Danelectro Tuna Melt Tremolo (Mods + Advice request)

[noelyoung]

Hi, these days I'm working on the Tuna Melt. I'm not very satisfied on the sound, I needed a tremolo with more modern vibe, this is too subtle, so I worked on some mods and now is "almost" perfect (to my needs).

First I replaced C101, it was a 10 uF electrolytic, with a 4,7 nF ceramic capacitor. I'm not crazy, I took the idea from the Vox Repeat Percussion, that has a feature I like so much: it roll-off a lot of bass frequencies, making the tremolo effect more present. A sort of glossy sound that cuts the distortion, too.

After replacing the capacitor, I noticed a drastic volume drop, so I worked on the resistors R120 and R102 to get the correct balance. Finally

R120 = 60 k (two 120 k in parallel)
R102 = 47 k

In this way there are no volume drop.

At last, the most interesting mod: in Soft mode (the triangular wave) the volume doesn't reach the Zero, and this is the feature that makes this tremolo too subtle. A work around is to replace R101 and  R111 with two Jumpers. Now the tremolo modulate from Zero gain to 1.

As I have just written above, now is "almost" perfect. I just want to realize how increase the pause between oscillations to give a more impulsive behavior to the tremolo. In other words: increase the time when the volume is off, and decrease the time when the volume is at max.

Any suggestions?

P.S. I'm Italian, sorry for my bad English

[mortad]

hello... Do you have some pics of your mod ??

[anotherjim]

R115. - EDIT - I now think it's R117!
If this is changed for 2 different resistors controlled by series diodes, you get a different time for the triangle ramp up or down. The Square output will follow this change.

This is done a lot, but Google didn't want to find many illustrations for me, this the best I could get for now...

You can see the pair of resistors and diodes feeding in to pin6 of amp A2 in this example.

[mortad]

Thanks for posting this !