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Uh oh. Ampex MM1200 power switch died.
Old 13th June 2006
  #1
Gear Maniac
 
FunkFaker's Avatar
 
🎧 15 years
Uh oh. Ampex MM1200 power switch died.

After calibrating our MM1200 2" 24trk, our power switch decided to kick the bucket.

Atleast it got stuck on!!

Does anyone know a good source for the switch?
Old 14th June 2006
  #2
Lives for gear
 
brianroth's Avatar
 
🎧 15 years
Geeez...I had to dig through my 1200 manual to even find that sub-assembly.

From the photos in the sales brochure and the mechanical diagram in the service manual it looks like a relatively "common" sort of switch. Unfortunately, the service manual only has an Ampex part number with no generic part number cross-reference.

Pull out the old switch to determine the original manufacturer.

Bri
Old 14th June 2006 | Show parent
  #3
Gear Maniac
 
FunkFaker's Avatar
 
🎧 15 years
Thanks Brian. I'll check the switch after the session tonight!

tommy
Old 14th June 2006 | Show parent
  #4
Lives for gear
 
paully's Avatar
 
🎧 15 years
If you can, take a picture of it and attach it, along with diminsions and anything else relevant. Watch the pic's byte size. Must be small enough to be accepted.

Paul
Old 19th June 2006 | Show parent
  #5
Gear Maniac
 
FunkFaker's Avatar
 
🎧 15 years
Thanks for being patient, folks.

Here is the info on the switch.

on one side:
UND. LAB. INC.
LIST
10A 250V AC
15A 125V AC
3/4 HP 250V AC

on the other side:
1/2 HP 125V AC
U.S.A.

Thanks for your help!
Old 19th June 2006 | Show parent
  #6
Lives for gear
 
paully's Avatar
 
🎧 15 years
If Brian could post-up the manu. part number, there are a bunch of parts available at:

http://www.blevinsaudioexchange.com/parts.html

Genericilly, a picture and diminsional description would really help.

Paul
Old 20th June 2006 | Show parent
  #7
Lives for gear
 
brianroth's Avatar
 
🎧 15 years
Quote:
Originally Posted by FunkFaker
Thanks for being patient, folks.

Here is the info on the switch.

on one side:
UND. LAB. INC.
LIST
10A 250V AC
15A 125V AC
3/4 HP 250V AC

on the other side:
1/2 HP 125V AC
U.S.A.

Thanks for your help!
And there was no manufacturer's info/logo? I seem to recall that Ampex used Cutler-Hammer switches in various places, but am unsure in this application.

EDIT: Cutler Hammer is now owned by Eaton.

Thumb through a Mouser, Digikey, Allied, etc. catalog to see if there is a switch with a similar picture. The switch is a DPST (although a DPDT will work just fine if the mechanical dimensions are the same). It appears to be a toggle switch with a fancy plastic cover for the actuator.

Bri
Old 20th June 2006 | Show parent
  #8
Lives for gear
 
brianroth's Avatar
 
🎧 15 years
Quote:
Originally Posted by paully
If Brian could post-up the manu. part number, there are a bunch of parts available at:

http://www.blevinsaudioexchange.com/parts.html

Genericilly, a picture and diminsional description would really help.

Paul
My 1200 manual has Ampex part number of 119-350 and description:

SWITCH, TOGGLE, DPST.

Bri
Old 20th June 2006 | Show parent
  #9
Lives for gear
 
paully's Avatar
 
🎧 15 years
I have real good luck finding replacement plastic-handle switches at NTE (yep, the transistor guys!). Unfortunately you have to order/buy through a distributor.

http://www.nteinc.com

Take a look at:

http://www.nteinc.com/switches/pdf/switch.pdf

I think it's a short, flat black handle; standard diminsions.
Old 20th June 2006 | Show parent
  #10
Gear Maniac
 
FunkFaker's Avatar
 
🎧 15 years
Thanks Brian and Paully.

I think I have enough info to find one that will work.

sorry for the ignorance, but what does DPST stand for? is it double pole-single trip?

so: on - none - off would be the action?

thanks again,

tommy
Old 20th June 2006 | Show parent
  #11
Lives for gear
 
paully's Avatar
 
🎧 15 years
Quote:
Originally Posted by FunkFaker
... what does DPST stand for? is it double pole-single trip?
so: on - none - off would be the action?...
>>>>>>>>>>>>>>>
Hey Tommy,

Nope, it's double pole-single "throw". DPST is like having two discreet on/off house switches in one package with one handle. There are 2 poles to make or break a connection for each of the 2 sections: 4 poles in all. This allows two different circuits to be switched on/off at the same time. You don't really need the DPDT, as you're only switching one thing. A SPST switch is ideal for you. DPST is fine also. If you get desperate, most hardware or automotive stores have toggles in these configurations. An auto store or 'performance' auto store might be a good source. Also try to find one with the right poles to match the wire-ends that you disconnected (solder, spade connect or screw). It'll save time.

Paul

Edit: I missed Brian's description. Apparently you DO need a DPST switch.
Old 21st June 2006 | Show parent
  #12
Lives for gear
 
brianroth's Avatar
 
🎧 15 years
Yeah, apparently Ampex was opening/closing both of the AC mains lines (hence the DPST switch), maybe because it was available in a 240VAC version??

And yes, On-Non-Off should be the correct designation.

Bri
Old 22nd June 2006 | Show parent
  #13
Gear Maniac
 
FunkFaker's Avatar
 
🎧 15 years
Very cool.

Thanks for the educations and sources gentlemen!

again,

Tommy
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