Lin og log?

[Tdale]

Where do you guys use logarithmic pots, and where do you use linear?

Also, I see that some of you use clean master. That's all done with a pot and a special wiring at the OD/Clean switch, right, like in the 97 overdraft specimen.? It can't hurt to put it in, can it?

Tommy

[jazzyjoepass]

TDale,

The Clean master and OD levels are both 1M pots on the 97 but on the Hybrid, the OD is a 100K pot. I assume if the pot is to be wired as Master for both (post OD/post clean) then the OD will have to be reduced so that levels are balanced between OD and clean.

I'm not sure ... haven't tried a 97 schematic .... maybe Dogears or Gil could chime in ...

[Tdale]

Ok..

But which pots are log and which are lin ?

Tommy

[dogears]

The hybrid uses a 100k feeding the 1M global master. If you use a dedicated master on the OD. it must be a 1M so the PI looks back into the correct load. You then need to add a 100k trimmer between the 150k series resistor and the 1M pot. This simulates the OD level control of the hybrid A. Alternatively, you could raise the 150k series resistor to a 200k and hang a 50k across the 1M OD pot from input to ground. This correctly loads the OD2 cap, simulates the hybrid level at noon, and maintains the correct load looking backwards from the PI.

A side benefit of seperate masters is the ability to run seperately sized small bright caps on the masters. I prefer something real small on the OD, and something a little larger on the clean. Think 10pf to 15pf

Do not ever run a 100k pot into the phase inverter. It is wrong. It is too easy to implement seperate masters, preserving the circuit integrity as designed.

As far as log vs lin.... I definately prefer log for the clean gain, bass, and mid pots. Treble can be either depending on whether you like seeing it at 10 pm or 3pm. OD controls are lin (except 97 OD 250ka pot), masters can be either. I have audios in mine. Presence is lin.

[jazzyjoepass]

Out of convenience, I had mine all linear - rather work on the amp than deciding on log/linear issues - the resistance is still same; it's just visual/psychological.

Having linear also allows me to know what sort of resistance I'm dialing on the pots ... of course it doesn't really look good when you have pots on extreme ends....