Juan , are your capacitors all already "burn in " , at least an 100 hours ??
it is well known that the Silmics need long burn in
also , the higher the voltage rating the lower the ESR
.
yes the Silmic had burn in as i remove it from my Dac before ... second try on the Vfet , i don't like it here too .. end of the story..
I soldered mine in as is, and did not turn them ahead of time like some others did. When it was time to check them and adjust… they barely needed an adjustment to achieve the 20v reading.
Hi, Juanitox.
Just curious. I have some Silmic II 1000uF that I was going to try in my build.
I was wondering what positions you tried the Silmic II in. Was it everywhere the 1000uF caps were specified? Or just in the front end circuit in front of the Edcore transformers.
Thanks!
On a tangential note, some years back when Peter Daniel was selling his premium Gainclone kits, I purchased several of those kits and built only one of them.
At that time, Blackgates STD were offered as part of the kit until the Blackgates were discontinued. I believe the kits shipped with Panasonic FC or FM in its place after that.
IIRC, the Blackgate caps in question were 1,000uF. I could be wrong, but I think that's what they were (Please correct me if I'm wrong, here).
Since the VFet is a very special build, I'm tempted to dig those out for this amp.
But I'm not holding my breath. They are in deep, deep storage, and will be very disruptive to dig out. So that may have to wait for some time. Tempting, though.
In the meantime, I'm very curious how the Silmics IIs will work out. I understand you did not like them, Juanitox, but could you tell us why?
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I wonder why the difference as Nelson adjusts to 20V when he builds them? Is your meter reading correctly or is the Meanwell putting out less than 36V? I see the Meanwell spec. is +/- 3% so maybe thats why.
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So are you saying you didn't adjust those pots to midway and they measured 16.5V or you did adjust them and they measured 16.5V?
I also wondered.
My Meanwell is close to 36V (36.2)......but I did not measure it at "full bias" so I can't say exactly.....but I assume that it is close to 36V. There is some voltage drop over SMPS filter. I do not use the on/off switch on chassis so at least no voltage drop over switch.
My "factory settings" seems to be on the "high side" most others measures about 16-17 VDC?
This time I also use soldered connections everywhere (no screw terminal connections).
Thank you.After looking at the schematic the +V to the boards is after the L1 filter inductor so maybe voltage drop across it (L1).
My pots where incidently (?) set midway, I did not fiddle with them, and when turning it on as is I measured around 16,5V on both channels.
Suited me well, some bias with headroom to start with..
EDIT: That said, I don't get the fuss about the "factory setting" thing, it's a kit, put the meter(s) on, fire it up and set it according to the article
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Err, sorry, I didn't get that last one...
At the end, is the bias adjusted with your (much greater than mine) skills and top equipment... or should we in fact check voltages with our voltmeters for mere mortals... and possibly dare to alter your initial adjustment?
Sorry for being slow tonight (mean even slower than usual
Claude
At the end, is the bias adjusted with your (much greater than mine) skills and top equipment... or should we in fact check voltages with our voltmeters for mere mortals... and possibly dare to alter your initial adjustment?
Sorry for being slow tonight (mean even slower than usual
Claude
@ Claude G
Yes, we need check voltages.
Start with trimmer position in the middle, then adjust to 20V,
after 1hour warm of the Vfet amp adjust one more time if needed.
My was easy and quickly stable. Read Mr. Pass article..
Look at excellent 6L6 guide
Sony Vfet (P, 2021) - diyAudio Guides
