DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: Ivan Drago on January 02, 2018, 11:18:19 AM

Title: Tubes and transistors in tremolo circuit
Post by: Ivan Drago on January 02, 2018, 11:18:19 AM
Hello, everybody!

I am new on this forum, and also new in diy'ing stuff, so please, don't blame me if i have silly question, but... :)

I am working on tube preamp, based on 6n17bv soviet military submini tube, which is double triode good enough to handle any 12ax7 circuit. What i want is to have 2 stages of preamplification+ tonestack after second half of tube, + i want to have a sine wave tremolo in same unit, and here i have some questions.

Did somebody tried to put a transistor/opamp based LFO as a cathode shifter in tube circuit?
I was thinking to put ldr after tonestack, but cathodephase shifting tremolo sounds better for me, and i leaving ldr option as a last.

The idea is to make this unit as small as posible, so i don't want to put a second tube, to build tremolo around it.

And ideas, please?
Title: Re: Tubes and transistors in tremolo circuit
Post by: GibsonGM on January 02, 2018, 01:13:27 PM
Hi Ivan, welcome!

A gentleman by the name of Andrew, "The Tone God", had plans for a nice tube tremolo several years back.  I guess now they call it the "Bullit".   Here is a link:  http://www.thetonegod.com/tech/bullitt/bullitt.html (http://www.thetonegod.com/tech/bullitt/bullitt.html)

It requires FOUR triodes, however, and a dual opamp.    I think if you have some experience, you can remake this design to use only one tube (2 triodes)...or to replace 2 triodes with opamps.   

So the answer is "YES, this is very possible.   
Title: Re: Tubes and transistors in tremolo circuit
Post by: Kevin Mitchell on January 02, 2018, 01:51:32 PM
Here's a clip of the Vintage Vibe I did a while back on breadboard using 6n16b tubes. Sadly I can't seem to recover Frequency Central's drawing though if you could dig it up, it may be a useful reference.




Just planting info.
Title: Re: Tubes and transistors in tremolo circuit
Post by: Ivan Drago on January 02, 2018, 02:50:47 PM
GibsonGM
Thank you for your answer! This us a great design, althrough i don't know alot about low plate voltage designs, and i would stick to high voltage, couse idealy the plan is to drive class d power amp, and i am not sure if the will be enough amplification out of 12VDC. But, anyway, this is great design, and i think i could take alot out of it.
Thank you :)


Kevin!
This unit sounds good to my ears :) I will dig for aomething like that. Thanks alot for sharing video!
Title: Re: Tubes and transistors in tremolo circuit
Post by: bluebunny on January 03, 2018, 03:14:51 AM
Some of Rick's stuff is in the Layouts Gallery (http://www.aronnelson.com/gallery/main.php/v/frequencycentral/), including a couple of versions of his Vibracaster and the Vintage Vibe.  (He said before Christmas that he's planning to gather all his old artwork and post them on his website - so something to look forward to.)
Title: Re: Tubes and transistors in tremolo circuit
Post by: duck_arse on January 03, 2018, 09:07:19 AM
izzit not possible, hazzit not yet been done: can the EA trem method of modulating the emitter bypass cap not be translated to valves? even at proper anode volts, there is only low volts on the cathodes, isn't there? and a nice pso osc driving?