Your preference on DR tremolo?

[arjepsen]

Hey.
Im planning out a build of a blackface Deluxe Reverb.
Now, I am looking over HoffmanAmps schematics, and see that he has implemented a different tremolo in his version.
So now of course I'm curious.
I think I have found various clips on youtube that to some extend showcase the difference in these tremolos:
The original circuit sounds a bit "punchy/pulsing", where as the other version sounds more like a sine-wave modulation...

Now, unfortunately I dont have the possibility to hear both options, that's why I ask peoples opinions here.
Actually, I dont use tremolo all that much - what I'm more curious about is whether the change in that circuit has any discernable change in the tone of the amp generally?

Regards
Anders

[maxkracht]

I tend to prefer the bias wiggle trem. I believe Hoffman was using a version of that, if I remember correctly. The only downside to this is you need to keep the poweramp bias cooler for good trem depth, though I tend to prefer fixed bias fenders on the cooler side anyway. Sluckey's trem-o-nator is another good option. Optical tremolo doesn't care how you set the bias.

[Stevem]

Bias wiggle tremolo to me effects the feel of the amp as you play it louder, opto induced tremolo does not anywhere near as much.

[cdemike]

I tend to prefer the bias wiggle trem. I believe Hoffman was using a version of that, if I remember correctly. The only downside to this is you need to keep the poweramp bias cooler for good trem depth, though I tend to prefer fixed bias fenders on the cooler side anyway. Sluckey's trem-o-nator is another good option. Optical tremolo doesn't care how you set the bias.

Yeah, the schematic I'm able able to find shows a bias wiggle trem: https://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf
I'm sure this is something someone has tried, but I wonder if a source follower would help widen the range of bias settings that also allow for good tremolo depth since a source follower would be able to nearly rail-to-rail rather than (B+)/3 as with a cathode follower.

I've been really impressed by all the sound clips I've heard of the trem-o-nator, and the Supro-style oscillator with the dual ganged 500k speed pot that Sluckey has on the trem-o-nator sounds excellent.

If you already have any BJT's on hand, all optical tremolo does is shunt signal to ground, so I've had good results also with variations of the Marshall-style transistor tremolo.

The original circuit sounds a bit "punchy/pulsing", where as the other version sounds more like a sine-wave modulation...

Now, unfortunately I dont have the possibility to hear both options, that's why I ask peoples opinions here.

All the different version of tremolo circuits will give you different sounds, but thankfully each is pretty well-documented which makes picking one you like easier. This one shows the difference between several different implementations of bias wiggle tremolos (the Gretsch wiggles a preamp triode's bias, whereas the Brown Princeton and the Gibson are output section bias wigglers) as well as the optical tremolo in the Black Princeton. The Fender opto trem tends to sound pretty choppy, whereas the bias wiggle trems are smoother:
https://www.youtube.com/watch?v=ktfK_ok36kw

Actually, I dont use tremolo all that much - what I'm more curious about is whether the change in that circuit has any discernable change in the tone of the amp generally?

Both opto-trem and versions of the bias wiggle trem that affect power tube bias (i.e., the versions in the original DR and in the Hoffman, respectively) can be made so that they will not meaningfully affect the sound of the amp when off. The versions of bias wiggle trem that affect the power tubes' bias won't impact the sound of the amp if the trem isn't running. The Valco-style preamp bias wiggle trem that the Gretsch has in that demo video will impact the sound by having the one gain stage share a cathode resistor with either the LFO or a cathode follower (depending on the circuit), but that's not the style of trem in the Hoffman anyway.

Opto trem (either the original Fender version with a "roach" optocoupler or Sluckey's version with a vactrol) functions by rhythmically shunting signal to ground. In the Fender and Sluckey versions, the depth control places the optocoupler on the depth control's wiper, but the depth control itself will slightly reduce the AC impedance to ground at the point where the tremolo circuit is inserted as compared to a version with no tremolo circuit. An easy way around that is shown on Sluckey's trem-o-nator page:

The drawback to this version is that the depth control probably won't turn the tremolo completely off, but you could also just defeat the tremolo using either the footswitch or by using a push-pull pot in parallel to the footswitch that also turns off the LFO.

Either way you go, the trem doesn't necessarily impact the sound of the amp when turned off.

If you're not planning on using the trem, though, why not just build a "lite" version that doesn't have one? It'd spare you a whole double triode and potentially having to troubleshoot noise, thumping, and other issues that often happen with tremolo circuits.

[nuke]

I'd expect optical in a Deluxe Reverb. Even though, the CDS photo cell is now fully banned in Europe.

Follow this link:

https://ampgarage.com/forum/viewtopic.p ... 37#p469937

I posted a simple transistor based tremolo oscillator, based on Peavey's "transtube" patent. The "cool" part, is it works perfectly with the original Fender 3M-Reverse Audio pot and the same capacitors values, and you can easily power it from the same source as the bias supply, and it will work with the same footswitch arrangement, stay off when there's no foot switch, and generally, behave exactly as one expects from a black or silver panel Fender.

It can flash an LED easily with another transistor, and the LED can go in the tremolo roach in place of the neon.

I found a little TO92, 600V mosfet that would easily fire a neon bulb or an LED driven by the oscillator.

I got to finish working on it one of these days. My goal was to free up the tube socket used by the tremolo LFO in the typical Fender amp, while maintaining the same pots and behavior, while not requiring a special power source.

Cause there's more cool stuff one can do with that 12AX7 than flashing a neon light.