pucho's exploratative surgery on new console documented pics

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

pucho812

Well-known member
Joined
Oct 4, 2004
Messages
14,950
Location
third stone from the sun
O.k. this post will be long very long. So please do not quote any of the pictures as I have about a total of 30 in this posting.

Ladies and gents this is the documented exploritative surgery of a origial 1968 custon consle made for a studio called mcginly(sp?) audio studios. As seen from this post
http://www.groupdiy.com/index.php?topic=12945

Here we go into the first of many explorations as each time I find something new and sometimes unusual. The brief discription of the console is that it is a 12 tracking recording/mixing console designed to run with a 12 track recorder. Me thinks a scully,stephens as 12 tracks is unusual. it has 12 mic pres, 12 line amps, gotham faders, electrodyne eq's, pan buttons and 2 selectable pan knobs. Aside from L,C,R placement with buttons I can choose to use 2 pan knobs and do real time panning. Anyway here is the bloody details. some questions will follow as I am sctraching my head about a few things...


The night started off like any other night. A cup of coffee and Working on something or other.
1.jpg


last night was working on
2.jpg


and the console attached to it.

First we took off the wood shell to work on the conse. Here we see some shots of back part of the console

3.jpg

4.jpg


What do we see here. Why it's a bunch of UTC input transformers total should be 18 but 2 are missing and currently on order from leeds radio in NYC. I have labeled the trafos as the label is on the bottom and do not wish to remove them just to read it. There are also 2 UTC a-24 output trafos at the end. curious :shock:
5.jpg


We then propped up the main part of the console which has a flip up lid. It has no real way of supporting it but this part of a broom stick did the job. This is the underneith of the main channels section. It was taken before putting up similar stick on the other side.
6.jpg



The the left of that we have the mic pre and line cards. Complete seperate from the rest of the console. All wired together with wire as seen in previous pics. the Mic pres/pre amp cards are the top cards and are martin audio model 114-BC. The first 12 have Beyer tr45 mic trafos attached.

7.jpg


So we pulled a card out to examine.

Parts side
8.jpg



Traces side
9.jpg


Another overview shot, See those beyers :cool:
10.jpg


Next we see the line amp cards
Parts side
11.jpg


traces side
12.jpg

Very nice....
Moving along got into the gotham faders.
connected with a touchel
14.jpg


And of course the your fader is showing shot

15.jpg


Here we see the bottom of the main out left and right. No stereo fader just 2 mono ones. And what do we see attached the the faders why some more beyer trafos. this time model tr-145

17.jpg



Moving along to the electrodyne eq's. here we see the top. it's a concentric pot. The lower portion has a switch like so

18.jpg


A few have been broken off so we are looking for a replacement. Might go with different concentric pots all together. :grin:

Here we see the edge connector that is attached to each eq.
20.jpg

but with a quick gental pull we get
21.jpg


Now we can remove the eq and place it on a table as seen here.
22.jpg


Remove some screws and we see the inside.
Traces are found here.
23.jpg


The parts are on this side.
24.jpg

Has a trafo or looks like a trafo. on it andf I am thinking that black circular think is the inductor. could be?

And last but not least we have our power supplies

Starting off we have this.

25.jpg


The 3 power supplies connect to it. One end conencts to the console and the other end connects to AC.

This goes to the console
27.jpg


This end goes to AC. Not sure as to how much. The plug says 250V 10 amps / 125 V 15 amps. Could it be a eupropean/ US thing and that depending on which country you would select one? Pulled it apart and nothing on the inside to denote that. Could it be it runs on either or? could it be a 2 phase plug? I'm a lil lost on that one but will figure it out.

26.jpg




and lastly the PSU. 1 of 3 all exactly the same all pulling about 2 amps as denoted by the fuses in front.

28.jpg


Enjoy guys...
 
That black thingy on the Electrodyne... it might be an op-amp! (Make up gain for the passive eq.) I see another inductor.

The history of Electrodyne from a recent Tape Op.

http://www.cinemag.biz/electrodyne/electrodyne_part_1.html

Similar tape op discussion:
http://messageboard.tapeop.com/viewtopic.php?t=30593&highlight=electrodyne
 
Very cool! Check the traces and edge connector. It looks like you have audio and power. Which means that black thing could be a potted opamp. Possibly the AM-3, the predecessor to the AM-4 used in electrodyne, langevin, and quad eight modules. Show me the graphics now!
 
You may have modules there with an undocumented discrete op-amp!!

King went on to share with me that year later, Art Moser, who had retainer the name ?Electrodyne,? agreed to sell Don McLaughlin (a friend of his) the name ?Electrodyne? and the second incarnation of Electrodyne was born. ?This time, however, they did not use the tube-based design but the new integrated circuit [IC op amp] designs that were just coming out about that time.? Actually theirs was an improved Fairchild 709 integrated circuit redesigned and called the A1000. Later this would morph into the Electrodyne A2000.

It also states the AM3 was square. You have a round can there. Any chance of reverse engineering!?!? :shock:
 
The black can is an A-1000 opamp. It really a Fairchild UA-709 IC opamp with discrete current boost transistors on its output. According to Ken Hirsch.
 
nice miko. thanks for the info... :thumb: MY missing trafos come in tomorrow... UPS willing... :roll: As for reverse engineering will take some time but will get done. At the moment looking for concentric knobs to fix the broken EQ. all EQ's are working but some of them have a broken bottom lever for switching the EQ freq. So all that is going adious and will be putting in concentric knobs and will have it all purty.

what do you think of these.( l like the one on the right. looks killer and will work with the console.)

Dakaware_concentric.JPG
 
That reminds me,

I recently inherited a big honkin' McCurdy broadcast console as well... with a total of 12 transformer input mic preamps, 4 parametric EQ's and 2 compressors... woo hoo !

dang... another project for the workbench. :shock:
 
It depends on your situtation and oppurtunist mind... when you're a techie for a place like the public broadcasting industry, which was uniquely my situation as a tech... I've picked up free secondhand McCurdy, Neve, cabling, patchbays, racks etc... simply because I asked for it before it went to the dumpster... but I seem to be the only one in my circle that wants to take the time to haul the stuff away and re-cap/refurbish such gear for recording use.

Although, the more you and I praise/hype McCurdy or anything else for that matter... the more valuable it may become.

because of digital broadcast technology, McCurdy CANADA is pretty much out of the console market... if they were wanting to get back into the game, I think re-issu'ing some of those boutique McCurdy mic channels of the 50's, 60's, 70's and 80's would be an awsome flavour of products for the ever growing market of boutique mic preamps.

Some of the more interesting McCurdy stuff is becoming somewhat rare now.
 
People seem to hold the AU300 in very high regard. Too bad you can't touch them for less than $300 a piece. Dave do you know if they use any tricky transformers like the Altecs of the era?
 
[quote author="NewYorkDave"]Like the AU300 :wink:

I've never used one, but I've seen the schematic and I like the design. Legend is that Howard Tremaine did the design, but I don't know that for certain.[/quote]

Hey Dave,

I'm not sure about the Howard Tremaine claim as well...?
I'm sure there's been several generations of people designing stuff at McCurdy over the years, and it would be nice if someone from that company could confirm this ?? Has their been anybody in this forum that has worked for McCurdy Radio Industries ?
McCurdy is apparently still in business though, with a much smaller operation of sorts, and website seems kinda primitive ? http://www.mcradio.com ... and I actually bought the a AU300 schematic from them.

I did a schematic layout file of the AU300 not too long ago, in Express SCH and haven't seen how importing this file to Express PCB has been relevant for the PCB design ??? I'm merly attempting my first PCB layout and I'm pretty much a greenhorn with these programs.

Many of the older transformers in McCurdy gear are specific wound from Hammond and are stamped MRI with a number of sorts ? You usually need the schematic or manual to know the exact specs of them.
 
[quote author="MikoKensington"]People seem to hold the AU300 in very high regard. Too bad you can't touch them for less than $300 a piece. Dave do you know if they use any tricky transformers like the Altecs of the era?[/quote]

more like $600 a peice these days...?

http://cgi.ebay.com/McCurdy-AU-300-Qty-2-Tube-Mic-Pre-Amps-AU300_W0QQitemZ7385368966QQcategoryZ119018QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/McCurdy-AU-300-Universal-Audio-Amp-Qty-2_W0QQitemZ7383545135QQcategoryZ23790QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
 

Latest posts

Back
Top