Express bench measurements, anyone?

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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FenderLover
Posts: 2
Joined: Wed Feb 09, 2011 6:19 pm
Location: Minnesota

Express bench measurements, anyone?

Post by FenderLover »

Hello all - Long time lurker, first time poster. I'm interested in building an Express, and taking the Trainwreck Technology in a different direction using different tubes some day. Research first.

Has anyone ever taken a signal generator and scope probe to the Express? I can appreciate all of the fine work in defining the cosmetics and identifying parts, and even posting the DC voltages, but what about the dynamic performance?

All controls at 12:00, 1KHz input. At what input level does the signal start to clip? which stage clips first? At the point of clipping, what are the levels after the first stage/EQ/second stage/third stage/PI/speaker?

...and as long as I have you on the line...What about the 6V6 vs. EL34 outputs? What other circuit changes are needed to accomodate either output? (surely, the 6V6's overdrive before the EL34's, right?)

Thanks
I can't complain, but sometimes I still do.
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fishy
Posts: 377
Joined: Fri Jul 20, 2007 12:09 am
Location: Chandler, Az

Re: Express bench measurements, anyone?

Post by fishy »

These plots are of an Express style build. The builder does note differences in his build from the norm...

home.polstra.com/amps/wreck1/scope/

hope that helps.
FenderLover
Posts: 2
Joined: Wed Feb 09, 2011 6:19 pm
Location: Minnesota

Re: Express bench measurements, anyone?

Post by FenderLover »

That's a nice qualitative look, and confirms a few of my assumptions by reviewing the schematic. It would be nice to put some numbers on it though. Maybe someone else will chime in too.
Thanks
I can't complain, but sometimes I still do.
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