Mesa Express 5:50 Replacement pot

[steveneddy]

Help please

I have a Mesa Express 5:50 Combo amp in my shop - needs a replacement pot - Channel 1 - treble pot - # on pot 590148

Measures 215K - which seems a little odd to me - but it is a Mesa

Does anyone know how I can get a replacement pot for this machine?

- OR -

Is there an aftermarket replacement part available for this pot?

Photo attached

[Phil_S]

Contact Mesa?

[xtian]

Don't you think it's a standard 250K pot? With, like, 14% tolerance?

[steveneddy]

Don't you think it's a standard 250K pot? With, like, 14% tolerance?

I haven't been able to locate a schematic either - so it's either a 250K - or a 200K - either of which could have drifted a little.

Or knowing Mesa - it's a 220K -

If I only had a schematic ......

But - yes - I have contacted Mesa - but I sent the message last night - so the amp will sit for the entire three day weekend.

[martin manning]

250kA. What symptom tells you it's bad? If it's scratchy, is a cap between it and the high DCV leaky? Is there any DC on the input lug?

[ToneMerc]

Don't you think it's a standard 250K pot? With, like, 14% tolerance?

I haven't been able to locate a schematic either - so it's either a 250K - or a 200K - either of which could have drifted a little.

Or knowing Mesa - it's a 220K -

If I only had a schematic ......

But - yes - I have contacted Mesa - but I sent the message last night - so the amp will sit for the entire three day weekend.

591048 is 250KA D short shaft pot, 591148 is the long shaft version.

TM

[steveneddy]

250kA. What symptom tells you it's bad? If it's scratchy, is a cap between it and the high DCV leaky? Is there any DC on the input lug?

Thanks for the schematic.

The owner broke off the shaft from the pot. I suppose it fell against something.

Mechanical failure - so I have to replace it.

[steveneddy]

Thank you to everyone who helped with this issue.

I was able to order a new pot and knob from CTS - which should be here is a few days - and I can finally get this job outa here.

I appreciate all of the help.