Yaqin SD-CD3 Tube Buffer - upgrading caps

What ever has this person done with c2(a|b) and c4(a|b)?

They should have just attached c2a and c4a but needed the extra wire because they connected c2a and c2b?

IMG_2857.jpg

This one went crazy with mods and I’ll try translate to see why they put a capacitor across the leads of the power caps.

Yaqin SD-CD3のバージョンアップ:コンデンサと抵抗の交換 : 雲フェチ
 
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Update after installing input and output resistors.

I followed the guide to do it where you connect one lead of a resistor to the Center of the rca and the other to the outer connector spot. I did this on all 4 RCA’s

The unit makes no sonic difference when powered on or not. It’s like the RCA’s are ‘jumped’ and the audio signal does t follow the circuit just jumps across the RCA’s. The tubes can be on or off and the audio still passes.

What have I done wrong, or is this unit a lie?

I must have done something wrong yeah?
 
Along with that I would recommend the following...
* Add a 1M resistor across each input jack.
* Add a 100K resistor across each output jack.
* Add a 220K/2W power resistor across the leads of filter cap C5. This will provide a discharge path to ground for both filter caps.


These values worked like a charm on my setup. The buffer still sounds great too.



Pardon the ugly pictures. I didn't go with audiophile grade caps. I had a pile of Kemet C4G 5% 450VAC/850VDC caps on hand and used them. Used 1/2w resistors for the input and output and 2w for the psu.



Before:
p.jpeg



Upgraded Caps and added PSU bleeder:
p.jpeg


Horrible ugly input and output:
p.jpeg
 
Yes digging up an old thread again. So I acquired one of these and currently have some Tungsol new issue 6Sn7 in the unit. So im a bit confused here. Some members are saying that having this in unit on or off its the same. I can confirm when I have it off it barely plays music and there is static sound. So on makes a difference. Secondly lots of takl about upgrading the caps etc. One person says why not use a 1uf cap instead tow .47 in parralel. Should I just use one or is it best to do the both of them? Also whats a decent cap that can be found online. Im in the US. Parts express has a few offerings and then there is Mouser etc.
 
yes, you can remove the tubes and your system still worked, albeit lower volumes than with tubes but just slightly, try it, you may even like that without the tubes plugged in...

you see, that buffer has an input cap, a grid leak resistor tied to a cathode resistor then to an output capacitor.., circuit is complete either way...