D-AOC PCBs - the building and help Thread

[Sredna]

Hey Volker!

Almost finished, just some wireing/tidying up to do. I'm on vacation from next week til end of August so it´ll have to wait... Have to see the sun sometimes :wink:

It passes sound and compresses well after I found and removed a solder bridge at the stereo link connector

Dont worry about your rack, you already got a Purusha case there. Mine just got different knobs and lamp. But hey, it´s my first tube build so I wanted to concentrate on the electronics...

Thanks again for a beautiful design and almost foolproof even for a noob like me!

See you after the summer,

Anders

 

[maxheadroom]

today i fired my unit up. all supply voltages are ok.
i checked the voltages on the tubes like this: http://www.groupdiy.com/index.php?topic=26585&start=290

all voltages are fine, except the PIN1 voltage on tube Vx01.
volker measured 109V and i measured 244V.

measured with tube inside. pots and transformer not connected.
both channel the same.

anybody an idea?

EDIT

i connected the input to ground (Rx03), after this i get the right value!

 

[Benny]

My D-AOC is working now. Second channel had no bass etc. After a long time searching for wrong parts etc I found out that the wire between + and CT on the output edcor got torn off the solder lug. Just soldered it in place and ...tada... we've got sound on both channels. :grin:

 

[mikeyB]

[quote author="Benny"]My D-AOC is working now. Second channel had no bass etc. After a long time searching for wrong parts etc I found out that the wire between + and CT on the output edcor got torn off the solder lug. Just soldered it in place and ...tada... we've got sound on both channels. :grin:[/quote]

I bet it was pin 8?

Please let Edcor know about this - the quality control seems a little lapse!
I bought 10 Edcors from Edcor Europe. One XSM10k/600 - had no continuity between tags 6 & 8 (antiphase half of secondary). On inspection - the wire was soldered but not stripped of varnish - I carefully scraped the wire and resoldered - SORTED!
No so lucky with a WSM 10k/10k - exact same problem - nothing on pin 8 - tried the same method as above - but no continuity - wire must be broke in winding
I've informed tonydB about this - through Edcor europe and am currently waiting a replacement.
Benny - please let tony know about your problem - he'll hopefully report back to Edcor USA and in turn they'll sort their quality control out.

Moderators :idea: - is it worth starting a thread - "Dodgy Edcors" or something like to make everyone aware of these problems - I'm just thinking of the amount of Edcor iron thats going around the world for the Poorman project :!:

Edit - just noticed you said between + and CT - so thats different to my 2 - pin 8 problems :?

 

[Benny]

[quote author="mikeyB"] Edit - just noticed you said between + and CT - so thats different to my 2 - pin 8 problems :?[/quote]

Could have been between pin 8 and CT. I did not look inside the D-AOC since I got it working.

 

[crisotop]

A quick question on transformer hookup, since this is my first project with offboard trafos: The Edcors have plus - centertap - negative connectors on both in- and output. Let's say I'm hooking up the input trafo, I connect signal-hot to trafo-plus, cold to negative and ground to centertap? And the unbalanced output is between plus and negative, leaving centertap unconnected?

Thanks in advance,
christoph

 

[flintan]

You don't need the CT at all. Just leave it and connect pos to pos and neg to neg. That's the fine thing with having transformers on the in/out, you can make a completely isolated floating connection.

 

[crisotop]

I see, I thought the CT might need the reference for the inverted/cold signal connection...

thanks!
Christoph

 

[Benny]

The unit worked perfectly for about two weeks but now I see that after power-up the NE2 neon lamp in Ch 1 lights up but then after a few second stops shining. It also seems to shine darker than the NE2 in Ch 2.
I put in another NE2 but the new one behaves the same.

Any ideas?

 

[maxheadroom]

do you checked the supply voltages?

 

[bernbrue]

Benny,
check R124 and R126 for correct values. What kind of meteres do you use?
regards
Bernd

 

[Benny]

Bernd,
I'm using Sifam Al29 VUs.

R124 and R126 seem to be right.

 

[bernbrue]

Hi Benny,
could it be, that you missed the 3K6 resistor in series with the VU meter on one side? Check please!
regards
Bernd

 

[Benny]

3,6k resistor is there. But i didn't already connect the VU of the other channel. Do these interact somehow???

 

[bernbrue]

Connect the second meter as well and see what happens. Normally everything should be fine.
regards
Bernd

 

[Benny]

Thanks. I'll check that tomorrow.

 

[emrr]

[quote author="mikeyB"][quote author="Benny"]My D-AOC is working now. Second channel had no bass etc. After a long time searching for wrong parts etc I found out that the wire between + and CT on the output edcor got torn off the solder lug. Just soldered it in place and ...tada... we've got sound on both channels. :grin:[/quote]

I bet it was pin 8?

Please let Edcor know about this - the quality control seems a little lapse!
I bought 10 Edcors from Edcor Europe. One XSM10k/600 - had no continuity between tags 6 & 8 (antiphase half of secondary). On inspection - the wire was soldered but not stripped of varnish - I carefully scraped the wire and resoldered - SORTED!
No so lucky with a WSM 10k/10k - exact same problem - nothing on pin 8 - tried the same method as above - but no continuity - wire must be broke in winding
I've informed tonydB about this - through Edcor europe and am currently waiting a replacement.
Benny - please let tony know about your problem - he'll hopefully report back to Edcor USA and in turn they'll sort their quality control out.

Moderators :idea: - is it worth starting a thread - "Dodgy Edcors" or something like to make everyone aware of these problems - I'm just thinking of the amount of Edcor iron thats going around the world for the Poorman project :!:

Edit - just noticed you said between + and CT - so thats different to my 2 - pin 8 problems :?[/quote]


yes, 2 of about 20 edcors I've purchased have either had dead windings or incorrectly connected windings. Always check upon receipt!

 

[crisotop]

I thought I share my happiness - just (nearly) finished my D-AOC, I'm just missing the VUs which shoud arrive in the next week...

Was a fairly easy and flawless build (purusha case), just had troubles wiht the edcor XSM as ohter users. Two out of four trafos had bad solder points, one even had the islotation on the windings and no contact at all..

whatever, the comp has a very unique sound, at least with the dark edcor 10k/10k on the input, and I love the fact you have to set the dials like on a nice marshall plexi, all controls to 11!

Will post pictures once the VUs are in there.

One last question, I also connected a Fender Jewel light to the 6.3V heater supply, would it be too much to also connect 2 VU lamps on it, since the regulator is getting farily hot already?

Thanks!
Christoph

 

[maxheadroom]

what voltages have the two vu lamps?
you can connect it seriel to the 24V supply

 

[crisotop]

I ordered the light kit with 12 Volt lamps, but could easily change them for 6V types. But it would make sense to use both 12V lamps in series on the 24V supply, haven't thought of that

thanks max!
christoph