MCI mic pre

Hi All!! :grin:
I'm trying to rebuild a MCI mic preamp, the one with Jensen 115K.
On the schematics there's an opamp named 2003M.
Anyone can tell me where I can find it? If it is obsolete there's a valid alternative?
I would like to keep the original design (round pinout)

I'm trying to find a valid PSU too (+/-36V, +48V)

Thank you very much.
Nick

Go to recordingconsoles.net and ask around for Steve Sadler. He'll be the guy to help you with this.

there are quite a few variants of the 500 series. The orginals used 2002 IC's through-out. These will run on +/-36V rails. At some point MCI began using 2003 ( 5534 ), but to run these off +/-36V rails required redesigning the circuity around the IC and transforming the use of the transistors that originally formed the buffer circuit for the 2002 into a natty little circuit that pumps the rails around the 2003 in response to the signal passing through them to maintain a max of 36V across the +/-v pins. Hard to explain easier to draw.
So what schematic are you following? Are you able to post it up?

I've seen MCI 500 that have had 2003 ( 5534 ) directly subsituted into place of 2002 running of the original +/- 36V power. That they survive this abuse is quite remarkable.

The 2003 were also used in the JH100 machines. I was told years ago (early 80's) that the round can 2003's were actually LF356 opamps. In my JH100 I did replace them with 5534's because they are a much more stable IC and sound better than the LF356's.

If you do have any with the round metal cans, what I recommend doing is getting the Augut 8-pin DIP sockets with wire-wrap pins. These are long enough that you can bend them around to fit into the round can config. It will sit close to 1/2" above the board, but atleast you can use the regular DIP package.

That 2002 running on +/-24v is a nice sounding IC! Great mic pres in the 400 series IMO.


M@

[quote author="mediatechnology"]You can still buy the 2002 as an HA2-2645-5 (in metal) for about $35 each! The 8 pin DIP in ceramic HA7-2645-5 (same part) is about $8.50 each.

See:

http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail.jsp;jsessionid=JSYPX4QUCYBI2CXDUY0SFGAK2OTCGIV1?SKU=06F5266&N=0 [/quote]

Interesting to read all this. Years ago a local studio owner was indeed looking for these '2002's as well for his MCI-console. We couldn't think of a replacement back then.

Thanks guys!

This is the schematic I'm looking at:
[/img]

Did you mean youre building it from scratch or youre fixing an existing one?

If youre building it from scratch you can put any opamp in there, perhaps an OPA2604 if you want to turn the rails down to +/-24v or if you want to go to +/-34v our (JLM) 99V is the only opamp I know that can do it. But then you wouldnt need the output transistors.

Actually our Hybrid opamp is probably nearly the same as this circuit if you add an input transformer...


What are you trying to do again?


M@

I would try to rebuild it, using the original design.
I have details of the original pcb (it was separate from the channel pcb) and i would like to use it instead of design a new one...

I think the language barrier is getting in the way... Please correct me if I'm wrong, but I don't think Nickos is rebuilding one of these things - I think he wants to make one from scratch.

Peace,
Al.

Sorry... I think I can't explain myself very well :roll:

I have an original preamp card an I want to build some other unit like that.
I would like to copy the original pcb and then add a psu and an out transformer.
Everything like the original.

Nickos

Hi
Can anyone make some drawing of MCI 500 preamp without EQ.
I lost chance to buy one channel and maybe try to make only mic preamp.
Also we have +/- 36V what IC is substitute for 2002?
Thanks
Duka

[quote author="mediatechnology"]The HA2-2645-5 is the substitute for the 2002.

The device page and data sheet are here:

http://www.intersil.com/cda/deviceinfo/0,1477,HA%252D2645,00.html#data

http://www.intersil.com/data/fn/fn2904.pdf

Sorry but I don't have the schematic for the 500 preamp using the 2002.[/quote]
On my 500 schematic (who is unreadable) I think all IC for in, out and EQ are 2002 :?

[quote author="mediatechnology"]I've seen JH-500Bs that were all 2002. Are the modules on your console yellow? I think that would either make it a JH-500B or earlier.[/quote]
I havent yet MCI but I wanna know concept because I would like to rack one channell if I buy it.
Thanks
Duka