Philips EL3542 tape recorder problem
 

I have a Philips EL3542 four track tape recorder dating from 1961 which after a few years of trouble free service has now developed an annoying noise through the speaker. This gets worse as the volume control is advanced. It is present in the stop position and in the playing position with or without tape.

Tape playback is still possible but the additional noise makes listening to a tape difficult. The best description I can think of at the moment is a cross between rustling a brown paper bag and the noise a coffee machine makes when heating milk with a steam pipe in Costa Coffee !!! (Other coffee shops are available !!)

I have cleaned the valve pins and all switches. Visually I can’t see anything bulging or getting hot. I have found a circuit diagram and intend to check voltages quoted over the next few days with Avo 7 or Avo 8. Valve line up EF86, ECC83, EF86, EZ80, EM81.

I was wondering if anyone has had experience of these tape recorders or could suggest a possible starting point or solution.

Many thanks in anticipation.
Nick

Re: Philips EL3542 tape recorder problem
 

Those German made "Wima" brown lozenge shaped capacitors are as notorious as wax and "Hunts" Moldseal capacitors are in the UK! I'd certainly start by replacing them.

Re: Philips EL3542 tape recorder problem
 

Thanks Dazzlevision. I can only see one of those so far. Will order a replacement.

Mods I think I have posted this in wrong section, could you move it please if that is so? Thanks

Nick

Re: Philips EL3542 tape recorder problem
 

According to the UK Philips full service manual, available on HiFi Engine website (if you join - no charge), that Wima is C2, the EF86 g2 decoupler.

https://www.hifiengine.com/manual_li...s/el3542.shtml

Your valve line up is incorrect, it should be EF86, ECC83, ECL82, EZ80 and EM81.

It's very unlikely that any of those "Mullard mustard" capacitors are faulty (actually the Philips/Mullard C296 series of axial Polyester dielectric types).

There are a couple of small axial leaded capacitors on the large tag trips, which have a transparent outer coating - not sure of the make. If they have a paper dielectric, they are suspect, especially if one end is connected to an HT source.

Other than that, I'd suspect those darker bodied small resistors (that are probably carbon composition types) of being electrically "noisy", especially if they are anode load resistors.

Re: Philips EL3542 tape recorder problem
 

It was was hifiengine where I got the circuit diagram from, thanks. Must check the valve line up again too. Excellent info on which components to check, thanks again dazzlevision, much appreciated.

Re: Philips EL3542 tape recorder problem
 

I bought one of those new - brilliant machine,not that it helps you. That sort of noise on radios I have had due to a break down in insulation of multi contact switches, the paxolin type anyway, by leakage of HT voltage into the signal circuit.

If you have an external amplifier of some sort you could try tapping the signal off at various points to locate the section that its originating in, or you could use a scope if you have one.

Peter

Re: Philips EL3542 tape recorder problem
 

You're lucky, my Cossor CR1601 clone of this machine had all Wimas. Leaky as Hunt's finest I had to change the lot! :-(

Re: Philips EL3542 tape recorder problem
 

The fact that the noise seems to be proportional to the volume control setting indicates that it at least is one of the stages prior to the volume control.

Re: Philips EL3542 tape recorder problem
 

If it's a constant light crackle(like frying bacon) then could be DC getting onto a pot due to a leaky cap.

Re: Philips EL3542 tape recorder problem
 

Thanks again for very valuable advice. I did read the same valve twice Dazzlevision, so the line up is correct as per service sheet.

I always thought these were a great machines and I saw my very first one at the age of 10 in school back in 1959. That was a Stellaphone 2 track mono. At one time I had collected seven of these machines badged with Philips, Stellaphone and Cossor and various configurations two and four track.

I will work my way through all the suggestions changing caps etc one at a time and retesting as I go. Will post any progress, or lack of !!!

Nick

Re: Philips EL3542 tape recorder problem
 

As stated, those Mullard 'mustard' caps will not be faulty. However that 'toffee' Wima is a 'change on sight' type....they were giving trouble in the 1960's......!

It is very unlikely you will need to change any of the 'mustards' so don't bother ordering loads of caps.

Re: Philips EL3542 tape recorder problem
 

Thanks Sideband, I will follow the advice over which caps to replace and report any progress.

Nick

Re: Philips EL3542 tape recorder problem
 

Only the EF86 is prior to the volume control so this is the obvious starting point.

Re: Philips EL3542 tape recorder problem
 

The discussion so far has covered the usual bases. There is one thing
that I remember about the EL 3542 A from the past.

The automatic stop circuit derives voltage to work the metallic
leader relay from the cathode of output tube.

This voltage charges a capacitor which discharges into a relay,
which in turn applies a high voltage to the release magnet.

Check that assembly thoroughly . If worn, dirty, or arcing,
it may throw noise.

Re: Philips EL3542 tape recorder problem
 

Another thing to check: Has the machine been used in ‘Record’ recently? From my previous experience of servicing a Philips machine of similar age one problem that caused noise/distortion was dirty switch contacts in the Rec/Play changeover switch. Try a bit of contact cleaner and working the switch back and forth a few times - with the power off.

Bill

Re: Philips EL3542 tape recorder problem
 

Thanks. Have had a look at this area and as far as I can see it all seems ok.

Many thanks Bill. It has not been used for recording for about a year but all switch contacts have been cleaned. The noise still persists and I am waiting for replacement capacitors to arrive. I will update any progress, or lack of, as and when.

Nick

Re: Philips EL3542 tape recorder problem
 

I'd agree, considering the noise level seems to be affected by the volume control, the anode resistor for the EF86 in the input stage would be a prime suspect.

Re: Philips EL3542 tape recorder problem
 

If you have an oscilloscope, play a tape and check the audio waveform through the stages of the amp, starting with the EF86 section. You'll soon find the fault. :)
The axial Wima cap needs to go - even if it's seemingly behaving itself - they are trouble!

Also, it may be worth removing re-seating all the valves a few times, in case the pin to base contact has oxidised over time. Free to do and sometimes successful :)

These are very nice machines and worth restoring if it's in generally good nick - (although I 've seen many poor examples I've had to scrap.)
I have some heads here somewhere and perhaps a pinch roller - if you need it.

Re: Philips EL3542 tape recorder problem
 

I have one of these, they are a good machine. I have posted a copy of my user manual on the Radio Museum page. https://www.radiomuseum.org/r/philips_el3542.html
Scroll down to near the bottom of the page.

Mike

Re: Philips EL3542 tape recorder problem
 

Thanks again for all the suggestions and help/advice - Crackle, Whiskas and Ricard. I have an original copy of the user manual too, thanks Crackle. As soon as the ordered components arrive and I get chance to work on the machine I will post any updates.

Nick