Harrison 4032 restoration?!

[nrgrecording]

Who! There is some history with serial number 65: it was on fire in the past.  Powersupply seems to be stable. 
Hmm... note to self: check gnd against + and - rails before putting the channel back into the console. 
The -24V psu goldfinger contact is unusable. I think I will use this channel for spare parts I need in the master section. (switches... I can't get the old ITT ones, only the newer alps but the don't have solder lugs on top of the switch and I need some switch-caps anyway)

 

[Rob Flinn]

Why don't you use the Toneluck switches ?? Their quality has improved, & I've have found them to be ok.

 

[pucho812]

Who! There is some history with serial number 65: it was on fire in the past.  Powersupply seems to be stable. 
Hmm... note to self: check gnd against + and - rails before putting the channel back into the console. 
The -24V psu goldfinger contact is unusable. I think I will use this channel for spare parts I need in the master section. (switches... I can't get the old ITT ones, only the newer alps but the don't have solder lugs on top of the switch and I need some switch-caps anyway)

you mean your not going to use a trace repair pen and fix it ;D

 

[nrgrecording]

Why don't you use the Toneluck switches ?? Their quality has improved, & I've have found them to be ok.

Hmm... ok. Thanks for the info! I have to ask the german distributors. Or is there any online shop where I can get these switches in small quantities like 50 or so?

you mean your not going to use a trace repair pen and fix it ;D

Someone used the "hot repair pen" before! Hopefully he found out what the right side of the soldering iron was! 

Someone cutted some traces between some LEDs and the led's current source. And the monitor master module was modded from a quad monitoring module with transformer outputs into a none channel monitoring module with a potentiometer and a mute switch plus a nice non-working-leds-mod.

Problem/Question:
The emitter resistors of the output driver (line/driver or output transformer circuit) (complementary pair) burnt through. (10 ohms). Whats the best idea to fix it? Replacing them with the same 1/4watt 10R resistors? Or replacing them with 0,5W types or two 20R parallel resistors? (one at the top pcb, the other the bottom pcb)

Any ideas?

(I added some plastic screws to one transistor to avoid shorts between both transistor legs.)

Frank.

 

[porkyc]

With regard to doing the faders.
DO NOT get any silicon lubricant on the conductive plastic track. PG use a Dow-Corning lubricant. Caig make a fader lube that will last you through another 6 console rebuilds because you use it so sparingly, and you can put a microscopic wipe of this on the track. Like any Caig product, the price is culture-shock, but I think their products are worth it. (No connection with Caig, just use their products 'cos they work).
PC

 

[porkyc]

Re the output stage and the 10R resistors,
Note that the resistor(s) in the amp stage next to the one in question have "burnt" resistors. Those resistors are probably only carbon; fit 1/2W metal-oxide ones and stand them off of the board. Again, it's a bit like cars. AirCon is now pretty much standard and non-negotiable, whereas 30 years ago it was unheard of as a standard for the average car. Similarly, metal-oxide resistors were a luxury, nasty, noisy carbon resistors would do.
Remember, we recorded to tape and so no matter what you did, you had a noise floor that was audible, so carbon vs metal oxide was purely an economic discussion. The console noise floor improvement from MO resistors was going to marginal in the grand scheme. Tape covered up a multitude of sins!
PC

 

[nrgrecording]

Thanks PC for the info!
I ordered Caigs Faderlube... will ask P&G for the Dow-Corning stuff.
10R 1/2watts are on the ordering list, too.

Frank.

 

[SSLtech]

...Is this a (LARGE) 4032 in the occasional control room shots of this tune:

http://www.youtube.com/watch?v=IarQsEd0mLg

Anyone hazard a guess regarding what the room is?

-Keith

 

[nrgrecording]

Oh... a 4032 with mastersection in the middle. Or is it a 4832?

I finished the first extender this week... the pcb can be used as a male or female connector...
or both if you want to make harrison riser-cards like they're used for computers.  ;D

Got a reply from anotherone with a 4032 - he said it lasts 9-11 month to 'get all the gremlins out'.
I think its time to order some electrolytics now and plug the masterchannels back to the console.

 

[SSLtech]

Oh... a 4032 with mastersection in the middle. Or is it a 4832?

The extenders look NICE!!!

In the video I counted 28 channels to the right ("high number" side) of the center section, and it looks like another 24-28 over on the other side, to the left hand side as you'd look at it from the engineer's position... That means most likely a 56-channel ('5632') unless I'm mistaken...

Keith

 

[porkyc]

There were lots of 4832 consoles made. There were at least 6 sold in Londonto my knowledge On the other hand, some people did cobble together 2 consoles and extend them themselves. I've seen a 3624 and a 2824 put together. There was a beautifully refurbished genuine 5632 that came on the market a couple of years ago, this was 32,masters,24, and that was the only one made, right at the end before the MR2 came out.

 

[SIXTYNINER]

that in picture is in italy and for sale

6T9R

 

[SSLtech]

Ooh... what are those two extra knobs where the scribble-strip should be?

Nice D827 remote... and it's not often you see the remote meterbridge also.

Keith

 

[MartyMart]

That's Bob Sargent ( producer ) sitting in the middle of the desk with "stick on ears" !
He's a mate so I can ask about the desk if you like ..... doubt that he will remember much though !

Marty.

 

[porkyc]

I think the 4832 at Marcus Music had this fitted as well, the extra pots on the scribble strip. They are extra sends, and might use the rear quad busses. other contributors might be able to confirm this. I didn't like it because it ruined the look, but then I wasn't mixing on it!

 

[nrgrecording]

Cool... spareparts for my 4032!    only 500.000$

http://cgi.ebay.com/HARRISON-4032-CONSOLE-USED-TO-RECORD-THRILLER-OTHERS_W0QQitemZ110476022950QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item19b8e254a6

Iam working on a vca replacement circuit at the moment... to replace the dbx202 with a modern that218x. Iam not sure if the circuit is correct or not. Maybe someone could take a look?
Its based on Jakobs "DBX202 Emulation Circuit". The series resistor to the control port in the console is 1,43K so I changed the 1K resistor at the feedback loop of the opamp to 1,43K.
I think I would like to use the pre trimmed 2180 vca while they're pretrimmed in the factory. I have a distortionmeter but it sounds easier and better to use the pre trimmed ones, although I can't add some nice harmonics by trimming them 'wrong'.  ;D I found a company who offers VCA replacement pcbs for the MCI consoles, they seem to have adjustments for distortion, ControlVoltage and the possibility to add 3 more vcas in parallel. As far as I know this reduces noise because the signal is linear and the noise is in "only" RMS? How can I add more vcas in parallel? Do the vca inputs needs a resistor and all other pins are in parallel?

I did a small schematic...
http://www.nrgrecording.de/temporary/VCA1.pdf

Maybe I can put everything on the same size of the original dbx202, so it can be used to replace other old dbx202 in other applications.

Thanks,
Frank.

 

[[silent:arts]]

Frank, I'm sure you know this:
http://www.thatcorp.com/datashts/dn127.pdf

 

[nrgrecording]

Yes... I read it several times.

There is an info about paralleling vcas and that there is an 6dB Improvement with 4 paralled VCAs.
They used 10k resistors in series with the signal input to stop "thumbs" and offsets when paralleling the inputs without 10k resistors. It feels that the "31K6" resistor (in the console circuit) at the imput needs to be changed when using more paralleld vcas because of the changed (internal) input resistance. (like shown on page 4) in the 'design note 127'. But I don't know the input resistance of the 2180 vca?

In the THAT2002 the used 4 THAT2181 in parallel. Input series resistor is 1,4k.
So the 31,6k reistor needs to be replaced with a 30,2k resistor.  (31,6k (existing input resistor) - 1,4k (internal input resistor) = 30,2k (resulting new input resistor)
Instead of 10k, the 4 VCAs will need four 5,6k input series resistors.
The recommended circuit "20002N" has a 3,57k resistor at the input and 4k99k resistor at the feedback of the following opamp.

I would still like to know the input resistance of the 2180. It feels like I have to add different resistors in series to the input when using 1,2,3 or 4 vcas in parallel?

The dn127 pdf is more or less made as an info for replacing the dbx202 with a that2002, isn't it?

Frank.

 

[tommypiper]

if your "Harry" have penny & giles faders
don't use contact spray cleaner for clean it

It HAS Penny&Giles. Thanks for the info... I read that the conductive plastic types should be cleaned just with water, and if that doesn't help some dish liquid or so. For the metal bars i used some silicon oil. The faders move much quieter now! (the mechanical part)

There is just some tobacco, pubic hairs, dust - but no bread crumbs this time.  ;D
The pre owner used the desk as a computer desk before. I don't know if he ever recorded something with this desk when it was in his house.

;D ;D ;D ;D
Amazing thread, Frank...  I hope to visit you next time I'm within 1000 miles. 

 

[mpc3000limited]

You are doing a great Job Frank!  ;D Nice heavy project I know you are not afraid to get your hands dirty!!! Keep up the Good work!! Happy New Year too!!!