6BQ5\EL84 line amp

[amp_guy]

with all this interest in using unusual tubes for line stages, 12B4's
6C45's and so forth I was wondering if anyone hadany thoughts on using
6BQ5 or 6V6 in triode mode. they should be able to drive most any power amp.

Idid find a line amp using an 6AQ5 in an srpp online at

http://audiotropic.netfirms.com/projects/mobius/linepre6AQ5.gif

but I have a bunch of 6BQ5 laying around.

 

[Geek]

404 on the link

 

[leadbelly]

http://audiotropic.netfirms.com/Projects/Mobius/linePre6AQ5.gif

 

[tubemaster]

Hello,

the EL84 makes for a great preamp tube but it needn't be SRPP.

You can use a normal anode follower configuration with a nice wirewound plate resistor (like a Mills) of around 7500 ohm (use two 15K in parallel) running at 30-35 mA to give very low distortion and an output impedance of around 1500 ohms.

Alternatively and even better still you can use a special output transformer like the Sowter 9040: http://www.sowter.co.uk/specs/9040.htm which is perfect for the job and gives you an ouput impedance well below 600 ohms.

Both options are sonically and especially musically far superior to the SRPP configuration.

Best regards
Michael

 

[amp_guy]

Hey thanks for the encouragement michael.
what you described is very close to what I figured up.
I cosidered using some iron but For now I think Ill build it up.
on the cheap.


regards Dave

 

[Miniwatt]

http://audiotropic.netfirms.com/Projects/Mobius/linePre6AQ5.gif

I wonder why he uses different kathode resistors (82 and 100 Ohm) in a SRPP.
I like the idea though..