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MP-1 V2: FET Questions

Started by Fdesalvo, May 10, 2018, 09:58:05 AM

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Fdesalvo

Hi, all.

Long time lurker. So glad this site iis back up.

Ive got a v2 MP1 and am refreshing the caps and have moved on to the fets/jfets/etc. I have a couple of questions due to my ignorance of all things FET and the dearth of info for the v2 online.

1. I am unable to locate replacements for Q1/2: K364 GR91. Are these "2SK364's" that I'm seeing referenced elsewhere?  I have some updated equivalents on hand (LSK170's) if this is the case.

2. Q3/4 are MPSA92's. I have these on hand, but is there a higher performing equivalent out there?

Many thanks for the help/education. I build all analog vacuum tube amps and do restorations on a variety of preamps, but venturing into the digital/ss realm has been eye-opening, if not exciting.

Best regards,

Frank
"Ruining good moments since 1975."



MarshallJMP

Yes these are 2SK364 (in rare cases 363), but why do you want to change these?
Same with Q3/4, no need to change them, if they work they work.

Fdesalvo

Quote from: MarshallJMP on May 10, 2018, 01:37:51 PM
Yes these are 2SK364 (in rare cases 363), but why do you want to change these?
Same with Q3/4, no need to change them, if they work they work.

Thanks for the response. I can't imagine how busy you are.  I'm looking for other areas to reduce background noise if possible. 

MarshallJMP

Well you could replace all the resistors with metal film, also replace those 33µF caps on the tubeboard with 10µF except C13.

Fdesalvo

Thank you for your advice. I'll give that a whirl.