Acoustech IV find

mhardy6647

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Cool.
I have always been fascinated by the early transistor hardware, and Acoustech in particular. Nice, rather timeless cosmetics, especially the preamp.
Should be... interesting. :)
 
First look on the inside. I do not think it has been opened since the preamp was built. I will test on headphones first. Plans are to upgrade with better parts . Nice to see the transistors are still stock.
 

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Tested with headphones and very impressed. Power resistors temp at 123 f. Transistors on board were 83 f. No crosstalk on the selector. Switches are quiet except for the pushbutton for the comp/tone on. Cleaning of switches will be next. Quite surprised by this device. I may leave it as is. The capacitors are what worries me.
 

mhardy6647

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Wow. It is gorgeous inside.

Looks rather Dynaco-y inside architecturally, doesn't it? (or maybe vice versa?)

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OK, not so much, I guess. :confused: :o
The P/S layout actually reminded me more of a PAS-3, but, you know, those had them tuber things. :)
 
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The build quality is impressive. The address of the company was next to M.I.T.. No moisture damage to be seen. I have a Pas 3x and this is much nicer inside.
 

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mhardy6647

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Yeah, OK, not so much like a PAS-3 either ;)
But, yes, it is a nice lookin' beast under the hood.
I knew the company was in Cambridge -- so many hifi companies were there, in the golden age of 'murrican hifi.
 
Ordered press on heat sinks for the germanium transistors. Heat seems to be an issue with their longevity. Cables for output to a PS 200 Crown amplifier. They both use 1/4" phone cables. The speakers will be the Klipsch Cornwall II.
 

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Ordered press on heat sinks for the germanium transistors. Heat seems to be an issue with their longevity. Cables for output to a PS 200 Crown amplifier. They both use 1/4" phone cables. The speakers will be the Klipsch Cornwall II.
I’ve thought of adding those heat sinks to various pieces I have here. Are there any potential downsides you can think of? I can’t, but I don’t know everything.
 
No downside I can see. Careful fitment when applying them so as not to damage the transistor. Thermal management was in it's infancy in 1965.
 
No downside I can see. Careful fitment when applying them so as not to damage the transistor. Thermal management was in it's infancy in 1965.
Thank you. These pieces I’m considering are a lot newer- late 80’s-mid 90’s- and I have to assume that either the designer/engineer deemed it overkill and unneeded for the application or that the budget department was pinching pennies for a target price point.

I’m just looking at prolonging life of the components and anything that may help (and not hurt), I’m game.
 
The heatsinks were too tight of fit to use. Ran the Acoustech into a Crown PS200 for a test today. I used the Cornwalls. At full gain on the PS200 there is noise with the volume down. Sounds nice after turning the gain on the crown down. Only tested through the aux from the computer. Time to find an assembly manual and schematic.
 
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