AMEK Angela Console, any comment and opinion? Thanks!

[Sandersonic]

Problem solved.

I bypassed & removed the automation card & everything seems to work fine now. Fortunately, the faders on these channels were logarithmic so I didn't need to swap them. I think I'll pull the automation cards from the remaining channels as well. I have no intention of ever using automation on this board and I don't even know if they're all working anyway. As such, they're just a whole lot of extra op amps & components in the signal path that aren't doing anything.

I'd also like to thank Colin Adshead at Audio Maintenance for his assistance via email some time ago when I asked about the cards & faders. The answer I received was very helpful when re-connecting the faders. I've pasted in the relevant part below in case others need the info:

"Frank,

The faders on your grey modules are Logrithmic.

The faders on your blue modules are Linear.

They will all work..... but the scaling on the linear faders will be wrong..... the "0" will be in the wrong place.

If you look at the circuit diagram it will show you where an "audio only" fader would be connected...... there are usually 3 pins fitted to the circuit board (on the same side as the faders) which are used to connect the wires to......

Black = fader bottom
Yellow = fader wiper
Red = fader top

The black wire pin is near to the 2 axial capacitors at the bottom of the module....
The yellow wire pin is near to the long connector which is used for the automation.... at the upper end....
The red wire pin is near to the top of the fader.... close to the fader but in the electronics (transistor/relay)...

[That info is from memory.... I am not actually looking at a module at the moment..... so use the schematic to get it correct].

Regards,
Colin"

...his memory was spot on. The connection points are exactly where he said. Many thanks!!!

Regards,
Frank

 

[J.P. Ambrogi]

Hi Frank...

just trying to bypass the VCA´s on my Brown Amek Angela without success! I´ve dessoldered the yellow and red wires from the VCA card and soldered them to the points indicated on your last post and got no sound out of the channel. Am I missing something? Do I need to do some jumpering on the VCA card (which is still connected to the main board, by the way)?

Thanks in advance!

J.P. Ambrogi
BRAZIL

 

[Sandersonic]

Hi J.P.
If you're absolutely certain you followed everything as Colin described (the quote in my post), then I'm not sure what could be the problem. For me, it worked straight away so there wasn't any head-scratching going on. If you haven't already, double & triple check that you put everything in the right place & post your results here!
-Frank

 

[Sandersonic]

Ok,
As per Jensenmans recommendation, I've replaced U3, U4 & U5 with OPA2134 chips to open up the monitoring a bit. Otherwise, I've kept all the TL072 and TL074 chips where they are but upgraded to the "Excalibur" versions: TLE2072 and TLE2074 respectively. I figured this was a safe way to get a bit more bandwidth without needing to worry about bypass-caps or other changes in the surrounding circuitry. I've also kept all the NE5534 chips and simply replaced them with new ones. I'm happy to say that all channels are working fine & sounding great!
My next and final step is a refurbishment of the PSUs just for good measure. Then the board will be rock-solid for years to come. I'm looking over the schematics now and thinking that replacing electrolytics with higher-temperature versions and probably replacing & re-greasing the regulators. Any other suggestions would be most welcome! Particularly regarding which cap values can be increased etc. Images are attached of the PSUs.