Need help with Amek Angela A10 modules

Posted: Thu Nov 01, 2007 5:50 am

Hi there.
I'm racking up two Amek A10 (A10-A2, actually) input/output modules from a Amek Angela console.
I allready made the power supply and now I'm in the making of the in/out connections (MIC in, LINE in, PATCH send and return, BALLANCED output: IF there is one on this module?).
Now I realize that a schematik plan for this (A10-A2) module would be usefull to have, because I do have a folder full of troubleshooting hints (issued by AMEK), but I don't have any schematics of this precise module.

Could somebody help me???
Please???

Posted: Thu Nov 01, 2007 6:21 am

Have you tried the Audio Asylum website?

Posted: Thu Nov 01, 2007 8:52 am

Try Bo Hansen in Sweden. I believe he has rebuilt an Amek Angela console.
http://www.hansenaudio.se

Posted: Thu Nov 01, 2007 12:32 pm

Nothing there on the Audio Asylum Website.
And I've just contacted Bo Hansen. Let's see I've I'm lucky.
By the way, I managed to put the modules to work (they are amasingly quite), but they only work in unballanced mode.

Posted: Sun Nov 04, 2007 2:26 pm

www.groupdiy.com

lots of people there that do that sort of stuff
including Bo
who was a very early member when Group DIY used to live here

also try Joe Malaone (JLM Audio) for power supply and driver boards etc

or you could contact me if you need any further advice or suggestions

Posted: Sun Nov 04, 2007 2:54 pm

Thanks Kev.

Actually, I could use some advise.
Bo told me that I could put an op-amp on the module, connected as an inverted amp with 1:1 unity gain, starting from pin 2 and then phase reversing the signal to pin 3.
I was thinking of a NE5534 op-amp, since this type is allready used on the module on various parts.
What do you think? Do you know if in this case I have to connect a 10pF capacitor between pin 5 and pin 8?

Posted: Mon Nov 05, 2007 6:51 am

PhantomBox wrote:

Thanks Kev.

Actually, I could use some advise.
Bo told me that I could put an op-amp on the module, connected as an inverted amp with 1:1 unity gain, starting from pin 2 and then phase reversing the signal to pin 3.
I was thinking of a NE5534 op-amp, since this type is allready used on the module on various parts.
What do you think? Do you know if in this case I have to connect a 10pF capacitor between pin 5 and pin 8?

Yes, if you are going with the NE5534 you should connect a capacitor between pins 5 & 8. I would favour 22pF rather than 10pF for unity-gain configurations. Beware that there are sonic differences between the various makes of NE5534. If you can find samples of the original Signetics part you would get best consistency. Try 10K for the feedforward and feedback resistors, although the value is not critical as long as they are matched.

Posted: Mon Nov 05, 2007 2:38 pm

I take it that the you are most interested in a balanced output ??

yes a unity inverted NE5534 amp ... with the above suggestions is a fair start

however
I'd be more inclined to use a dedicated driver unit ... with or without an output transformer

this output driver could be more powerful than a simple 5534 pair

something that can driver multiple inputs and can be loaded with a 600ohm input ... like an LA2 ... without fear of loading effects.

these can be configured to provide output levels from -10 to +28 dbu
and
balanced(transformer'd or psudo balanced)
or unbalanced

keep the versitility up

for inspiration ... excuse the shameless plug

JLM Hybrid
http://www.jlmaudio.com/JLM%20Hybrid%20opamp.htm
JLM Dingo
http://www.jlmaudio.com/dINgO.htm

This topic sponsored by: