Access-312 Build Thread

[soundsactive]

@sl1200 - what model of trans did you get from Avel? i'm also rocking the Whistle Rock 16/16/12 PSU.

also, how has everyone's luck been with Cinemag? i emailed Dave at the beginning of November, did receive an email back, then called him, payed, and now it has been since Nov 18th and i haven't gotten anything :'( he also has been to quick to get back to recent emails...

 

[sr1200]

Ive found emailing cinemag gets ya nowhere but if you get em on the phone stuff happens right away, i know they were out of stock on the TX's for this project for a while (which is why you might be waiting)

As far as what tx i used for the ML powersupply from WhistleRock... i didnt use an avil, i used a triad from Mouser I believe it was the http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT36-1390/?qs=wkKrz7WmEgM2EIrgD3Tzhw%3d%3d  a bit of warning though, its a little fat, the case is a bit swollen where that thing sits.

Does anyone know if the 30VCT version would work for this project?  I remember reading that you can use a 30 or 36, and i think the 30 is a little bit smaller than the one i used...

 

[sr1200]

Hey did 3nity ever divulge the secret to adding some of Whistlerocks DI boards to the access board?

 

[buildafriend]

Ive found emailing cinemag gets ya nowhere but if you get em on the phone stuff happens right away, i know they were out of stock on the TX's for this project for a while (which is why you might be waiting)

As far as what tx i used for the ML powersupply from WhistleRock... i didnt use an avil, i used a triad from Mouser I believe it was the http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT36-1390/?qs=wkKrz7WmEgM2EIrgD3Tzhw%3d%3d  a bit of warning though, its a little fat, the case is a bit swollen where that thing sits.

Does anyone know if the 30VCT version would work for this project?  I remember reading that you can use a 30 or 36, and i think the 30 is a little bit smaller than the one i used...

yeah you have to call him up, and bug him a little bit. i called to check the status on mine and he sent mine out right then. im not sure if he was sitting on them or if he gave me some that he did not plan sell at the moment.

 

[thesystem]

3nity or someone else who knows:

I want to add an output attenuation pot to the access preamps. This way I can drive the input transformer and opamp harder and get some saturation but not clip when going into pro tools.
How can this be done?

 

[3nity]

An easy solution an many people did this is try a 1k linear pot...at pin 2 and 3 at the output.
you can wire a 5K pot in series with a 5K resistance in place of R4 too.

 

[thesystem]

So you combine two wires together and solder it to the XLR pins right? xlr-out 2 on the PCB goes to pin 2 on the xlr plus the 1k linear pot goes to pin 2, same for pin 3. That should be it?
Any suggestions for a 1k linear pot?

hmm I wonder if I can fit 4 PCBs with an extra output pot+ impedance switch and powersupply in a 1RU case.  ??? anyone who has done this succesfully or should I consider mounting them vertically in a 2RU case..

 

[sr1200]

i have 4 units in a 1u and would have had room to have a pot between channels (more than enough room actually)

I think putting the pot at R4 would make more sense since you only have a single lead to deal with and its pre transformer. my 2c.

 

[thesystem]

i have 4 units in a 1u and would have had room to have a pot between channels (more than enough room actually)

great, good to hear!

I think putting the pot at R4 would make more sense since you only have a single lead to deal with and its pre transformer. my 2c.

I take it you mean pre output transformer? I don't know if that's better or not. What are the advantages/disadvantages for putting it pre transformer? Just for comparison, is the attenuation on the Vp312 from classic api pre or post tx.

Final question (for now  ): if I would put the pot at R4 how is this done then? Just a wire from one lege of the resistor to one of the legs of the pot?

Thanks for helping guys!

 

[sr1200]

Yeah i think that's what hes saying to do (im gonna have to do the same thing for the new boards im getting).  Would be the resistor to a wire to the wiper i guess of the pot then out of the pot back to the now empty pad of R4.  My question is does it make a difference which side the resistor is on?

 

[soundsactive]

what is the average current draw on these puppies? say, 4 cinemag with 2 gar 2520/2 SLL red dots? trying to find a power transformer that isn't way to over board.

and yea, finally got an email back from cinemag, the guy i was talking to left the company shortly after i placed my order and it fell through the cracks. 

at least now i can hopefully get it into the mail system!

 

[buildafriend]

well.. I got them all wired up and I was really excited. until one of my PSU caps started smoking.

 

[frazzman]

what is the average current draw on these puppies? say, 4 cinemag with 2 gar 2520/2 SLL red dots? trying to find a power transformer that isn't way to over board.

and yea, finally got an email back from cinemag, the guy i was talking to left the company shortly after i placed my order and it fell through the cracks. 

at least now i can hopefully get it into the mail system!

30VA does the job

 

[buildafriend]

They are thick and responsive as hell. I would build more if I could afford it. Thanks for all the help everyone.

 

[3nity]

wow.
Neat and clean man!
Good looking build!
Thanks

 

[buildafriend]

wow.
Neat and clean man!
Good looking build!
Thanks

Thanks very much 3nity! 

 

[thesystem]

An easy solution an many people did this is try a 1k linear pot...at pin 2 and 3 at the output.
you can wire a 5K pot in series with a 5K resistance in place of R4 too.

Can someone elaborate on the pros and cons of wiring the pot pre transformer (at R4) or post (output pot)?

 

[buildafriend]

An easy solution an many people did this is try a 1k linear pot...at pin 2 and 3 at the output.
you can wire a 5K pot in series with a 5K resistance in place of R4 too.

Can someone elaborate on the pros and cons of wiring the pot pre transformer (at R4) or post (output pot)?

Who says you can't do both?

 

[thesystem]

An easy solution an many people did this is try a 1k linear pot...at pin 2 and 3 at the output.
you can wire a 5K pot in series with a 5K resistance in place of R4 too.

Can someone elaborate on the pros and cons of wiring the pot pre transformer (at R4) or post (output pot)?

Who says you can't do both?

you mean with 2 different output pots? i don't think that's what I want. So, to make my choice I'd like to know the difference

 

[buildafriend]

From what I would imagine, simply attenuating the gain post xfrmr would give you the most driven sound the gain stage offers, since it would be at max potential. Changing the gain from the amplifier it's self allows for softer gain staging. I could be dillusional though. Haha.