EMI TG Summing Amp?!!

[sine_wave]

I just drudged up an old thread from '07 in which the OP shows his schematics for a TG Summing amp. Here's the topic link:
http://www.groupdiy.com/index.php?topic=23252.0

The thread isn't very long (strange)  ??? and it seems like at least one person got the circuit running. So what the deal with this thing!! I'd never dream of seeing a project like this and I'm shocked there wasn't any chatter about it here on this forum. Has anyone else built one? Post pics? Is anyone interested in building one? I know I am but I'd like to get some opinions on what it sounds like. If any members here have info regarding this project please share!!  ;D

 

[Niketouille]

The schematic posted are incomplete. The mixing part of the TG is based around voltage to current converter in each channel and a current to voltage converter for the master. It's unbalanced and transformerless (concering the mixing part).

The line amp schematic posted is the generic output amp in the mixing desk (insert, echo, group,...). Concerning the summing amp I wil check but as far as I remember the main bus summer is a bit different...

 

[haima]

hmm. thanks for the info Niketouille! please let us know if you have anything else to share  8)

BTW - welcome to the forum!

 

[SIXTYNINER]

8)

 

[Niketouille]

What do you want to know haima ?
A lots of information concerning EMI desk can be found on the Handbook available at vintageking :
http://www.vintageking.com/site/Pdf_specifications/EMI_Recording-Console-Handbook%20Mk2.doc
It only concerns the mk2 version which is totally germanium. Last version (mk4 aka mkq) includes both silicon and germanium.
The handbook do not have any schematic (!!!)

I checked the master summing amp and the schematic previously posted is definitly wrong. I mean in the mkq it is much more simplier, only 2 transistors in the summing amp, and one in the channel buffer. Power supply is +20/-20V (each channel have a dedicaded power transformer with regulator...a kind of no compromise design ?)

 

[haima]

that's a cool link, haven't seen that one before. lots of info.. but pity no schematics!  ;D

the line amp schematic that "sonic screwdriver" originally posted is very similar to the output stage of the TG1, as seen here:

http://twin-x.com/groupdiy/thumbnails.php?album=325

i think it's probably a generic output stage for EMI from that period...?

like everyone, i'd love to see the mic cassette & eq schematics etc  ;D they must be out there, but they haven't surfaced yet....

Niketouille - do you own some TG gear? or schematics?

 

[Niketouille]

I'm used to service emi desk, limiter, tone bender and filter...
I own some schematic of the desk like preamp and the line amp, summing part, band pass filter, solo section, panpot... I do not have any schematic concerning EQ, tone bender or filter.
I just know that everything is inductor based.
I plan to clone a tone bender but it's a huge work, 4 euro size pcb, tons of wiring, no value on inductor, tons of components....huge work. Not really motivating. Furthermore the studio own 6 of them so....

 

[haima]

I own some schematic of the desk like preamp and the line amp, summing part, band pass filter, solo section, panpot... I do not have any schematic concerning EQ, tone bender or filter.

very interesting, great to have you around. DIY tonebender sounds like a decent amount of work 

feel free to post photos or schematics!  

 

[waltzingbear]

the vintage king link is gone, but you can still download the manual at the wayback machine which archived it.  this link is not going away anytime soon.

https://web.archive.org/web/20100213055959/http://www.vintageking.com/site/Pdf_specifications/EMI_Recording-Console-Handbook%20Mk2.doc

cheers
Alan

 

[rafafredd]

That's wonderful to have all this info, but without the schematic drawings to go with it, are basically worthless.

Is there anywhere I can find associated drawings?