Vibracaster - or "How to turn your Valvecaster into a Tremolo"

[easilyamused]

Anyone?....

I'm trying to do the same... I have two separate successful builds: a vibracaster and a boobtube (variant of valvecaster) already, so I'm about to try the grafting procedure. I'm trying to get my head around the possible switching to provide clean boost (V1), clean boost (V1) + tremolo, clean boost (V1) + dirty overdrive (V2), clean boost (V1) + trem + dirty overdrive (V2)... Will update when I come up with some ideas!

BTW I built both tube circuits as P-to-P right on the back of the socket. Tight, but works well.


Here's a shot of my work in progress. From left: the boobtube with only Gain Pot connected; MAX1044 powered charge pump (I'm using the 40V tap); The vibracaster LFO board with LED addition; Vibracaster tube portion. Ins and Outs are not fully finished - I'm planning the switching and wiring to actually be neat so I'm holding off until I get it straight!

https://www.dropbox.com/s/0cac56q08vjulwi/WIP.jpg

[peterg]

Does anyone have an up-to-date schematic of the vibracaster?

[lluis3.0]

After building my valvecaster, liking it, and realising I don't have a tremolo. I went ahead and made this stripboard layout for the vibracaster LFO taken from Rick's vibratone schematic. Pot connections may need reversing.



Verified and working well.

I'm running it off the regulated 12.6v heater supply. My valvecaster uses a 12at7 and runs on 21v, it also worked well wired to this. Had a bit of ticking which was removed by putting a 220uf cap across the + and gnd. The 8k2 resistor may need changing if yours runs on other voltages. 27k gives me a nice range from subtle wobble to chopping. 47k is stock for 12v.

Added a flashing rate LED. Based on Taylor's rather artistic post here.
http://www.diystompboxes.com/smfforum/index.php?topic=79078.msg657184#msg657184

...and added to the vibracaster schem like so.


I've put the LED on the emitter as the non inverted signal makes it flash clearer. Flashes on rather than flashing off.
I'd be interested to know if there should be any reason not to do it this way.
I tested it with various gain settings and checked with a scope. Works well and doesn't affect the sound or LFO waveform, not a tick or bump to be seen.

if i had a valvecaster, all i need is to wire lfo out to pin 8 ???

thank you

[disabled_shredder]

I don't know if this thread is current or not but I have a big problem and want RESOLVE WITH THIS BUILD. I used version 2 12au7 version. I have great oscillation but I have a huge ground hum (or so that's the description I'll use) and the depth pot works but fully counter clockwise I get a major hum even more so than any other setting. I've shielded the input and output this driving me nuts because I repair amps and mixers as a second income. Does anyone have any thoughts? I'm thinking the input cap might be too high or the dc blocking caps need to be lowered also? Just a though. Would love any input.