D-AOC PCBs - the building and help Thread

[[silent:arts]]

Do i need to replace R126 & R226 with a trimmer in order to make the meters read zero dB?
At the moment they stay on the complete left side.

No. Meter switch wired correctly?

 

[weiss]

No. Meter switch wired correctly?

yes, + of GR on the pcb is connected to + on meter side.
btw. No audio passing when not in bypass mode  :'( :'( :'(


I think i got to check the lundahl wiring again as i wasn't sure about the connections in the first place..

I did it like this:

Primary: pins 2+4 tied, pin 1(+), pin 3(-) - From Bypass board XLR
Secondary: pins 5+7 tied, pin 8(+), pin 6+pin E(-) - To PCB

For the output I wanted to wire reversed 2:1

Primary: pins 8+5 tied as (+), pin E to ground - From PCB
Secondary: pins 2+4 tied, pin 1(+), pin 3(-) - To Bypass PCB

 

[Potato Cakes]

yes, + of GR on the pcb is connected to + on meter side.
btw. No audio passing when not in bypass mode  :'( :'( :'(


I think i got to check the lundahl wiring again as i wasn't sure about the connections in the first place..

I did it like this:

Primary: pins 2+4 tied, pin 1(+), pin 3(-) - From Bypass board XLR
Secondary: pins 5+7 tied, pin 8(+), pin 6+pin E(-) - To PCB

For the output I wanted to wire reversed 2:1

Primary: pins 8+5 tied as (+), pin E to ground - From PCB
Secondary: pins 2+4 tied, pin 1(+), pin 3(-) - To Bypass PCB

Are you using Volker's HWBP boards to do your bypass function? If so, there shouldn't be any signal going to the transformers when in bypass. It should just go from input to output XLR directly. The small boards by the connectors make it hard to see what is going on there.

Thanks!

Paul

 

[[silent:arts]]

Your Lundahls are wired wrong. The input may work but the output won't.

For 2:1
Primary: pins 2+4 tied, pin 1(+), pin 3(-)  (PCB)
Secondary: pins 5+8 tied(+), pin 8(+), pin 6+7 tied(-) (Bypass PCB)

Pin E is shield & case and should go to gnd (I would use the shield of the cable from / to the Bypass PCB).

 

[weiss]

Are you using Volker's HWBP boards to do your bypass function? If so, there shouldn't be any signal going to the transformers when in bypass. It should just go from input to output XLR directly. The small boards by the connectors make it hard to see what is going on there.

Thanks!

Paul

Hi Paul, thank you.
These are Volkers boards, they work fine. I get signal when in bypass so that’s okay.

Your Lundahls are wired wrong. The input may work but the output won't.

For 2:1
Primary: pins 2+4 tied, pin 1(+), pin 3(-)  (PCB)
Secondary: pins 5+8 tied(+), pin 8(+), pin 6+7 tied(-) (Bypass PCB)

Pin E is shield & case and should go to gnd (I would use the shield of the cable from / to the Bypass PCB).

Ahh.. thank you Volker !!
I‘m gonna rewire and check again.

 

[Potato Cakes]

My reading skills are failing. I see now that you said no audio when not in bypass. Hence HWBP working, whilst signal through the unit is not. My apologies.

On a side note, I an interested to see yours up and running. I have a completed DAOC board that I have been staring at for a couple of years with the intent of making a mastering compressor, which I have wanted but never really liked any of the expensive ones I've rented. Please continue to keep up updated.

Thanks!

Paul

 

[weiss]

My reading skills are failing. I see now that you said no audio when not in bypass. Hence HWBP working, whilst signal through the unit is not. My apologies.

On a side note, I an interested to see yours up and running. I have a completed DAOC board that I have been staring at for a couple of years with the intent of making a mastering compressor, which I have wanted but never really liked any of the expensive ones I've rented. Please continue to keep up updated.

Thanks!

Paul

No worries!
I will keep you updated. My only intention is to let this thing end up in my rack  ;D

 

[weiss]

I started a second DAOC and this one worked from the first time!
Awesome project, really happy about the sound, worth the effort !!

Thank you everyone for the support.

Now it’s time to finish my earlier build....

 

[weiss]

Your Lundahls are wired wrong. The input may work but the output won't.

For 2:1
Primary: pins 2+4 tied, pin 1(+), pin 3(-)  (PCB)
Secondary: pins 5+8 tied(+), pin 8(+), pin 6+7 tied(-) (Bypass PCB)

Pin E is shield & case and should go to gnd (I would use the shield of the cable from / to the Bypass PCB).

i wired it like this but i still don't get any signal through.. 

 

[weiss]

Is this the correct wiring?

 

[[silent:arts]]

Looks fine to me.

 

[weiss]

Looks fine to me.

hmm.. i completely rewired the audio transformers after this schematic but still can't get any signal..

 

[[silent:arts]]

- You managed to build another working D-AOC?
- It affects both channels?
- Chances are low all 4 transformers are bad?

Check the transformers by connecting the two (in your drawing) "MAIN PCB" cables.
Check the Main PCB without transformers by connecting the "BYPASS PCB" to the MAIN PCB" Points .

 

[weiss]

- You managed to build another working D-AOC?
- It affects both channels?
- Chances are low all 4 transformers are bad?

Check the transformers by connecting the two (in your drawing) "MAIN PCB" cables.
Check the Main PCB without transformers by connecting the "BYPASS PCB" to the MAIN PCB" Points .

- Yes i got one completely working with edcors
- both channels are silent
- yes very unlikely as i bought them from different sellers

i will check the wiring again before and after the lundahls and report back!

 

[weiss]

Check the transformers by connecting the two (in your drawing) "MAIN PCB" cables.
Check the Main PCB without transformers by connecting the "BYPASS PCB" to the MAIN PCB" Points .

Thank you volker!

I now hooked up the transformers and bypass boards from my second unit with my non-working unit to check where the problem lies: Everything was working using the transformers from the other unit. I got signal on both channels and compression & all the controls were working fine!

So either the wiring of the lundahls is wrong or my bypass board has errors.. ???
Could you confirm for me, hot is + and cold - going and coming from the transformers?

I already checked if the signal from the xlrs goes into the board and i found continuity to the relais.
What else could i check?

Maybe some of the people who used the LL1540 transformers had similar experiences ??

Thanks!

 

[[silent:arts]]

Could you confirm for me, hot is + and cold - going and coming from the transformers?

Sure. But even if you swap hot and cold there will be signal.
It must be something stupid and easily overlooked, something like a swapped in and output maybe?

 

[weiss]

Sure. But even if you swap hot and cold there will be signal.
It must be something stupid and easily overlooked, something like a swapped in and output maybe?

yes something like that! but i can't see anything obvious...
is there a way to check?!

i mean there is some kind of sound getting through on one channel but this is so extremely low that i have to turn up the signal for 40 db or something and it's extremely distorted...  ???

I'll post a picture, i am certainly overlooking something

 

[[silent:arts]]

Compare every single cable with your working Edcor Unit.

 

[weiss]

Compare every single cable with your working Edcor Unit.

ok i will! are the numbers equal? thanks for the tip.

here the pictures

 

[weiss]

not sure if this will help.