Arcam Amp

[The Natural Philosopher]

If its a switch (not a pot), *extremely* likely.

Go for it.

[The Natural Philosopher]

NEVER silver PLATED

Always solid/alloy silver or no silver at all.

Also worth a thought.

[The Natural Philosopher]

pretty easy to avoid the main big caps. Up to 100v on thm thats all.

[The Natural Philosopher]

utter bollox.

the other way round. Volts kill, not amps.

because the human body is the resistor.

[Andrew Gabriel]

In my first year at university, we were all taught to punch cards on an IBM 029 card punch:

quickly discovered the multi-access terminals to login to the main cimputer, which were new in our year and our lecturers didn't yet know how to use them.

The department was full of IBM 029 card punches, and it was a status symbol for a reader or researcher to have their own one in their office. Within a year, with the introduction of terminal access, the status symbol quickly changed to having a DECwriter in your office, and all the IBM 029 card punches started appearing stacked 3-high in the corridors and other places where people dumped them.

Then someone discovered there was about £1000 worth of platinum on all the relay contacts in each one, and they didn't half all vanish quickly. Actually, the departments even had difficulty hanging on to a few of them for editing the large decks of cards (fortan programs mostly) that were still around and important for various projects.

[Huge]

In which case I'd have bought a replacement amp on eBay.

(Which was probably being sold because of a noisy input switch!)

[Huge]

Thank you.

(And everyone else.)

[Clint Sharp]

In message , Graham. writes

Ahh, you were one of the flashing light brigade then... If you were really sophisticated then you had a selection of different wattage bulbs for it.

Better than the ex Granada engineer I followed around after he went self employed, he recommended Jif on a J cloth to more than a few customers.

[Dave Plowman (News)]

I've seen small switch contacts which were silver coloured originally but wore through to brass. Dunno what the original 'coating' was or how it was applied, though.

[Clint Sharp]

In message , Huge writes

Have a look at the switch and try to find it in any of the online catalogues, Farnell or RS.

Often things like input selector switches or volume controls aren't custom and a little browsing will find something the same or similar enough to fit with a little modification (mounting brackets swapped across from the old part or some such simple mod).

If you can't find the correct part in an online catalogue then finding the manufacturer's website will yield a list of distributors who may be happy to help.

Speaking to the workshop at Arcam (if they have one and they will let you) may also yield a 'pulled' part or one lurking in the drawer of a tech who didn't fit the part.

First things first though, try a good quality cleaning fluid. I used to swear by the Philips switch cleaner in a silver/black and red aerosol tin, then for the really tricky stuff Colclene TF if you can find it (which may or may not have actually been switch cleaner but it worked wonderfully).

[Steve Firth]

Bullshit. But then again you make a habit of this.

[John Rumm]

I hate to think what IBM must have charged for a new one then!

[Man at B&Q]

Busicom [1] "computer". Really a glorified calculator, but it had a CRT screen and needed a trolley to wheel it around.

It was quite fun to watch. it had no program store so if the program had a loop the card was wound backwards and forwards for each iteration.

MBQ

[1] The peoplw who contracted Intel to produce a calculator chip that led to the 4004 microprocessor.

[Man at B&Q]

football card or similar into his card deck at the local Polytechnic where we were allowed to play on the mainframe as part of our Computer Studies 'O' level. The computer room staff were not happy!

MBQ

[Man at B&Q]

If it's that simple [1] then the human resistor forms a potential divider with the impedance of the supply.

What voltage do you think you are going to get across the resistor from a high impedance v. a low impedance?

MBQ

[1] I suspect it's not

[The Natural Philosopher]

I don't think, I know.

[Graham.]

In the case of pots, sometimes you can just remove the knob and dribble the solvent down the spindle.

[Man at B&Q]

Then you need to spend more time thinking, and less time knowing.

MBQ

[The Natural Philosopher]

well thats as stupid as anything else you have said, so I wont take your advice.

I'll rely on a masters in electrical sciences and 50 years of building and designing electrical circuits.

[Dave Liquorice]

So the saying "it's volts that jolts, mills that kills" is bollox as well then?

You be better of thinking a bit before making such rash statements as "utter bollox".

Agreed but I'd be a lot happier picking up a supply where the current was limited by the total circuit impedance to 10mA or less than one where it was higher than 10mA irrespective of the supply voltage.