AKAI AA-6000 Amp

Hi all,
I have picked up a 1971 AKAI AA-6000 amp (amp only, not receiver) but have found very little info about it. Another AK-er has the same unit and provided me with some great info, but anyone else with feedback I'd love to hear.

The main issue for me is I'm a complete electronics amateur, so while I love the look and sound of the old gear, I have no ability technically.

The AKAI sounds good, but there is a distinct 'pop' through the left channel when I turn off the unit, as well as a low hum.

I have cleaned all the contacts, and blown out all the dust, thus exhausting my DIY skills!

Any clues as to what may be causing this, and would the pop be potentially damaging to my KEF Concerto speakers?

Cheers, Hodgie (down under)

Hard to say without proper testing but I would lean towards the large filter caps reaching the end of the road. The pop, not great for the speakers but not as damaging as what the caps failing can cause. If the power supply is compromised the amp may not be able to produce much power without hard clipping. Hard clipping can cause major damage if not remedied.

Perhaps an Akai guru can step in here and tell whether that pop is just cap bleeding down which some amps are famous for. If your pre has a speaker disconnect switch kill that before powering down the amp. In any case I would have the amp looked over and some proper work done to return it to greatness.

hum

Agreed, you need some proper testing.
A low hum ususally indicated capacitor issues or a ground problem.

I work on an old Akai once with a bad channel and as soon as I got that sorted out, a diode in the bridge rectifier blew out.

Thanks

Thanks all for the advice - I'll get someone with some experience to have a look for me. Still happy to receive any suggestions, and I will let you know how I go.
Cheers,
Hodgie

From a AKAI flyer AA-6000, some specs.

PERFORMANCE SPECIFICATIONS
POWER OUTPUT MUSIC POWER:
120W (60W/60W) at 8 ohms
RATED POWER: 90W (45W/45W) at 8 ohms
FREQUENCY RESPONSE
PHONO: RIAA
TAPE AUX: 20 to 50,000 Hz - 3 db
S/N RATIO
PHONO: Better than 65 db, TAPE AUX: Better than 70 db
RESIDUAL NOISE: 2 mV (80 db)
HARMONIC DISTORTION:
Less than 0.2 % (45W/8 ohms 1 KHz), Less than 0.08 % (30W/8 ohms 1 KHz)
INPUT SENSITIVITY
PHONO: 3.0 mV in 50 Kohms
AUX: 150 mV in 100 Kohms
TAPE: 200 mV in 200 Kohms
OUTPUT TERMINAL: REC. out, HEADPHONE out, SPEAKER out, DIN out
TONE CONTROL BASS: 100 Hz ± 10 db, TREBLE: 10 KHz ± 10 db
LOUDNESS CONTROL: 100 Hz + 6 db, 10 KHz + 6 db
CUT FILTER HIGH: 10 KHz – 6 db, LOW: 50 Hz - 8 db
CROSS TALK: Better than 60 db
POWER BAND WIDTH:20 Hz – 35 KHz (Less than 0,5 %)
OTHER
SILICON TRANSISTOR: 16, GERMANIUM DIODE : 10, THERMISTER : 2
POWER SUPPLY: AC 100 - 240V, 50/60 Hz
POWER CONSUMPTION : 30W (at non signal), 180W (at maximum)
DIMENSIONS: 6-1/4" x 15-7/8" x 11-3/8", (160 x 405 x 290 mm)
WEIGHT: 24.2 Ibs (11 kg)

Michael-Otto

Thanks for the specs - much appreciated.
Cheers,
Hodgie