Fuchs ODS problem, need help !

[j0k3335]

I have a problem with my FUCHS ODS amp.

For the overdrive channel, I have a Input ( drive ) and a output (volume ) pots.

My problem is that this OD volume pot is not progressive at all! ( furthermore that I use it mostly in Home recording and need to adjust low levels of volume )

I would like to have a wider adjustment range (that a tenth of a turn becomes a quarter turn to be clearer).

I recently bought a such volume pot from Fuchs BECAUSE I knew neither its value nor whether the function Push-pull was special: in fact it is a simple potentiometer of 100K with a classic push-pull function!

I do not have the schematic of my Fuchs but the overdrive must be close to the Dumble, with the typical 100k volume pot (like my present pot )

I would like :

. That my usual volume setting of the OD is not so "low": the first tenth of the pot !!! == do I have to add a resistance in SERIE with the potentiometer in order to shift this range?

. I would also like the variation to be wider (that I have a MORE possible variation on the potentiometer, so that the variation in volume is less brutal, more gradual.)

Do you think it's more complicated?

Should I change the value of this potentiometer ? If yes in what direction (higher value? what type lin or log will be better for my need ?).

may I have to put a resistance in parallel on the new potentiometer (in addition to that in series in the circuit)?

I do not see too much?

Thanks a lot to all your possible advices

[mojotom]

The OD volume should be a linear potentiometer, B100k, so you could always use an audio one, A100k.
That way you will have the same volume @50% that you had @25% with a linear.

But considering the topology of your amp you should have a global master volume. It means that you could control amp in OD mode with 2 master volume, the OD volume by itself to balance with the clean then the global master to set the overall volume of the amp. That way you could always skip switching channel if you're recording only on OD so push the OD volume up and turn down the global master.

[j0k3335]

The OD volume should be a linear potentiometer, B100k, so you could always use an audio one, A100k.
That way you will have the same volume @50% that you had @25% with a linear.

But considering the topology of your amp you should have a global master volume. It means that you could control amp in OD mode with 2 master volume, the OD volume by itself to balance with the clean then the global master to set the overall volume of the amp. That way you could always skip switching channel if you're recording only on OD so push the OD volume up and turn down the global master.

Thanks for this pot advice for sure this will help me.

For the second point, I understand and agree on your point of view : but I have this problem too when I pratice and could not really get a good balance between clean and OD channel !
May be your suggestion concerning the pot will improve the situation !

Thanks again mojotom

I may be please to any other suggestions

[mojotom]

Happy to help.

You could try to run a volume pedal in the loop so you can lower the OD volume when switching at lower volume, or lower your guitar vol pot while in OD.

You could also run an 8 Ohms speaker with the 4 Ohms output to lower the output volume (more useable at low volume).

I have a Fuchs modded PA100 at home and it seemed balanced enough and not too loud (4R out to 8R speaker). You have to open the amp master a bit to find a proper balance between channel.