D-AOC PCBs - the building and help Thread

[MartyMart]

Here's some Farnell codes for the stuff I ordered for the D_AOC.
It's NOT complete, as I had some things anyway, but hope it helps
save the 2+ hrs that it took me to find it all !!

Capacitors -
100uf 50v ( 35v use ) 969-6660 NOTE this is a "bipolar" and probably wrong - intended for the Pico Comp board
47uf 350v 969-6440 12 needed
1000uf 25v 969-2193
2200uf 35v 969-2347
3300uf 25v 969-2223
Poly -
0.22uf 400v 116-6132
1uf 400v 116-6136
0.1uf 400v 121-5494

Resistors -
470ohms 2 watt 933-8250
2k2 2 watt 933-8160
10k 2 watt 933-8063
39k 2 watt 947-5257
100k 2 watt 933-8071 ( all 10 pieces minimum )
1M trimpot 935-4328 ( 5 pieces minimum )

Other -
LM350T 131-7673
TL783CKC 959-4582
1N5371 955-8284
1N5400G diode 145-8988
1N4007 diode 146-7514
5w zener 39v 955-8233
Heatsink - undrilled 232-968 ( bigger one to attach to case for heat dissipation !! )
Heatsink - board 121-9493 ( matches board pattern 2 needed )

VTL5C4/2 - ordered from ; www.smallbearelec.com
Transformer/ solen fast 10uf/ tubes and sockets ordered from
www.musikding.de and found very easily.

Marty.

EDIT - Board arrived whilst typing this
Thanks Volker .
EDIT - I had the numbers spaced out evenly but it goes away in "preview"
and when posted !! - **** !

 

[Jonkan]

Im cheap, so im going to buy all edcor transformers for this project.
Quick question:
Since the edcor wsm 600:10k transformer in reverse seems to be working fine for the output as shown in the measurements silent:arts provided, is it safe to say that the 10k:600r edcor used in a non reverse configuration will probably work fine here also?

Im trying to work out what to order. Im thinking edcor xs1100 on input, and wsm 10k:600r on output (or 600r:10k reversed).

Thanks!
/J

 

[MartyMart]

OOPS - missed out the 1N5371's from the order, if anyone has 2x spare
could you PM me, I have extra's of several other things so a "postal swop"
would be fine
( all other diodes/2W resistors etc )

Ta,
Marty.

 

[bernbrue]

[quote author="sinestaraudio"]
no matter how high i drove the input, the output level did not drop when compression knob was turned.

Also I am using 1ma meters which adjusting with the meter trim can only just get off the floor, I am wondering if this might be a clue to whats happening in the GR circuit.
[/quote]

Pete,
I tried a 250uA meter successfully whereas a 1mA meter barely moved. Changing R124/126 might help, although I didn´t test it. As I mentioned earlier, compression is very subtile. Feed the compressor with some percussive sounds (drums) and you´ll hear it. Otherwise check the connection of the input pot. Don´t forget the red or blue LED parallel to the vactrols LED, as Volker mentioned earlier.
regards
Bernd

 

[user 10827]

Hi Bernd,

Thanks for your reply and meter info, I will let you know how it goes.

I am really suprised about the quality of the audio specs, I only did a few quick tests, as the input / output amps working wonderfully, and only using the Edcors the response was incredible, I can post some images of the sweeps later.

all the best
Pete

 

[cannikin]

[quote author="sinestaraudio"]
Thanks for your reply and meter info, I will let you know how it goes.
[/quote]

Hey Pete, definitely let us know if changing R124/126 solves the meter issue.
I have a couple 1ma meters that I want to use.

David

 

[user 10827]

hi David,

most certainly will tonight for you.

I was wondering what the reason behind the factor of ten between the values of the two resistors? if any one can shed some light on it that would be interesting.

Pete

 

[MikoKensington]

[quote author="cannikin"]
I have a couple 1ma meters that I want to use.

David[/quote]

Me too.

 

[bernbrue]

changing resistor values was just a guess, don´t nail me down on that ..
Miko, were do you get those beautiful meters?

 

[MartyMart]

Guys, BOM says 12 x 47uf 350v and the board has 47uf 400v silkscreened !
Can I get away with the 350v caps as they were quite expensive ??
Don't think I can change them as it's a few weeks since I got them.

Ta,
Marty.

 

[MikoKensington]

Cheap on ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=270222836163&ssPageName=STRK:MEWN:IT&ih=017

I just hope they look the same when they come. :?

 

[[silent:arts]]

[quote author="MartyMart"]Can I get away with the 350v caps as they were quite expensive ??[/quote]
all 47uF after the regulator are fine with 350V.
the voltage of C2, C3 & C4 are depending on your Power Transformer.

 

[bernbrue]

Marty,
with 47uF 350V you are just fine, took them as well and mine didn´t blow up.
regards
Bernd

 

[bernbrue]

:grin: the master himself, received the pcb, what a nice sticker, wow.
regards
Bernd

 

[MartyMart]

Thanks :roll:
`panic attack about £20 worth of caps !!

:green:

 

[[silent:arts]]

for the Meter:
the circuit is taken from the LA2A
(which uses a VU Meter)
btw, there is a 3K9 resistor needed in series with the VU which is not on the PCB
(since I wanted to have a switchable "Gain Reduction" / Output VU)

some comments from Keith:
http://www.groupdiy.com/index.php?topic=25646

and how to calibrate it:
http://www.groupdiy.com/index.php?topic=23253.msg276178#msg276178
(R25 = R126 & R226 in the D-AOC)

 

[MartyMart]

Could I use 2x 39v zener diodes for the 5371's as I happened to order 5watt
versions anyway .. they are a little large !
5371 is 60v and I would have either 39v with one or almost 80v with two.
Or is the application wrong for these ?

MM.[/i]

 

[Jonkan]

Hey, where is the 5371 diodes mentioned? I cannot find anything about them in the BOM.

Are they needed for this project, and if so...how many?

/J

 

[bernbrue]

Jonkan,
you´re right, they are not on the BOM. Volker, would you update the pdf file on your server, plz? You need two 1N5371 (Farnell 9558284)
regards
Bernd

 

[[silent:arts]]

I would still prefer the Neon Lamps here ...
for the safety reason (you can see there is power on)

and I haven't tested the 1N5371, neither for PCB spacing nor for the meter circuit.

roughly you want to have 67V. any zener with this specs could be used here.

the board layout is for the Farnell PartNr Bernd posted above (which is a 60V/5Watt Zener btw). I haven't found any closer value while doing the PCB Layout.
one of the reasons the BOM I posted states "incomplete"