anyone up to matching a few mpsa56/mpsa06...
Subject says it plus I'm short on time/equipment/expertise to do same to repair 2 amps.
Both w/DC offset problems one 33mV/77mV, the other 150mV/1V!
I plan to provide 50 pieces of each, purchase pending, pay shipping both ways, plus what your time is worth to ya. My PP account is ready.
I can include schematic or for your perusal click on...
http://www.diyaudio.com/forums/solid-state/177067-will-pay-belles-1-series-amp-info-schematic-4.html
Per schematic of this dual differential, each channel needs 3 each mpsa56/mpsa06.
I hope to come out of this w/ 2 spare sets for future repairs to two amps as I have 3 of these amps; the third w/out issues for the moment.
thanks in advance, Tony
Subject says it plus I'm short on time/equipment/expertise to do same to repair 2 amps.
Both w/DC offset problems one 33mV/77mV, the other 150mV/1V!
I plan to provide 50 pieces of each, purchase pending, pay shipping both ways, plus what your time is worth to ya. My PP account is ready.
I can include schematic or for your perusal click on...
http://www.diyaudio.com/forums/solid-state/177067-will-pay-belles-1-series-amp-info-schematic-4.html
Per schematic of this dual differential, each channel needs 3 each mpsa56/mpsa06.
I hope to come out of this w/ 2 spare sets for future repairs to two amps as I have 3 of these amps; the third w/out issues for the moment.
thanks in advance, Tony
Hi,
I have built one nmos350 mk2, on the pcb available (nmos350) modifyed "on the fly". I have put only 4 mos-fet (it's enough power for me).
I have a couple of question for QUASI:
- the pcb board of mk2 is available?
- in the first setup of bias current I have only 1V (with 100 ohm resistors) instead of 8V required.
Thank a lot for the reply.
I have built one nmos350 mk2, on the pcb available (nmos350) modifyed "on the fly". I have put only 4 mos-fet (it's enough power for me).
I have a couple of question for QUASI:
- the pcb board of mk2 is available?
- in the first setup of bias current I have only 1V (with 100 ohm resistors) instead of 8V required.
Thank a lot for the reply.
Thanks AndrewT,
- I have measured the total current of circuit (how is described in construction guide doc
- I discovered that have - 69 V on the output rail;
- T2 it's a little bit too hot, but across R4 I don't have any absorbtion (0 mV);
- the schematic:
- I have measured the total current of circuit (how is described in construction guide doc
An externally hosted image should be here but it was not working when we last tested it.
) across the 100 ohm resistor put instead of fuse on the positive rail (+ 69 V);- I discovered that have - 69 V on the output rail;
- T2 it's a little bit too hot, but across R4 I don't have any absorbtion (0 mV);
- the schematic:
An externally hosted image should be here but it was not working when we last tested it.
Construction guide doc
Schematic:
An externally hosted image should be here but it was not working when we last tested it.
Schematic:
An externally hosted image should be here but it was not working when we last tested it.
updated:
I had made an error in the connection of R12: I connected to the collector of T7 (the red LED (LED 1) would not turn on and I had no absorption in the differential in VAS and in the driver.
Restored to the right connection of R12 to the base of T7 absorptions are returned to the correct values EXCEPT that measured at the terminals of R22 (driver stage) that is approximately 1V instead of 3.96 V (0.018 V / 220 ohm). Furthermore, the bias current (VR2) is not moved by approximately 2V.
I had made an error in the connection of R12: I connected to the collector of T7 (the red LED (LED 1) would not turn on and I had no absorption in the differential in VAS and in the driver.
Restored to the right connection of R12 to the base of T7 absorptions are returned to the correct values EXCEPT that measured at the terminals of R22 (driver stage) that is approximately 1V instead of 3.96 V (0.018 V / 220 ohm). Furthermore, the bias current (VR2) is not moved by approximately 2V.
That's all right!!! T9 was bad connected, fix and it work! I post Two photos... hope can view..
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.
http://1drv.ms/1mDqnU9
Parisitic oscillation on NMOS350 Mk2
Hi,
I'm testing my NOS350 Mk2 and, under charge (loudspeaker or dummy load - 8 ohm), I have a parasitic oscillation on the negative half-wave
Please, somebody can help me?
Thanks so much!!!!
Hi,
I'm testing my NOS350 Mk2 and, under charge (loudspeaker or dummy load - 8 ohm), I have a parasitic oscillation on the negative half-wave
An externally hosted image should be here but it was not working when we last tested it.
http://1drv.ms/1rL9JY5 .Please, somebody can help me?
Thanks so much!!!!
An externally hosted image should be here but it was not working when we last tested it.
http://1drv.ms/1rLa4tS
