Fnord

Magnetophon 97 Preamp Build
« on: July 09, 2018, 02:32:42 PM »
I posted this in a different section earlier, but got no responses.  Hope crossposting is ok.

I have an old Telefunken Magnetophon 97 Tape machine.  The wheels dont turn, but the tubes have been testing fine.  I'm trying to salvage the mic pres out of it, make something rack mountable.  Any documentation i've been able to find has been in German
https://www.doctsf.com/documents/afficher_document.php?num_doc=55140&num_fic=1&PHPSESSID=55f3b852aa6b97f97642db94468775b5

Is this dumb? Should I just steal the tubes and build something from scratch?  Theres a pair each of EF86, ECC81, and EL95.  And one busted EM84 catseye tube.  It would be really rad to use that as a level meter, if i can find a working one.

I can recognize most of the stuff on the circuit diagram, except for what looks like a dotted circle with a T coming out of it.  Maybe a ground? You can see em around K or M.


TillM

Re: Magnetophon 97 Preamp Build
« Reply #1 on: July 10, 2018, 03:39:55 PM »
a tape Maschine is a tape Maschine.
I can't find a real preamp section in the schematic.
So I would say, you repair the Magnetophon or take the tubes out and build a preamp with the tubes.

The first sentence in the documentation is funny :D "...the Magnetophon fulfils all the wishes of the amateurs for a stereo tape maschine."

EDIT: changed the word demands to fulfill
« Last Edit: July 11, 2018, 02:31:15 AM by TillM »

ruffrecords

Re: Magnetophon 97 Preamp Build
« Reply #2 on: July 10, 2018, 05:28:48 PM »
a tape Maschine is a tape Maschine.
I can't find a real preamp section in the schematic.
So I would say, you repair the Magnetophon or take the tubes out and build a preamp with the tubes.

The first sentence in the documentation is funny :D "...the Magnetophon demands all the wishes of the amateurs for a stereo tape maschine."

I think they meant fulfils.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Magnetophon 97
« Reply #3 on: July 11, 2018, 01:59:08 AM »
Is this dumb?
no. 
Should I just steal the tubes and build something from scratch?  Theres a pair each of EF86, ECC81, and EL95.  And one busted EM84 catseye tube.  It would be really rad to use that as a level meter, if i can find a working one.
 
the basics of a stereo preamp are there, all except a suitable input transformer
(anything from 1:8 to 1:14 should be adequate if not ideal).

lets look at the positives:
chassis,
power supplies,
DIN connectors are perfectly adequate  with adapters,
output stage that can feed any converter,
and 600 ohm devices.
the EM84 would not only be useful (fast) but look good.

plenty of smart contributors on this forum can help.


Pief

Re: Magnetophon 97 Preamp Build
« Reply #4 on: August 26, 2018, 09:06:00 AM »
I have a few em84's flying around somewhere. Em84 is not called a catseye b.t.w. That name is used for the Dm71 only.
In case you get to the point of needing them just give a shout.

Personally, i would dissasemble it in subunits en drop them in a new housing. Leaving more room for alteration.  Can caps in magnetphon are very toxic ! Beware!

Although these units fetch pretty high prices if in good working order...the demand for them is small. Think before you gut it.
« Last Edit: August 26, 2018, 09:17:20 AM by Pief »

cyrano

Re: Magnetophon 97 Preamp Build
« Reply #5 on: August 26, 2018, 11:24:07 AM »
I would restore the tape machine.

These old Telfunken recorders are quite capable and sound nice. A bit like the Revox G36.

And it's not as if these tubes have any serious value. You can still buy those for a couple of bucks. At least, around here, NOS still seems to surface in numbers.
Why is it people love to believe and hate to know?


 

Related Topics

  Subject / Started by Replies Last post
158 Replies
50773 Views
Last post February 12, 2009, 10:32:26 PM
by bahrens
100 Replies
59857 Views
Last post April 29, 2008, 09:13:45 AM
by Moby
64 Replies
22649 Views
Last post January 09, 2017, 10:32:15 AM
by kosi
3 Replies
302 Views
Last post July 09, 2018, 02:57:42 PM
by Michael Tibes