APOX volume-input for Aleph P1.7 question

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You should connect -(neg) and gnd on INPUT to the vol-controller.
The Apox software-switch for bal/se only(?) control the input/selector-board, if I remember correct?

The hum/dropout-issue might be a bad ULN2003(?) driver-chip. If they are in sockets, try swapping. And check for solder-drops/bridges...

Arne K

Arne K
 
You should connect -(neg) and gnd on INPUT to the vol-controller.

I don't quite understand this. My interpretation of your writing is that I have changed the wiring at the output of the Aleph board tot the volume input as follows: + to +, - to - and G to G.

The Apox software-switch for bal/se only(?) control the input/selector-board, if I remember correct?

The hum/dropout-issue might be a bad ULN2003(?) driver-chip. If they are in sockets, try swapping. And check for solder-drops/bridges...

Arne K

The bal/se relay is on the volume board (K11) See pdf below.

http://www.apoxcontrols.com/APOX1/apox1rev3.pdf

I do not see solderdrops or bridges...

Chip is a ULN2803A switched position but the humm remained at the right channel.

I do have sound at the moment but the volume is way to low. My Pass B1 had more volume...

Appreciate your help Arne!
 
I would connect the inputs to the board in balanced mode and let the relay on the board determine the output configuration. That's what the board is set up to do. You might as well use the feature.

But I don't think that is a likely cause of your problem. I'd short the input to the volume control board (amp off, of course) put your multimeter across the outputs and start adjusting the volume. See what you find.

Sheldon
 
I would connect the inputs to the board in balanced mode and let the relay on the board determine the output configuration. That's what the board is set up to do. You might as well use the feature.

But I don't think that is a likely cause of your problem. I'd short the input to the volume control board (amp off, of course) put your multimeter across the outputs and start adjusting the volume. See what you find.

Sheldon

Sheldon,

Can I do this without the Aleph's attached? Just short the input of the volumeboard and measure at the output?

Shorting the input means + to - to Ground and than measuring the output, the output being - shorted to Ground and measuring between that and +?

Jan
 
Sheldon,

Can I do this without the Aleph's attached? Just short the input of the volumeboard and measure at the output?

Shorting the input means + to - to Ground and than measuring the output, the output being - shorted to Ground and measuring between that and +?

Jan

Yes, I'd recommend disconnecting the amps - if for no other reason than it makes it easier to manipulate the board, if you want to probe points on the bottom.

You can short the input or leave it open. Measure across the outputs. Look at the schematic while you test, and you can check to make sure the mute works properly, and that the SE/balanced relay works properly. The resistance values will jump around because the volume control in not constant impedance. Main thing is to have both channels give same resistance value. If they don't, something is amiss.

Sheldon
 
Checked like you said, Sheldon. Had a different reading at the minus from output B. First part from that point is relay K7. Resoldered this relay and now I'm getting the same numbers on both sides. I guess this could also account for the humm I had. Going to put it back together with the Aleph tomorrow to see if we really solved the problem!

Jan
 
Put the APOX volume board back at the output of the Aleph.

And guesss what... IT IS ALIVE!!!!! Only a bit humm when the volume is turned up completely. I can live with that I think.

Thank you Doug, Sheldon and Arne for helping me! You guys are absolutely great!


Now I'm almost there! Still have a problem with the Aleph. If I turn up the volume completely the volume is still very low. I have the switches on the Aleph board set in maximum attenuation... There is also a trim pot on the board which is also for attennuation. But nothing happens. Any idea's?
Boards are from Veterans group buy. I bought them stuffed with al the parts form somebody over here in The Netherlands...
 
No zwolle for me anymore but still in the electronics at a big international company in drachten.

Anyway you aleph. maybe you want to check your input resistors from signal to ground, if they have the correct value can you post a schematic or link of which aleph you use ?
 
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