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6SL7 in parallel driving 6550

artosalo

Member
2010-02-16 9:00 am
Not tried exactly that schematic but almost similar.

Some comments:

- there is no reason to "waste" two triode sections for driving EL34, not even when triode connected
- grid resistor can be larger than 100 k when auto bias is used, this improves the linearity of 6SL7
- there are few odd component values; cathode bypass capacitor do not need 450 V voltage rating, 50 V is sufficient, and grid resistor do not need 3 W power rating
 
The two sections of 6SL7 could be implemented differently
 

Attachments

  • EL34_SE.GIF
    EL34_SE.GIF
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Bas Horneman

diyAudio Moderator Emeritus
2002-04-03 12:03 am
The Netherlands
Strongly disagree with comments about not doubling 6SL7, which is a low transconductance tube. Search on experiences and designs of member yvesm
Which posts out of the 900 or so?

The thing is. For some applications doubling up might be beneficial. For a tube as easy to drive as the EL34. It really is not needed in my opinion.

I would suggest the OP finds out for himself. There really is no substitute for trying things out for yourself.
 

artosalo

Member
2010-02-16 9:00 am
Strongly disagree with comments about not doubling 6SL7, which is a low transconductance tube. Search on experiences and designs of member yvesm

I in turn fully agree what Bas said. And I have my own experience about this too. Actually 6SL7 with CCS is a very good driver.

leadbelly; what do you think that would go wrong when one 6SL7 instead of two is used to drive triode connected EL34 ?
Distortion ? Frequency response ? or what ?
But please, do not just say that it does not sound good. Then we nothing to discuss about this.
 
I also agree with all the points artosalo brought up.

I was just curious because i never tryied the 6sl7 in SE aplication as driver...

Yes! The grid resistor can be increased, and i am thinking of changing the EL34 with 6550.

And what do you think that would go wrong when two 6SL7 parallel triodes are used to drive a 6550???
 
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