Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

Sony Vfet Illustrated build guide
Sony Vfet Illustrated build guide
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th July 2020, 05:05 PM   #1151
fabrice63 is offline fabrice63  France
diyAudio Member
 
fabrice63's Avatar
 
Join Date: May 2015
Location: Fréjus
It seems that the trimpots are a real "thing" in this build , is the lower the ppm /° the better , like this : Y0056500R000K0L Vishay Precision Group Foil Resistors | Mouser France

price is not a concern for me , i want my amp to be stable


.
  Reply With Quote
Old 17th July 2020, 05:38 PM   #1152
RainfallSky is online now RainfallSky  Russian Federation
diyAudio Member
 
RainfallSky's Avatar
 
Join Date: Jul 2015
Location: Saint-Petersburg
Quote:
Originally Posted by fabrice63 View Post
It seems that the trimpots are a real "thing" in this build , is the lower the ppm /° the better , like this : Y0056500R000K0L Vishay Precision Group Foil Resistors | Mouser France

price is not a concern for me , i want my amp to be stable


.
If price is not a concern, those could be one of the best:
j. 1240W (5K ohm @ 5%) (5K ohm)
g. 1240W (500 ohm @ 5%) (500 Ohm)



P.S.: Although I'm not sure if trimpots affect the sound in DIY Sony VFet build..
  Reply With Quote
Old 17th July 2020, 07:09 PM   #1153
fabrice63 is offline fabrice63  France
diyAudio Member
 
fabrice63's Avatar
 
Join Date: May 2015
Location: Fréjus
I already have those trimpots in my F6 , not for the sound , but for the stability , it's all i like to have


.
  Reply With Quote
Old 17th July 2020, 07:17 PM   #1154
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
Sony Vfet Illustrated build guide
Wow! Those are pricey pot(s)!
  Reply With Quote
Old 17th July 2020, 07:27 PM   #1155
Dennis Hui is online now Dennis Hui  Canada
Hoopy Frood
diyAudio Member
 
Join Date: Aug 2002
Location: Toronto, Canada
Sony Vfet Illustrated build guide
Price aside, they do seem like nice trimmers. I particularly like their monotonic nature.
__________________
We are fearless amplifier builders. A little heat doesn't scare us at all.
- NP 2002
  Reply With Quote
Old 17th July 2020, 11:39 PM   #1156
Eric is offline Eric  United States
Knows enough to be dangerous
diyAudio Member
 
Eric's Avatar
 
Join Date: Nov 2000
Location: Central PA, USA
Sony Vfet Illustrated build guide
I would think that using a multi-turn pot will pay the largest dividends in terms of setting the adjustments properly. I used single-turn pots that came with the kit and it took a bit of effort tweaking back and forth. Once it was set, I checked it a few times and not I just don't think about it anymore.
__________________
DIY Theater, Aleph-X Amps, LDR based BA-3 pre, B1 Korg, Pearl II, modified SL-1200 TT, F4, M2, Aleph-J, MoFo, a40, VFet-2, ACAs, FHXL & TB 1772 speakers
  Reply With Quote
Old 21st August 2020, 03:40 AM   #1157
Joca is offline Joca  Portugal
diyAudio Member
 
Join Date: Oct 2014
Location: Aveiro
Hi

I had my Vfet running for a while but one channel did not went so well. I want to rebias the FE and tune the amps. Is it possible to do it without desoldering the vfets and dismantle?

thanks
  Reply With Quote
Old 21st August 2020, 04:57 AM   #1158
Rodeodave is offline Rodeodave  Austria
hates ground loops
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Sony Vfet Illustrated build guide
I've done exactly that. It's possible, but all the pots interact with each other, especially since the feedback loop is closed. Go slowly with tiny changes to the potentiometer settings, let the temperature equalize after each setting. You'll get a feeling for the direction the circuit is going in.

I described my setup in post #88 Sony Vfet Illustrated build guide
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 22nd August 2020, 01:43 AM   #1159
Joca is offline Joca  Portugal
diyAudio Member
 
Join Date: Oct 2014
Location: Aveiro
i saw it but i dont have 4 DMM. only 2. that way is almost insane to achieve good results. I saw a procedure where we would lift some resistors and other things. But didnt really understood it
  Reply With Quote
Old 22nd August 2020, 05:09 AM   #1160
Joca is offline Joca  Portugal
diyAudio Member
 
Join Date: Oct 2014
Location: Aveiro
well, done it with only 2 DMM. just 4 hours.
  Reply With Quote

Reply


Sony Vfet Illustrated build guideHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
BA-3 Amplifier illustrated build guide 6L6 Pass Labs 338 Today 08:25 PM
F6 Illustrated Build Guide 6L6 Pass Labs 2794 Today 10:59 AM
Aleph J illustrated build guide 6L6 Pass Labs 5540 Yesterday 01:05 PM
F5Turbo Illustrated Build Guide 6L6 Pass Labs 638 28th September 2020 08:49 PM
ACA illustrated build guide 6L6 Pass Labs 169 16th June 2020 03:12 PM


New To Site? Need Help?

All times are GMT. The time now is 10:02 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki