values of OD controls (non HRM)??

[Pete]

Can anyone clear up my confusion regarding pot values for the OD controls, specifically in NON HRM amps?

Reading the discussion of these in the recent thread "Everything You Ever Wanted to Know ... " seems to make it less clear (to me anyway).

The Hybrid Rev A schem indicates both as 100K A, but I read in some threads here that this is incorrect and in fact they should both be 100K LINEAR. (I currently have the 100K linear).

The info in that thread and pics indicate 250K A Drive pot and 100K A for the level.

I'm specifically interested in the era of amp mentioned in that thread (or slightly earlier). I did briefly try a 250K A in the Drive position and it seemed like too much gain with a loss of that transitional area of OD (where you can get almost clean at low settings).

So what's the current consensus for the non HRM amp?

Just wondering if anyone has experimented in this area and thanks in advance for any suggestions and comments.

[Bob-I]

The debate is what HAD used. Personally I like Audio taper. I tried linear and found it too sensitive at the lower settings.

100K give the correct load. A or B is up to you.

[ayan]

Can anyone clear up my confusion regarding pot values for the OD controls, specifically in NON HRM amps?

Reading the discussion of these in the recent thread "Everything You Ever Wanted to Know ... " seems to make it less clear (to me anyway).

The Hybrid Rev A schem indicates both as 100K A, but I read in some threads here that this is incorrect and in fact they should both be 100K LINEAR. (I currently have the 100K linear).

The info in that thread and pics indicate 250K A Drive pot and 100K A for the level.

I'm specifically interested in the era of amp mentioned in that thread (or slightly earlier). I did briefly try a 250K A in the Drive position and it seemed like too much gain with a loss of that transitional area of OD (where you can get almost clean at low settings).

So what's the current consensus for the non HRM amp?

Just wondering if anyone has experimented in this area and thanks in advance for any suggestions and comments.

Pete,

The amp I posted the pictures of was a transitional thing, so you can't quite go by that. That particular head had the Skyliner mod to it (.01uF midrange cap and different -- modern -- tone pot values), and that weird 250KA "Level" control for a non HRM amp.

To clarify, the early non HRM amp used 100K Linear pots for both "Level" and "Ratio" controls (as well as the Midrange control). Those were standard pot values at the time, since Fender used 100KL pots for the reverb control. There were no commercially available 100K Audio pots back in the day, and that's probably why Dumble used what he used back then (70s and early 80s).

The gain of the amp kind of comes in all of a sudden with a 100KL "Level" control, but you learn to find the sweet spots. Otherwise, you can always try a 100KA control there and you will find that you need to turn the pot past 1 o 'clock to get a decent amount of gain.

Cheers,

Gil

[Pete]

Thanks guys, I appreciate the comments.

I like how the controls are working now so I guess I'll leave things as is.

It just occurred to me that if an amp of that model and vintage was serviced by the builder in current times, it might be preferable (or not) to "upgrade" either of those controls to audio taper.