bias-varying tremolo on a stand alone unit ?

[mat]

Is it possible without the power tubes but with built in bias circuit ? ..
Propably it is not.

[pdf64]

See http://www.webphix.com/schematic%20heav ... _schem.pdf
or
http://www.vintagehofner.co.uk/britamps ... /dom2.html
Pete

[JazzGuitarGimp]

Mat,

If you're just looking to purchase rather than build, you might want to check out the Strymon Flint pedal:

http://www.strymon.net/products/flint/

It does a very convincing bias vary trem. Lots of sound clips and demo videos on the website. I have no affiliation with them, just dig their stuff.

Cheers,
Lou

[Blackburn]

Years ago I saw this clip and thought this box was awesome. With another listen, it still sounds pretty good. Quite a few options in a small box, but expensive. I dig!

https://www.youtube.com/watch?v=hT5kqI-TIgI

[rdjones]

The VibroChamp comes to mind.

Bias vary on the driver stage.

[img976]http://www.cnjradio.net/fenderamps/bron ... _schem.gif[/img]

rd

[mat]

Thanks for the links. I'm definitely building, not buying.

I'm planning to build a standalone box that contains dumbleator style buffer, a tremolo and two tube reverb in a box. I could build a tremolo with opto but would prefer the bias option.

Next question: would it be possible to use the dumbleators tube for the bias changing destination ?

I'll start to study the Bronco-Amp schem.

[d95err]

Checkout the Tore-Vibe:
http://taweber.powweb.com/store/5h15t_schem.jpg

Kit available from Weber:
http://taweber.powweb.com/store/kits_weber.htm

[mat]

Checkout the Tore-Vibe:
http://taweber.powweb.com/store/5h15t_schem.jpg

Kit available from Weber:
http://taweber.powweb.com/store/kits_weber.htm

Thanks for the links d95err. I have built the box ready except the turretboard. The low parts count of the broncos tremolo would be perfect for my build.

[rp]

The VibroChamp comes to mind.

Bias vary on the driver stage.

[img976]http://www.cnjradio.net/fenderamps/bron ... _schem.gif[/img]

rd

or maybe use/build a vibro-champ with a line out and load resistor and use the whole thing as a vibro-overdrive? I built my 5C1 with this option and forgot to ever try it.

[mat]

The whole vibro-champ does not fit in to my chassis and the transformer is not suitable for the job.

The remaining question: would it be possible to use the dumbleators tube for the bias changing destination ? (is that proper english )

[Wallbanger]

http://www.lynx.bc.ca/~jc/tremoloCircuits.html

Check out the Supro ckt at the bottom, they wiggled the bias of the input triode. I have a Supro 6422 Tremoverb with a similar very simple and elegant tremolo ckt and it sounds delicious.

[cbass]

http://www.prowessamplifiers.com/schema ... ch6152.pdf

He3res another take on Wiggling the input cathode.

[Gaz]

The whole vibro-champ does not fit in to my chassis and the transformer is not suitable for the job.

The remaining question: would it be possible to use the dumbleators tube for the bias changing destination ? (is that proper english )

Sure, you could try it on the recovery triode, which is just a normal gain stage. You will just need an extra triode or two to try the suggested circuits.

[Gaz]

And Wallbanger + cbass thank you for posting that circuit found in the Supro and Gretsch. Anyone know how to add an intensity control?

[martin manning]

Anyone know how to add an intensity control?

Since this pre-amp tube bias varying type of circuit couples the term signal into the audio path via a shared cathode resistor, one way to do it would be to split the shared cathode resistor (use two at half of the original value for each, at least to start) and connect the cathodes together using a pot (maybe 10k?) wired as a variable resistor. This might make a little noise when the pot is turned, but I don't think it will be a problem.