BM OD low level

lovetone · Post by **lovetone** » Fri Jul 21, 2023 8:09 am

Sometime ago I built a Blues Master, I am very pleased with the overall tone including the OD which I really enjoy.

The issue I have always had is that the OD level is much lower than the Clean. Its never been a problem before but I would like to us the amp foe gigs and just can't get enough OD level in a bad situation.
I'm wondering if anyone else has this problem? I have checked my build to the schematic and can't find any problems.

Cheers

jazzbass · Post by **jazzbass** » Fri Jul 21, 2023 10:48 am

Hi Lovetone,

can you please send photos of your amplifier, possibly in high resolution.

Franco

martin manning · Post by **martin manning** » Fri Jul 21, 2023 12:31 pm

lovetone wrote: ↑Fri Jul 21, 2023 8:09 am Sometime ago I built a Blues Master, I am very pleased with the overall tone including the OD which I really enjoy.

The issue I have always had is that the OD level is much lower than the Clean. Its never been a problem before but I would like to us the amp foe gigs and just can't get enough OD level in a bad situation.
I'm wondering if anyone else has this problem? I have checked my build to the schematic and can't find any problems.

Since the OD is working and sounds good, I would suspect something is not right between the OD 2nd stage output and the PI input, possibly an incorrect part value, bad solder connection, or wiring error. I would send some signal through the amp, and with the OD master all he way up, look for a drop in signal level starting at the OD output coupling cap. You will of course expect a large signal loss through the HRM. You could do this with a DMM if you don't have a scope.

Guitarman18 · Post by **Guitarman18** » Mon Jul 24, 2023 6:28 am

It’s worth remembering that the OD of a BM is traditionally used in conjunction with PAB. If OD+PAD is lacking in volume, then yes, you have an issue, but it’s normal for a BM OD without PAB engaged to be lower volume.

I hope that helps.

lovetone · Post by **lovetone** » Mon Jul 24, 2023 6:36 am

lovetone wrote: ↑Fri Jul 21, 2023 8:09 am Sometime ago I built a Blues Master, I am very pleased with the overall tone including the OD which I really enjoy.

The issue I have always had is that the OD level is much lower than the Clean. Its never been a problem before but I would like to us the amp foe gigs and just can't get enough OD level in a bad situation.
I'm wondering if anyone else has this problem? I have checked my build to the schematic and can't find any problems.

Cheers

Okay that may be the issue i'll check that out.

martin manning · Post by **martin manning** » Mon Jul 24, 2023 4:03 pm

Have you tried adjusting the OD entrance trimmer?

The Amp Garage

BM OD low level

BM OD low level

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Re: BM OD low level