500 series modular API style console...625CR Control Room Module Done Page 21!!

[jsteiger]

Jeff : I was wrong about the 2503 , the xfmrs inside the 528 modules are 2157 , Do you know something about them ? the only purpose is to balance the insert send and the multi out channel. Can be replaced by a 2623 ? I think the 2157 are smaller . Does yur modules have 2157 's ?

Regards

pedro

Pedro,
I have a channel here from a friend's 1604 that has a 2157 on it. The 2157 is exactly the same physical size as a 2623-1. I really don't know much about them but I'm sure Ed or CJ do if they see this. I don't think you would need to replace them though. So, no, my input channels are all 2623-1's. I have no 2157's in my desk at all. What year is your board? Mine is a 1976. That was stamped on the underside of the original 440 fader faceplates.

Cheers, Jeff

 

[PATAPETER]

jeff: the date in the schematics is 1973.Yes they're smaller than the 2503. And in the aca/booster cards there're all 2623 xfrms. No 2503.
May be the 2157 are equal as the 2623 ?. I will ask CJ. Are you familiar with the xfrmrs from sowter ? They provide a replica of API's transformers.
Ed is eddie cilietti ? I know him. I've got a pair of urei la-4 modified by him.

pedro.

 

[Tubemooley]

Ed is Ed Anderson. He designs audio transformers (among other things I'm guessing). He may be located somewhere in the NYC area but I'm not sure. He seems to stay off the radar most of the time but he's around somewhere. Jeff knows how to contact him. Eddie Ciletti is a good dude too. If he works on something, he does it right. DW.

 

[PATAPETER]

Jeff : I've been thinking about the xfmrs 2157, i have a page with spec of all API xfmrs. Looking at it i discover that there are 2 2503 , there's the 2503-1 and the 2503-2 , and looking at the size of them , i realize that one is smaller than the other , so may i saw one 2503-1 inside my 528 module and the 2503-2 is the one in the 312/325 cards. Could that be that way? I will look in other modules , may be i've grab an too old one.
Here's the spec for Api xfmrs.

 

[PATAPETER]

and the other page

 

[jsteiger]

Jeff : I've been thinking about the xfmrs 2157, i have a page with spec of all API xfmrs. Looking at it i discover that there are 2 2503 , there's the 2503-1 and the 2503-2 , and looking at the size of them , i realize that one is smaller than the other , so may i saw one 2503-1 inside my 528 module and the 2503-2 is the one in the 312/325 cards. Could that be that way? I will look in other modules , may be i've grab an too old one.
Here's the spec for Api xfmrs.

Pedro,

The only difference is that the 2503-2 is mounted in a channel-frame, the 2503 is not. The actual transformer is the same size. You either saw a 2157 or a 2623-1 in your 528 modules.

The 2157 is not shown on that spec sheet.

Have you seen the reference documents page at my site?

Cheers, Jeff

 

[PATAPETER]

Yes jeff i think the xfmrs spec are from your page...sorry about that. But the 2488 diagram has a new 528 T ,mine have the 528 B and C, no vca's. I promise you that i will investigate more about my modules and tell you later.
Thanks for your time.
Best regards,
Pedro.

 

[jsteiger]

Yes jeff i think the xfmrs spec are from your page...sorry about that. But the 2488 diagram has a new 528 T ,mine have the 528 B and C, no vca's. I promise you that i will investigate more about my modules and tell you later.
Thanks for your time.
Best regards,
Pedro.

Pedro,

That block diagram is from a friend. That is not my board. But anyhow, I am not sure where the "T" came from on the 528T. The VCA's shown there do not reside on the 528 modules. They are on 350 cards used for submaster boosters 1-4 for the quad. My desk used them too for boosters 1-4. The 350 card is similar to a 325 but had a 2551 VCA on it as well as a 2520 and some other bits. The output trafo on this card was a 2623-1. I rewired the first 4 slots of my card cage and just use the same style 325's as the rest of the submasters and 2-mix.

I would gather that the PCB's for your input modules are labeled the same as mine. The transformer/opamp side is 2149-119 and the switch side is 2149-122. You'll have to remove the shield PCB to see the 2149-119.

FWIW, my friend has a Datatronix 1604 that was born about 1979. His input modules are the same PCB's as mine.

Cheers, Jeff

 

[PATAPETER]

jeff : i will investigate and tell you soon. This days the api is working full time and i can't take a module out . The letter beside de 528 means the version of the module, on the schematics of your friend there's a date REV 9/10/01, and the module is 528 T . I have 528 B & C and the differences are that the c version has a dual concentric panpot (pan+level in the center) and also c has an IC very small than the B that has an transistor don't know what's that for.
Thanks again for you chatting with me about this stuff.
Best Regards.
Pedro.
PS: could you ask CJ about the api 2157 ? I've tried to send him a PM but his box is full.

 

[PATAPETER]

JEFF : here's a picture of the module this is a c version datatronix....see the assy #. I trying to get the schematic for the 528 module but i've gave it to a tech and he didn't brought it back. Do you have one ? or the one that have your console or the 1604 ?
THanks.
Pedro.

 

[jsteiger]

Pedro,

The IC is only for the peak detection circuit, not for audio signal path. No worries there. 

The older PCB's were not labeled like yours/those from Datatronics. I assume my friends 1604 was still built from old parts that were in stock when Datatronics bought API. Kind of like the 550a/550a-1 story.

Cheers, Jeff

 

[AP carrier]

Brilliant work so far Jeff. I'm watching with keen interest.

With the input module I'm assuming the 2623 is used for balancing the direct out? If this is the case could the x-former be excluded to run an unbalanced direct out? At this stage I've got no real need for balanced direct outs but it would to have the option of 'updating' in the future if the need arises.

Cheers,
Andrew

 

[jsteiger]

...With the input module I'm assuming the 2623 is used for balancing the direct out? If this is the case could the x-former be excluded to run an unbalanced direct out? At this stage I've got no real need for balanced direct outs but it would to have the option of 'updating' in the future if the need arises.

Andrew,

The 2623-1 that is shown on the input channel module is 1:2 and is actually used to balance the "preamp" or "1st stage" output, which is essentially the insert send. The balanced signal from this transformer typically goes to a patchbay. The return signal from this patch-point goes to the channel eq input. The channel eq output then returns to the input module channel and directly drives the fader unbalanced. Long story short, the 2623-1 you see is not for direct out purposes. I will get to the "direct out" in a moment. BTW, a small jumper under the motherboard to connect this transformer directly to the fader can also be used if someone so desires.

I spent the day tweaking the metal work CAD for the input module section yesterday. I am very happy with it so far. The are only 2 different parts required for each bucket. The top/bottom are the same part and interchangeable. The sides are also interchangeable. It works our perfectly to just keep adding sections together. It is a little hard to explain. I have a few more drillings/tappings to finalize before I get a small proto run of metal parts done. To complete the hole layout, I need to finalize the bus module depth.

The input module motherboard is completely designed. I just need to send the CAD files/layers to my friend for a conversion to Gerbers.

I am trying to think 15 steps down the road so all the pieces and parts work together nicely without any modification or major problems.

So, today I am working on the 16 subgroup busing module. I am starting that one first as it is the easiest. Andrew's direct out question gave me the idea to add an optional 2623-1 to the bus module for direct out duties. It is not necessary but with be there for anyone who wants it.

I only have a few hours today as I have 7 or 8 store orders to pull and package. Like Volker, I would like to be cloned please.

...is a projecy for a full modular desk?

Yes 6t9r. This is the beginning stages but that is concept. API style like they did it in the 1970's.  8)

Cheers, Jeff

 

[analogical]

I know a trustworthy dealer of methamphetamines off of Madison ave. if you are intrested, I can send him to your door.   =P

 

[zayance]

anyway great to see you still putting some time for this project, really cool...

 

[jsteiger]

I know a trustworthy dealer of methamphetamines off of Madison ave. if you are intrested, I can send him to your door.   =P

LOL! Thanks but I have my own legal solution. I take it in IV form.

Bad Ass Coffee

I just wish I lived there... :'(

 

[PATAPETER]

Jeff : question: the Eq out going to fader means that the hi (+) goes to fader in and the low (-) goes to the common audio bus ? Or the low goes to chassis to unbalance the signal ?
And I don't see the purpose of having 16 busses in a line summing desk . May be you can explain me that a little more.
Another issue : I want to know if you can do for me a project . I want to clone the 528 with out the 8 busses and aux & cue send.Only a ST button for assign to st buss.
Meaning : Mic/line switch ( the exact copy of the mic/line preamp).
             Pad switch (only for mic )
             Reverse pol ( Mic/Line )
             Gain pot. And phantom switch.
             Preamp out ( to patch bay and normalized with the EQ , exact our consoles patch.
             Ch on switch and Pan Pot. And maybe solo in place too. But optional.
             Fader ( a rotary one , could the T-pad be used as a fader ? it's 600 ohm like the 440 fader)
             Then the most precious thing about this design the 2 buttons filter (It sound so nice.I think because there's a 2520 on that).
             And Finally the Multi out With another 2621-1
             Also the ST buss out unbalanced going to the ST Mix ACA / Stero Fader / and then Stereo booster. That pcb you already have.
Well jeff.....Could you do that for me ? I want to get from you 24 pcb of that an all components. 2621-1  and gar2520 kits and 2622 too.
Well it's a big project.Tell me what you think.
Cheers...Best regards.
Pedro.

 

[analogical]

Hey Jeff great idea with the the plug and play DI, that's gonna be fun!
Any updates on this side of your efforts? 

 

[jsteiger]

I have been pretty busy with pre-built modules and fighting with my recently discharged paint shop for screwing up 150 VP faceplates.  ???  Unfortunately, I have only spent a few hours on the modular console over the last week or so.

Where I left off was during the layout of the standard type 500/51x series bucket that will be used for this. I envision 2 or more uses for this bucket. Overall, it will be the same 18 pin edge connectors, exactly as we are doing for the 51x project. Outside connections I am aiming for .156" Molex (like on the input channel motherboard) and also DB25's. Works nice since they are in 8 channel buckets.  ;D  First use will be channel eq and or dynamics if you want. Pretty straight forward connection wise to the input channels.

2nd use will be for 500/51x mic preamps. Here I am thinking on a small daughter board that will have a Dsub for line input and relays. This will allow the user to select what device is feeding the input channel. Same main backplane for either bucket use.

I am trying to get the main building blocks set so I can standardize the metal as much as possible. The fewer over all parts the better.

Cheers for now...
Jeff

 

[zayance]

8)