Deluxe Reverb Build - noisy vibrato and slow response to vibrato pedal

[Bluefinger]

Hi

I have a problem with a BFDR build which I cannot figure out. The amp is pretty much stock except for a couple of different values in the tone stacks. The only real mod is the usual reverb on both channels mod where the normal channel is connected to the reverb input as opposed to the PI.

There are two problems which are probably related:
first the vibrato on the normal channel is noisy. There is a loud tock.tock sound. it doesn't do that on the vibrato channel. Also after the vibrato foot switch in engaged it takes around 5 seconds for the vibrato to set in.

Otherwise the amp sounds great.

any ideas?

thanks a lot!

[pdf64]

Have you tried a known good tube, ie with plenty of gain, in V5?
Regarding the ticking, some detailed photos of the amp internals would be helpful.

[loudthud]

Is there some DC Voltage on the footswitch jack when tremolo is switched off? There should be. Most Fender tremolos have a kick starter that feeds some DC to the footswitch. Shorting the DC to ground causes the oscillator to start quickly.

Please post a link to the exact schematic you are using so everyone is on the same page.

[Bluefinger]

Here's the schematic (it's a stock BFDR schematic): http://www.tubeampdoctor.com/images/...b_07.10.15.pdf
The only real difference is that I xonnected the "X" coming from the normal CHannel to the "Z".

Here's a pic of the internals:


Since the tremolo noise occurs only on the normal channel I guess it must be a lead dress issue but I tried to stay as close as possible to the wiring of an original DR. ok, they don't have a tremolo on the normal channel so maybe I need to route things differently

[loudthud]

As to the slow start problem, have you tried a different tube? The kick starter is where the raw bias Voltage is feed to the oscillator via a 2.2Meg resistor. The problem with this circuit is that both halves of the 12AX7 are biased off when the Tremolo is disabled. Some tubes don't like this condition and may not want to start. Other versions of this circuit use the cathode Voltage from the oscillator tube as the kick start Voltage but they are not the opto-isolator type you see on blackface amps.