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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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12th Feb 2008, 10:01 pm | #1 |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Muffled sound gets better- Tape or tape recorder?
Hi All
I've got a Philips EL3542 reel to reel and have been buying original pre-recorded tapes for it, some play at 3 3/4 some at 7 1/2 ips (stereo) from the US. The 7 1/2 sound amazing (played thru my hi-fi amp). However the 3 3/4 are very hit and miss. UK tapes (Beatles) are of varying quality but consistent all the way through (thoug a bit wowy). But I've got a couple from the US (Led Zep) where the quality suddenly gets really good after sounding muffled for a while and some wow and flutter. Is it the tape or the machine? Can't see anything wrong with tape. I'm wondering if it's the 3 3/4 wheel - muffled at start of tape then gets better. Is there more strain at the start of the tape? Also this machine has a switch so you can hear the other track of the stereo. The normal track is good but the other is always more muffled. Any ideas? Should sound same as it uses the same circuit. Or is it bit like with cassettes where sometimes they were muffled but after a rewind sounded OK again? Cheers John |
12th Feb 2008, 10:46 pm | #2 |
Retired Dormant Member
Join Date: Aug 2004
Location: Blackpool, Lancashire, UK.
Posts: 1,488
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Re: Muffled sound gets better- Tape or tape recorder?
It's an old machine so check the state of the heads to start with for wear & cleanliness, also check the pressure pad.
The US pre rec. tapes were excellent & were 4 track, most of the UK were from memory half track, although not all. Start with that before you go further, if you can degauss the heads etc. that would eliminate any possible damage to your pre re. tapes. Colin |
12th Feb 2008, 11:36 pm | #3 | |||
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Muffled sound gets better- Tape or tape recorder?
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Ben. Last edited by Mike Phelan; 13th Feb 2008 at 8:56 am. Reason: Fixed quote tag |
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16th Feb 2008, 8:25 pm | #4 | |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
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I might have a problem recording - it didn't seem to work when I used the mic (but it does work in PA mode) |
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16th Feb 2008, 8:29 pm | #5 | |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
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18th Feb 2008, 1:01 am | #6 | ||
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Muffled sound gets better- Tape or tape recorder?
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if this is the small machine i'm thinking of (a pic might be useful if you can do it) then the take up i seem to recall did not start too well - think it was just the design. |
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18th Feb 2008, 11:49 am | #7 | |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
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This is the machine as you requested, Philips EL3542: http://i138.photobucket.com/albums/q...erc/el3542.jpg And even better the circuits and mechanical drawings: http://images.google.co.uk/imgres?im...%3D1%26hl%3Den |
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19th Feb 2008, 3:17 pm | #8 |
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Muffled sound gets better- Tape or tape recorder?
thats a much older one than i'd imagined. nice unit, good features and well worth restoring. let us know how the checks go.
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19th Feb 2008, 4:05 pm | #9 |
Heptode
Join Date: Feb 2008
Location: Leven, Fife, Scotland
Posts: 823
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Re: Muffled sound gets better- Tape or tape recorder?
Hi John, I think the problem may be a worn pinch roller which causes the tape to run off line causing the tape to ride up and down. Try giving it a good clean with some proprietry head cleaning fluid. Norman
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22nd Feb 2008, 11:39 pm | #10 | |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
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So is there something wrong with the feed reel? - if I over-feed the tape the feed reel doesn't move. Should it be turning the other way? I can't believe how good it sounds when I do this! Cheers for the pointer. But what's the problem with the mechanics then? |
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22nd Feb 2008, 11:43 pm | #11 | |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
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23rd Feb 2008, 12:03 am | #12 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,846
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Re: Muffled sound gets better- Tape or tape recorder?
By slowing the supply reel, you are increasing the "bsck tension" and thus forcing the tape make better contact with playback head.
I'll leave it to the experts to tell you what's wrong. Could be pressure pads, head wear or something else |
23rd Feb 2008, 1:27 am | #13 |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
I hope it's not head wear that'd mean finding another head! The pressure pad doesn't look good - is there something that I could replace it with?
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23rd Feb 2008, 7:17 am | #14 |
Retired Dormant Member
Join Date: Sep 2007
Location: Hobart Australia
Posts: 241
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Re: Muffled sound gets better- Tape or tape recorder?
If you can't find one try making one out of a bit of foam and glueing it in place? I've got one that came off and I'm contemplating glueing it back on. What sort of glue should one use - spot of superglue...mmmm..?
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23rd Feb 2008, 10:56 am | #15 |
Triode
Join Date: Feb 2008
Location: Didcot
Posts: 17
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Re: Muffled sound gets better- Tape or tape recorder?
Providing the pad is felt a thin coating of a contact adhesive applied to both the felt and the mounting will hold it - make sure that you are happy with the location of the pad first as you will have difficulty relocating it if you get it wrong.
Pads seem to have been mainly felt, the variety without long hairy strands seems to stay put on mountings. Getting the correct or close to thickness is something else to take into account. I have not had a chance to look at the mechanical view to see what mechanism is in place to give "back tension" on your deck but will do shortly. Depending on how good you manual is we should have some clues. On a more unpleasant note I do recall that the "rubber" used for certain parts in Philips tape recorders had a habit of degrading to a sticky black mess, in fact some belts were starting to do this in the plastic packets many, many years ago ! |
23rd Feb 2008, 4:10 pm | #16 | |
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Muffled sound gets better- Tape or tape recorder?
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i would firstly check the pressure pads,then as oxide says, check the manual to see what if any backtension arrangement was used. good luck. |
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24th Feb 2008, 11:12 pm | #17 |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
OK I've tried a few things
1) I had cleaned the heads but that was a few weeks ago so thought they should be OK - but as people had suggested this as the problem I double checked. And lo and behold they were covered in tape dust. I cleaned them up which improved the sound and solved the one-sided stereo muffled sound. Now both sides are the same. But it didn't bring the treble to full quality. 2) So the sound is still improved by braking the feed reel. I tried putting pressure on the pressure pad but this didn't seem to make any difference so I guess it's not that. 3) Is it normal to have the feed spindle to rotate the opposite way to the tape direction when you press play without a tape in? When I do it on this machine it doesn't move. Only the takeup spindle rotates. Also if I press FForward only the take-up spindle rotates. However if I do FRewind BOTH spindles rotate (in opposite directions). Shouldn't they do the same? |
25th Feb 2008, 12:16 am | #18 |
Octode
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,969
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Re: Muffled sound gets better- Tape or tape recorder?
Whether the supply reel tries to run backwards in play depends on the make and model, but if yours has a pressure pad for the head, it's the pressure pad's job to make sure the tape contacts the head correctly.
If it doesnt (as shown by weak treble) then as Doffery said in the first reply either the pressure pad or the head (or both) should be suspected. You seem to be assuming that because manually braking the supply reel temporarily "fixes" the problem that the supply reel tension is the cause of the poor treble. I suggest though, it is only pointing to a problem with the head and/or pressure pad. Re-read Doffery's post. In my experience he's usually right! Tim |
25th Feb 2008, 6:00 pm | #19 |
Pentode
Join Date: Aug 2007
Location: London, UK.
Posts: 115
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Re: Muffled sound gets better- Tape or tape recorder?
Is a worn head visibly so? It looks quite nice and shiny smooth, though it's hard to get close 'cos of other gubbins in the way. If the head is worn I assume that means the only way to fix it is with a 'new' one?
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25th Feb 2008, 8:52 pm | #20 |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
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Re: Muffled sound gets better- Tape or tape recorder?
First visible indication of a worn head is often a polished band over the gap. Some heads are ground that way to start with, so a certain amount of experience helps, but if you can see a vertical 'stripe' more than, say, 3mm wide, the chances are that the head is significantly worn.
Heads can be reground, but it's only financially viable for expensive professional jobs. Replacement heads to suit most decks used to be available. One such supplier was Monolith, but a quick Google returns no results, so they've probably gone, but I'm sure there must still be similar firms. Philips heads shouldn't be too hard to find ex scrap machines though. |