UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Audio (record players, hi-fi etc) (https://www.vintage-radio.net/forum/forumdisplay.php?f=14)
-   -   Philips Hi-Z record player (https://www.vintage-radio.net/forum/showthread.php?t=52798)

roxarama 10th Apr 2010 3:05 pm

Philips Hi-Z record player
 
I restore windup gramophones and so quantities of old 78rpms come my way. To check out these 78s less labouriously I bought an electric autochanger player in as found condition at a general auction in Exeter a couple of years ago. It's a tabletop model in dark wood veneer, a Philips Hi-Z mk 40102.

To my great surprise it worked! Lovely tone and plenty of volume. Rather clunky to operate but it let me listen to eight 78s at a time while getting on with other things - instead of winding and changing needles all the time. However I've not found any info or images on the internet.

Sadly it has just fallen silent. Everything seems to work as normal but no sound - or just the faintest sound with thw volume on max. I'd love to get it back in action but electronics aren't my field, and given the complete absence of info I wonder whether it's economically viable.

I want a working machine not a project or museum piece. So any and all info on this record player or clues regarding the problem will be greatly appreciated.

Michael Maurice 10th Apr 2010 5:22 pm

Re: Philips Hi-Z record player
 
Can you post some pictures of the record player?

Also do you know if the amplifier is transistorised or valved?

If you are confident about removing a cover or two, some pictures of the electronics might help.

Audio1950 10th Apr 2010 9:49 pm

Re: Philips Hi-Z record player
 
I think this machine uses he famous "tilting" cartridge, i.e. with a red and a green dot at the back of the cartridge, and which pivots slightly to select the stylus. If it does, then it's a good bet the cartridge is now defunct, as they all are by now. They are available, but at enormous expense, something over £40.00. It is, possible though to empty the cartridge shell of all the existing contents, and then fit a small, modern replacement.

Barry

roxarama 12th Apr 2010 1:58 pm

Re: Philips Hi-Z record player
 
Thanks. I will post some photos. It is valved. May have had screw-in legs. It is the tilting cartridge but there are 2 other non-tilting heads clipped in the lid but haven't got them to work so far.

roxarama 12th Apr 2010 2:23 pm

Re: Philips Hi-Z record player
 
5 Attachment(s)
I have posted photos of the Hi-Z. There is a valve diagram inside. Would a new cartridge play 78s and vinyl?

roxarama 12th Apr 2010 3:02 pm

Re: Philips Hi-Z record player
 
Barry - I've the working cartridge from a Philips Discjockey Major but still no sound. Would a tilting cartridge fail all at once without deteriorating first? I don't know the answer to that. The valve diagram inside shows 4 of them - ECC83, EL84, UL84 and EZ80. A 5th is an 8073D-00 which may be the power light, which works fine.

Audio1950 12th Apr 2010 6:47 pm

Re: Philips Hi-Z record player
 
Those tilting cartridges can be fine one moment, and dud the next! As to the two non-tilting cartridges in the lid, they are even less likely to be any good, as they were the forerunners of the "tilting" ones, and will probably be the original ones supplied with the player.

Barry

roxarama 12th Apr 2010 8:44 pm

Re: Philips Hi-Z record player
 
Thanks, Barry. Have you any info on date, etc? Where can I find a new original tilting cartridge? I'll start saving up! I was very happy wtih the player and would like to get it working once more. I'm still puzzled the lack of info online.

Michael Maurice 12th Apr 2010 10:11 pm

Re: Philips Hi-Z record player
 
Quote:

Originally Posted by roxarama (Post 321179)
The valve diagram inside shows 4 of them - ECC83, EL84, UL84 and EZ80. A 5th is an 8073D-00 which may be the power light, which works fine.

That UL84 appears to be wrong, should be another EL84 unless the valve diagram actually shows UL84 which I doubt that it does.

Let me explain, the first letter denotes the valve heater,

E = 6.3V the current will vary depending on the valve. the heaters on these valves are wired in parallel

U = 100mA the current through the valve is 100mA but the voltage will differ according to the valve. The heaters on these valves are wired in series.

P = 300mA ditto the above.

Sideband 12th Apr 2010 10:25 pm

Re: Philips Hi-Z record player
 
No I think the UL84 is right. It's heater is run from a separate winding on the mains transformer. It's called 'Hi Z' because it uses an 800 ohm speaker. The EL84 and UL84 are run in a transformerless circuit (the UL84 drives the speaker). The cathode of the UL84 is connected directly to the anode of the EL84 so therefore the cathode of the UL84 is running at a high voltage...probably about 150V. Therefore the heater/cathode insulation needs to be good hence the use of the UL84. Effectively they are 'in series' across the HT rail. I think it's called 'cascode'.

It's a bit like the 'Bi-Ampli' designs of the continental sets. Only ever seen one and it worked very well.

I'm sure the circuit is in the Newnes servicing books but I've no idea what year...guess between 57 and 59.
Rich.

yestertech 12th Apr 2010 11:57 pm

Re: Philips Hi-Z record player
 
Squinting at the magnified serial plate reveals AG2126x - Data for an AG2126 exists in Pauls Service data ( top right) adn seems to match
As Rich correctly states a typically Philips unusual idea of cascode transformerless output stage using EL and UL 84 and twin 800 ohm speakers, hence the 'Hi-Z' moniker.
Very repairable I would have thought, unless of course the main speaker is U/S. ( but then in theory you'd still hear some treble ? )
Perhaps this is what Roxarama alludes to in his opening post ?

Is there any response touching the pickup head contacts ?

PS appears to date from 1957/8
Andy

Michael Maurice 13th Apr 2010 8:11 am

Re: Philips Hi-Z record player
 
Thank you Rich & Andy for explaining this to me, I must admit that it is unusual to see a UL and EL mix of valves but then Philips were, - in fact actually still are - known for their unusual designs.

One concern is if the output coupling capacitor C15 goes leaky or short circuit, then DC would be present on the speaker coil causing it to burn out.

Measure the resistance of the speaker which should be approx 800ohms, also check the inductor marked on the diagram as S6 to make sure it hasn't gone O/C.

May I suggest that you recap this set changing C4, C6, C12 and C15 at the very least.

Sideband 13th Apr 2010 12:36 pm

Re: Philips Hi-Z record player
 
I was working from memory and I couldn't remember now if the speaker is fed from the cathode/anode connection of the EL/UL via a capacitor or if it was in the anode of the UL. Seems from Michael that it's fed from the cathode/anode via a cap so it more closely resembles the Bi-ampli circuits. When I heard one of these in the 60's, it really worked well despite it's unusual configuration.

As Andy says, highly restorable and it should work very well. What do you do if the speaker is O/C though?

Rich.

Michael Maurice 13th Apr 2010 5:22 pm

Re: Philips Hi-Z record player
 
Rich, it is fed from the Anode/Cathode via a cap.

If the speaker goes O/C you have two choices,

Find someone who'll rewind the coil probably at great expense or use a small output transformer, this wont be ideal but better than nothing.

Audio1950 13th Apr 2010 8:26 pm

Re: Philips Hi-Z record player
 
Have just looked closely at your pictures, and have noticed that the cartridge on the deck at the moment is not the "Tilting " one. Or is this the cartridge you have borrowed from another machine? It's actually a stereo cartridge, and if it has gone, it's much easier to fit a replacement cartridge to this headshell. I have to say, though that it would be a heck of a coincidence if both cartridges had gone at the same time. If the Disc Jockey machine is in working order, have you tried both cartridges on that to test them?

Barry

roxarama 13th Apr 2010 11:30 pm

Re: Philips Hi-Z record player
 
Blimey - so much info. Thanks so much everyone. The headshell tilts between N and M and was on it when I bought it. Lots of helpful ideas although the electronic stuff is way over my head. I'll test the cartridge by putting it on the DJ Major and will try touching the PU input. Feeling much more confident that it'll be back in action soon. Still learning how to use this site but very glad I signed up. The date 57/58 seems to fit. Thanks again.

roxarama 13th Apr 2010 11:52 pm

Re: Philips Hi-Z record player
 
My silly mistake - the cartridge rotates between N and M and doesn't tilt. Sorry for wasting your time on that red herring. It works OK on the DJ Major and the PU contacts do buzz when touched. In fact it is now a tiny bit louder now than before but distorted. All very odd - to a wind-up dunce like me at least. My fixes rarely need more than oil and grease! Seems we can rule out £40+ cartridges. Phew! UPDATE - the little volume there is goes down when I turn up the bass (middle knob). I bet that's a clue, although not to me.

Michael Maurice 14th Apr 2010 12:03 am

Re: Philips Hi-Z record player
 
Which leaves the electronics and the loudspeaker.

If you dont mind me asking, do you have any knowledge/experience of electronics?

Do you have a testmeter? Can you solder etc?

If the answer to the above is no, then hopefuly someone local to you will be able to help you on a practical level.

Of course if the answer is yes, then you can rely on us to give you every assistance possible.

Michael

KeithEllis 14th Apr 2010 1:13 am

Re: Philips Hi-Z record player
 
2 Attachment(s)
I wondered if I'd ever see one of these in the flesh, so to speak.

It does in fact date from 1957/58 and according to my Currys brochure (see attached) is called a 'Magic Box'... hopefully my dubious photographic skills haven't rendered the description unreadable!

As can be seen it's included in the Hi-fidelity section of the brochure (I have the other two machines pictured but not the magic box), and if it sounds anything like these then it must sound good. I wouldn't imagine at 49GNS many were sold, so it's probably extremely rare.

I'd have to agree with Barry that it's highly unlikely all the cartridges are duds. I have two, one I obtained from a Disc Jockey Major and a NOS one I paid twenty pounds for. The one from the Disc Jockey sounds good but the other takes the sound to another level. Before I bought it I did experiment by gutting another Philips headshell , but none of the cartridges I tried – including a Sonotone, Acos and BSR – sounded anything like the NOS one, which surprised me.
I think the best thing you can do is replace the caps Michael mentions, and just hope it's not the speaker.
Good luck.
Keith

Michael Maurice 14th Apr 2010 9:06 am

Re: Philips Hi-Z record player
 
Quote:

Originally Posted by KeithEllis (Post 321651)
I wouldn't imagine at 49GNS many were sold, so it's probably extremely rare.

For those members who dont know what a Guinea was (GNS), a Guinea was 21 shillings or £1.05 in decimal coinage.

The average wage was approx £5 per week in those days so this would have cost around 10 - 11 weeks wages. Put it another way, its approx £4000 in todays money so a small fortune in those days.


All times are GMT +1. The time now is 6:32 pm.

Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.