Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on September 10, 2016, 06:24:57 am

Title: Marshall Blusebreaker TREMOLO
Post by: TIMBO on September 10, 2016, 06:24:57 am
Hi guys,Interested in camsna Ceriatone build and eager to here the TREM, although I'm not a big fan of the trem. :dontknow:
Form all the vids of the original amp it seem that the trem works and sounds fine.
I see that Ceriatone has gone down a different path in a bias trem. Is this just a safe bet or a copyright thing, although Metro amps have done a close version of the original trem.

Has anyone played an original BB an confirm that if works and sounds fine.
I'm thinking of a clone using the Ceriatone layout but I need to settle on a trem.
It seems that the J174 FET is a tad hard to find, any ideas on a substitute. Thanks
Title: Re: Marshall Blusebreaker TREMOLO
Post by: sluckey on September 10, 2016, 07:32:51 am
Quote
I see that Ceriatone has gone down a different path in a bias trem. Is this just a safe bet or a copyright thing
The circuit is a Fender 6G16 circuit with a couple parts values changed. It also uses a red LED rather than a cap/resistor on the cathode of the oscillator. The LED produces a much bigger tremolo signal, although since it's modulating EL84s, the LED is not really necessary. The 6G15 is a very smooth, effective tremolo circuit. Hoffman uses this circuit in his AB763 amps.

Quote
It seems that the J174 FET is a tad hard to find, any ideas on a substitute.
Most any general purpose N-channel JFET will work. It's just being used as a voltage controlled resistor. I've never heard this circuit before so I have no idea how effective it is.
Title: Re: Marshall Blusebreaker TREMOLO
Post by: bnwitt on September 10, 2016, 09:50:17 am
actually it's EL34s or KT66s
Title: Re: Marshall Blusebreaker TREMOLO
Post by: sluckey on September 10, 2016, 10:58:18 am
Yep. Had a brain freeze.