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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 1st Nov 2010, 1:27 pm   #1
Roger13
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Default 'Frying Tonight' on record.

Hi.

Me again. I have just acquired a Pioneer RT707 which sounds every bit as good as it looks. However, it has a problem on record. On the right channel there is a background noise which sounds like someone frying eggs in the next room. Initial troubleshooting has revealed the following:

1. It appears on both speeds.
2. The volume of the noise does not vary with adjustment of the level control.
3. The noise gets recorded.
4. The 'wanted' signal is recorded with, as far as I can tell, no degradation.
5. The problem is 'record based' as the noise does not appear when playing tapes recorded on another machine.

I'm thinking 'leaky capacitor' but any suggestions will be gratefully received, as always.

Cheers,
Roger.
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Old 4th Nov 2010, 1:31 am   #2
TIMTAPE
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Default Re: 'Frying Tonight' on record.

Roger,
It could also be a noisy transistor, probably closer to the front end. ie: not in the actual record amplifier. Substitution might be the easiest way to fix. The parts cost is insignificant.

Cheers Tim
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Old 4th Nov 2010, 9:20 am   #3
Top Cap
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Default Re: 'Frying Tonight' on record.

Don't forget the Aerosol Freezer or hair drier trick, you may find the noisy component using these. Always worth a try before getting stuck in with the soldering iron.
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Old 4th Nov 2010, 12:41 pm   #4
Roger13
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Default Re: 'Frying Tonight' on record.

Thanks guys.
I'll have to source some freezer spray and I don't have a hair dryer (what IS hair?). I have the service manuals etc but I'll need a little help interpreting them, so I'll be treading carefully on this one - I want this right! I found a blown capacitor on a friend's PVR the other day by sight, but no such luck with my Pioneer. Sometimes life, as the Americans say, 'sucks'!
This is a machine I'd be happy to pay to have put right so if anyone knows of a good reliable technician in the Suffolk area please let me know. Thanks for the input.

Cheers,
Roger.
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Old 6th Nov 2010, 8:21 am   #5
Roger13
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Default Re: 'Frying Tonight' on record.

Hi.

I think it's worth clearing something up. My original post stated that this problem is on 'record'. However, that's not entirely accurate.

The noise is present as soon as the unit is powered up - switch to source monitor and there it is. It is not affected in any way by switching the 'REC enable' circuitry in or out. It does not vary in volume and is independent of level settings. The noise is recorded as witnessed by playback on another machine.

I am assuming that because it is limited to the right channel only, the faulty component will not be something common to both channels. A visual inspection has thrown up no clues and I am lacking the necessary expertise/test equipment to look much further. So any pointers would be gratefully received.....

Cheers,
Roger.
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Old 6th Nov 2010, 8:44 am   #6
dseymo1
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Default Re: 'Frying Tonight' on record.

Quote:
I don't have a hair dryer
A soldering iron carefully applied to a (non-plastic) component body works just as well.
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Old 20th Mar 2011, 6:05 pm   #7
Roger13
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Default Re: 'Frying Tonight' on record.

Hi all,

This problem is now sorted. It turned out to be a dodgy transistor(s) on the mic. board. Replaced all four and now singing like a bird. What a lovely machine this is - even better now that I have BOTH channels. Thanks for your help everyone.

Cheers,
Roger.
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