69 Style JMP50 1987 Build

martin manning · Post by **martin manning** » Sun Mar 11, 2018 2:03 am

Thanks for the explanation of your capacitance calculation. Keeping it simple, doubling or halving the value of the coupling caps moves the frequency roll-off one octave, which is approximately what you did going from 0.022 to 0.01. Actually log(22/10)/log2 = 1.14 octaves.

deeder · Post by **deeder** » Mon Mar 19, 2018 5:33 pm

I appreciate your input on that point.
Beyond the math I note with satisfaction this arrangement let more pass through.

Roe wrote: ↑Sat Mar 10, 2018 6:50 pm I'll help you to get rid of those LCR caps - they're dangerous and should only be sent to a marshall junkie like myself

With pleasure, you're welcome ;^)

Roe · Post by **Roe** » Tue Mar 20, 2018 9:11 am

The caps should be sent to Frankfurt am Main, Nordend!

deeder · Post by **deeder** » Sat Mar 24, 2018 9:21 am

Roe take a look at your inbox ;^)

Roe · Post by **Roe** » Sat Mar 31, 2018 4:27 pm

Thanks so much!

BIG Dave · Post by **BIG Dave** » Mon Apr 30, 2018 6:36 am

That board material looks like the same board material used in my original 1971 JMP50.

deeder · Post by **deeder** » Sat May 05, 2018 10:08 am

Actually it was the idea to dig the replica sort of thing. Sourcing the old components at the fair price was the big deal.

The turret board comes from my friend Brian H who is no longer doing this kind of material: https://www.facebook.com/Reproduction-T ... 54/?ref=ts
He is making knives now.

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69 Style JMP50 1987 Build

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