Why not switch OD & PAB at once?

[ChopSauce]

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.

Please, let me know - eventually

[xtian]

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.

[ChopSauce]

Thanks for the info! That does make sense.

I have been suggested that the PAB provides too much of a gap in output volume but it doesn't seem to be.

[xtian]

Thanks for the info! That does make sense.

I have been suggested that the PAB provides too much of a gap in output volume but it doesn't seem to be.

The boost from PAB in Rock mode is moderate. Maybe 3dB. But in Jazz mode, the boost is large, maybe 12dB.

[dorrisant]

I've thought about using a pot to determine the amount of PAB... I know, yet another knob...

But, yes, "keep 'em separated."

[martin manning]

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.

[mojotom]

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.

[ChopSauce]

This is it! I could read about similar experiments, and thus (wrongly) guessed that was something wrong with the PAB - without the OD.

I've thought about using a pot to determine the amount of PAB... I know, yet another knob...

But, yes, "keep 'em separated."

That's noted!

[jam-mill]

I've experimented with several variations of PAB show here on TAG:
1. change resistors to 4M7
2. change resistors to 10M
3. add hi-pass filter shunt

and, ultimately returned to the original 22M.

I think PAB behavior largely depends on the tuning of the amp and type of pickups.

My 2p.

-jack

[Aaron]

ODS #065 had PAB in OD channel.

I like the Bass and Middle pots lifted with resistors. You could do a board with trim pots and tweak away as much as you want.

Aaron

[ChopSauce]

Yet another possibility. I coulnd't find any information about ODS #065, though (even using Google search with appended option "site:ampgarage.com")...

Information

The following words in your search query were ignored because they are too common words: ODS 065.
You must specify at least one word to search for. Each word must consist of at least 4 characters and must not contain more than 84 characters excluding wildcards.

... & thanks for all these informations!

[Bob-I]

I have big feet, so I can step on them together.

[ChopSauce]

Well, this is also what this suggests.



Seems I was wrong, though.

[mhartman]

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.

[tictac]

My ODS footswitch was: relay 1 = Clean-OD / relay 2 = Clean-OD+Midboost...

No reason you couldn't have a Clean-OD+PAB footswitch in addition to a standard Clean-OD switch is there?

TT