Anybody done the "full" mp105 mod?

[phantom power]

I did the simpleswitch out of the opamps and tube. However it is still so damn noisy. I was wondering if anyone here paid the $8 for the book off Black Lion and did the mod and if so, how is it? How much for parts? -AE

[charles bronson]

phantom power,

yeah i somewhat recently performed the extensive mod to the mp105.

i am definately glad i did. sounds alot quiter. a little bassier too. for me that's a good
thing.

all the parts for the mod were no more than i believe like 13 or 14 bucks.

i should say however that i have yet to install the new pots(input/output). that's
suppose to take care of the remaining amount of noise. as soon as i get a better
soldering iron i will take care of that too.

i say definately go for it. pretty easy.

plan to buy a couple more of the things and mod them to when i get the chance.

good luck and have fun

[Skipwave]

Yep, I've done it too. Huge improvement over just the opamps, although there is a lot of variation between the different opamps you can use. I used LM6172s (I think). Make sure to put a nice tube in there as well. I like JJ/Tesla ECC83s.

The finished box is not so noisy and pretty nice.

[eeldip]

i have a pair of fully modded mp105s... yeap, the noise, it gets to acceptable levels, thats the main benefit. also it hi-fis the amp a bit, the top is much less hashy.

but its never gonna be a "quiet" amp. and it doesnt end up with a ton of headroom- but when it craps out, it overdrives nicely. you lose a bit of gain with the "full" mod, but you gain more usable gain cause of lost noise.

i put in new pots in both of them, in one i put some fancy $12 each clarostats at 100k, the other sort of average $2 pots at 500k. both are a huge improvement. the 100k pots required a reworking of the input stage (matt helped me out figuring a solution for this). i dont recomend 100k. and i would say the $2 each pots are worth the saving. its a bit silly throwing down too much money for mp105s.

its a reasonably easy board to work with, i didnt have any pads pull off, and i pretty well abused it.

oh, getting those old pots out is a bit annoying, the first one i ended up just destroying them. second time around i managed to preserve the crappy pots for some reason i cannot think of.

oh, one more thing, after the full mod, you can hear the differences between opamps quite a bit more. i had a lot of trouble distinguishing different opamps pre mod... i mean, i could tell when the shitty ones were in.

[jdmcgee]

i have a pair of fully modded mp105s... yeap, the noise, it gets to acceptable levels, thats the main benefit. also it hi-fis the amp a bit, the top is much less hashy.

but its never gonna be a "quiet" amp. and it doesnt end up with a ton of headroom- but when it craps out, it overdrives nicely. you lose a bit of gain with the "full" mod, but you gain more usable gain cause of lost noise.

i put in new pots in both of them, in one i put some fancy $12 each clarostats at 100k, the other sort of average $2 pots at 500k. both are a huge improvement. the 100k pots required a reworking of the input stage (matt helped me out figuring a solution for this). i dont recomend 100k. and i would say the $2 each pots are worth the saving. its a bit silly throwing down too much money for mp105s.

its a reasonably easy board to work with, i didnt have any pads pull off, and i pretty well abused it.

oh, getting those old pots out is a bit annoying, the first one i ended up just destroying them. second time around i managed to preserve the crappy pots for some reason i cannot think of.

oh, one more thing, after the full mod, you can hear the differences between opamps quite a bit more. i had a lot of trouble distinguishing different opamps pre mod... i mean, i could tell when the shitty ones were in.

eeldip,

just curious, do you remember what did you have to do to the input stage when you changed to the 100k pots. I just got an MP105 super cheap & I was going to do the "Full Mod" (100k Clarostat pots, new opamps, new tube), already got the parts ordered, but I'm intrigued by your problems with the input stage.

Thanks,

jd