CAPI-Gear; CA-0252 (2520 Type), CA202 Opamp Kits and DIY Parts Galore!!!

[jsteiger]

Hey Rob, Sorry for the delay in response. I went to Nashville over the past weekend.

What is the size of this card, is it much taller than a 500 series card ?   Sorry I've never seen an API console in the flesh.

The face-plates for the 812 modules are .75" wide by 10.65". The PCB's are 10" by 4.6875". Not quite as deep as a 500 series card.

Also what is the connector like ?  Is it similar to the 500 series connector or different ?

The cards have 2 sets of gold finger edge connectors of 15 pins each, .156" pitch. So, the required connectors are exactly the same as used for the 500 series.

How many transformers does the board require & of what type ?

For transformers, I use Ed's 2623-1's. They are implemented in exactly the same way as on the original input channels. Something similar could also be used. They are wired for 6db of step-up gain. Only 1 is required. It balances the "send" signal of the insert point. Due to the .75" wide spacing, I am mounting mine under the motherboard on a dedicated PCB that is standoff mounted to the motherboard.

A second x-fo could be used for a direct out feature if so desired. I have no need for this in my application. It is just a parallel feed taken after the 2nd 2520. I would have to dbl check, but I don't think there are any edge connectors available. If so, they are all bused together and I didn't want to cut all the traces. That is really for my application though seeing as how I am working off of the original motherboards from my desk.

Cheers, Jeff

 

[gar381]

gar2520 update...

500 PCBs are in the mail to me from the board house. 

With a bit of luck LOTS of PCBs and full kits will be on the
classicapi store by Weds June 24 !!

GARY

 

[Rob Flinn]

Jeff,

Thanks for your responseun, I hope Nashville was fun.

I'm trying to work out how feasible logistically & financially it would be to maybe make a 16 ch desk out of your parts. I suspect I'm not the only one thinking of this sort of project.   So I'm sorry if I'm asking loads of dumb questions but you're probably giving me info that is useful to a few people.
 

With just the ACA & booster board, is it simple to make a basic stereo mixer so you could say plug 16 ch out of Pro tools into 8 st pairs ?
i.e it looks like you could just make that board up & plug straight in, or are some input transformer required to make it really work ?

When using the monitor boards would it be possible to use 2 of the 4 channel ACA boards to create 6 summing amps for 4 echo sends & 2 monitor sends, with a bit of track cutting  ?

Obviously this sort of project is not for the faint hearted, but I was looking at it from the point of view that one could start basic & build the thing up into quite a comprehensive mixdown desk.  Is there anything info you can add to the feasibility of this idea ?

 

[alexc]

Received DOAs, thanks Jeff and Gary

Looking good! Now to have me some DOA fun.

Until my next order!

Regards
Alex

 

[pryoga]

Also received order downunder.

Also thanks to Jeff and Gary.

 

[Tubemooley]

With just the ACA & booster board, is it simple to make a basic stereo mixer so you could say plug 16 ch out of Pro tools into 8 st pairs ? i.e it looks like you could just make that board up & plug straight in, or are some input transformer required to make it really work ?

When using the monitor boards would it be possible to use 2 of the 4 channel ACA boards to create 6 summing amps for 4 echo sends & 2 monitor sends, with a bit of track cutting  ?

Rob - I can answer some of this until Jeff comments......

With just the ACA & booster board, is it simple to make a basic stereo mixer so you could say plug 16 ch out of Pro tools into 8 st pairs ? YES. But it depends on what you consider a "basic stereo mixer" to be. It could be matched resistors for passive summing into the ACA's. Or you could have level and pan for each channel before heading to the ACA's. But the outputs from the DAC's only have so much drive before you need make-up gain. So then your simple mixer just added a bunch of amplifiers. It depends on how simple or not simple you want this mixer to be.

i.e it looks like you could just make that board up & plug straight in, or are some input transformer required to make it really work ? I think YES. I believe the input to the monitor module can be (or just is) the so-called BTA (balanced transformerless amplifier). Or input trannie's could also be used.

When using the monitor boards would it be possible to use 2 of the 4 channel ACA boards to create 6 summing amps for 4 echo sends & 2 monitor sends, with a bit of track cutting ? I think YES. You can grab all the echo and monitor sends from each monitor module and sum them up and then output those signals for additional external processing.

I'm sure Jeff will help confirm or deny my replies to your questions when he gets a minute. DW.

 

[Rob Flinn]

Thanks Tube,

I just need to work out if I have the £1k+ needed to do this.  Then there's the shipping......... & the customs charges............... & the chassis to mount it all in................ PSU.

Anyone want to buy a Trident ??

 

[jsteiger]

I'm sure Jeff will help confirm or deny my replies to your questions when he gets a minute. DW.

Hey guys,

Rob, Dana is right on with all of his comments and answers to your questions.

For dedicated L-R summing only, no sends, level or panning, (would all be done ITB), you would essentially unbalance and route all signals thru 47K bus R's and into the respective ACA.

As for the summing of the Cue and Echo sends, the 2-ACA-Bo cards are currently the easiest way of handling this. This will also be the method I plan on using for my monitor section. The original Master Cue modules in my board have a few more features. Mostly Solo and a few different routing options. They also can sum the monitor Echo return in with the Cue mix. Originally there was only 1 monitor Echo.

I do have a proto board all ready made that is 4 Echo returns in a .75" by 10.65" module (same as 812d). Basically just 4 DOA balanced receivers with level and pan. I haven't had the time to populate or test the board yet. It's also been a while since I worked with it at all. It has Solo, Mute and Stereo Bus on/off. This would actually be a kind of "down and dirty" way of a simple line input mixer with no sends. With 8 modules that would total 6" in width, you would have 32 "discrete" line inputs.

I guess I have a lot of work to do...

Thanks for the help Dana. :-*

Cheers, Jeff

 

[jsteiger]

Hello gentlemen,

I have just received the first batch of Ed's EA2623-4 PCB mount version of the 2623-1 transformer. These are perfect for the 2-ACA-Bo boards among many other things.

Here's a quick link if you are interested.

Cheers, Jeff

 

[Tubemooley]

Rob..... That is the trick right there. These projects we dream up (not being sarcastic) get expensive quickly. PCB's, passive components, connectors, power supply, sheet metal and chassis, hardware, pots, knobs, DOA's, transformers, shipping, customs...... It can be very depressing. Start with a small, realistic project and don't keep adding features. Try to design in some "hooks" to add features later. Try to make the box serviceable and upgradeable so you can go back in later. Or build a small project knowing that you will build additional complementary boxes in the future. DW.

 

[alexc]

Expensive quickly, no doubt!

Still, it seems like making an interesting small sum/router box with some nice iron and doas
is definitely doable.  Here's looking foward to another potential pcb in the Jeff's set. 

Thanks for the interesting descriptions on some of the possibilities everyone.
It's giving me lots of ideas to try out.

 

[jsteiger]

Expensive quickly, no doubt!...

For sure Alex! Very expensive. I added a few new things to my Ref Docs page today and had a chuckle when I saw the front of a 1974 API 2488 Brochure that Dennis Johansson sent to me. I thought of your comment and had to post the pic. Not trying to be a smart *** but I guess the good stuff has always been costly! 

BTW, Gary mailed me 70 full parts kits and 30 pcb's to go with the 30 kits I have here. So, I will have about 100 gar2520 complete kits by Monday.

Cheers, Jeff

 

[jsteiger]

Hey all,

Here is a link to a post in my VP2x support thread. Volker has ran about a dozen Audio Precision tests of my pre with many different DOA's in it. He also has a reference of a vintage BAE racked 312 card.

Very interesting. I have to say the gar2520 fares very respectably in these tests.

http://www.groupdiy.com/index.php?topic=33501.msg418425#msg418425

Cheers, Jeff

 

[alexc]

That 2488 is mighty sweet. Great. Just excellent.

 

[jsteiger]

gar2520 Full Kit Bundles are back in stock!!  ;D

Here's a quick link http://classicapi.com/catalog/product_info.php?cPath=71_72&products_id=136

Cheers, Jeff

 

[jsteiger]

Gentlemen,

I have finally received more stock on the Plain 5/8" knobs for 1/4" shaft. It was exactly 1 full month after my the promised delivery date on my order acknoledgement.  :-\

Oh well...nothing I can do about that.

Here's a link: http://classicapi.com/catalog/product_info.php?cPath=23_24_40&products_id=38

Have a great day 

Jeff

 

[Benny]

Received my 2520s and knobs yesterday.  ;D

Thanx

 

[jsteiger]

Received my 2520s and knobs yesterday.  ;D

Thanx

Thanks Benny

A few updates:

For the 812d, I have the new board revision due in to me by July 10th. I incorporated a handful of circuit tweaks, mostly in the meter buffer, along with a better physical layout for the relay circuit. I moved around quite a few things near the relay to reduce some vias too. I also incorporated a 3 pin and a 7 pin Molex header to accept a small daughter board for Bourns PC mount pots. The most time consuming thing about building the protos was the jumper wiring for all the pots. This will clean and speed things up nicely. I already have all of my pots and they are Bourns. For those who have something else or are getting something else, make sure the pot body is not more than .5" X .5" or they will not work with the faceplates. 10K logs are required.

Due to all the changes I made, I only have 1 of each board coming. I want to build and test before ordering a small mother-load! I will keep this thread updated on the progress.

On the EA2622 front, I have another batch of 50 on the way to me now. I still have a handful in stock, but they seem to go pretty fast.

As as far as the EA2503's, they are in production and will hopefully ship to Ed any day now...then to me. I am expecting a more definite time frame from Ed today.

My 2 DIY pre modules have been added to the LunchBoxHero website database, which is cool. If you're not familiar, it's a quirky little site for pro audio cats who are in love with the 500 series. Check it out here. Pan60 is a moderator over there. I think he may just be more insane than our Tubemooley, DW! 

That's about it for now.

Cheers all!
Jeff 

 

[alexc]

Look forward to the improved monitor boards.

I think I'm going to have a go at a modest line mixer with wood and steel and faders and vu meters.

Can't help thinking that it all evolves to attempting a console at some point in time.
812ds and acas look like a real opportunity to make a nice, serious monitor board.

Exciting! 

 

[jsteiger]

Hey guys,

For the month of July, I have put the VP25 pcb and VP26 pcb on special.

Also updated the expected delivery on the next batch of Ed's 2503's to July 13th.

Cheer!
Jeff