Metropoulos Forum

Hi guys, after a yeah and a half , collecting parts, i may start my JTM 45/100 build soon. i may actualy build a second one, with some variations, and sometimes i thought about this fender harmonic vibrato, a tube driven tremolo that sounds sweet.
i'm thinking of adding it, do you think it's very hard ?

the early fender amps featured such tremolo ( concert amp , early showman 62 ... )
in the marhall version of a fender, that could be nice.

Do any of you knows more about this effect ?

i'm linking some clips of this tremolo :

http://www.youtube.com/watch?v=xatlYBqp7cY" onclick="window.open(this.href);return false;

http://www.youtube.com/watch?v=_qacyyzms9c" onclick="window.open(this.href);return false;

I do a lot of work with trem setups, and I can tell you that with one extra 12ax7 (both sides) it is easy to add a bias-vary trem with speed and intensity to practically any amp. Or, you can go the Valco route, and add a trem that varies the bias on a preamp tube cathode and will not affect power tube bias at all. Also very easy to do. There are schematics for both all over the place. If you are willing to put high B+ across a pot, preferably a 2W PEC for safety overkill, you can even do a Valco type with only half of a 12AX7. Of course, it's useful if you actually use it! My experience, building a lot of amps with trem, is most people are initially smitten with it, but over time, end up almost completely ignoring its existence.

thank you ! that's what i thought too. yes, i'd love to be guided to the right schematic, but honestly i don't have enough understanding of the tubes, and all i'd be able to do would be to observe, see and reproduce it, hoping that it'd work.

this kind of vibrato seems to sound a tad like a univibe. i believe you when you say that most peoples forget it even exists at some point. I like to use just a tad of it sometimes anyway, with a small amount of depth. see electric ladyland guitar part for example, etc ..
or with more depth, the most beautiful tremolo work ever made : "i got the blues" intro of the rolling stones.

http://www.youtube.com/watch?v=lR5DbMQg ... re=related" onclick="window.open(this.href);return false;

but i have much more use of a nice delay, an echoplex, that's true. and some fuzz.

what do you mean by "both sides" for the tube ? and what is a Valco ?

so , basicaly i have two ways ? one that would affect the amplified signal directly, varying the voltage, and the other way would be to act on the signal only into the preamp section ?
"half of a tube" you say ?

cheers !