D-AOC PCBs - the building and help Thread

[MartyMart]

Thanks J

MM.

 

[mikeyB]

Finished mine last night :grin:
But it not working good :sad:
HT heatsink way hot so I guess it's back to the drilling board

 

[mikeyB]

A Bit Better :!:
Had an awful buzz - which I thought would be some earth loop **** going on - shorted out the relay psu3 ground to the rest of the board ground - buzz gone :thumb: Can someone explain why this would be the case - I cant see how having the relay pcbs floating supply cause such a problem with the ground - I thought the idea of seperate ground was to keep switching noise out of the audio ground.
Now working but sounding a bit light on bass - I'm going from a hifi amp tape out - is the input tranny loading this too much :?: Will hook-up with something with more drive.
Also got the blue LED with a switch in parallel with the opto LED. Should it light with gain reduction - seems to have no effect on compression :?:

Volker - enough adjust in 2 Meg trimmer to align the meter to 0dB.

I had similar voltages to Volker - EXCEPT - neon voltage only 52 volts - any ideas/ should I change something :?:

 

[mikeyB]

[quote author="Benny"]After putting my D-AOC stuff in the new case and testing it I've got a problem with the right channel.
Both channels input and output pots work, both channels are compressing
but the second channel has no bass. Just high frequencies and it sounds like it is distorting when it's compressing heavily. I just checked if I've got some wrong parts in channel 2. But compared to channel 1 everything seems to be the same. I'm using Edcor WSM on input and XSM on output.
I'm gonna look over it again tomorrow morning. Any ideas?[/quote]

Benny - Did you sort the 2nd channel :?: - this could be my problem as well

 

[mikeyB]

Volker said "I put in a (red) LED, paralleled to the Vactrol LED (to watch if it will light - since I was able to measure Audio at that point). There was no light, but - compression."

Lookiing at the picture with the blue led in antiparallel - is the LED lit or does it just look like it from the picture :?:

 

[[silent:arts]]

blue LEDs antiparallel will lit.
all others won't.
don't ask me why :grin:

 

[jrfred453]

I also installed blue LEDs in parallel and anti parallel attached to a switch with no change in compression. I suspected the problem was that the LEDs I purchased were water clear. I have ordered some blue diffused to replace them with. The red LED works fine. Silent Arts picture showed using a blue diffused LED.
My red LED which (I think) I put in parallel does light with compression

I used the on board jumper for the PSU3 ground/ floating ground. Should I have left that out since I'm using relays?

Got my D-AOC fired up last week. I had only one problem (mistakenly put in 470K resistors in place of 470R) which threw all the voltages off a whole lot. Glad I spotted the wrong resistor values because this is my first tube project and I was a little lost.
Sounded great but now I'm waiting for a replacement tube that seems to have been defective and my front panel to arrive.

 

[[silent:arts]]

[quote author="jrfred453"]I used the on board jumper for the PSU3 ground/ floating ground. Should I have left that out since I'm using relays?[/quote]
no. this is just an option if you actually have clicks.
don't know why I always doing this ground jumper thing, have been unsure with the relays in my first PCB :grin:
have always jumpered the grounds together with no problem since ...

 

[seavote]

i have no molex crimping tool for the molex connectors used in this project. if i read correctly the crimping tool cost over $200. will any crimping tool do? ive seen these connectors assembled(crimped and in the sleeve? or base) it looks like the wire is crimped while in the sleeve. or is it done outside the sleeve and then pushed in(easier than im making it? i hope so) i was thinking of salvaging enough from discarded electronics (i have access to large amounts) i was able to find the exact heat sink for thispcb from salvage. the larger one. i was able to get the other two from mouser. but buying new connectors would save on time and labor. any ideas?

 

[MartyMart]

I have only used the Molex stuff a few times, I took the wire - pre tinned and
poked it into the metal "sleeve" as far as the first open "crimp" section.
Squeeze that with needle nose pliers and apply solder - not too much or it
will run down and spoil the little "spring" part of the connection at the bottom.

Done !!

I prefer to use those "screw terminal" connections, more expensive but very
quick and solid too.

MM.

 

[mikeyB]

[quote author="mikeyB"][quote author="Benny"]After putting my D-AOC stuff in the new case and testing it I've got a problem with the right channel.
Both channels input and output pots work, both channels are compressing
but the second channel has no bass. Just high frequencies and it sounds like it is distorting when it's compressing heavily. I just checked if I've got some wrong parts in channel 2. But compared to channel 1 everything seems to be the same. I'm using Edcor WSM on input and XSM on output.
I'm gonna look over it again tomorrow morning. Any ideas?[/quote]

Benny - Did you sort the 2nd channel :?: - this could be my problem as well[/quote]

BUMP :? - scratching my head on this one - checked on the wiring, looks ok - tried other valves that are known working in other gear - not the valves. Bass starts to roll off below about 200hz - looks about 10db down at 40Hz
Any help much appreciated :thumb:

 

[mikeyB]

I was starting to suspect the transformers and then just read this thread
http://www.groupdiy.com/index.php?topic=9813
Analag - your original comp was transformerless? I'll try this - do i need to pad the output any, or just use the output pot to control gain. I just go unbalanced from the output of the 10u solen and ground?
By the way - using Edcor XSM 10k/10k on input and XSM10k/600 on output

:?

 

[maxwall]

Anyone kind enough to respond....


Input transformers

1:1(600:600)

UTC A20
Altec 15356A

will these work as inputs ? any circuit mods required ?
or does it have to be 10K:10K or 15K:15K to work properly ?
_______________________________________________________
Output Transformers
15K:600

Seems several Edcors are mentioned but which Model # yields best results for $$ ?


XSM10K/600
WSM600/10K backwards

 

[user 10827]

ha! Kubi that is awesome....love em!

:thumb: :thumb:

 

[analag]

What can I say

analag

 

[[silent:arts]]

ah, there is your coming out :green:
please, give me an "infront" shot for my virtual rack :grin:

 

[MartyMart]

WOW - Darius that looks awesome !!
Blown away man !!

Marty.

 

[skipwave]

Darius, that's insane! I'm actually a little scare looking at those. :thumb:

What is meant by "Precision Edition" on the silverface one? The already discussed modifications, or something else?

 

[toffifee]

Beeeeyouuutiful!!! :grin:

 

[maxwall]

Anyone kind enough to respond....


Input transformers

1:1(600:600)

UTC A20
Altec 15356A

will these work as inputs ? any circuit mods required ?
or does it have to be 10K:10K or 15K:15K to work properly ?
_______________________________________________________
Output Transformers
15K:600

Seems several Edcors are mentioned but which Model # yields best results for $$ ?


XSM10K/600
WSM600/10K backwards