Akai AA-5000s

This thing is old, really old.
Some of the regulars here may have seen this languishing on eprey for a long time. I grabbed it.:scratch2:
I haven't cleaned it up yet, but I have tested it. It works, has scratchy controls, no audible hum or hiss. The face is a beauty; nice engraved lettering.
Check out that rectifier set up~








I'm fairly impressed with the design of this ancient rig. Once I get it cleaned up and running on speakers ( I tested with a Zune and headphones) I'll post the results.

It's an interesting comparison between the interior layout of the 5000 and the 1175 that I have posted. The 5000 has many more freestanding (non PC mounted) components. But they do share a fairly open, easy to access layout, although, on the 1175 a lot of the service must be done with the bottom off and the unit on its side.

It looks like everything is fastened to the bottom plate. The back panel comes off, so access is available there. The amp modules look to be removable just like my AS-970.
I'm curious about the rectifier diodes. Doesn't look much like a fullwave bridge rectifier.

So, I've begun recapping this old thing. I'm doing pull one, replace one method since there is no manual for the 5000S (S for Silicon outputs I think). I have a Peak capacitor checker, and I'm checking the caps as I pull them. Nearly all the low voltage caps read several Ohms ESR, with a few reading over 15 Ohms. One read over 20 Ohms. The few 50V caps read OK for ESR, but ALL caps were over 20% high in capacitance. Some were 100% over rating. I wasn't sure my meter was reading correctly, so I started measuring the new caps. All of those look like what one would expect.
This amp is from the late 1960's, and I guess electros were not so good back then. Still, I'm rather surprised at the results.

A little bit info over AA-5000S from a AKAI flyer/end sixties.
Silicon Power Transistors for the final stage obtainable highest performance and temperature characteristics.
E.P.C.(Electronics Protection Circuit), protecting the power transistors from damage in case of short
circuit at the Output terminals.
Completely 0. T. L. system distortion free will damped reproduction.
110W m power.
Direct reproduction from the tape head by equalizer for head.
DIN jack, Headphone jack.
Independent filters for high and low, and also tone controls for right and left respectively.
Dimensions & Weight : 17" x 5.3/8" x 10.5/8", 17.6 lbs.

Michael-Otto

Nice amp ryuuoh! Your Akai makes mine look like new! BTW, the caps arived for my recap! Will report soon I hope

may i ask who sold it to you?..i had a AA-5000s...sold it to a dealer in TX...i had the original speakers to go with it...another AK member has them now user name of "Frazier" they were something? 130's?
I also had a AA-8000 which is a receiver with front panel controls for the Akai R2R

I got it off of ebay. It was listed for so long, I felt sorry for it.
I also bought a reproduction manual for the 5000 (non S). It's pretty much identical to the S.

I think that front panel styling looks fantastic... that's my kind of retro :yes:.
Hope you manage to get her working well again. :thmbsp:

I'm about to button this thing up and call it done.
I've recapped the amp boards and installed new power supply caps (which were comically shorter than the originals), set the DC balance (for a cap coupled amp) and adjusted the current draw of the amp board. This I guess is the equivalent of the bias adjustment. The procedure has you disconnecting the mains wires to the amp boards and inserting your ammeter. I let it warm up a long time playing Jethro Tull , then adjusted.
My thoughts on this amp are that it sounds pretty good through head phones, but it has the germanium transistor noise (hiss) in the back ground. not sure if I'll put in in the main system. Maybe it can do duty as an amp with full range speakers.
Once I clean up the wood sideburns and put the top on, i'll post some pics.

Done

Finished with the amp, now to find a home for it. I might try it out in the night stand.





I like this one:

This is same like Coral A-707,indentical amplifer. I have one this Coral and very nice sounding.