Marantz 2275 Restoration Reproduction Lamp Housing
In the last several days I finished restoring the two P700 power amp boards. I replaced Transistors H701 through H704 as well as several diodes and all the electrolytic and several of the film capacitors. I also replaced the output transistors on both boards with Onsemi outputs to maintain channel symmetry. One board had the original output transistors and the other had replacements. I also restored the P400 phono board, replacing all of the transistors, electrolytic capacitors and several of the film caps that were in the signal path.
After I finished the restoration I aligned the phono board per the maintenance manual. I set the idle current and DC offset per the maintenance manual.
I then attached a signal generator to the AUX input and 8 ohm non-inductive dummy loads to the speaker terminals. I fed a 1Khz tone into both channels and drove each channel until I observed clipping on the scope. I was able to drive both channels simultaneously to just shy of 27V RMS across the dummy loads which come out to 27/8*27 or about 90 watts per channel with both channels driven. The 2275 is sounding great and I am pleased with things so far.
This 2275 has some cosmetic warts but electronically is is performing well. In the next day or so I will check out the FM section's alignment but suspect I will not have to do much, in the past other 2275's FM sections I worked on did not require any adjustment other than adjusting the tuning meter centering a bit. Will see if this holds true with this particular 2275 but the FM section seems to be working quite well currently.
I then attached a signal generator to the AUX input and 8 ohm non-inductive dummy loads to the speaker terminals. I fed a 1Khz tone into both channels and drove each channel until I observed clipping on the scope. I was able to drive both channels simultaneously to just shy of 27V RMS across the dummy loads which come out to 27/8*27 or about 90 watts per channel with both channels driven. The 2275 is sounding great and I am pleased with things so far.
This 2275 has some cosmetic warts but electronically is is performing well. In the next day or so I will check out the FM section's alignment but suspect I will not have to do much, in the past other 2275's FM sections I worked on did not require any adjustment other than adjusting the tuning meter centering a bit. Will see if this holds true with this particular 2275 but the FM section seems to be working quite well currently.
I’m in a similar situation with a melted housing on a 2225 I’m in the process of restoring. There’s lots of great info in this thread, but I’d love to avoid having the housing printed myself if possible. Would you be able to share info for the eBay seller you referenced?
No problem. I’ll look into getting it done locally. Will post results if it works out! Thanks for the response.