TG Diagrams

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
chrisregent said:
You are welcome Jakob!
I wish I could just scan the service manual as a pdf and go "here's the service manual for the TG12345 Mk2" sadly its not possible.

The other thing that is very important to me is serviceability and transparency of manufacturers.

I am doing something similar for the AMS DMX and RMX units, There is a lot of mystery surrounding them that there doesn't need to be. As I now service and repair many of them including making new PCB's I do think the more people that have the data they need the more these things can be made to last without high costs.

Thanks for this. I would be curious to peak at your AMS and RMX stuff. 
 
pucho812 said:
Thanks for this. I would be curious to peak at your AMS and RMX stuff.

I'm getting there with AMS information, the document is a mess at the moment. I have 10 AMS's in for repair and have the opportunity to reverse engineer some of the AMS boards that could be very useful to those that want to repair them. One of them is also being upgraded to maximum delay using my new ram cards.
I will be making all the info public though as there needs to be more people with an understanding of them and a willingness to work on them. I don't want to be doing much more of it. so much of it is cleaning and undoing bad work.
 
I haven't looked at all of your redrawn schems Chris, but since they're out there now, one typo error I saw that might be of interest or concern for some is in your "Amp B" drawing: Collector load for this V to I amp should read 27K rather than 2K7.

As you were :)
 
Hi guys (presuming you are all guys) an interesting thread. I have always collected as many circuit diagrams as possible and as I worked at AMS many moons ago I think I have a couple of the schematics although a 'half trancon board' schematic is probably a bit esoteric for most.
I don't forward schematics, or at least not in their entirety mainly because I can't be bothered with the effort of doing it. Of course many circuit 'concepts' were proposed a very long time ago and it is largely 'blue sky' thinking applied to old schemes that appear. I rail against the notion that you can't record music properly unless you use a vintage Neve/EMI/whoever desk simply because NONE of them are in original condition as their time and situation has passed.simply copying (cloning) gear is not an advancement. I take some pleasure in seeing some copies where the cloner has incorporated the original mistakes (that were eventually corrected ).
Having a decent stash of Plessey quadrant stud faders would be nice though.
Matt S
 
Hey Matt, whatever schem you think is applicable to anyone on here, yep.
However, I don't think you'll get any complaints regardless of how esoteric it might be 😉
 
It would be interesting to know what happened to AMSs' first digital mixing desk which used a network of transputers. I tested out the prototype (treating it as an 'analogue desk' as it was before digital recording really took off although the AMS Audiofile was an interesting beast. Kids these days don't know they are born. what is the fun in a 192K/24 bit A/D chip for a few Pounds/Dollars/Euros when you can have a 4 U rack card stuffed with logic chips to manage 48K 16 bit!
Repairing most of the AMS units seemed to involve clearing out dead spiders/fluff/beer puddles, repairing the dead bits in the (early switchmode) supply which just got too hot and sometimes tantalum caps across the supply rails (that would fail) and of course clean the card edge connectors.
 
aah, the AMS Audiofile.. That one was such a horror to service - most of the digital was depending on individual chip propagation delays for timing, so you couldn't replace a broken 7474 IC with anything but the same batch..

I literally spent weeks of my life sitting and waiting for it to churn out fails that had interpretive value

Word has it that the head designer took most of documentation with him in the grave before AMS ever succeeded getting it to run all 8 expected channels simultaneously (never seen the original AudioFile in more than 4 channels)

The AMS Studio computer - as used for the automation in our Calrec UA8000 - was a branch of this system. Horror.

/Jakob E.
 
Hi Jakob
I could tell you a story about that, but not publicly as I nominally installed the first AMS automation system onto a UA8000 (out of the 5 sets of hardware that were built).
 
I made a few maintenance calls for Audiofiles (minor upgrades) and started to get into the conversion/upgrade to colour screens but left AMS before the kits for all the necessary bits of hardware had been manufactured. Like some Sinclair (radionics) stuff if some boards didn't work when assembled they were quietly 'dumped' into a little corner rather than struggling for days trying to find the one bad plated hole or hair line trace that stopped it working. The extender boards allowed you to probe for 'basic life' (supply and clocks) but only a few would actually WORK on an extender.
Of course it introduces you to the normally unspecified logic device, the 'Sometimes When' gate. meaning it sometimes works When IT feels like it and changing any parameter will make it sulk.
 
I haven't looked at all of your redrawn schems Chris, but since they're out there now, one typo error I saw that might be of interest or concern for some is in your "Amp B" drawing: Collector load for this V to I amp should read 27K rather than 2K7.

As you were :)
Thank you for the catch, the drawing is amended on the shared file now. Hopefully I haven't made any other mistakes.
 
Hi Chris, thanks for posting these schematics!
I was wondering which value the resistors in the Gain switch of the Type X & Z EQs have? Thanks! :)
[thanks for posting these schematics!] -- Where are they??? Can you direct me to a working link? The link shown in Post #4 does not work for me. I get shown this error message when I click on that link:

This item is no longer available.

Items may be taken down for various reasons, including by decision of the uploader or due to a violation of our Terms of Use.

THANKS!!!

/
 
Here'ya go..
 

Attachments

  • Bass circuit.pdf
    53.2 KB · Views: 7
  • Desk block diagram.pdf
    51.9 KB · Views: 8
  • Input Amp.pdf
    29.7 KB · Views: 7
  • Limiter info.pdf
    66.8 KB · Views: 6
  • Output.pdf
    41.6 KB · Views: 8
  • TG_12345_mkii_Manual.pdf
    643.2 KB · Views: 6
  • Treble circuit.pdf
    42.1 KB · Views: 6
Back
Top