[adastra]

may I ask which board rev. you have?
Mine is rev.1.3


Thanks,


Udo.

Hey Udo,
Mine is also ver1.3

[kante1603]

thanks,


Udo.

[JPK]

@Udo
-9,1 vdc : not good. Check the voltage before linear reg U25 (device case). If it is lower than 19V, you must check the switcher for a reverted electrolytic, a misplaced diode, a bad solder...
Encoder and output switches not working : check the connections between connectors CN38 a and b, check correct direction on RN7.

@adastra
Is that without U6 & U8? If so, check components values and solders around U7 & U9: R108 to R112, R125 to R127.
Check supply voltages of U7 & U9 on R110-left & R111-left and R126-top & R127-top.

[kante1603]

@Udo
-9,1 vdc : not good. Check the voltage before linear reg U25 (device case). If it is lower than 19V, you must check the switcher for a reverted electrolytic, a misplaced diode, a bad solder...
Encoder and output switches not working : check the connections between connectors CN38 a and b, check correct direction on RN7.

O.K.,psu problem solved,had a reversed lytic at the reg (c71),all good so far.
I shouldn't do so long solder stuff in my age anymore,especially with bad lights.


Next is the encoder issue,will check in the next days when I find some time.A quick check measuring from the encoder pins against the corresponding pic microcontroller pins didn't  show any continuity at all,weird.....!
So I'll check RN7 and CN38.


Udo.

[adastra]

Listed values were all correct and voltages at 110/111/126/127 were all +/- 16Vdc.  I am finding that TP9 started dropping a bit after I reflowed a few things, its now around +11vdc, while TP10 is consistently +14.5vdc.

On the plus side, I ran audio tests on everything but the headphone outs and everything else works perfectly, very exciting!

[JPK]

You must check with U6 and U8 inserted.

[adastra]

Aha, well don't I feel silly now.  Anyway,  with U6 and U8 in, I have near zero DC on TP9 & 10.  I appear to be fully functioning now, everything sounds as it should.  Haven't played with all of the logic functions yet (offsets) but I'm off to the races.  Well done JPK, much appreciate a great project at a great price!  I think you saved me dropping a few grand on an Avocet.

[kante1603]

Congrats,well done!
May I ask if you've done the opamp-zeroing or left the jumpers out?


Best,


Udo.

[adastra]

Also, FWIW, I've been playing around with an IR remote and an Arduino IR transmitter setup and I have to say the response is much better than I expected and really is a great option, especially with a relay-based volume control. Its fast and just as seamless as the front panel buttons.  I honestly can't see the need for any kind of hardwired remote, with the possible exception of being able to put the dB level on a remote display.  If anyone can tell me how to do that via IR, I'd be thrilled.

[adastra]

Congrats,well done!
May I ask if you've done the opamp-zeroing or left the jumpers out?


Best,


Udo.

Thanks Udo!  I used the jumpers and zero'd them since I have a pretty nice Fluke bench meter.  They were all well within .5mV though, so I definitely wouldn't sweat it.

[kante1603]

Thanks Udo!  I used the jumpers and zero'd them since I have a pretty nice Fluke bench meter.  They were all well within .5mV though, so I definitely wouldn't sweat it.

Thank you very much indeed.I only have handheld Flukes here at home,one very old 75 and one brandnew 175 that I bought last week and is still in its' package.Will give it a good reading theough the manual once I'm on it.
Meanwhile I must solve my encoder (not working) and odd output switcher behaviour.
Time do disassemble,fingers crossed.RN7 looks correct so far,now I have a vague idea......
Wish me luck,


Udo.

[kante1603]

Issue solved!
My idea was that I might have stressed it mechanically and a pad/trace might have a microscopic break.
So I thought about reflowing the joints on CN38a & b.What made it feel strange was that none of the encoder pins had contact to anywhere,neither to gnd nor the two joints to the pic after the schematics.
After disassembly it was very clear:I just didn't solder a complete row of 10 pins on CN38b.
Long story short the first digital test (point 3 in the setup guide) works flawless now!
As said before,I might be too old    or shouldn't do way too long soldering sessions anymore.


Now up to proceed testing,maybe tomorrow if time permitting.


Cheers,


Udo.

[adastra]

Congrats Udo!

[kante1603]

Congrats Udo!

Thank you!
"CLICKEDDICLACK".....relays test passed too (couldn't resist proceeding,this project is too exiting)!


Udo.

[kante1603]

I'm done-HOOOORRRRAAY!
Audio passing,all functions working (Difference mode plus Mono is really powerful),and the phonesamp is absolutely great!I wouldn't have expected being it that good,seriously!
I even was able to zero the amps,I simply forgot that my lab DMM is capable of reading at least the 10th of a mV,great.Have the trimmers sealed now.


Jean-Pierre,this is an excellent kit,and I really appreciated your help and being here for us,thank you so much.
Finishing this build made my day:Good-Bye "Central Station",welcome you serious controler
If you guys are looking for an affordable and professional "non-sounding" monitor controler....here it is!


Time to sleep now,


best regards,


Udo.


P.S.:Will get an ir remote now to see how it behaves,but still have a small (wired) remote with a dial knob for volume in mind.Would also be very happy if the mentioned multiple phones amp will come to happen!

[adastra]

Not sure anyone would care, but FWIW, if you are interested in an arduino-based IR remote for this monitor controller its quite simple. 

Just use this library:
https://github.com/shirriff/Arduino-IRremote

and use the "irsend.sendSony" function

An example is;
if (digitalRead(dim) == HIGH){
      irsend.sendSony(0xCD0, 12);

where CDO is the specific code for the controller function.

Vol Up: 490
Vol Down: C90
in 1: 10
in 2: 810
in 3: 410
in 4: C10
in 5: 210
in 6: A10
out1: 338
out2: B38
out3: 738
out4: F38
mute: A70
L/R: 2D0
mono: AF0
diff: 2F0
dim: CD0

You could, of course, use whatever codes with the learn function, but I thought this way I could still use the recommended remote for a "producer on the couch" type thing.

[adastra]

Ok, total noob question here, but I have a pair of Sifam AL20's I'd like to hook up to the MC624.  Would this require a buffer?

I suspect so, but the meter out is after the units unity gain buffer, so... anyway I'd appreciate any thoughts on the matter.

Cheers.

[JPK]

It is preferable to use a buffer on this meter output in order not to load the main signal.

[adastra]

Thanks JPK.

[kante1603]

Hello and a happy new year everybody,


may I ask if there are any news on a little remote and/or the mentioned multiple phones-amp?


Thank you in advance,


best,


Udo.