weak tremolo intensity

[isaac_teller]

Hello. First off I want to say thank you to all on the forum who have helped me over the past year. Great advice! Here's another situation that I'm stuck on. I built Sluckeys one-channel AB763 with reverb and tremolo. The amp and the reverb work fine. The tremolo speed works fine but the intensity is weak even on full strength. What could cause this?


https://el34world.com/Hoffman/files/Hoffman_AB763_1.pdf

[sluckey]

I built Sluckeys one-channel AB763 with reverb and tremolo.

I don't think so! I never had such an amp or any plans for such.

Maybe you mean Hoffman's AB763 since you posted his docs. If so, he uses a bias vary tremolo circuit that can be difficult to get the intensity right, especially if you are using 6L6s. 6V6s seem to get along with this tremolo circuit just fine. The problem is that the tremolo strength depends on the bias setting. Tweaking the bias will affect the tremolo strength. You will have to compromise between your "optimum bias point" and tremolo strength.

There are several things you can do to increase the tremolo strength. See the link below. Note 5 will get you the strongest tremolo. Use a red LED. I've use a red (or yellow) LED on all my tremolo circuits.

     https://el34world.com/Hoffman/files/Hoffman_AB763_Mods.pdf

[isaac_teller]

My bad. It is Mr. Hoffmans amp. I'll implement the changes. Thank you.

[sluckey]

Which output tubes are in your amp?

[isaac_teller]

6V6(6P6S Russian)

[isaac_teller]

Well, I implemented changes #3, #4 and # 5 and now it's working great! Thank you sir for your help! I don't play guitar(unfortunately) so when my friend comes by to pick up the amp I'll send a video clip.

[BlackCrowe604]

Hello. First off I want to say thank you to all on the forum who have helped me over the past year. Great advice! Here's another situation that I'm stuck on. I built Sluckeys one-channel AB763 with reverb and tremolo. The amp and the reverb work fine. The tremolo speed works fine but the intensity is weak even on full strength. What could cause this?


https://el34world.com/Hoffman/files/Hoffman_AB763_1.pdf

Likely too hot of a bias. I was facing same issue on a '69 Princeton and posted on here. Reduced bias and changed tremolo oscillator resistor from 1M to 470K and was successful.