Hoffman Deluxe Reverb Tremolo Mods

[plaidzebra]

Hey all,

Just got done building a Deluxe Reverb clone with a Hoffman board and schematic. I'm don't really like with how weak the tremolo is. It isn't audible until the intensity pot is well past halfway and even when dimed the tremolo is still kind of subtle.

I've been reading through forum posts, and tried 4 and 5 on Sluckey's tremolo mods - changing the cap didn't make too much of a difference, and I put an LED in from an old effects pedal I had laying around, and that made a popping noise along with the speed of the tremolo that was as loud as my guitar was.

What other modifications can I make to the circuit to make the tremolo stronger? I'm not against putting a roach in it and changing the circuit, I'm just not sure exactly what I would need besides a roach. Also, would changing out the resistor like mentioned in number 3 on Sluckey's post make a huge difference?

[shooter]

[quote I put an LED ][/quote]
 I've used this method 3 times, 2 in trem circuits and once is a sorta fixed gain preamp section.  They all worked well, maybe try 2 or 3 different diodes?

[plaidzebra]

That's possible, and definitely not difficult to do. I could rip apart a few more old pedals 

[sluckey]

Different colors have a different forward voltage drop. Red or yellow LEDs work best.

[plaidzebra]

I tried a red one and it was pretty noisy like I said. I might just order some different ones and test them out until one of them works.

As for installing an optoisolator, do I need any more components that aren't on the Hoffman board?

[sluckey]

The optoisolator is a very different circuit. You need to study the original AB763 schematic/layout and compare to the modified Hoffman AB763 schematic/layout to see what's involved. There will be quite a few component changes, additions, and omissions. Probably have to add turrets also. I don't recommend going this path unless you understand both circuits and are experienced with designing layouts.

If you are using 6V6s in your amp you should be able to get a nice strong trem effect. I would change R63 to a 100K resistor. Changing bias will have a big effect on the trem. You will likely have to compromise between 'perfect' bias and strong trem. The red LED (cathode connected to ground) will give you way more trem signal than you need.

Another forum member just went through this weak trem issue just a couple weeks ago and was satisfied with his solution. Look back through the list of topics and you'll find it.

[Deric]

I put an LED in from an old effects pedal I had laying around, and that made a popping noise along with the speed of the tremolo that was as loud as my guitar was.

Popping noise aside....did it make the trem work better?  Perhaps the "pop" was always there but the trem was just too weak to hear it.  Lead dress (especially around the phase inverter grid) can be a big source of popping/ticking trem.


Just thinking (typing) out loud....


Good luck!

[Willabe]

agree. 

[plaidzebra]

Yeah, the tremolo definitely worked better with the LED. I'll shop around and get some new components.

The optoisolator is a very different circuit. You need to study the original AB763 schematic/layout and compare to the modified Hoffman AB763 schematic/layout to see what's involved. There will be quite a few component changes, additions, and omissions. Probably have to add turrets also. I don't recommend going this path unless you understand both circuits and are experienced with designing layouts.

I'm sure that given enough time andparts I could work something out, but that's definitely another project for another day