MCI JH-636 Story

briank

analog for the people!
Where did you get your Gepco cable? Redco has it in all colors of the rainbow for $0.14/ft. That's probabl what I'm going to do because then I can make up the harness in the original colors MCI spec'ed.

My studiomate got it, I think through Full Compass. Redco is excellent too.


Yeah this whole wiring thing with this caliber of console is just a new and interesting thing. And yes it makes a WHOLE lot of sense when you think about the jack panels in the recording rooms as essentially a remote jack panel for the mixer, so why would you have jacks on the mixer too? Same thing at church...we have a Allen & Heath GL-3300-32 there.

I used to have a GL-3300-24. Nice mixers. But yeah, makes me wonder who was popping for the Mic Patching option on this console in their day--not many people, apparently! The 'bays don't pop up too much. Who needed them when the studio lines were all intended to hit the console mic channel inputs first thing!


I must say, though, yes the Tuchel's seem like the bane of the late model MCI owner, but the Tuchel jack rack on the back of your JH-600 is...cooooooool. :cool:

They do look cool :D And they do have their pluses. Nice to be able to move things around, at least in groups of 4-8. Example, since I only have one Tuchel made up for the preamp breakouts right now, that's 8 mic preamp lines that I can pop into whatever group of 8 channels I'm wanting to use on the console--1-8, 9-16, 17-24 etc...also if we were to, say, add another 8ch of digital converter i/o, I'd probably move the 8-track channels over 8 places on the patch bay to accommodate them; this would simply mean unplugging its two Tuchels and snapping them into the next two sockets over...so worth a bit of the hassle for a little mobility should I want or need to reconfigure.

Brian, what is the module with the transistors above the power terminals at the lower right of the back of the console?

That's part of the PSU connection module; the transistors (and red test points above 'em) are +5v. That whole cover plate with the transistors and PSU terminals comes off with some screws and there are four more 8,700uf audio rail caps lurking behind it in big silver GE cans like the ones in your 416 PSU...I guess the eight 8,700ufs in the audio PSU weren't enough lol. I'm not overtly looking forward to replacing the big power supply caps...
 
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sweetbeats

Reel deep thoughts...
Get your big caps from TEDSS.com. MUCH better stock and MUCH better prices than Mouser, Digikey, etc. I like the Mallory CGS caps.

You got a lotta big cans on that thing.
 

briank

analog for the people!
Get your big caps from TEDSS.com. MUCH better stock and MUCH better prices than Mouser, Digikey, etc. I like the Mallory CGS caps.

You got a lotta big cans on that thing.


I recall seeing your link there in a different thread. Have you ordered from them before? They consistent and reputable? I checked prices on 10,000uf replacements in correct can size and their prices were indeed MUCH better than Mouser and in stock as you say--saving five-ish bucks per cap really adds up!
 
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sweetbeats

Reel deep thoughts...
Yep! Ordered from them three times, and every time the order was quick and accurate. Totally satisfied.
 

briank

analog for the people!
Great, thanks Cory!

Can sizes and temp ratings being equal, Mouser can get me 10,000uf, 40-50v audio PSU caps for $15-23 a pop depending; TEDSS can do them for $10-15. No brainer there, though admittedly none of those are Mallorys...I think Philips and Cornell Dublier.
 
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briank

analog for the people!
So Sweetbeats was asking for a little vid of our MCI machine in his Ampex thread...and I had to roll some tape tracks into SchmoeTools yesterday so I decided to catch a bit o' the setup for it for y'all. Nothing too fancy, just a geek at work with a slightly grouchy machine that I added some subtitles to when I got home. The machine is

owned by my studiomate Jeremy, though I brought it back to life, do all the maintenance, and am the main user of it. Alan The Bearded Console also has a cameo...so I guess we're semi on topic here! I'll get back to the "story" soon!

Sorry I don't have a video camera, had to make do with my ancient point and shoot...also never mind my mid-summer heatwave whiteboy 'fro...LOL :D

I'll tell you what Cory, your Ampex machine still wins the "boss transport and relay noises" and "ultimate heavy-duty mofo" awards hands down! :p


Password: tapeisgood (shh, don't tell anyone) :rolleyes::D:D
 
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sweetbeats

Reel deep thoughts...
I love it!!!!!

I love itIloveitIloveit!!!

You get the Oscar...your video is AWESOME!

AND...If I ever get an MCI JH-110C you are coming out for a visit.

Brian I'm really impressed with your fluid setup technique. You know that machine. It is lucky to have you around...and It is really cool to see Alan with the 8-track machine. What a treat! And it is wonderful how great the project sounds even through the camera mic...

Thanks so much for putting that video up! Captions, editing and all...very cool. I imagine many will enjoy watching it. I think for any analog tape enthusiast it will make us all want to play with our machines.

Kudos! :D:D:D
 

sweetbeats

Reel deep thoughts...
And I really like how the MCI machine is setup...the electronics drawers are just...nice. Oh and the reel motors doing that little twirl when you first power up? I wouldn't sweat that...likely just the result of inrush current when you first turn it on and the main filter caps are charging...there's peak current there and I'm pretty sure that makes the logic circuitry briefly wig-out.
 

briank

analog for the people!
Yeah, I like the drawers! I didn't show it in the vid, but the whole transport decks flips up like, "open up and say 'ahh!'" I like that too!

Cory, it's only a matter of time before you come up with a JH-110. "A guy wanted $50 bucks for it, little beat up and only a 200 mile drive!" I will be green with envy. I'm DYING for a good 2-track deck, it's SORELY missing from my rig and another JH-110 would be the natural choice due to familiarity (and good sound!)

I never worried about the reel motors on startup, I'd swear there was some language somewhere in the manual saying this is normal, but all the same I like to avoid powering the machine up with tape spooled in case the tape load sensor were to fail--don't wanna go stretching tape!

Thanks for the kind words gents, I was indeed happy with how those tracks turned out. 499 at +9, 15ips really is the business for those who are about to rawk! :D I hate to say you really do lose some magic when you turn it all into 1s and 0s though...
 

sweetbeats

Reel deep thoughts...
I think I'm set for mastering decks...the MCI's are very nice, but I have my Tascam BR-20T which is just slick-slick-slick as far as tape handling and I think it sounds great too, and its box stock right now. I may look at minor changes in the future just to lower the noise floor though it really isn't a problem. It is loaded with...4580 opamps? Can't recall for sure, but whatever they are they are basically a low current draw version of the 5532. It sounds really nice.

And I ALSO have my Ampex 440C project machine. Don't know when/if that will ever come to fruition, but if I ever had the time to go through that machine I'd have a nice match philosophically with the MM-1000. The 440C is a basket case right now but has tremendous potential cosmetically and functionally. In the end it'd all be loaded in a good condition factory Ampex roll-around and equipped with the servo capstan motor...I even have the stainless covers for the amp cards. I have thoughts of loading a Flux ME head for the play head and running at 30ips. Anyway, pick your poison!

But I look at how your MCI JH-110 was setup and it is clear that it was designed by people that work the machines...it is a production machine. Very cool.

Hey and on the whole 1's and 0's thing...yes...Some time back I did an A/B test of a rough mix monitored straight off the DAW, and then looped through the BR-20T...had both sources setup on a monitor flip switch on the mixer so I could just A/B in real time and the difference was astonishing to my ears. I truly love the sound of analog tape. I recorded the the two rough master versions and put them up on the web. I think some people couldn't hear the difference that much but I just listened back to them recently and it is vast to me. I'll put links below. So both wav failes were mastered through the exact same path except that one took the loop through the Tascam halftrack. Keep in mind these are rough mixes. No mastering processing, and actually IIRC no eq either...just rough levels and pans...no effects. The reverb is from the hall mics. So my point is that I can still hear a significant difference in the one that went through the (uncalibrated) Tascam, but some of the shock factor got sucked out when they both went back through the A/D converters.

Go here: Index of /audio/test 2010_04_07

Just right click on each and save to your PC and then set them up in your media player so that you can kind of go back and forth between them.
 

briank

analog for the people!
Cory, I somehow missed your post until now! I took a listen between the files a couple times just on a decent pair of headphones (Grado 225s) and the differences were immediately obvious for sure.

I know what you mean on the shock value being reduced once the signal becomes 1s and 0s. Mixing tape through a console down to a DAW is killing me. Going from the console monitor feed to the ProStools output monitor feed during mixdown, it's just...a bummer hearing what's getting lost in the conversion. I need a good 2-track deck, like, yesterday. LOL!
 

briank

analog for the people!
RIGHT! Sooooo...forgive my neglect of this thread, I'm way behind! Let's see, let's see...where did I leave off...well, I'd gotten Alan wired up and did a general sit-rep. I expected that there would be a few funky pots, some tired switches, some IC pins that would need a good cleaning and lots of cooked caps and that's...pretty much exactly what my tests revealed. A number of EQ sections wouldn't even work due to shot caps, and I also had several channels that wouldn't light up which again turned out to be cooked caps--in fact, a couple of them had shorted and caused the console to be clandestinely stuck in solo, which was a real bitch to figure out :spank: :D The automation also seemed to be completely batty, as is typical with un-refurbished 600s.

The good news for the latter was that I could switch off the JH-50 automation system and worry about it later, as the faders still worked manually. Leaving the auto switched off cost me the grouping system--which is a bummer as it lets you slave any faders to any fader you want set as a master (say you want to control your whole drum submix just with the kick fader, for example)--and it also cost me the soft mute and solo-in place, which isn't a big deal because each channel also has a hard mute, and two more solos (one for the buss out and another for the monitor). Generally, I felt I could do without these for a while and decided to make a basic cleaning of the console and PSUs and full re-cap of all modules my top priorities.

On the plus side, even in its tired condition, I was pleased and quite relieved that the channels that did pass audio OK hinted at this being a very decent sounding console indeed. There was undeniable punch and weight to what I was hearing and I knew right away that this was going to be a console worth the hard work. I was face to face with a whole new sonic ballgame!

Ah, but first thing's first...wiggle your big toe! I started by cleaning the fader packs so I could start mitigating compound signal loss problems. My method was basically to open up the faders (which as far as I can tell are MCI-made P&G-ish types, or at least they sure look familiar), give them a dusting with a shop vac and mini-nozzle kit (really REALLY handy around electronics!), loosen up and remove crud and oxide with swabs dipped in alcohol, then give a final polish/lube with faders dipped in Fader F5 on the rails only. Some of the rails were so oxidized and crusted with dust, boogers and beard hair that they could barely move. Others weren't so bad, but I didn't run into a fader that didn't benefit from the cleaning. Afterward, the faders were all muuuch smoother and more consistent.


Here are some pics of a typical fader pack. As it turns out, my console's fader packs have the venerable DBX 202C "goldcan" VCAs!

IMG_6762.jpg



Here's a fader pack with the fader assembly pulled out of the way. There are more ICs and caps in the packages that have been causing problems. Once the channel module re-cap is completed, the fader packs are getting the same treatment with fresh 'lytics. Keeping the IC pins clean will be an ongoing maintenance point along with keeping the faders themselves clean; I just take a pencil eraser to 'em.

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Here's a typical fader needing cleaning. This one was neither the cleanest nor dirtiest, but lookit all that crap!

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Here's a first and second pass with a swab. Eyyyooooo!

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And here's a fader pulled apart, with cleaned up rails--but looks like I hadn't gotten to the felts yet.

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Cleaning the faders was tedious and it won't be the last time I have to swab them, but it was clear that nobody had touched these suckers for many, many years and now that I've caught them up, it won't be such a big job to keep them tidy now. Note that the fader packs are also one of the few parts on a 600 series to have the infamously didgy Molex connectors. Between Molexes that need routine re-flowing, faders that need dusting, and the IC pins that like to oxidize, I will have ongoing reason to pull out the fader packs and give them a general cleaning up ( BTW, oddly it's mostly the 741 IC pins that get all black and gross, and seems to be tied in not so much to the red sockets, but a certain couple brands of ICs that are prone to oxidation).



At this time, I also opened up the power supplies for a cleaning and sit-rep. Again, they were dusty and neglected, and I wanted to inventory the capacitors and anything else I wanted to slate for replacement. The shop vac and mini-nozzles again proved really, really handy--much better than an overpriced can of compressed air sending gobs of dust flying all over the room!

IMG_6836.jpg



Here are the two PSUs. On the right is the audio supply, which has the +/-18v rails as well as 48v phantom power. On the left is the peripheral supply, which supplies the lamps and logic and also houses the automation power, which has its own on/off toggle. On a side note, I have already re-capped all the regulator boards, and will be doing the big filter caps very soon, starting with the audio supply.

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The audio supply is fan-cooled and also packed pretty tight; as such, it's pretty prone to dustiness, as I found when popping the top.

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There are two fans on the back of the audio PSU; these are attached to "chimneys" that pull out for access to the heatsinks, which are especially prone to a dust carpeting!

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Here are a couple of the big audio filter caps, 8700uf 40v. In total there are 8 or them in the supply chassis....

IMG_6834.jpg



...and four more in the console frame just behind the power cord terminal strips, for a total of 12! I will be replacing them all sooner than later, and with higher values: at least 10,000uf each, and I might possibly go as high as 22,000uf!! Hehe :D

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Now here's the top popped off the Peripheral supply. Not quite so densely packed, but there are seven of those tall 10,000uf Mallorys and a short fat little 10,000uf/75v lurking in the back corner. This supply is not fan cooled, just a couple big sinks on the back of the chassis.

peripheraltopview.jpg



I had tons-o-fun pulling the chassis apart to get between caps for a dusting, and to remove the regulator board for a re-cap, which you can see on the floor in front of the PSU here. There were only a few caps to do on the board itself.

IMG_7123.jpg




OK, I'm sick of typing :D In the next installment, we will FINALLY get to The Great Re-cap of all the modules, which has turned out to be a real tedious pile o' fun and games :D
 

sweetbeats

Reel deep thoughts...
Cory, I somehow missed your post until now! I took a listen between the files a couple times just on a decent pair of headphones (Grado 225s) and the differences were immediately obvious for sure.

I know what you mean on the shock value being reduced once the signal becomes 1s and 0s. Mixing tape through a console down to a DAW is killing me. Going from the console monitor feed to the ProStools output monitor feed during mixdown, it's just...a bummer hearing what's getting lost in the conversion. I need a good 2-track deck, like, yesterday. LOL!

IIRC version "A" is the one taking the trip through the Tascam BR-20T. It sounds more dynamic, wider image stage, softer but with more presence...so many things upon which its hard to place finger but to my ears undeniable "better". I can't understand why any recording facility home or otherwise doesn't have at least a good analog halftrack tape machine in use.
 

sweetbeats

Reel deep thoughts...
Brian,

Are the elements in those faders conductive plastic? I've had some advisement from folks I heed to only use distilled water on those and use new cheesecloth for wiping. Anyway that's what I'll be using on the P&G packs on my JH-416...no Molex's on the packs, just those outrageously cool gold-plated locking cinch connectors, but I make up for with a buhjillion Molex connectors on the motherboard. :( :rolleyes:

Your pics are great.

Those PSU's are beeeeefy. Even at the stock values of all the main filter caps are you considering adding soft-start circuit? You really ought to look at doing that especially if you bump the capacitance up. I think with the Power-One module filter caps and the local filter caps in my JH-416 I'll have around 180,000uF of filter capacitance to charge when I hit the "go" button...you'll have a bit more than that I figure if you bump to 22,000uF for each of those filter caps, yes?

Keep up the great work. Alan is in great hands.

Thumbs up to this thread!
 

sweetbeats

Reel deep thoughts...
Oh SNAP I just noticed you've got "dreaded red sockets" on your fader pack PCB's, yes?! Is that going to be a problem?

What is carried on that ribbon connector on the fader PCB?
 

briank

analog for the people!
IIRC version "A" is the one taking the trip through the Tascam BR-20T. It sounds more dynamic, wider image stage, softer but with more presence...so many things upon which its hard to place finger but to my ears undeniable "better".

I had A pegged for the analogified file, and confirmed it to myself literally before the first note on B played. Even just the noise at the beginning sounded thinner and harder, digital calling cards lol. I agree, A has much more mojo on the bottom, more musical, little more dull on top but yet somehow not missing anything up there unlike how digital is missing something "down there" if you get me. I hear the same things going between console and ProTools monitors while printing mixes, so going between your files sounded familiar to me.

On a side note, I can't wait for you to hear your 416 :D


Brian,

Are the elements in those faders conductive plastic? I've had some advisement from folks I heed to only use distilled water on those and use new cheesecloth for wiping. Anyway that's what I'll be using on the P&G packs on my JH-416...no Molex's on the packs, just those outrageously cool gold-plated locking cinch connectors, but I make up for with a buhjillion Molex connectors on the motherboard. :( :rolleyes:

Far as cleaning the faders, I should explain that only hit the metal parts up with any alc, made sure to let it evaporate and not contact any plastic. The Fader F5 is safe for conductive plastic. Hadn't had any problems so far. I don't expect to use alc for future cleaning, but a lot of those suckers were really grimy!

Your gold cinch connectors really ARE super cool :D I wonder if they were optional or de rigueur on the 416s? The console and tape machine PSU quick conns, and the tape machine's Autolocator connectors are all standard cinches, no gold to be found and they do need their "teeth brushed" periodically :D On a side note, I noticed in the options section of my console's manual that there were gold-plated Tuchels optionally available. I don't think I've ever actually seen an example of one though, bummer!


Those PSU's are beeeeefy. Even at the stock values of all the main filter caps are you considering adding soft-start circuit? You really ought to look at doing that especially if you bump the capacitance up. I think with the Power-One module filter caps and the local filter caps in my JH-416 I'll have around 180,000uF of filter capacitance to charge when I hit the "go" button...you'll have a bit more than that I figure if you bump to 22,000uF for each of those filter caps, yes?

Yeah if I went up to 22,000uf that would be, what, more than a quarter mil mfd...hehehe :D Soft start definitely crossed my mind! Need to look into that!

BTW, did you notice the little breadboard at the back of the audio supply? Has a couple 'lytics and a resistor on it. I really need to figure out wtf that is!


Oh SNAP I just noticed you've got "dreaded red sockets" on your fader pack PCB's, yes?! Is that going to be a problem?

De-snap, de-snap! :D This console is chock FULL of the red sockets and based on some things I'd read about them, I'd expected them to be disasters and have to suck it up and change them out as part of the re-cap, but several guys on (and off) the MCI forum talked me out of it and I'm glad they did, because those red sockets have been the least of my problems in this console.

The "dreaded reds" have been pretty heavily demonized by some people on the internets--probably fairly in some cases, I'm guessing especially cases where pins were seated and re-seated a million times until the wipers wore out--and they're indeed not great quality, but really, they just haven't been directly causing me any wholesale problems. I think I've pulled out maybe 3 of them for new machined Mil-Max sockets because they'd "let lose" and weren't holding the ICs properly...3...and there are hundreds upon hundreds of the things in this console. I'm just not that worried by them. Incidentally, between the console and tape machine, I've run into other sockets that were green or black that looked and felt just like the red ones.

The real IC related problems I've found have been that certain brands and types of ICs are especially prone to oxidizing--in particular XC branded 5534s, and especially XC and TI 741s (like this. These chips have had the old "black pins" going on, and not just in red sockets--I have found this to be the case in somee much better machined sockets too, so although I don't care to run to the red sockets' defense too much because they're not the greatest quality, I can't scapegoat them too much. Interestingly I have had much lower incidence of severely oxidized pins on MCI's OEM chips which I presume to mostly be originals (MCI2003, 2004 which are 5534 and 5532 equiv respectively).

My resolution with the sockets in question was to buy a tray of a couple dozen Mil-Max machined sockets in DIP8 and DIP14 for the spares bin, and if I have any sockets of any color or type directly causing problems, I'll change 'em out case-by-case.

At any rate, whatever socket it came out of, 10 seconds with my pretty Pink Pet :D will turn this...

IMG_7027.jpg


...into this ;)

IMG_7033.jpg



The biggest problem spots on this console so far as I've found are spent caps (by far the biggest problem), the F switches which need cleaning/exercising, the fader pack Molexes which need re-flowing and "spring" bent back into the contacts as is familiar to all other MCI equipment, and a handful of dodgy pots which turn out to be a PITA to get replacements for. Far as oxidized IC pins, each channel has a couple dozen chips and on average I probably pull a couple for cleaning as part of my re-capping prep.


What is carried on that ribbon connector on the fader PCB?

The red ribbons are automation cables. Signal and power are via Molexes. The 2mix and monitor master packs have not auto and are hard wired.
 
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lo.fi.love

Functionally obsessed.
Hey, I'm really curious about the dbx componentry on the faders. Does this mean that each channel strip has VCA compression?
 

briank

analog for the people!
Hey, I'm really curious about the dbx componentry on the faders. Does this mean that each channel strip has VCA compression?

No compression, they're for VCA automation.

There HAS been some murmurings among the MCI boffins about ditching the automation and modding the dickens out of those suckers for channel compression which I have to say could be interesting, but it never went past murmurings.

These dbx goldcans are sought after and fetching decent prices on the used parts market. The thought has also crossed my mind that they could possibly be replaced with, for example, modern THAT VCAs that could conceivably sound better and cost a fraction of what the old dbx's could fetch. This could raise enough bucks for a good 2-track deck or even a 2" or both...ah, but who knows!
 
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sweetbeats

Reel deep thoughts...
Oh I missed that little proto board at the back of your PSU...huh! I see the two caps, resistor annnnd...is that a little TO-220 IC on there? Can't tell where the wires go/come from. You ask anybody on the MCI forum about that?

I have some chips in my Soundtracs board that look a little black like that...reminded me of the tarnished contacts on the silver plated Switchcraft XLR's. Messing around with using Tarn-X to deoxidize, water to rinse and DeoxIT D5 to do a final cleanse and protect. "Pink pet"...sick, but clearly effective...heheh.

That's a good dose of relativity on the red sockets...seems mere mention sends the faint of heart running for the hills when maybe in some or many cases its a matter of dealling with the bad parts, being prepared for more down the road and moving on. Certainly your point is important in that there are plenty of other components that fail through course of time and normal use. Its the way it goes.

Quick comment too on the differences in the quality of the materials of amplifier IC's...yeah those 2003 chips for instance are 5534's but I'm pretty sure MCI was descriminating in where they were sourced and the material spec, etc. I know the 2001 opamp cans in my JH-416, which are Harris HA-911 opamps, have nice gold-plated pins and such. Quality is more than skin-deep.

And the connectors on my faders...I'm pretty sure that was the standard interconnect for those P&G faders.

*sigh*

I can't wait to hear my JH-416 too...gonna be awhile, but it'll be fun getting there. Focusing on finishing up my Soundtracs cleanup first...16 channels to go...and getting the MM-1000 working reliably and getting it calibrated...getting a working studio basically, and that's all on the back-burner right now with more important projects here at home. All in good time.

In the meantime you're keeping me entertained with the guts of your JH-600.

Are those cinch Jones connectors inside your PSU? The one with the proto-board? And I just really like the backplane on the mixer frame. Their mixer design really went through vast changes in refinement from 400 to 500 to 600. So many great little ideas you know?
 
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