Posted by Shaun Browne on March 06, 2003 at 17:44:24:
In Reply to: AU-70 posted by Bob Araneta on March 04, 2003 at 01:34:55:
I just purchased an AU-70 and find it quite musical. It uses a tube compliment of 4 7189A power tubes (replaceable by EL84s) 2 6AN8s and 3 12 AX7s. My unit has all original tubes.
In time I will have the caps done, and the tubes checked (power tubes may be a little suspect)but for now, the amp is powering my Tangent speakers very well.
The amp is rated at 25 watts per side and has a nifty pair of power meters (not VU meters) that indicate the relative power being presented to the speakers.
THD is 0.15%, quite acceptable even compared to todays solid state or digital amps.
Like a digital amp found in home theatre set-ups, the AU-70 will produce sound from 10 - 80,000 CPS. That is much better than the average 20 - 20,000 that most amps seem to be able to produce.
One thing that you will find interesting is the centre channel output on the rear of the amp. It appears that it could send signal to a powered sub-woofer. I don't think that was the original intent in 1964.
The amp is solidly built (weighs a 'ton') and has a small form factor, much like a small solid state amp.
I was able to buy the amp for $145 Canadian, which I think was a good deal for a running, quiet amp in very good cosmetic condition.
All the best as you check this one out.
SB