How do you take out a tremelo circuit?

eagertokill · Post by **eagertokill** » 17 Oct 2008, 02:49

Hello to everyone! I am new in here but not new to the field. I have been building guitars for a while and have been getting into building effects and now amps.

So, my question is, how can I remove a tremelo out of a circuit when it is bias modulating? Example would be maybe a Sears 1482 amp but I want to re-create is without the tremelo. Or any amp for that matter. I want to mess around with a simple clean circuit but I don;t want a tremelo on it. Thanks and I will try to contribute too as often as I can.

chromaticdeth87 · Post by **chromaticdeth87** » 17 Oct 2008, 07:57

Do you have a schematic handy? This may sound daft, but couldn't you jumper the preamp circuit from pre-tremelo to post with a a lead wire and effectively cut out the circuit? Like bypassing an effects loop. You just merely "skip" over the part of the circuit and connect it I would guess straight to your PI and output stage. The sears stuff usually ends up being fender clones usually anyhow. I know Valco designed most of the sears, kay, and supro stuff and they are all deluxe and champ ripoffs in their own right which are RCA circuits originally anyhow. If you can post a schematic it would help.

eagertokill · Post by **eagertokill** » 18 Oct 2008, 00:33

This is the schematic I am referring too. The tremolo modulates the bias so how do I take it out?

SirElwood · Post by **SirElwood** » 18 Oct 2008, 09:06

Here you go. Same amp, no tremolo.

And it's not bias vary trem.

eagertokill · Post by **eagertokill** » 18 Oct 2008, 12:04

Thanks a lot! I'm still new at a lot of this. I have tons of books I am reading to learn as much as I can but I am still not quite there. How do you tell if the trem modulatese the bias?

Also, can anyone explain the cascode circuit better? The same one in the Firefly. I can't find anything in any of my books and I don't quite understand it. Are there any other applications for it in larger wattage amps? Why?

Sorry for the noob questions but this seems to be the best place for ACTUALL circuit talk unlike HCAF. You guys seem very cool. Thanks!

SirElwood · Post by **SirElwood** » 18 Oct 2008, 13:30

eagertokill wrote:I have tons of books I am reading to learn as much as I can but I am still not quite there.

Take it easy. Slow down and take one thing at a time. You can read alot, but if you don't understand what you are reading (context or something like that) you don't learn. And you also have to build something. Because you will learn alot more by doing things. Actually I think the best way of learning things is to make mistakes and then fix them.

eagertokill wrote:How do you tell if the trem modulatese the bias?

Here's few circuits to look at: http://www.lynx.bc.ca/~jc/tremoloCircuits.html As you can see, the oscillator is tied to amps fixed bias circuit. You can also mudulate cathode bias, but it is usealy done on preamp tubes (see fender AA764 vibrochamp).[/quote]

eagertokill · Post by **eagertokill** » 18 Oct 2008, 14:53

Thanks! I have built 1 kit amp and 4 pedals and I agree with you about doing as well as reading. That is why I am going to build one from scratch from a schematic so I can really cut my teeth. I want a simple circuit but something I would actually use when I am done. I will log it all and post the results. Thanks again!

chromaticdeth87 · Post by **chromaticdeth87** » 20 Oct 2008, 05:59

Also, always make sure you have a good layout. A layout, schematic, and a good election of highlighters goes a long way. Out of all of the most useful stuff I've ever read, and if you haven't read head over to Aiken amps site, and check out what he has to say about grounding. A good grounding scheme is the fastest way to eliminate most humming, motorboating and feedback problems from your first start up of the amp.