[Adcandour]

Hey guys,

Any recommendations on swapping the volume knob, so it doesn't go from quiet to loud so fast?

I wasn't really considering keeping it, but just might, if this works.

Essentially looking at any recommendation and type of volume pot to switch it to (brand, etc)

 

[greco]

Any recommendations on swapping the volume knob, so it doesn't go from quiet to loud so fast?

Get a volume knob with fewer numbers that are placed further apart. It will get to loud slower (visually ...and in theory).

 

[Granny Gremlin]

I wonder if this is one of them Linear vs Log pot situations. I'd have to look at a schem to see.

There's also the option (whether lin or log) to use a tapering resistor (and avoid changing the pot at all).

 

[Adcandour]

I wonder if this is one of them Linear vs Log pot situations. I'd have to look at a schem to see.

There's also the option (whether lin or log) to use a tapering resistor (and avoid changing the pot at all).

I tried 3 resistors at different values, but all seemed to make it fizzy instead of helping with the taper. Is there a special resistor I should be using? I believe the resistor values were 180, 200, and 220 values.

 

[Cups]

There's e a mod in London Power's Tonnes of Tone 3 that ( if memory serves me correctly) ties the wiper of the pot wth the splitter section. It's supposed to help with the jump in volume.

If you're looking into a mod let me know and I can dig further.

 

[Adcandour]

There's e a mod in London Power's Tonnes of Tone 3 that ( if memory serves me correctly) ties the wiper of the pot wth the splitter section. It's supposed to help with the jump in volume.

If you're looking into a mod let me know and I can dig further.

Definitely interested. If you come across it, let me know. Thanks.

Sent from my Pixel using Tapatalk

 

[jb welder]

Which model of 800? Master or channel vol. ?
Agree with the others that it is probably due to taper of the pot.
Assuming that the resistors you tried went on the pot, which lugs did it go to?

 

[Adcandour]

It's from 1985 and has the master volume. Canadian version. with vertical input jacks.

I did it a while ago. I can track down the mod - I believe I got it off the marshall forum, iirc.

 

[SG-Rocker]

The master volume pot is a 1M log.

Perhaps a 1M linear will give a more favorable curve... a reverse log pot would have a similar effect.

 

[High/Deaf]

IMO, JCM800s don't sound so good quiet. They need to be wound up some to sound their best. So I think the volume taper was chosen on purpose - "Those low level sounds aren't so good so we're gonna shoot you right past those to where the good stuff is."