM8804, doesn't want its input tied to ground. It wants to float and so you still need a DC blocking cap at the input, which isolates the WM8804 input from the 75ohm input resistor (R2), which would pull the input to ground.
---Gary
hi,
i was planning on removing the spdif input cap and putting a jumper wire there instead, per jp's suggestion on page 2 of the thread. my source uses a pulse transformer and i recently added some electrical tape to the source to ensure the output ground is completely isolated from the case.
but now garyb says the coupling cap is still necessary due to r2. so which is it?
thanks,
-matt
i was planning on removing the spdif input cap and putting a jumper wire there instead, per jp's suggestion on page 2 of the thread. my source uses a pulse transformer and i recently added some electrical tape to the source to ensure the output ground is completely isolated from the case.
but now garyb says the coupling cap is still necessary due to r2. so which is it?
thanks,
-matt
Matt,
I don't recognize the picture that you included of the SPDIF input / pulse transformer. It certainly doesn't look like a Subbu DAC.
Regarding needing an input capacitor, that was specific to the WM8804 receiver used in the Subbu DAC. If your DAC uses another receiver chips then that could be different.
---Gary
I don't recognize the picture that you included of the SPDIF input / pulse transformer. It certainly doesn't look like a Subbu DAC.
Regarding needing an input capacitor, that was specific to the WM8804 receiver used in the Subbu DAC. If your DAC uses another receiver chips then that could be different.
---Gary
OK - so your source uses an SPDIF output transformer. It's normal that it would not have an output capacitor.
You still need the input cap for the Subbu DAC's SPDIF input.
---Gary
Hello Gary,
My Subbu is still in burning mode (just ten hours, I still wait 100 hours before try some light tweaking to adapt for my hifi environment)
As you seem to have some knowledge about "digital" interfaces. Do you think we can go lower than 0,1 uf to have our floating point. Behind this question I strongly think about a little polystyren cap (1 nano) or a silver Mica (1nano) ?
Did you use the polymer Nichicon "red" FP caps in first intention for C2, C3, C18 (your photographs) instead of the panasonic aluminium FC of the BOM?
Jean-Paul, because of the // 4,7 uF do we have to care about the importance of the 100 uF for tweaking (as a non professional in my mind a cap with a low ESR is bad JUST after a reg for out because of the impedance (solid Tantal is used because of that ? but this particular tantal has always something bad for ears with real listening), but not before where a low esr is good).
I didn't understand if you talk about these caps (C2, C3, C18) when you said "too low esr caps can allow the regs to oscilate" (in a better english) ?
My Subbu is still in burning mode (just ten hours, I still wait 100 hours before try some light tweaking to adapt for my hifi environment)
As you seem to have some knowledge about "digital" interfaces. Do you think we can go lower than 0,1 uf to have our floating point. Behind this question I strongly think about a little polystyren cap (1 nano) or a silver Mica (1nano) ?
Did you use the polymer Nichicon "red" FP caps in first intention for C2, C3, C18 (your photographs) instead of the panasonic aluminium FC of the BOM?
Jean-Paul, because of the // 4,7 uF do we have to care about the importance of the 100 uF for tweaking (as a non professional in my mind a cap with a low ESR is bad JUST after a reg for out because of the impedance (solid Tantal is used because of that ? but this particular tantal has always something bad for ears with real listening), but not before where a low esr is good).
I didn't understand if you talk about these caps (C2, C3, C18) when you said "too low esr caps can allow the regs to oscilate" (in a better english) ?
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Eldam - my experience has been that there is benefit increasing the size of SPDIF coupling cap, C4. Early in this thread I recomended increasing C4 from 0.1uf to 3.3uf. It is always interesting to experiment, but I think that this is not likely to be a good direction.
The BOM recommends 100uf UCC polymer caps for C2, C3, C18, not panasonic FC caps. I had some bigger polymer caps in my parts box (270uf for C2, 220uf for C3, C18) and I used these just to save the trouble of ordering new parts. I didn't do controlled listening but I don't hear much difference between an older version of the DAC with 100uf polymer caps here and this version with the larger polymer caps.
---Gary
JP - I am sorry to contradict you but this is wrong. The spdif input capacitor is always needed. As I mentioned earlier, the spdif input pin of the WM8804 (pin 20) needs to float at 1/2 Vdd = ~ 1.65v. To prove this out to myself I did a simple experiment. With power off, I used a clip lead to bypass C4 with a 30ohm resistor. I then turned on the DAC and as expected there was no sound. As soon as I unclipped the resistor the DAC began to play music. So I am confident in my comments.
---Gary
Yes read it with great interest; As i have in my tool box 0,2 uF MKC or 3,3 uF wima MKS (=MKT) I choose MKC because you talk about it for its special properties. Do you think the no MKC WIma will be better ? Where was the difference ? Band pass in the low frequency (I think it was the reason of the "wrong direction" ?)
Yes you right, sorry my mistake. I put the "blue" polymer of the BOM. As I choose to follow you with SEPC470 uf for C22, I have now a doubt about the low value 100 uF of C18 in this particular conf. Here maybe after burn in and carefull listening I will populate C18 with the "red" FP 390 uf cap I already have.
thank you again for yours inputs, as you have two Subbu DAC and a Squeeze Box I follow what you write.
Eldam
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