Telefunken M15 schematics and info needed

[Mark mth001]

Just wanted to drop by and say the M15A is the most brill machine I used for editing back in the day. Good luck getting it going.

 

[Fok]

Just wanted to drop by and say the M15A is the most brill machine I used for editing back in the day. Good luck getting it going.

Can anyone provide their opinion on the sound of Telefunken M15 vs M15A?

 

[GermanTech]

Hi,

I can't seem to find schematics for this massive workshorse 1/4" two track unit. I found a brochure from AEG-Telefunken with some basic info.

The problem is this. It seems to be impossible to drive the tape into any kind of audible saturation (configured to 15 ips now). It's very transparent - originally a broadcast recorder - and no matter what I do, the internal gain staging doesn't seem to provide enough input level to tape. I could drive it externally with some line amps, but then I would be just saturating the input transformers, when it's tape saturation I want.

Maybe schemas will tell me what can be done.

Disclaimer,
the only point for using a clunky machine like this at this day and age is to use it as a saturation effect, and I'd like it to be a bit more pronounced.

Hi,

I can't seem to find schematics for this massive workshorse 1/4" two track unit. I found a brochure from AEG-Telefunken with some basic info.

The problem is this. It seems to be impossible to drive the tape into any kind of audible saturation (configured to 15 ips now). It's very transparent - originally a broadcast recorder - and no matter what I do, the internal gain staging doesn't seem to provide enough input level to tape. I could drive it externally with some line amps, but then I would be just saturating the input transformers, when it's tape saturation I want.

Maybe schemas will tell me what can be done.

Disclaimer,
the only point for using a clunky machine like this at this day and age is to use it as a saturation effect, and I'd like it to be a bit more pronounced.

http://www.kronborgelektronik.dk/wp...Telefunken-Magnetophon-15-A-Owners-Manual.pdf

 

[cocobot79]

Hi, sent you private message. MVmisho and smilan got their manuals, so will anyone else asking for it as long as this forum is alive and I get notification emails, not following the forum actively anymore. In case I'm not replying here in future try other forums like diyaudio com.

If you still have the English M15a manual I'd really appreciate a copy too. Can't find your email to send you a personal message so I hope you see this. Many thanks

 

[Renzo]

service manual, diagrams, editable and translatable version 500 pages here:
https://archive.org/details/manual_M15A_SM_TELEFUNKEN_DE_VOL1/mode/2up

 

[abbey road d enfer]

service manual, diagrams, editable and translatable version 500 pages here:
https://archive.org/details/manual_M15A_SM_TELEFUNKEN_DE_VOL1/mode/2up

It's the well-known document that's been availble for years. It lacks detailed schematics of the record/playback cards.

 

[Renzo]

It's the well-known document that's been availble for years. It lacks detailed schematics of the record/playback cards.

Unfortunately yes, the schematics for those cards were never found

 

[spiro.sekulovski]

Unfortunately yes, the schematics for those cards were never found

Actually, there is another German manual that has most schematics. I believe it's an older version from April 1979 with 404 pages. I found it on the German reel-to-reel forum tonbandforum.de downloads page. https://download.tonbandforum.de

If I'm not mistaken, all original versions of the Telefunken M15A handbooks are split into 5 parts:

• Teil 1 Beschreibung (Part 1 Description)
• Teil 2 Bedienungsanleitung (Part 2 Operating Instructions)
• Teil 3 Prüfung und Instandsetzung (Part 3 Testing and repair)
  • Laufwerk (Drive)
  • Zusatzausstattung (Additional equipment)
  • Zusatzgeräte (Additional devices)
• Teil 4 Prüfung und Instandsetzung: Köpfe und Verstärker (Part 4 Inspection and repair: Heads and amplifiers)
• Teil 5 Teileliste (Part 5 Parts list)

Unfortunately, most manuals online only have the first two parts.

I have uploaded the manual here:
Elektrotanya for electronics experts

You can find the BC-WV1 (Playback card) and BC-AV1 (Record card) schematics in Teil 4 (Part 4) of the Handbook.

I also have some other documents and brochures that I'm looking to upload somewhere public so that people can find this information more easily. I'll post a link in this thread when I do that eventually.

 

[spiro.sekulovski]

Hey @tmuikku I already reached out to you in a post on the diyaudio forum. If you still have the manuals and don't mind sharing them, can you please send them to me? Ultimately, if you don't mind, I would like to publish all documents and manuals somewhere where they will always remain publicly available for everyone, possibly on GitHub in a public repository.

I believe that one of the reasons why Studer machines are more popular than Telefukens is the better written and easily publically available documantation about them. Also, my current impression is that the Studer groups and forums have more people that want to help eachother out. I would like to change that and find a way to help other people with Telefunken machines.

 

[Renzo]

Thank you very much Spiro,
finally here are the card diagrams!
Mine has an audio output problem, residual of a 300Hz square wave which remains the same even when exchanging cards between channels.
In the photo the two signals on balanced outputs at 1mV cm.
There is also a slight ripple at 50Hz

 

[Rob Flinn]

If there's any specific diagrams you're missing I have a full service manual for the 2" 24 track M15A in English. I don't have time to copy everything, but might be able to fill in any gaps you might have.

 

[spiro.sekulovski]

Thank you very much Spiro,
finally here are the card diagrams!
Mine has an audio output problem, residual of a 300Hz square wave which remains the same even when exchanging cards between channels.
In the photo the two signals on balanced outputs at 1mV cm.
There is also a slight ripple at 50Hz

No problem @Renzo, glad I can help. I hope you figure out what's wrong with your playback card. Unfortunately, the manual doesn't contain the schematics for the newer BC-WV11 and BC-AV11 cards. However, as I've been told, the cards are similar, so the older schematics should help when diagnosing the newer cards.

Not fully related to the manuals:
My machine is a late model M15A with serial number Nr. 4892. The machine is supposed to have the newer cards (BC-WV11 and BC-AV11) unfortunately, for some reason it has mixed older and newer cards:
- Kanal 1 - Playback card - BC-WV11 - No label on the backplane connector
- Kanal 2 - Playback card - BC-WV1 - "Kanal 1" label on the backplane connector
- Kanal 1 - Record card - BC-AV11 - No label on the backplane connector
- Kanal 2 - Record card - BC-AV1 - "Kanal 2" label on the backplane connector
At the moment I'm looking to exchange cards with someone else who also has mismatched cards in their machine(s), so if there's anyone interested, please reach out. Ultimately, I'll have to purchase a "matched" set of cards one day from someone who is dismantling a stereo unit for parts.

If there's any specific diagrams you're missing I have a full service manual for the 2" 24 track M15A in English. I don't have time to copy everything, but might be able to fill in any gaps you might have.

Hello @Rob Flinn,
I completely understand. Scanning the entire Telefunken Handbook for the 2" 24 track M15A would be a tedious task that would take a lot of time. Believe me, if I lived somewhere near you, I'd already be asking you to borrow the manual to scan it myself. I am not sure if anyone else has the same handbook already scanned, but if I find it, I promise I'll post it somewhere in a public place.
If no other digital version of your manual exists, would you be willing to take it to a service to scan it for you?

Please forgive me if I sound harsh, that is not my intention. I'm not trying to offend or criticize anyone. The only thing that I'm trying to do is help myself and anyone else that has a Telefunken M15A by finding in the all the information that I can about these machines and making it publically available.

 

[Renzo]

Tanks Spiro, my M15A is n 1230
So I think it's fine BC AV 1 and BC WV 1

 

[spiro.sekulovski]

Hey @smilan , is there any chance you could forward me the documents that @tmuikku sent to you? I can't reach him on the diyaudio forum.

 

[tmuikku]

Hi spiro, sorry I haven't got your message on diyaudio!

Here is the manual that came with every machine: telefunken_m15a_english_manual_full.zip

Check out if it's helpfull. I got more, a much bigger manual as well and can send sections of it if you need something specific, that is not covered in the manual I've linked here.

 

[tmuikku]

Here is contents for big manual, if you want some section from it I'll send it for free. If you want the whole manual I must ask some compensation for it, sum of your choosing, as it was huge work to scan.
https://www.dropbox.com/s/8g0bf0v4vu43gur/telefunken_m15a_full_service_manual_content.pdf?dl=0
Here a section that contains both BC-BW1 and BC-BW11
https://www.dropbox.com/scl/fi/dssc...4-92.pdf?rlkey=36cuarxhuzqj9q9da8fp063bz&dl=0
This one contains BC-AV1 and BC-AV11
https://www.dropbox.com/scl/fi/l65g...-138.pdf?rlkey=sgwe1un2k3pwbfym7go8p95l0&dl=0
ps. this forum has gone south, so much advertizing it is hard to use, so I don't want to come here other than if I get message about the manual.

pps. I do not want to monetize on the manual either, nor be a stop for anyone to maintain their machines, I just don't want the big manual appear on some monetizing site that charges people for it. Hopefully people find this thread, and can ask for it, which indicates they really need it.

 

[spiro.sekulovski]

Hello @tmuikku,
I can't thank you enough for sending me the English manual. I'm very happy now that I finally have it. This will make it a lot easier for me to restore and calibrate my machine. Thank you very much!

If you want the whole manual I must ask some compensation for it, sum of your choosing, as it was huge work to scan.

I completely understand. Scanning old documents is a tedious and time consuming task. I would be more than happy to compensate you for it. However, us being from different countries and cultures make it hard for me to determine the price, you'll have to name your price. I wouldn't want to insult you or something like that. We can continue this conversation in a personal message or over email.

ps. this forum has gone south, so much advertizing it is hard to use, so I don't want to come here other than if I get message about the manual.

I understand. I tried to send a personal message to you on the diyaudio forum, but I'm not allowed to start a conversation with you because my account is under moderation. I have the diyaudio account for about 10 years now but my first post was just a few days ago where I asked for the Telefunken docs and pinged you in the message.

pps. I do not want to monetize on the manual either, nor be a stop for anyone to maintain their machines, I just don't want the big manual appear on some monetizing site that charges people for it. Hopefully people find this thread, and can ask for it, which indicates they really need it.

Good point. I didn't really think about that. However, I believe that distributing the manual in a couple of public places will steer people away from sites that try to monetize from something like this. So, I'm willing to pay you for your work and time to scan the large manual but, with your permission, I would like to distribute it for free to all other people that ask for it. I don't have any personal benefit from this. All I'm trying to do is help the community.

If you can, please start a conversation with me on diyaudio or send me an email at spiro(DOT)sekulovski(AT)gmail(DOT)com
Or if you prefer some other way of communicating, please let me know.

 

[Renzo]

Dear timuikku,
Thanks for sharing some of your hard work for the M15 English manual,
I have the German one but translating it is a problem.
I would really appreciate receiving it complete in English which is easier for me to read.
I understand well the danger that someone will take advantage of it to monetize your work,
think that two years ago, for the fiftieth anniversary of Pink Floyd's concert in Brescia Italy, I put my stereo recording of the entire concert online on a dedicated forum.
It was downloaded 1400 times but a week later a Japanese company "Sigma" put it on sale on two CDs,
then many other CDs and even LPs from other record companies followed.
You can see them on Google: Pink Floyd Brescia 19 June 1971.
So sharing for free is a risk you take!
Ciao
Thanks