Variable-mu lives!!!

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cheers kubi,

was just checking the forum before work and didn't have time to find the link.

chuck
perhaps take some inspiration from this

http://www.proaudioeurope.com/london/Product%20frames/fairman_frame.htm

uses quad 12au7 as the vca, then quad 12ax7 as the output amp i assume- sombody who has used the unit please correct me if i'm wrong these are all assumtions.

perhaps you could work form prrs design, and simply parrallel 12au7s for the gain reduction, and replace the solid state output amp with parralled 12ax7?or keep the output solid state to keep the cost down.

i understand the stuff like the 670 has an advantage for stereo or mixbus work as the parralelled tubes give consistency between the channels and lower the noise.

just afew thoughts

toby
 
> uses quad 12au7 as the vca, then quad 12ax7 as the output amp

Seems to be 12AT7. Interesting thing to use in quads.
 
If I remember rightly the Tube-Tech didn't use quads. It was just a single AT7 per channel. 'Course my memory usually sucks.

PRR, how about parallel AU7's?

cheers,
kent
 
Yeah crack that sucker open and take some shots...

I really was concerned about the statement PRR made that his hybrid wasn't really pro quality, which is why I was looking at Dale's .

Kent can you comment on the design and what you feel is the quality compared to the other "retail" versions?

I am not totally against doing a point to point project just that it would not be accessible to everyone here if it was.


-ChuckD
 
As far as doing it's GR thang it sounds great. It does the loud-squishy (can I TM that phrase?) bus comp thing very well. Even when pushing into distortion it's pleasing. What is lacking, and this is no suprise IMO, is the transformers. I used the Radio Shack ones as suggested in the sake of science and the bottom end disapears just a little bit and I'm guessing that they are the reason. My layout is sized for those trafo's so anyone would have to do off board ones as a replacement. If OEP's sound good we could have a true winner. I really want to get to this and try other options sometime in the near future but my DIY has taken a back seat as of late.

Side note: a guy I made one for LOVES it on kick. Go figure about the bottom end...

cheers,
kent
 
What is OEPs??

What about putting some really good transformers in there like a set of Lundalhs (is there a model that fits)? Where is your layout for the design?

-ChuckD
 

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