D-AOC PCBs - the building and help Thread

[delaymix]

I'm still working on it, but I can not yet confirm the existence of a crack in the PCB. I thought back to initiate a comprehensive and detailed comparison of all the pieces one by one compared with the right side of the compressor in the hope of finding a solution. These days I am not proved possible to work on the project because I had work commitments.

 

[diyfanatic]

smal question before ordering the rest of the parts for this toy!

I've got the Tx from Musikding so 250v/24v/9v.
what value for c11/c12/c13?

Lolo-m who whas kind enough to share is Bom with me, listed c11 @ 4700uf, c13 @ 100nf and nothing for c12.

for those who used this trafo, can you give the correct value you've used please...

thanks.
Jr.

somebody pleaaazzzzz!! 8)

 

[MartyMart]

smal question before ordering the rest of the parts for this toy!

I've got the Tx from Musikding so 250v/24v/9v.
what value for c11/c12/c13?

Lolo-m who whas kind enough to share is Bom with me, listed c11 @ 4700uf, c13 @ 100nf and nothing for c12.

for those who used this trafo, can you give the correct value you've used please...

thanks.
Jr.

somebody pleaaazzzzz!! 8)

From this thread

universal PSU
use this PSU for relay bypass, meter lamps, VU buffers, what you want.
if you don't plan to use any of the above you can just let this components out.
the output voltage is chosen by the 78XX you use.
take 7805 if you want 5V, 7812 for 12V, 7824 for 24V.
of course you need a matching secondary on your power transformer, and C11, C12 and C13 should be in the right voltage range.
if you want a real true hardwire bypass take very low values for C11 and C12.
at the moment my PSU3 holds the power for 4 seconds after switching off the unit, using 2200uF and 100uF (24V).
will have to change this since I want the compressor to be immediately in bypass after switching it off.

it is not necessary to insulate the 78XX from the heat-sink, but more elegant.
the PSU3 has its own ground path, you can use it floating, or use a little jumper (provided on the PCB) to connect the PSU3 ground to the main PCB ground.

I used 1000uf 35v/ 47uf 50v/ and 100nf 50v poly  ( IIRC )  this was using a 7824 so approx 24v in this area.

MM.

 

[diyfanatic]

perfect, thanks Marty!!

 

[pstcho]

hello, the pcb are still available?

thank you

 

[[silent:arts]]

hello, the pcb are still available?

5 PCBs of the white edition are still available

 

[pstcho]

what about the price? shpping? and are all the documentations with the pcbs?

thank you

 

[[silent:arts]]

what about the price? shpping? and are all the documentations with the pcbs?

PCB price is still EUR 33,- incl 2 Bypass PCBs.
I can tell you the shipping costs once you have updated your profile with your location, since it depends if you are in Germany, EU or rest of world.
You will find all documentations available here in this thread.

 

[pstcho]

perfect i'm in greece, in athens

thank you

 

[[silent:arts]]

thanks, locations in profiles make the live here much more easy
this would be EUR 33 for the PCBs + EUR 6,55 for shipping in a registered letter = EUR 39,55 in total.
paypal is to [email protected]

 

[pstcho]

maybe it will be a bit out of subject but: do you have another pcb to sell (for other diy projects)

thank you

 

[[silent:arts]]

maybe it will be a bit out of subject but: do you have another pcb to sell (for other diy projects)

yes, this is out of topic.
however, I have organized a few group buys, and the few D-AOC PCBs are the only leftovers I have.
there might be more to come in the future ;D

 

[Lowfreq]

Two words I will not soon forget: Cable Capacitance.

I replaced the input and output pots with trimmers mounted on the board and the frequency response is now flat to 20k. I was planning on making this a one knob compressor anyway. I am building four channel units so I have the boards mounted with the PS section towards the rear of the case. I probably have a longer run than most to the front panel.

My DAOC had quite the roll of on the high end, starting at 2k and was about 3dB down around 16-20kHz.
I tried a few things, and even running unbalanced without transformers it still had the roll off.
I messed around with different value output caps, and that made no difference....................

So I took some advice from Gold's post, and jumpered some pots to see what would happen.
Nothing really changed much when I jumpered the input pot, but left the ouput pot. Maybe 1/2 a dB better.

But when I jumpered the output pot, but left the input pot, it measured nearly ruler flat frequency response ;D

But why would this happen?? Cable capacatance?? I don't really understand it, or why it only seems to effect this project.
Other projects have cables all over the show, and have great frequency response.
This is my first valve comp, so maybe I'm missing something.................

A lot of people mention how it sounds very warm,analog, smooth on the highend......... Maybe it's this roll off from the output pot that they are hearing? Mine sounds very clear and crisp now.

What's the best way to get around this? Having the output pot is very useful, but it messes my sound up???

Btw I've got most of the Kubi mods on mine. All but the step up transformer, or the changed output cap

 

[seavote]

i've looked through the entire thread and even at the poor man 660 wiring diagram and i still cannot figure how to hook up the bypass(relay) boards to the project. i could speculte as i have some ideas but i think it would be simpler if someone could tell me how  rather than correct my incorrect assumptions. xlrs are no problem and i see from the poor man diagram that the 2 pin molex is for power. i need to know where the 3 pin input and output molex connecters go (do i leave out the ground connection?) and where does the bypass switch get hooked up to.
first time dealing with a bypass. thanks for any help

 

[Gold]

What's the best way to get around this?

A very short cable run to the pot. I think using separate wires instead of a screened cable would help but I could be wrong about that.

 

[crisotop]

@ seavote

Just follow the traces of the 3pin molex in/outpot connectors to the pcb-mount Neutrik XLRs - that should clearify things for sure. The Relais are in bypass when there's no voltage present (i.e. a switched off unit still passes dry audio), so you need to connect the bypass switch between your 5/12/24V relais voltage source and the 2pin molex at the bypass pcb.

hth, christoph

 

[seavote]

thanks. power through the on/off makes sense to me now.
so 3 pin xlr labeled input goes to primary of the input trans former??
    3 pin xlr labeled output comes from the secondary of the out put transformer??
i understand some but have a long way to go. so im not confident enough to hook up without confirmation from someone more knowledgable.

 

[[silent:arts]]

so 3 pin xlr labeled input goes to primary of the input trans former??
    3 pin xlr labeled output comes from the secondary of the out put transformer??

yes. the GND / HOT / COLD markings are in the position of the molex connectors for input and output.
if you are using screened cables I would suggest to only connect the screen at the Bypass PCB, and leave it open at the D-AOC PCB.
do a star ground from the D-AOC PCB, both Bypass PCBs and the Case, IEC outlet and you are fine.

 

[Lowfreq]

A very short cable run to the pot. I think using separate wires instead of a screened cable would help but I could be wrong about that.

You're on the money on this one ;D

Just took out my shielded cable and used two bits of cat5 wire. Figured the third shield wire could be skipped.

Ruler flat frequency response!!!! and I get to keep my output pot ;D

Now I just gotta sort out my relays again.............. but I'll ask stupid questions later, when I get time to mess with them......

 

[dagoose]

Not sure if it may have come up before but i wanted to let you all know.

Last night one of my channels let me down, no sound coming through.
troubleshooting a stereounit is quite simple and so i soon found out that i had a dead R105 (R205) 47k resistor.
When i looked at the schematic i found out (already measured that) that is quite an important resistor for the high voltage of the tubes and i thought it was a bit strange to see it's just a 1/4 watt resistor.
Could it be that it burned down because of the high voltage/power it's handling? Didn't really check if it runs hot though, it's back in the rack again.  ;D
I didn"t have any 47k's at hand so i paralled 2x 100k to get 50k which did the job (did this on both channels) and with that i also doubled the wattage of the resistors.
So.. are 1/4 watt's ok here or should it indeed be bit higher?

I also had a burned down (soldering even let lose) R1 in the psu (470r 2watt) recently and so i also paralled 2 x 1k 2watt's but they are still running very hot as well. So R1 is also prefered a bit more then 2 watt i think.