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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 6th Oct 2019, 9:31 pm   #61
TonyDuell
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Default Re: Philips N4450 Reel to Reel Tape Player

Do you get the same loss of signal level (and quality?) in both directions? If not then it points to a head (or head switch, the switch on the PCB that the heads connect to, that is operated by the pinch roller levers) problem. If the problem is the same in both directions then while it could be that both heads are giving problems it is more likely to be an electronic fault on the amplifier chassis.

You could also try swapping the track 1 and track 3 head connections (either on the back of the heads or on that PCB I mentioned) to see if the fault moves or stays on the same channel. If it moves, then the heads are suspect (as now the head handle the othe channel), if it stays the same then it's head trouble or similar.
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Old 9th Oct 2019, 7:47 pm   #62
Ray_Singh
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Default Re: Philips N4450 Reel to Reel Tape Player

Thanks Tony. I will follow your thought process verbatim tomorrow and report back. I have spent more money on a "new" reel to ensure that this is not to blame.

I really dont want it to be the heads, but have a spare machine.
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Old 9th Oct 2019, 8:22 pm   #63
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Default Re: Philips N4450 Reel to Reel Tape Player

Can you take a good close-up picture of the front of the heads? Don't forget the pressure felts in front of them. They used to wear frequently and it does also depend to some extent on the type of tape you use.
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Old 9th Oct 2019, 10:53 pm   #64
Michael Maurice
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Default Re: Philips N4450 Reel to Reel Tape Player

If it uses pressure pads, then back coated tapes could pose a problem.
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Old 10th Oct 2019, 7:00 am   #65
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Default Re: Philips N4450 Reel to Reel Tape Player

Track 1 or the left track in a quarter track machine notoriously loses the treble after significant head wear. Often it's just because dirt congregates in the "corner" of the wear ridge. Cleaning is difficult as the cotton bud often rides right over the dirt, missing it completely. The dirt needs to be very carefully removed without damaging the head. If this is the case, having removed the dirt, you'll just have to keep removing it periodically.

With serious audio work, the head would never have been be allowed to get to that state as both recording and playback become unreliable.

Also, as record heads wear, they tend to become overbiased, which robs the recordings of treble. I've lost count of the recorders I've rebiased to restore the highs in record.
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Old 12th Oct 2019, 7:11 pm   #66
Ray_Singh
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Default Re: Philips N4450 Reel to Reel Tape Player

I found time to clean the heads and take a picture:

https://www.vintage-radio.net/forum/...pictureid=4285

https://www.vintage-radio.net/forum/...pictureid=4284

https://www.vintage-radio.net/forum/...pictureid=4283
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Old Yesterday, 12:12 pm   #67
Sideband
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Default Re: Philips N4450 Reel to Reel Tape Player

They look pretty good and it's also been fitted with the better (harder) heads during its lifetime. If you play a known good tape and VERY GENTLY apply pressure to the pressure pads, see if the treble or play level improves. If it does then it's probably pressure pad wear but it could be an alignment problem if the particular head(s) is(are) not completely perpendicular (90 degrees).

In the good old days we had precision jigs for checking these things........
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