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-   -   Osram Four New Music Magnet (https://www.vintage-radio.net/forum/showthread.php?t=54850)

PWH 2nd Jun 2010 3:54 pm

Osram Four New Music Magnet
 
Hi could someone please advise the voltages for the supply

LT 2V
SG?
HT+
GB-

I can't find the circuit on disks 1-3 (as supplied by Paul.)

Thanks

wireful3 2nd Jun 2010 4:50 pm

Re: Osram Four New Music Magnet
 
I can't remember the specific voltages quoted for this set but The HT is almost certainly 120v. The SG is about 90v but 60v might also be OK. The GB will depend on the valve used but will probably be round about -3v or -1.5 volts. The original grid bias batteries had taps at 1.5 volt steps and I think the intention was to use trial and error. It would be less than 9v as this was the usual max voltage of the batteries.

The 9v batteries might even be later than the Music magnet, because it was normally used with a variable Mu valve as a volume control (RF gain)

Boom 2nd Jun 2010 5:42 pm

Re: Osram Four New Music Magnet
 
On the (3 valve) set I am playing with it has two grid bias battery connectors and from what I can see two is normal, one for the output stage and one for the earlier stage(s)

The bias volts are giving on the valve museum site if you are not sure.

Dave

AC/HL 2nd Jun 2010 7:14 pm

Re: Osram Four New Music Magnet
 
5 Attachment(s)
MM4 installation Instructions part 1

AC/HL 2nd Jun 2010 7:21 pm

Re: Osram Four New Music Magnet
 
3 Attachment(s)
MM4 installation Instructions part 2

For some reason, they are uploading as thumbnails, not attachments. On my PC they can be read quite easily. If you PM your Email address, I'll send them direct.

Ed_Dinning 2nd Jun 2010 9:04 pm

Re: Osram Four New Music Magnet
 
Hi PWH, just a note of caution. Do not adjust the GB tappings with the LT supply ON as this can damage the valves.

Ed

PWH 3rd Jun 2010 9:20 am

Re: Osram Four New Music Magnet
 
Thank you all, I now have the information I need

For the reference of others HT is 120V, SG is 72-60V depending on volume (lower voltage = greater battery economy) GB is -9 to -3V as the LT battery dies away...

g3zilgwyn 30th Aug 2010 7:38 pm

Re: Osram Four New Music Magnet
 
Quote:

Originally Posted by AC/HL (Post 335188)
MM4 installation Instructions part 2

For some reason, they are uploading as thumbnails, not attachments. On my PC they can be read quite easily. If you PM your Email address, I'll send them direct.

Dear Bill
I've just come across your very helpful post. Having just written a short article for the BVWS Bulletin on the restoration of my Osram Four New Music Magnet, without the benefit of the pages you've scanned, I must recall my article and make some changes, even from what I can see in the thumbnails. Would it be possible for you to email me higher resolution scans?

In particular have you any comment on the "Super Power" P2 valve suggested as an alternative audio amplifier?

many thanks

Gwyn G3ZIL BVWS member

AC/HL 31st Aug 2010 7:24 pm

Re: Osram Four New Music Magnet
 
Hello Gwyn,
Send me your Email address by PM and I'll send by return.
Regards, Bill

PS as regards the super power valve it's just a more powerful triode as far as I know, hence the higher HT consumption. It was also popular to replace the last valve with a pentode at this time, necessitating replacing the four pin holder with a five.

g3zilgwyn 1st Sep 2010 5:54 pm

Re: Osram Four New Music Magnet
 
Bill
Many thanks. Will PM you my email address in a moment.

Thanks for the comment re the P2 super power valve. I had got confused, in that I remembered that a P2 was a bright emitter valve, but on delving deeper, this was a Cossor valve, and Marconi used P2 for their equivalent of the Mullard PM202.
The set was very confusing as I received it, for there was a KT2 in the output valve position, in a 5 pin socket, with the screen unconnected, and a 220OT in the detector position! But, all sorted now.

Would it be OK with you if I quoted from the material you've scanned in the article I've written for The Bulletin, I will of course credit you as the source.

regards
Gwyn

Daimlernut 3rd Dec 2015 10:35 pm

Re: Osram Four New Music Magnet
 
Bill AC/HL I'm restoring an Osram 4 New Music Magnet, is there any chance of getting hold of the scans of the original instruction manual in high resolution as I can't read the ones on the forum very well - Alan

AC/HL 4th Dec 2015 12:47 am

Re: Osram Four New Music Magnet
 
Hi Alan,
PM your email address & I'll send what I have, I can't claim high res. but it is better.

Andrew B 4th Dec 2015 1:20 am

Re: Osram Four New Music Magnet
 
Hi AC/HL Bill.

I am always interested in these older radios, could you PM me the manual etc please.

Andrew

AC/HL 4th Dec 2015 2:40 am

Re: Osram Four New Music Magnet
 
Of course Andrew, PM your email address.

Daimlernut 4th Dec 2015 4:35 pm

Re: Osram Four New Music Magnet
 
Many thanks bill for the higher resolution scans they are just what I need. - Alan

Nungesser 12th Dec 2015 1:48 pm

Re: Osram Four New Music Magnet
 
Hi Bill,

I have just joined and have an Osram New Music magnet 4 without any instructions.
Could you send me some better resolution scans?

kind Regards

Dave

AC/HL 12th Dec 2015 2:48 pm

Re: Osram Four New Music Magnet
 
Hi Dave,
As above, send me a PM with your email address.


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