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McIntosh 1700 receiver TO-66 driver-stage PNP transistors

I got a r e a l l y rough-shape MAC 1700 receiver at a flea market for $25. [It, obviously, had been in a damp cellar for a long, long time...A LOT of the under-chassis was rusted at many of the electrical connections.] However, being familiar with rebuilding vintage gear (all flea market/garage sale finds...I've rebuilt -and run- a 1971 AKAI GX-365D r-t-r; 1972-era AR3a speakers [I've re-capped with polypro film caps and re-wired with 14AWG automotive-grade primary wire]; and, a -re'capped- 1981 AKAI UC-U3 "micro desktop amp" [but it handles 4-ohms better than most receivers 3x bigger!]). Anyhow, I'd like to COMPLETELY rebuild and use the MAC. However, one channel DID NOT match the other on this unit; and I just want to be certain about parts (I do know the power transistors are all MJ15003). My question is this (I don't have a newer-enough mobile browser to receive the schematic outright): Of the 6, chassis-mounted driver-stage transistors; how many of them are PNP? See, I'm using two NTE 175s (NPN) with the compl. NTE 38 (PNP) on the outward-facing left on each side. I apologize if this question is stupid, but: Is this correct(?); because, one channel will work perfectly; however, the fuse on the TRIAC board (facing the tuner sub-chassis) blows immediately...even with all the protection diodes replaced on the power transistors; the TRIACS replaced; the BI-POLAR 10uF caps replaced; and the small, .0056uF cap across the 10k resistor bridging the base-of-the leftward transistor with forward voltage of the 1N4004 diode. Thank you.

Re: McIntosh 1700 receiver TO-66 driver-stage PNP transistors

With the front panel towards you: from left to right: PNP NPN NPN PNP NPN NPN.
Original type's: PNP 2N3741, NPN 2N3767, NPN 2N3738, PNP 2N3741, NPN 2N3767, NPN 2N3738.
The separate one NPN 2N3738.

The NPN type are replaced by McIntosh for 2N4240 which match NTE175
The PNP type will match NTE38

The TO-3 output transistors where 2N5305 replaced by McIntosh for MJ15003

The TRIAC's act as a symetrical crow-bar and have the function to protect the loudspeakers against DC.
This mean that at least on of the power amplifiers put DC on the output and need repair.
During repair you can disconnect pin 8 ( grn/wht wire ) en pin 5 ( red/wht wire ) from this output monitor board 034-821 to disable it temporary in order to repair the amplifier. DO NOT CONNECT ANY LOUDSPEAKER OR LOAD AT THIS TIME.


Re: McIntosh 1700 receiver TO-66 driver-stage PNP transistors

Hi check if theres any dc or ac sitting on the chassis. Could be leaking or shorted electrolytic capacitors but you may be recapping the unit anyway to ensure reliability esp if the speakers are cap coupled, i had a similar fault on a Marantz1060 dc offset was unstable due to bad coupler bypass cap on left channel but no speaker protection so lost a vifa to it. Sob. U lucky u have fuses n speaker protection. Good luck.