Valve Wizard Tube Phono Preamp - Page 3

spoontex · 17th January 2019, 01:57 PM

I think that I got it,

I've noticed that I haven't voltage on pin 3 of V2 ( cathode ? ), so I swapped the V2 tube until I've found one with more or less the same readings on pin 3 and 8. And now I've balanced output.

osci — imgbb.com

It's possible that Brand new tubes are faulty?!!??!

Anyway, you can tell me if the other voltages are correct?

Thanks a lot!!

Alan4411 · 17th January 2019, 02:08 PM

Quote:

Originally Posted by spoontex

Yes I've installed the T1-T2 and T3-T4 links. My heater supply is 6.3v. I change V3 for a ECC88.

And this are the new readings of two channels.

There is still some confusion here.

Look at the circuit diagram again, see heater chain, only pins 4 and 5 are used on the board. When using pins 4 and 5 with ECC82 and ECC83s you must use a 12 volt heater supply. Using a 6 volt supply in this configuration only half heats the filaments... and leads to very odd behaviour.

See the valve layout and there are two 6.3 volt filaments in there joined in series at pin 9.

The ECC88 or 6N1P valves have their filaments joined in parallel and they are 6.3 volt valves.

Do Not mix ECC83 family and ECC88 family valves on this board.

spoontex · 17th January 2019, 02:12 PM

What??

I think that I can use:

V1 ecc83
V2 ecc83
V3 ecc88

In paralel with 6.3v supply?

Merlinb · 02:30 PM

No, not on this PCB, it is not wired that way!

I suggest you use 6N2P and ECC88 at 6.3V
Or:
ECC83 and ECC82 at 12V.

spoontex · 17th January 2019, 02:22 PM

Okey, what valve for V3 do you recommend me for this board?

For 6.3v in paralel?

Merlinb · 02:31 PM

V1 = 6N2P
V2 = 6N2P
V3 = ECC88

or:

V1 = ECC88 (R5/R6 & R25/R26 will need to be adjusted)
V2 = ECC88 (R13 & R213 will need to be adjusted)
V3 = ECC88

spoontex · 17th January 2019, 02:28 PM

Uau... it's time to change everthing.

Thanks and sorry...

Alan4411 · 17th January 2019, 02:31 PM

Why not just alter the heater supply for 12.6 volts and use the ECC83, ECC83 and ECC82 configuration as you started with?

spoontex · 17th January 2019, 02:37 PM

Because my tranformer only have 6.3 sec. I need a new teansformer and are expensive. The other way I have a little toroid with 12V 1A. It's enough for heater supply?

Alan4411 · 17th January 2019, 02:42 PM

Yes it will be fine.
Remember when in 12 volt configuration each ECC83 and ECC82 valve only draws 0.15A. So three valves will use just 0.45A. Ample...

17th January 2019, 02:19 PM	#24
Merlinb diyAudio Member Join Date: May 2006 Location: Lancashire	No, not on this PCB, it is not wired that way! I suggest you use 6N2P and ECC88 at 6.3V Or: ECC83 and ECC82 at 12V. __________________ Buy my tube hi-fi book! www.valvewizard.co.uk Last edited by Merlinb; 17th January 2019 at 02:30 PM.

17th January 2019, 02:27 PM	#26
Merlinb diyAudio Member Join Date: May 2006 Location: Lancashire	V1 = 6N2P V2 = 6N2P V3 = ECC88 or: V1 = ECC88 (R5/R6 & R25/R26 will need to be adjusted) V2 = ECC88 (R13 & R213 will need to be adjusted) V3 = ECC88 __________________ Buy my tube hi-fi book! www.valvewizard.co.uk Last edited by Merlinb; 17th January 2019 at 02:31 PM.

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17th January 2019, 01:57 PM	#21
spoontex diyAudio Member Join Date: Feb 2016	I think that I got it, I've noticed that I haven't voltage on pin 3 of V2 ( cathode ? ), so I swapped the V2 tube until I've found one with more or less the same readings on pin 3 and 8. And now I've balanced output. osci — imgbb.com It's possible that Brand new tubes are faulty?!!??! Anyway, you can tell me if the other voltages are correct? Thanks a lot!!

17th January 2019, 02:12 PM	#23
spoontex diyAudio Member Join Date: Feb 2016	What?? I think that I can use: V1 ecc83 V2 ecc83 V3 ecc88 In paralel with 6.3v supply?

17th January 2019, 02:22 PM	#25
spoontex diyAudio Member Join Date: Feb 2016	Okey, what valve for V3 do you recommend me for this board? For 6.3v in paralel?

17th January 2019, 02:28 PM	#27
spoontex diyAudio Member Join Date: Feb 2016	Uau... it's time to change everthing. Thanks and sorry...

17th January 2019, 02:31 PM	#28
Alan4411 diyAudio Member Join Date: Oct 2011 Location: West Wales	Why not just alter the heater supply for 12.6 volts and use the ECC83, ECC83 and ECC82 configuration as you started with?

17th January 2019, 02:37 PM	#29
spoontex diyAudio Member Join Date: Feb 2016	Because my tranformer only have 6.3 sec. I need a new teansformer and are expensive. The other way I have a little toroid with 12V 1A. It's enough for heater supply?

17th January 2019, 02:42 PM	#30
Alan4411 diyAudio Member Join Date: Oct 2011 Location: West Wales	Yes it will be fine. Remember when in 12 volt configuration each ECC83 and ECC82 valve only draws 0.15A. So three valves will use just 0.45A. Ample...