M-Series Refurbishment

With a comprehensive range of mixing consoles, Calrec has been a manufacturer of high quality audio products since 1964.

Moderators: GJC Designs, Richard Lumb

M-Series Refurbishment

Postby GJC Designs » Fri Feb 16, 2007 2:24 am

A 36-channel M-Series console has been acquired for refurbishment.
It has 24 mono mic/line inputs, 12 stereo line inputs, 8 stereo sub-groups and a stereo master output. It's from a broadcast studio that is getting a newer Calrec.

There is quite a lot of work to do to it in regard to cleaning and re-capping, but until recently it was on-air, so the overall quality as it stands should be ok. Of course the reality can only be determined once it is powered-up for testing. As it arrived late last night, power-up was not a priority.

More will be posted as the work progresses.


Update 1. 7 May 2007.

The PQ modules have been inspected for overall condition. Most have been recently re-capped...... well.... partially re-capped. The power rail decouplers have not been replaced and a small cap that lives under the gain switch shaft has not been replaced. In the 8 months prior to acquiring the console I was aware that an in-service console was being partially re-furbished, and as there were only 4 consoles of this exact type made, and as a colleague and I already owned 3 of them, it's a safe bet which one this was! The caps that are new are quality components, so are of no concern. The 3 old types will need to be replaced.

Module facia panels and knobs are a bit dirty, so a full strip-down is in progress to give them a thorough clean. Many of the knob-caps will be replaced as the present ones look old and worn. (Why is it that old green knob caps are more brittle any other colour, I wonder?).
Gareth
GJC Designs
Yacht Rocker
 
Posts: 304
Joined: Fri Oct 13, 2006 12:39 pm
Location: West Yorkshire, UK.

Postby Dr Benway » Tue May 06, 2008 7:24 pm

How is the refurb of the M series coming along Gareth?? Has it found a new home yet??
Dr Benway
Analog Enthusiast
 
Posts: 22
Joined: Sun Oct 08, 2006 6:40 am

Postby GJC Designs » Wed May 07, 2008 1:18 am

The refurb is going pretty well.... if a bit slow. It is not a full-time job. There has been some interest in it and its "big brother", a 48 channel M that was made around the same time but no-one has put their money on the table yet to secure ownership.

The partial re-cap that was done before I acquired the console has been stripped out and the console is undergoing a full re-cap with high-temperature low ESR caps. The EQ modules have been totally stripped to allow proper cleaning of the facia panels and control knobs. The majority of the coloured knob caps are being replaced. The overall appearance of the console is pretty good. Some of the LEDs were looking a bit dim, so all have been replaced.
Gareth
GJC Designs
Yacht Rocker
 
Posts: 304
Joined: Fri Oct 13, 2006 12:39 pm
Location: West Yorkshire, UK.

Postby Dr Benway » Wed May 07, 2008 5:04 am

Great to hear it's coming along!!!! And a 48ch desk too!! That I have to see!!
We are just about to install my M series out here in Australia.. In the next few months anyway..I'm sure there'll be plenty my tech and I stumble across during the install that'll suprise us. It's nice to know someone else out there is up to there neck in it too!!
What state of repair is the 48ch in?? Does it present a bigger challenge than the smaller one??
Dr Benway
Analog Enthusiast
 
Posts: 22
Joined: Sun Oct 08, 2006 6:40 am

Postby GJC Designs » Thu May 08, 2008 6:26 am

The 48 is actually refurbished and tested. The remote patch is pretty-much done with 11 metres of cable. There is a phantom power injector patchstrip that I have designed for the mic inputs - the console modules do not have a phantom switch, and phantom was usually applied by hard-wiring. My patch strip makes it much easier as you get the two TT sockets per mic inpu and an illuminated switch to show phantom is active. It's equally suitable for use on any other broadcast console that does not have individual phantom switching per channel.

As noted, the two M desks that I have are related. There were actually 4 consoles of a very similar spec (36/48 channel) that were made for one client. Over a period of time they got sold and moved around a bit, but through a series of coincidences, a friend/colleague who is a broadcast sound engineer (operational and technical) and I have bought two of the consoles, the modules & cards from console #3 (we were 2 days too late for the frame which got skipped!) and have an agreement relating to console #4. Spare modules/cards/PSUs are not a problem!

You have probably noted that this Calrec forum now has two moderators:
Richard Lumb works at Calrec and has been with the company for many years. His direct experience of more of the products is far more extensive than mine. I expect that between the two of us we will be able to resolve questions that you may have as your M-Series installation progresses.

The 48 channel M does not present many more technical challenges than the 36. Both consoles have press-fit connectors on the motherboards and these proved to be unreliable. The consoles were made at a time when press-fit was a developing technology. All motherboard connectors have now been soldered, and maneuvering the 48 channel empty frame off of the stand and upside-down to get better access to the motherboards for soldering was challenging. Not advisable as a one-man job! There have also been some changes made to the grounding of the centre section to improve noise and crosstalk.
Gareth
GJC Designs
Yacht Rocker
 
Posts: 304
Joined: Fri Oct 13, 2006 12:39 pm
Location: West Yorkshire, UK.

Postby Matt Syson » Thu May 08, 2008 9:47 am

Hi Gareth
Interesting to hear that the 'push fits' were not quite the revolution like 'sliced bread'.
I wonder what other ideas will fail in years to come (lead free perhaps?).
This was a general comment and NOT Calrec specific.
Matt S
Matt Syson
Engineer
 
Posts: 1030
Joined: Sun Oct 08, 2006 6:04 am
Location: North UK

Postby GJC Designs » Thu May 08, 2008 3:01 pm

Hi Matt,

Press-fit connector technology has moved on a lot in the almost 20 years since the M Series was made. Whilst at Soundcraft we looked at using press-fits, but the specifications for PCB hole size, plating, plus a load of other parameters was too much of a hassle to go with. Prior to Oliver and I buying the 48 channel M, I looked after it for about a year. There were issues with intermittent faults, and these all went away after the press fit connectors were soldered. This was not just a wild theory as Oliver was using the desk every day and kept a detailed log of the faults and repairs.... very useful when we acquired it!

Times do move on and progress takes place - the press-fit connectors of today, and the PCB manufacturing and hole plating technologies have improved tremendously to the point that for high-density connectors, press-fit is the only way to go!

PS. Any further thoughts on the SSL stuff we bounced ideas about on?

Cheers,
Gareth
GJC Designs
Yacht Rocker
 
Posts: 304
Joined: Fri Oct 13, 2006 12:39 pm
Location: West Yorkshire, UK.

Postby GJC Designs » Wed May 28, 2008 12:59 pm

Update for the end of May 2008.....

It's been a quite couple of weeks in the workshop so the time has been invested in doing some serious module refurbishment and the desks are coming on nicely. On the modules that had not been worked on, this is the type of stuff that has been going on to bring all modules to the same refurbishment standard:
- Re-capping with low ESR 105 degree C caps,
- Knobs & caps removed & cleaned in the ultrasonic bath,
- Facia panels removed to allow thorough cleaning of the facias and the switch caps.
- Replacement of any damaged knobs and coloured caps.
- Replacement of all LEDs.
- Audio testing using our own test jigs, prior to re-installation of the modules in the consoles.

The re-assembled and tested modules look really good!
Gareth
GJC Designs
Yacht Rocker
 
Posts: 304
Joined: Fri Oct 13, 2006 12:39 pm
Location: West Yorkshire, UK.

Postby Dr Benway » Fri Jun 20, 2008 11:22 pm

Well.. Tuesday is the day I, along with my Tech fire my Calrec M up for the 1st time..
It has sat for quite some time (2ish years) so I shudder to think what the out come will be.. Either way I have a bottle of wine to drink Tuesday evening. Hopefuly I'll not be drowning my sorrows!!!
Is there anything to look out for Gareth?? Anything un expected??
Dr Benway
Analog Enthusiast
 
Posts: 22
Joined: Sun Oct 08, 2006 6:40 am

Postby Matt Syson » Sat Jun 21, 2008 4:32 am

Hi
Keep the area QUIET and listen for any caps 'popping' for the first half an hour or so.
Kep a keen nose in case if overheating / smoke.
Do not leave it on unattended until it has been on for several hours.
Have a quick audio run through of as much as possible to identify any 'dead' chunks of circuitry. Get your CD and a speaker set up ready to use after it has been on for 10-20 minutes.
Good luck
Matt
Matt Syson
Engineer
 
Posts: 1030
Joined: Sun Oct 08, 2006 6:04 am
Location: North UK

Next

Return to Calrec Recording Consoles

Who is online

Users browsing this forum: No registered users and 1 guest

cron
 
Mr Patchbay sells patchbays, tt/bantam cables and more