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-   -   A Shot in the dark...Cambridge Soundworks (https://www.pprune.org/computer-internet-issues-troubleshooting/400326-shot-dark-cambridge-soundworks.html)

Sprogget 29th Dec 2009 22:45

A Shot in the dark...Cambridge Soundworks
 
I have a dearly loved Cambridge DT2200 5.1 speaker system. These haven't been made for 10 years or so, but are still superior in many ways to todays crop of pc speaker systems imho.

The pot on the volume control is wearing out, giving me fluctuations in volume from time to time, so I need to replace it. Needless to say it's not available anymore, so if by any slim chance, anyone has one of these knocking about in a box somewhere, unused and unloved, Sprogget towers has ready cash waiting for you.

How about that? a reverse ad on pprune. You could save my earholes.:)

Loose rivets 30th Dec 2009 03:35

Have you tried cleaning fluid into the pot?

Servisol Aerosols

Top left. Gosh, that brings back some memories.


Failing that, most pots are just bog-standard items. One of the main things is whether or not its Linear or Log or Log Log, etc., resistive and physical size is obvious, and remember, cutting the shaft must be done by clamping the bit that's coming off, in the vice. Not holding by 'tother end.

Peter Fanelli 30th Dec 2009 12:44


physical size is obvious, and remember, cutting the shaft must be done by clamping the bit that's coming off,
:eek:

Sounds very painful

Loose rivets 30th Dec 2009 17:04

That made I larf that did . . . until I remembered the bit about the vice. :ooh:

green granite 30th Dec 2009 17:40

The (metal)cut off bits make good replacement fuses for 13amp plugs :E :E :E

Bushfiva 31st Dec 2009 00:21

If you just want to replace the pot, it's probably a B50k, around 2 euros. Google would appear to be your friend, there are circuit diagrams and parts lists out there.

boguing 31st Dec 2009 07:16

With the power off (to save your ears) wind the volume knob up and down lots and lots of times.

This usually grinds the carbon dust up enough to clear the problem.

Free.

Sprogget 31st Dec 2009 08:19

The pot is a B50k and I'm wise enough to know that I ain't going anywhere near a soldering iron. I've destroyed more expensive kit than this in the past waving a stick of hot metal around.

Boguing, I did what you suggest and so far so good.:ok: My trouble is that I have set up this system such that there is a speaker in each corner of the room with the wiring running around the top of the picture rails and chased in to the wall, so it is immovable.

New systems tend to have the controls fixed in to one of the speakers such that I would have to stretch up to the ceiling to turn the things on and off or get into some heavy splicing/re-wiring to make the thing work. A non starter for me.

mad_jock 31st Dec 2009 09:09


The pot is a B50k and I'm wise enough to know that I ain't going anywhere near a soldering iron. I've destroyed more expensive kit than this in the past waving a stick of hot metal around.
Avionics engineer by any chance? ;)

Sprogget 31st Dec 2009 10:20

Nope, but I see what you mean...

Saab Dastard 31st Dec 2009 10:45

I had a Cambridge Soundworks DT3500 system, but the head unit failed. :{

Very, very good it was too, up 'til then.

Like you, the corner speakers were fixed in awkward places, so I bought a Creative something 5.1 system, and just replaced the head unit and unpowered sub with the new powered sub and cabled all the other existing speakers back to that - fortunately there was enough slack in all the cables to do so.

It isn't as good as the DT3500, though.

SD

srobarts 31st Dec 2009 10:54

Sprogget
I found a guy in the North-west who is a dab hand with a soldering iron. He solved the dry joints problem of my much loved Sony ICF2001D. He specialises in repairing older electronic kit and charges are very reasonable. I will PM his contact details if that helps.

Sprogget 31st Dec 2009 12:24

Thanks Mr Sr, but if i send it away to the far northwest. I'll be soundless for a week or more!:{

I've been reprieved for the time being by jiggling the pot and giving it a clean. As Saab says, I've looked into the idea of swapping the subwoofer out as speakers are speakers, but looking so far at Altec and Logitech stuff, the controls are wired into one of the satellite speakers, so it would require surgery to get them working with my particular setup.

It worries me that what ever follows won't be as good as what I have now, they really are a very good system.

boguing 31st Dec 2009 13:27

Stop worrying - the pot will be fine for ages. I've been impressing people with this trick since I was about 11 (a looong time)!

LordGrumpy 31st Dec 2009 15:58

This is a job for International Potentiometer Repair Man . When he has done yours, my surround sound amplifier needs his skills.
Thinks is this pot failure; part of a subversive act by others who don't want their vocal volume to be exceeded?

Loose rivets 31st Dec 2009 17:56

This is bringing back some memories. The old soft 'lead' pencil trick. Pry open the pot - often done in situ - and scribe many lines on the carbon track with the graphite.

On this forum, on which I'm Top Anode, they are full of tricks of the trade. They are mostly from my era, where we made old kit work from war-surplus stuff.

UK Vintage Radio Repair and Restoration Discussion Forum - Powered by vBulletin

Young people of today don't know how to fix things. My old science master's homemade t/v was 2 1/2" green screen. And then there was the bloke that breathed life into his tires every Sunday morning with Bandages and Bostic . . .



God, old people can really be boring.
:(

Marie B 24th Dec 2012 13:45

Hello Sprogget I hope you're still around now & still on here.

I've searched the net for pretty much the same problem as you other than mine is the balance control thats playing up. It just goes round & round infinitely but with no difference to the sound.

Did you get your problem sorted & if so how please?

Milo Minderbinder 25th Dec 2012 14:10

Someone with a similar problem - and some ideas - here
Ancient long shot in the dark - Overclockers UK Forums

or is that you?

tony draper 25th Dec 2012 17:40

Had the same prob with the same kit,the VC was on a flat ribbon cable and got beyond help,took it apart squirted it with switch clean did the usual things but eventually got fed up and binned it,still it had lasted a long time.
:(

Keef 26th Dec 2012 10:48

Oh, the frustration of realising that the old eyes can't focus properly at soldering distance.

Took me several minutes to change out the pot that had gone noisy. Where I used to be able to hold the iron in one hand and the solder sucker in the other while balancing the device on my knee, now it's bench, "helping hands" and patience.

FullOppositeRudder 26th Dec 2012 21:53


Oh, the frustration of realising that the old eyes can't focus properly at soldering distance.
I agree - it's all the wrong way around. When I was a mere youth with brilliant eyesight, resistors were the thickness of a pencil and capacitors were so large that the values were in a 10 point font. ( Heck I even used a plumber's soldering iron heated by blowtorch to build my first one valve receiver - and no! - I knew not to use HCl as the flux by then :eek:)

Now at the other end of the adventure, everything is ultra tiny, ICs have a miniscule type code on them in dark grey lettering on a light black surface, and diodes almost need a forensic microscope to establish who and what they are.

And don't even mention surface mount components at my age :(

Keef 26th Dec 2012 23:30

Surface mount - that's the throwaway version, innit? I don't go there.
Know what you mean about components getting smaller, too.

The latest is that the coloured bands seem to breed. I used to be able to recognise brown-black-yellow at 10 paces; now it's half the size or less and brown black black orange gold pink, and I have to stop and think.

I've got some sub-10-ohm resistors in the box for transistory stuff; I can't work out the colours on those. I've stuck them into pieces of paper with it written on 'em.

Loose rivets 27th Dec 2012 03:36

The only bit of poetry I've ever writ.

Valve radios, aaaaahh, the smell and the heat.
Ten killohm resistors wired ever so neat.
The whistles the pops, the heterodyne wine.
Getting ‘Much binding' was simply divine.
From body to spot, via tips, parts encoded.
‘tis a terrible shame, that it all came outmoded.

tony draper 27th Dec 2012 11:36

I bought this thingy about thirty years ago,of course I didn't need it then,I had hands steady as granite, eyes as sharp as a ere, sharp thing,and was a forth dan black belt solderizer, it had various crocodile clips to hold the job at any angle and a large magnifying glass that could be moved and tilted to cover any job, I didn't need it but it were a tool and I am a bloke so I had to have it.
Over the years of being unused in the back of cupboards and such bits have dropped off and gone missing, the magnifying glass was plundered,now when I do need it it is beyond help.
There must be a moral there somewhere.
the thingy or rather whats left of it.:(
http://i11.photobucket.com/albums/a1...psede54bf7.jpg

A A Gruntpuddock 27th Dec 2012 12:11

I bought one of these v cheaply from Lidl.

Not top quality but has an LED light as well.

V useful.

Loose rivets 27th Dec 2012 15:07

That's probably one of the finest thingies I've ever seen. Superb workmanship - so, I'd plunder someone else's thingie for the spare parts, even adding some of your own inventions.

Forget those modern LED pinprick lights, but a good old-fashioned socket for a light bulb comes to mind.;)

Keef 27th Dec 2012 22:37

It's called a "Helping Hands" (or was when I bought mine). Refer post number 20 above. Mine's still in regular use.

Available from Maplin in the 1980s, maybe still.

Loose rivets 28th Dec 2012 04:33

One likes crinkly paint. Reminds one of a prewar fillum projector I was given c 1949.

handsfree 28th Dec 2012 07:54

Not built to the quality of Mr D's piece of kit but a modern day version of Helping Hands

Silverline 282589 Heavy Duty Helping Hands 90mm 3x

Or even better the Draper 31324

Draper 31324 - Helping Hand Bracket and Magnifier (N148)


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