nakamichi amplifier 1

[reddish75]

i was cleaning out a friend of mines loft when we came across this amp, does anyone know anything about it, is it any good?
any help would be appreciated

[Cloth Ears]

This one?

I think it's about 80w/ch, probably from the mid-80's. Should be reasonably robust (think middle level Rotel/NAD) and probably cost about the same.

If there's no power or capacitor problems it'll probably give you as good a sound as anything rated 80w in todays money.

Otherwise, check that it's working and eBay it!

[stephensank]

The "Amplifier 1" is a relatively rare integrated amp model from 1988-90, if I recall correctly, and was simply a "Receiver 1" without a tuner. Sadly, this was the model year after Nak stopped licensing Threshold's "Stasis" amp topology, so it won't sound as good as it could have, but it is still a very open, spacious & fairly smooth amp. Not as bulletproof as Nak's stasis amps & receivers, but much more reliable, nevertheless, than the average Denon, Yamaha, or etc. If it's in very clean cosmetic condition, I'd say it's worth $200-300. But a stasis receiver like Nak's SR-4 or SR-3 is a far better sound and value in the same ballpark.

[reddish75]

ok thanks, we have tried it and it doesent power up but im quite handy when it comes to things like this, i was thinking it was just a capasitor problem but ill look properly tommrow.
do you think that this amp will sound better than a cambridge audio a300?

[stephensank]

Oh, god, yes. Much better amp than the A300. 99% of the time one of this series of Nak amps/receivers dies, it is due to output transistor failure(2SA1492 & 2SC3856) in a channel, often with no other parts damaged.

[reddish75]

thats great a big help, could you point me in the right direction of new part numbers?

thanks in advance

[jacco vermeulen]

You could try switching to 2SA1294/2SC3263.
SOA of those is 1 Amp higher at 100Vce than the originals, and are considerably faster.
ISC(Inforcomm) in Taiwan is supposed to produce these as well, some state they're preferred over Sankens.

Or, if you're an amp hacker and there's a way to squeeze in a parallel duo : 2SA1186/2SC2837.
Extremely fast, and much lower Cob.(about $5 each in GB, $3.50 here, $2 in the US)

[reddish75]

thanks for all the replies does anyone have a user/service manual they could post

[homertooties]

Hi there dont know about a schematic but there is an ebay (uk)seller who sells the first choice of out put trannies very cheap (sankens) bought few myself and sap15 n/p very very cheap

[Leolabs]

Originally posted by homertooties
Hi there dont know about a schematic but there is an ebay (uk)seller who sells the first choice of out put trannies very cheap (sankens) bought few myself and sap15 n/p very very cheap

Those are 5-pin darlington with on chip bias diode.