Hey everyone. I just picked up a Marantz 2245 from a local vintage stereo equipment shop. He told me that he serviced it and fully tested, but after hooking it up the right channel has a very quiet hum on all inputs (I switched speakers and isolated it to the right channel) and on phono playback there is some crackling/fuzz that happens periodically on both channels. I’m kind of thinking some of the capacitors need to be replaced. The guy that I bought it off is a good dude and offered a warranty, but he’s also super in inundated with work orders. What are everyone’s thoughts on a DIY recap? I’d consider myself pretty handy, but it seems a little out of my scope. I watched a video and learned where the typical caps that fail are located. Any suggestions on testing the capacitors at home? Is this something I should try to tackle? Are there any detailed guides that anyone knows of? Any help would be great. Thanks in advance!
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Where are the transistors? Also, to separate the amp and pre amp am I taking out the bridges in the back between pre out and main in?
Yes, pull those jumpers. They easily unplug.
Transistors are on the phono amp board, P700. HiFi Engine has the service manual. Free download when you set up an account.
There may be 2SC458 transistors on the P700. They should be replaced and may take care of the noise. I would replace the other 4 transistors as well, if I was doing it.
Rob
Transistors are on the phono amp board, P700. HiFi Engine has the service manual. Free download when you set up an account.
There may be 2SC458 transistors on the P700. They should be replaced and may take care of the noise. I would replace the other 4 transistors as well, if I was doing it.
Rob
FinalVinyl
Active Member
while you're in there you might as well do a recap because the originals are 50 years old. At least recap the power section
catrafter
Marantz Specialist
Replace the epoxy gob diodes while you are in there. H707,H708 with 1 ea. 1N4148 or 1N4448. H709 with 2 ea. 1N4148 or 1N4448 in series.
Tom
Pulled the jumpers. Speakers were dead quiet, but Tuner wouldn’t play through the speakers. The tuner shouldn’t need the preamp, right?
Also, do you know how many transistors there are on the P700 total? Are the H707 and H708 the transistors? What other boards have the rest of the transistors on them and what are they called? Sorry, I am a little lost in the sauce with this stuff. Thanks for your help.
Thank you! That is exactly what I needed.
Do all inputs need the preamp? I don’t get the distortion that I get on phono playback when I use aux input with my iPhone or tuner.
so, I used deoxit and Faderlube to clean all pots, switches and inputs. Also, cut fresh speaker wire and redid connections in the back of my speakers. Both channels are sounding way clearer. I think I’m going to hold off on the restoration for now. Thanks for all of the input everyone. I’ve definitely saved a lot of useful info.