Ampeg tone stack modification

[tdbassman]

+ 1 on PCB module. It would give us a chance to roll our own sound with different capacitors & resistors.

Hey Steve, are you offering etched PCBs of this module? Do you also happen to have extra components? Or at least the caps. Are the resistors 1/4w? If so, I probably have the values.

[Hangman]

I will consider it, but the big issue with the choosing of ones own values/brands is that the board wont accommodate any capacitor. The space is so tight on that board. if the .01 was bumped up to a .022 it might not even fit. additionally orange drops are too large, wimas are too tall, etc... The high frequency caps have some room to work with, but as i mentioned, I am planning on offering the tone stack in 3 or 4 different configurations. so perhaps wait and see if your preferred configuration is offered.. or even better: make a suggestion.

[DALEALDERMAN]

Hi Steve(and Ampeg enthusiasts),

First post here; I joined specifically to find out more on this module after a search and find regarding my Ampeg GV22 I picked up this summer.
I love the reverb and trem/vib, but found the eq/voicing to be a little harsh AND tubby at the same time...these modules(installed by my amp tech) cured this problem perfectly!
I can now crank the bass AND treble for a somewhat scooped blackface tone with a pinch more gain: I love it!
Now onward for some speaker experimentation(I understand the OT has an 8 ohm tap).

Thanks again Steve,

Dale A.

[tdbassman]

I am not sure what cap configuration I would prefer, so maybe the additional caps could be included for experimentation purposes? I would clip them in/out of the pc board to save the copper traces and have choice of the sound I like.

Also, are these modules the same as in a B15-NF fliptop?

I will consider it, but the big issue with the choosing of ones own values/brands is that the board wont accommodate any capacitor. The space is so tight on that board. if the .01 was bumped up to a .022 it might not even fit. additionally orange drops are too large, wimas are too tall, etc... The high frequency caps have some room to work with, but as i mentioned, I am planning on offering the tone stack in 3 or 4 different configurations. so perhaps wait and see if your preferred configuration is offered.. or even better: make a suggestion.

[Hangman]

ampeg used these in every amp made after early to mid 1967.

[beedoola]

I installed the mod board I got from Steve (Hangman) today. I don't recall seeing any pictures of the mod board installed online. I should have taken pictures.

I initially tried installing it on the component side but I left the leads too short and the board wouldn't bend back far enough to allow the MID pot to go back to its proper position. I removed the board and then installed it on the trace side of the control board - there is enough room between the control board and the main PCB that the mod board can reside without touching anything.

I was able to get the control board out without having to unscrew and move the main PCB.

I also replaced C101,102,103 and 104. I couldn't get 250pf silver mica as Steve suggested in the article linked in this thread's OP, but I used 250pf SMica 500v. I also replaced c105.

The amp sounds REALLY good. To me the overall tone is much more clear, open, tight. I'm very pleased with the results.

Thanks Steve!!

[itsonlyadam]

I installed the mod board I got from Steve (Hangman) today. I don't recall seeing any pictures of the mod board installed online. I should have taken pictures.

I initially tried installing it on the component side but I left the leads too short and the board wouldn't bend back far enough to allow the MID pot to go back to its proper position. I removed the board and then installed it on the trace side of the control board - there is enough room between the control board and the main PCB that the mod board can reside without touching anything.

I was able to get the control board out without having to unscrew and move the main PCB.

I also replaced C101,102,103 and 104. I couldn't get 250pf silver mica as Steve suggested in the article linked in this thread's OP, but I used 250pf SMica 500v. I also replaced c105.

The amp sounds REALLY good. To me the overall tone is much more clear, open, tight. I'm very pleased with the results.

Thanks Steve!!

Steve,

How do we go about ordering some of these? I didn't know they were ready to ship out!

[Hangman]

Thanks for posting your thoughts! I do plan on taking some pictures and posting the simplified install once I get the conformal coating. Which might also allow the module to fit between the pot and circuit board as the old one did with only a small amount of manipulation.

I installed the mod board I got from Steve (Hangman) today. I don't recall seeing any pictures of the mod board installed online. I should have taken pictures.

I initially tried installing it on the component side but I left the leads too short and the board wouldn't bend back far enough to allow the MID pot to go back to its proper position. I removed the board and then installed it on the trace side of the control board - there is enough room between the control board and the main PCB that the mod board can reside without touching anything.

I was able to get the control board out without having to unscrew and move the main PCB.

I also replaced C101,102,103 and 104. I couldn't get 250pf silver mica as Steve suggested in the article linked in this thread's OP, but I used 250pf SMica 500v. I also replaced c105.

The amp sounds REALLY good. To me the overall tone is much more clear, open, tight. I'm very pleased with the results.

Thanks Steve!!

---

I did send a few out to people that were very interested and didn't care about the module being coated or not. If you are interested in one just private message me.
I am working on a "store" on this site where you can buy the kit, but I am dividing my time between a lot of projects, So if you are ready to install, Just message me and we can go from there.

I installed the mod board I got from Steve (Hangman) today. I don't recall seeing any pictures of the mod board installed online. I should have taken pictures.

I initially tried installing it on the component side but I left the leads too short and the board wouldn't bend back far enough to allow the MID pot to go back to its proper position. I removed the board and then installed it on the trace side of the control board - there is enough room between the control board and the main PCB that the mod board can reside without touching anything.

I was able to get the control board out without having to unscrew and move the main PCB.

I also replaced C101,102,103 and 104. I couldn't get 250pf silver mica as Steve suggested in the article linked in this thread's OP, but I used 250pf SMica 500v. I also replaced c105.

The amp sounds REALLY good. To me the overall tone is much more clear, open, tight. I'm very pleased with the results.

Thanks Steve!!

Steve,

How do we go about ordering some of these? I didn't know they were ready to ship out!

[Roman Ships]

Regarding the replacement of the ceramic caps C101 - C104 to 250pF.

What about that big mess of ceramic caps on the end ? ( 1971 v4b )
C108 - C110.. I think. The big discs in row there.

Replace those with Silver Mica as well? Stock values or change?

[Hangman]

which caps are you talking about? I don't see C108-110 on the schematic at first glance.