Which MP1 mods are reversible?

[astrobushido]

Hi folks,
I am looking to grab either a stock MP1 or one of the MP1 Classics and an MP1 just showed up near me.

Unfortunately, it's not a purely stock one as I wished. It's been modded with the 3.666 mod.

Does anyone know if this mod is reversible to stock specifications or not? And if this is an easy service or if it is tricky somehow to perform?

Since I am asking this, it would be nice to have the information on what common MP1 modifications can be reverted to original stock specs, the reversion respective difficulty level or if they can't be reverted at all.

Glad to hear from you.

Cheers everyone!

[rnolan]

Kim dd this post (http://adadepot.com/index.php?topic=1515.15) which gives a brief description of some of the various mods.  He describes the 3.666 mod as extensive, MJMP will be able to give you a more definitive answer, but from what I read of it you may want to keep bits of it, like the eq centre frequency selection trim pots  :dunno: .For the most part, most mods should be able to be reversed although some aspects you wouldn't want to eg if it's the noise mod (which is mostly replacing old electrolytic caps which are noisy from age).  The level of difficulty will depend on the original mod and also if the original parts are still available.  MJMP has stock tube boards he has made with more modern/better new components. So if you got a 3TM MP-1 you could replace the 3TM tube board with a stock board etc.  If you source a stock MP-1, there are a bunch of sensible modernising mods you'd want to do just because the units are getting quite old, ie all the electrolytic caps are old and noisy (noise mod), the memory battery will be flat (battery mod), later versions changed the rear line in jack to be inst level (rear jack mod).MP-1 classics are much harder to find, and MJMP says they are a pain to work on.  That said, they incorporated some of the good things from the MP-2 like stereo parallel Fx loop and cab sim outs.  Moreover, as the Classic was the last preamp of that era (came out after the MP-2), they are the newest.

[Samuraipanda]

AstroB, the 3.666 mod is a good sounding one. One of my MP-1's is this mod and it is definitely a plus to be able to adjust the eq pots internally.

[MarshallJMP]

All mods except for the 3TM are reversible. But you need some good solder/desolder skills to do it.