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Sony Vfet Illustrated build guide
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Old 18th January 2018, 12:42 AM   #431
Eric is offline Eric  United States
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Sony Vfet Illustrated build guide
Just started populating my boards last week. Need a transformer and a set of sinks to finish things off...
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Old 18th January 2018, 01:57 AM   #432
delecoy is offline delecoy  United States
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There is something special about how it sounds. I won't waste anyone's time trying to describe it, but I like it more than my F4. And I love the F4.

My BA3FE preamp now officially has waaayyy to much gain...so fixing that is next on the list.
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Old 18th January 2018, 04:45 AM   #433
slimecity is offline slimecity  New Zealand
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I need to ask a stupid question on every thread.

This one is - Like many of you will also have (I suspect) I have an Antek trafo with the purple static shield wire.

I assume this wire connects to chassis earth?

thanks!
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Old 18th January 2018, 06:33 AM   #434
Zen Mod is offline Zen Mod  Serbia
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Sony Vfet Illustrated build guide
yup
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Old 18th January 2018, 10:27 AM   #435
wdecho is offline wdecho  United States
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Sony Vfet Illustrated build guide
Quote:
Originally Posted by delecoy View Post
There is something special about how it sounds. I won't waste anyone's time trying to describe it, but I like it more than my F4. And I love the F4.

My BA3FE preamp now officially has waaayyy to much gain...so fixing that is next on the list.
Are you using linear pots on your BA-3? Try changing to audio pots if so before making changes to pre. Zen posted the changes needed when I asked the same question on another thread but changing from linear to audio pots solved it for me.
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Old 18th January 2018, 10:37 AM   #436
Zen Mod is offline Zen Mod  Serbia
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one should have log pot from the start

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Old 19th January 2018, 04:23 AM   #437
delecoy is offline delecoy  United States
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It's an Alps blue velvet 20k. I'm almost certain it's a log pot. My speakers are 93db ish. With the ba3fe ( exactly built as original schematic, full gain ) driving the f4 antthing approaching half way on the volume knob was really loud in an 800sf room. Pre driven by schiit modo multibit ( 2v rms iirc ).
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Old 19th January 2018, 11:12 AM   #438
wdecho is offline wdecho  United States
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BA-3 As Preamp
#1242

Zen gave me the solution.
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Old 19th January 2018, 08:59 PM   #439
delecoy is offline delecoy  United States
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Found a couple 220R in the random parts stash and put those in R5 on my BA3FE instead of the 100R...and I now have a volume knob again ( instead of full blast at less than 1/8 turn ).



Thanks again guys!

Last edited by delecoy; 19th January 2018 at 09:02 PM. Reason: Clarity...again
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Old 22nd January 2018, 03:40 AM   #440
slimecity is offline slimecity  New Zealand
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Hi - hoping to get a little help with this. I am building and powering up one board at a time. I have the Antek trafo that gives 22VAC. That is giving me 30VDC at the input to the connected board. Problem is with about half of the voltages I am getting exactly half what I should be - like I have lost a + or - rail somewhere. The voltages I am getting (compared with what I should be getting) are below in brackets.

Note that I have the full kit with the supplied parts. I carefully installed the resistors previously and checked all the readings using the procedure for them and all those readings were OK. No VFETs are in yet.

POINTS VOLTS (Actual Volts)

G – T6 +28V (15.06)
G – T8 -28V (-14)
G – T4 -24V (-14)
G – T2 +24V (14)
T6 – T7 0V (0
)
T8 – T9 0V (0)
T6 – T11 ~ 5V (7.2)
T8 – T13 ~ 5V (7.2)
G – T18 less than a few +/- volts (17mV)
G – T14 +13V (6.8)
G – T15 -13V (-6.8)
G – T19 ~+12V (11.88)
G – T20 ~-12V (11.88)
G – T17 ~-10V (9.7)
G – T16 ~+10V (9.7)

Any ideas on where to look? I have checked for solder bridges on the board - no issues there. Should I first be looking for a dodgy component or perhaps a bad solder join?

Thanks
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