Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Pastortom on September 17, 2010, 09:09:25 am

Title: Fender Vibrato...Opto Lights, but............
Post by: Pastortom on September 17, 2010, 09:09:25 am

I just took a Fender Bandmaster Reverb into the shop for a complete facelift.............gettin' the works with new hardware, grill and such............

The Vibrato isn't working........When I short out the RCA Jack (with a coupled plug) the Opto (roach) surges quickly with light, then dims a bit.....but at full intensity, no oscillation at all.......

Now to the more learned and wise among us here, isn't the Opto supposed to oscillate?  Correct me if I'm wrong here....... :undecided:

Title: Re: Fender Vibrato...Opto Lights, but............
Post by: tubenit on September 17, 2010, 09:29:43 am

Just an option out of ARCHIVES to consider as you think thru this vibrato and "roach" issue:

http://www.el34world.com/Forum/index.php?topic=604.0

With respect, Tubenit

Title: Re: Fender Vibrato...Opto Lights, but............
Post by: phsyconoodler on September 17, 2010, 09:42:33 am

The tube is what oscillates.The roach just transmits it to the rest of the circuit.Try a new tube in V5,right next to the PI tube.

Title: Re: Fender Vibrato...Opto Lights, but............
Post by: Pastortom on September 17, 2010, 04:14:23 pm

Tube socket was not quite up to snuff........OK now.........Works fine.  Thanks 'fer the tips........ :grin: