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previous: steve conner I'd love a vari-mu tube compressor ... -- 10/2/2003 4:28 PM View Thread

Re: remote cutoff pentodes for compression?

10/3/2003 3:26 PM
dpcoyle
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Re: remote cutoff pentodes for compression?
Thanks for the responses.  
 
Marc that was a great site. The circuit looks "dog" simple.  
 
There are remote cutoff pentodes, which are also called variable mu, and there are sharp cutoff, which have a harsher action and more distortion, I believe.  
 
The matchless clubman schematic I have lists a 6sh7 for the pentode after the first stage triode, not an ef86, as another thread states. The 6sh7 is a remote pentode IIRR.  
 
I can report anecdotally I haven't noticed a pumping on AVC circuits on two old tube Hammarlund radios I have. Re pushpull, I guess it would be more trouble than it's worth on a guitar amp, but I prefer SE in low level stages, generally, for religious reasons.  
 
Steve, just being told they are in a couple of fancy units kinda makes me think they may prove useful.  
 
They are dirt cheap and widely available. I came to the question because I was searching for tubes with a small pentode, ca. 3w, for a tiny pp amp. One of the most common were the 6xx8 series of tubes, which feature a remote or sharp cut off pentode and a triode in the same bottle, but only a few, like the 6bm8 are staight pentodes. Most are sharp or remote.  
 
Dan

 
Replies:
steve conner [QUOTE]only a few, like the 6bm8 ar... -- 10/6/2003 2:30 PM