Hi End Tube Project

Stee · 27th August 2008, 09:13 AM

hello
see my project with 6C33C and old Push-Pull
better then this

ErikdeBest · 27th August 2008, 09:38 AM

Hi Stee

With my limited knowledge I already see some problems.

A pair of 6V6 in pentode delivers, lets say, 15W into 8 ohms. This is about 10V RMS, which won't drive the 6S33S to full output, as for full output you need rather 50V RMS, or more.

Much care with fixed bias on a 6S33S, it can and has been done, but is not recommended by the manufacturer.

You have global feedback, which does not (always) go well with an interstage transformer. You may experience oscillation...

And then there is the driver stage with the ECC82. It will probably work, but won't do more than that. The ECC82 ain't a good tube, and the choice of the phase splitter is even worse. Expect high distortion from it!

Good luck, Erik

Yvesm · 27th August 2008, 10:08 AM

Ciao Stee,

I second Erik.

The basic problem when driving those lo voltage tubes is that you invariably need more B+ for the driver than for the power stage.

You did that ... but lost in the step down IT !

What about a single Hi Gain stage ?

http://www.dissident-audio.com/SE_845/Amp.gif

Yves.

Stee · 27th August 2008, 03:17 PM

I thought at one stage push pull that was not the SRPP

ErikdeBest · 27th August 2008, 03:26 PM

Hi Stee

If you want to go PP in the driver stage you can use a differential amplifier loaded with an interstage transformer. The Raven by Lynn Olson is an example, but you want a 1+1:2 or 1+1:1+1 interstage transformer, and not the step down one used in the Raven.

Still have to look if you will have enough gain, though.

Erik

Stee · 27th August 2008, 03:58 PM

like japan style

Miles Prower · 27th August 2008, 09:14 PM

No, just no. PP 6V6s can give you about 12W. Why waste that for 4.5W from that final? Other objections seconded.

Stee · 28th August 2008, 01:06 PM

best escalation is ECC82 - 6V6 - 6C33C all in push pull (six/ch)

Jeb-D. · 29th August 2008, 04:29 PM

Why are you using an output stage to drive another output stage?

Stee · 29th August 2008, 07:03 PM

6C33C have 36W each
low gain (6 - 7 times)
but are suggestive and ideal to exibit

27th August 2008, 09:38 AM	#2
ErikdeBest diyAudio Member Join Date: Mar 2003 Location: Itoculo	Hi Stee With my limited knowledge I already see some problems. A pair of 6V6 in pentode delivers, lets say, 15W into 8 ohms. This is about 10V RMS, which won't drive the 6S33S to full output, as for full output you need rather 50V RMS, or more. Much care with fixed bias on a 6S33S, it can and has been done, but is not recommended by the manufacturer. You have global feedback, which does not (always) go well with an interstage transformer. You may experience oscillation... And then there is the driver stage with the ECC82. It will probably work, but won't do more than that. The ECC82 ain't a good tube, and the choice of the phase splitter is even worse. Expect high distortion from it! Good luck, Erik __________________ my surname is indeed 'de Best': neither misspelling nor snobbism! Ask SY!

27th August 2008, 03:17 PM	#4
Stee diyAudio Member Join Date: Jul 2005 Location: milan	sin I thought at one stage push pull that was not the SRPP __________________ visit my best audio idea http://www.esafono.it/DACTONE.htm

27th August 2008, 03:26 PM	#5
ErikdeBest diyAudio Member Join Date: Mar 2003 Location: Itoculo	Hi Stee If you want to go PP in the driver stage you can use a differential amplifier loaded with an interstage transformer. The Raven by Lynn Olson is an example, but you want a 1+1:2 or 1+1:1+1 interstage transformer, and not the step down one used in the Raven. Still have to look if you will have enough gain, though. Erik __________________ my surname is indeed 'de Best': neither misspelling nor snobbism! Ask SY!

27th August 2008, 03:58 PM	#6
Stee diyAudio Member Join Date: Jul 2005 Location: milan	Thanks a lot like japan style __________________ visit my best audio idea http://www.esafono.it/DACTONE.htm

27th August 2008, 09:14 PM	#7
Miles Prower diyAudio Member Join Date: May 2005 Location: USA Blog Entries: 2	No, just no. PP 6V6s can give you about 12W. Why waste that for 4.5W from that final? Other objections seconded. __________________ There are no foxes in atheistholes www.dolphin-hsl.com

27th August 2008, 10:08 AM	#3
Yvesm diyAudio Member Join Date: Jul 2004 Location: Ardeche	Ciao Stee, I second Erik. The basic problem when driving those lo voltage tubes is that you invariably need more B+ for the driver than for the power stage. You did that ... but lost in the step down IT ! What about a single Hi Gain stage ? http://www.dissident-audio.com/SE_845/Amp.gif Yves.

28th August 2008, 01:06 PM	#8
Stee diyAudio Member Join Date: Jul 2005 Location: milan	at last need two final best escalation is ECC82 - 6V6 - 6C33C all in push pull (six/ch) __________________ visit my best audio idea http://www.esafono.it/DACTONE.htm

29th August 2008, 04:29 PM	#9
Jeb-D. diyAudio Member Join Date: Nov 2005 Location: SoCal	Why are you using an output stage to drive another output stage?

29th August 2008, 07:03 PM	#10
Stee diyAudio Member Join Date: Jul 2005 Location: milan	for power and fashion 6C33C have 36W each low gain (6 - 7 times) but are suggestive and ideal to exibit __________________ visit my best audio idea http://www.esafono.it/DACTONE.htm

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