That's great to see posts summarizing Dumble amp features - for us, newcomers - as a side note
My question departs much from the original but my readings make me think (maybe I'm wrong) that the PAB is (somewhat) useless without the OD engaged (& vice-versa) - hence my question.
PAB is very “effective” on the normal channel as well as the OD channel, so allowing it to be switched separately from the clean/OD switch is worthwhile.
I find myself playing the OD channel a lot, with relatively low gain settings. Having the PAB available is a great way to boost solos when you’re already on the OD channel.
I build and repair tube amps. http://amps.monkeymatic.com
I recall a discussion here about PAB trimmer pot behind the front panel being used to dial it in.
PAB is frequency dependent, ranging from zero to 12-14 dB in the mid range from Rock. Jazz mode is about 12-14 dB down from Rock, so yes it's a much bigger boost in Jazz mode.
martin manning wrote: ↑Wed Jan 24, 2018 10:00 pm
I recall a discussion here about PAB trimmer pot behind the front panel being used to dial it in.
PAB is frequency dependent, ranging from zero to 12-14 dB in the mid range from Rock. Jazz mode is about 12-14 dB down from Rock, so yes it's a much bigger boost in Jazz mode.
It was supposed to be 189 PAB. Bass and mid grounds to a trimmer to ground around 170k if my memory is fine (rarely the case). This is a nice boost, great on the clean channel, but after trying it for a while I found that boost no longer provide the nasally boost that's nice to add to the OD (reminds me of a fixed wha with a very low Q) so I put it back to 22M PAB and I like it better for sure.
I read here some even try 2 trimmer for each ground (bass and mid) and this method could be nice to lessen the bass boost a bit (more lift on the mid pot side).
I try to lower the PAB but lowering the two 22M to 10M or 4M7 and it did lower the volume boost but it was less and less honky the lower I went so I came to 22M.
Lots of possibility here.
My amp is hardwired in rock mode though so less boost.
Yet another possibility. I coulnd't find any information about ODS #065, though (even using Google search with appended option "site:ampgarage.com")...
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Regarding your initial question, I make “ganged” OD&PAB switchable on the footswitch using a mini-switch. I use a DPDT footswitch on the OD using one half to switch the channel and using the other half to create a second ground that disengages when OD is off. Then, I use the mini switch to switch between the regular ground and the OD dependent ground for the PAB.
This way, on one setting, you have a fully independent PAB. On the other setting, PAB only works with the OD channel engaged.
Nice thing about this is that you don’t have to mod you Dumble. You can just make a new footswitch.