I recently bought on eBay a Marantz CD 330 portable cassette recorder sold as in working condition but with a couple of issues, in part solved but one remains, so I decided to seek advice here.
There was a VU-meter needle stuck at half height, but I solved that by loosening its back screw a little. Now the needle is back at -20dB.
There was a stray black (grounding) wire broken which caused a subtle hum, but I've found its place and soldered it back, hum is gone now.
Also, I put new belts on it as the tape counter was not working because of a belt too loose, and also the others didn't look good. Now the transport works like a charm.
BUT, after changing the belts I did some recording tests and discovered that the left channel is not recording, while the playback of pre recorded cassettes is even in both channels. With the monitor selector on Source I can see the signal coming on both channels, so the problem should be on the left channel recording circuit. Any suggestions? What should I check first in your opinion?
Apart from the dirt collected in 40+ years and the recording issue, the deck is working and looking fine. I would like to find a solution for that problem, so any help is appreciated!
Thanks a lot in advance,
Lorenzo
There was a VU-meter needle stuck at half height, but I solved that by loosening its back screw a little. Now the needle is back at -20dB.
There was a stray black (grounding) wire broken which caused a subtle hum, but I've found its place and soldered it back, hum is gone now.
Also, I put new belts on it as the tape counter was not working because of a belt too loose, and also the others didn't look good. Now the transport works like a charm.
BUT, after changing the belts I did some recording tests and discovered that the left channel is not recording, while the playback of pre recorded cassettes is even in both channels. With the monitor selector on Source I can see the signal coming on both channels, so the problem should be on the left channel recording circuit. Any suggestions? What should I check first in your opinion?
Apart from the dirt collected in 40+ years and the recording issue, the deck is working and looking fine. I would like to find a solution for that problem, so any help is appreciated!
Thanks a lot in advance,
Lorenzo
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I think I have solved a big part of the problem after cleaning the rec/play switch with isopropyl alcohol: now also the left channel is recorded on tape.
Anyway, looking at the VU meters during a test recording, the left channel seemed to be weaker than the right one, but the same cassette recorded on the CD 330 played on my Teac V-3010 shows even channels.
The left VU meter was the one with stuck needle, so I presume it has problems that go beyond that. Sounds strange, as during playback of pre recorded tapes or while monitoring the source it seems to give a correct lecture. I am a bit confused but indeed happy of the result, let's say it's a 80% success.
Anyway, looking at the VU meters during a test recording, the left channel seemed to be weaker than the right one, but the same cassette recorded on the CD 330 played on my Teac V-3010 shows even channels.
The left VU meter was the one with stuck needle, so I presume it has problems that go beyond that. Sounds strange, as during playback of pre recorded tapes or while monitoring the source it seems to give a correct lecture. I am a bit confused but indeed happy of the result, let's say it's a 80% success.
You need to apply a constant tone to check levels. If the VU meter movement is slightly sticky it may lag on transient peaks and give the appearance of showing a lower average level. You could try wiring the meters in parallel and checking both read the same (or not) on typical programme material.
