A newbie from Hanoi, Vietnam needs your help!
Hello PMik!
I'm a newbie from Hanoi, Vietnam.
Recently I bougth the MF P270-2 (Reference version of four MF P270 different versions?) showed in attach photos. But unfortunatly, I have the problem not only the same as the problem posted here: http://www.diyaudio.com/forums/solid-state/139506-musical-fidelity-p270-strange-power-off-noise.html but also even when switching it on and for all of two channels.
Please help me to find out and indicate capacitor(s) and/or resistor(s) in these photo and I will ask to replace by some one in Hanoi: Musical Fidelity P270-2 Reference pictures on Photobucket
Thank you very much!
Best regards,
The showed schematics is a first edition, this layout was used unchange for P140/P170 and for the A200/B200 int.amp.
For the P270/A370 improvements was made very rapidly after the release of this first version, by added reg. supply for the LM318, some changes of resistor values, after it succeded very well used in the A370
a buffer-stage was implanted betwin the front-end and the MOSFETs also in the P270, fact is that the P270 came in four different versions.
The last series of the P270 used 2SJ162/2SK1058
2SJ162/2SK1058 is not exactly the same as the 2SJ82/2SK226 (p170/P270) 2SJ83//2SK227 (A370/A470)
few changes/adjustments has be made to insure stability.
(ferrit leads for the gates, misc values of the resistors)
The a470 is roughly just a A370 with regulated power-supply and change of the cab/housing.
Already in 1990 is was imposible!!!
to find a stock of 2SJ82/2SK226 or 2SJ83//2SK227
Hitachi was asked and they had none of these MOSFETs
they was soldout for use in PA amps
If MOSFET-Amps is of prference
The showed schematics is best used with 2 pairs of 2SJ50/2SK135 and if small changes is made of the schematics, it actully sounds incredeble! even messured with todays standards
MF could not have the small versions beat the big ones you see (cost vs. performence)
Hello PMik!
I'm a newbie from Hanoi, Vietnam.
Recently I bougth the MF P270-2 (Reference version of four MF P270 different versions?) showed in attach photos. But unfortunatly, I have the problem not only the same as the problem posted here: http://www.diyaudio.com/forums/solid-state/139506-musical-fidelity-p270-strange-power-off-noise.html but also even when switching it on and for all of two channels.
Please help me to find out and indicate capacitor(s) and/or resistor(s) in these photo and I will ask to replace by some one in Hanoi: Musical Fidelity P270-2 Reference pictures on Photobucket
Thank you very much!
Best regards,
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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