I'm working on a Ceriatone clone of Dumble ODS 102 (Ceriatone's OTS FM model). I was concerned that the amp would be too bright, so Nik recommended that I use a snubber selector mod, put in a DP6T rotary switch to change the snubbers on V2.
I'm wondering if anyone has an image showing how to best implement this mod. It sounds challenging, because I'll want to have 10 capacitors (5 separate selectable snubbers, plus one lug for "no snubber", on each V2a and V2b) all crammed in and selectable in a small space.
I figure maybe I can run a wire from the plates of each V2a and V2b over to the common lugs and attach them there. Then, for each of the 10 selectable terminals that I'm attaching a cap to, I'll solder the cap to it, and point the cap's other lead up in the air, then twist the 5 on each side together, solder the 5 together to a wire that leads to the cathode of each V2a and V2b. Does that sound like it'd work, and be clean, easy to maintain, and not add extra noise or anything?
In addition, I'm wondering if I should do this mod immediately, or if I should build the amp normally first, and get that working, prior to trying to implement this mod. Thoughts?
How to implement V2 snubber selector mod?
Moderators: pompeiisneaks, Colossal
Re: How to implement V2 snubber selector mod?
Build it first. May well be fine.
Re: How to implement V2 snubber selector mod?
Higher snubber values are usually a bandaid for a bad lead dress. the 250 or 270pF snubber is just fine.
If your #102 is too bright in general , remove the 68pF cap on the master.
If your #102 is too bright in general , remove the 68pF cap on the master.
Re: How to implement V2 snubber selector mod?
Good point about the bright cap. I am planning on making the bright cap on the master switchable.
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Charlie Wilson
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- Joined: Thu Jan 23, 2014 7:32 pm
Re: How to implement V2 snubber selector mod?
Couple more reasons you don't want to do it. High voltage on a switch and wires coming off your plate possible adding noise to your OD.
CW
CW
Re: How to implement V2 snubber selector mod?
I'm not too worried about that. I've done many mods like this before successfully. As long as I'm careful about lead dress, i doubt it'd cause too much trouble.Charlie Wilson wrote: ↑Mon Jan 04, 2021 7:27 pm Couple more reasons you don't want to do it. High voltage on a switch and wires coming off your plate possible adding noise to your OD.
CW
I think I've decided just to do an on-off-on DPDT instead of the rotary. That way, I'll still have 3 settings, and I only have 2 caps to tie together each side, not 5.
Re: How to implement V2 snubber selector mod?
Charlie is right 
There is a reason why Dumble put those on the sockets,to keep those leads as short as possible and although it might not be noisy (to you) it could still effect performance in other ways..Just sayin..
IMO the best way to do it would be to put the snubbers on a rotary and run a wire to the 150K resistor just before the OD master input and dump highs there..This is how Dumble did his treble bleeder and tweaked gain and frequency response on his 2nd generation amps
Tony
There is a reason why Dumble put those on the sockets,to keep those leads as short as possible and although it might not be noisy (to you) it could still effect performance in other ways..Just sayin..
IMO the best way to do it would be to put the snubbers on a rotary and run a wire to the 150K resistor just before the OD master input and dump highs there..This is how Dumble did his treble bleeder and tweaked gain and frequency response on his 2nd generation amps
Tony
" The psychics on my bench is the same as Dumble'"
Re: How to implement V2 snubber selector mod?
Build the amp normally first (without ANY snubber). This is an easy mod to experiment with because there is no soldering required. Just use clips to temporarily try different capacitor values until you find the values you like. Once you find what you like solder in your preferred value in the same place that Dumble added snubbers.
Just keep in mind that when you are "clipping in" capacitors these wires with clips on them will add a good bit of noise. Ignore the noise and focus on the tone that you are looking for. Once the chosen caps are soldered in the correct place you will not have the noise.
Re: How to implement V2 snubber selector mod?
Alright, well I guess I'll avoid doing the snubber selector for now at least, partially because of the warnings about noise, partially because I was worried about lead dress, and partially because putting the switch in caused me to have to move a bunch of other wires around, making for worse wire routing. Maybe I'll revisit this in the future, but for now, I'll try to investigate the post-OD treble bleed mod as a workaround.