Access-312 Build Thread

[3nity]

Phantom led is supposed to be soldered on the phantom pushbottom.
solder on the front legs...

 

[3nity]

see how led is wired my friend...

 

[buildafriend]

thanks very much! i'll be sure to implement that as soon as I get it running! If I ever do. I mean I will.

 

[Harpo]

schematic

the schematic and parts/values question was related to the psu.

Any answer on the psu question or did you get the phantom voltage part running with all 4 Ch. +48V activated simultaniosly ?

 

[3nity]

I have been asked about a new batch.
Right now i have no plans but if interest is there.

I need at least 10 people interested in a couple each!

Let me know!

 

[dandeurloo]

I would do more cases as well.  Heck I may have a few in the shop still.

 

[buildafriend]

schematic

the schematic and parts/values question was related to the psu.

Any answer on the psu question or did you get the phantom voltage part running with all 4 Ch. +48V activated simultaniosly ?

+48 volts is running on all four channels, as is +/- 16v to every card. I noticed that +48v is hitting the output pins as well as the input pins but only when it is turned on. This is also hitting the chassis. Now I'm faced with challenge of figuring out where. A new problem has also arrived recently. when the gain gets half way up, a short oscillation occurs and the signal dies. This is with phantom power on or off.

I'm hitting my breaking point and considering selling it at as a fixer upper to a more advanced tech. The amount of hours that I have put into trying to repair this are getting to be too high. I am starting to feel that continuing would be a bit irrational. I've had it looked at by two friends who are more advanced than I am and we can't seem to isolate what is wrong. This idea kills me but sometimes knowing when to quit is wise. The money I make back will be going towards a new project.

To anyone considering going in on the next batch who might have read about my issue please be aware that mine were mistreated by a person other than myself and that the boards do work great. They sounded amazing.

I have a friend who asked me if I knew where to find 312 cards. I'll be sure to let him know about the possibility of the second batch coming.

 

[3nity]

I told you.
Send it to me and i,ll have a look.

 

[chipss36]

I sure hope another batch is made, think I would like to build a few.

 

[chipss36]

So I have ordered 4 boards and am hoping collective cases has a case left,
Out of you people who have built these , any advice ? What were your favorite in/ out transformers? Op amps? Or any other advice or lessons learned on your build?
Looks like dans case needs an external power supply?

 

[sr1200]

depending on how many units you put into it you can certainly fit a PS in there with everything ( i did a 4ch unit with PS) was a BIG 1U case but no noise or anything, and works great, I also did my own front panel  (i put little LED VU's on each channel).

 

[3nity]

I really like cinemag best for transformers.
Op-amps i cant tell enough good about John Burdij SMD2520.
Dan case for the 312 is fantastic...

Good luck.

 

[chipss36]

Great info , so I am looking at the 2520smd op amp , specs say 20 vdc,
What are y'all running them at? 18vdc? Just planning the major parts out.
I am planning on using psuniversal ps and have that ordered , CMOS-2s outs ,
What cinemag input are y'all using ?
Anyone try nickel cinemags On the outputs? 50% or high nickel? Overkill for a 312?
Dans case and ps built external ,
The vp gain switch bundle for a stepped gain,  that's about it so far

 

[Spencerleehorton]

Hi Guys,

well i would be in for say 4 boards to be put into a large case if they are available in the next few months?

regards

Spence.

 

[Humner]

Hey guys,

I have some 100k rev log pots spare - Will the 100k work ok? Would I need to make any adjustments to other components?

 

[3nity]

Im not sure 100K will work but for every different value theres R4, R5 and C7 to change...

 

[Humner]

not to worry, I have found a 10k kicking about my parts bin.

If I was using a GA80071 300:2k7 Tamura transformer - would I need R6-7 and C8?

 

[3nity]

GA80071 needs a 4.7K  @ RC.

 

[Humner]

excellent, thanks for your help.

 

[Spencerleehorton]

Hi Guys,

got my 4 boards and they look great!, just wanted to check a few things:

1. Power can come from the same as the SSL 9k psu board from gustav?
2. Gonna use OEP A262A3C so what should R6 and R7 be? any other considerations for the circuit if i use this?
3. Gonna use balancing board as per SSL 9k, could i use this as well as put another output to a transformer?
4. Can i etch my own DOA, is there a design for it available?
5. What should the jumpers be set to with this config?

Im only planning on doing 2 first of all with this config, the other two i was goning to use EA 2622 and EA 2503.

regards

Spence.