Yamaha A 500 Integrated Amp Modifications


I just bought a A 500 amp circa 1984 model off Ebay.  Owned one of these for nearly 8 years from 84 to 92.  Nice clean sounding amp.

I was wondering if there are any modifications that can be done to this amp that might improve the soundstage and perhaps also the imaging of the instruments?  I don't want to change the sonic character of the amp which is pretty neutral.  

Has anyone done any modifications to this amp or another Yamaha and noted some real improvements to the sound?
will62
the speaker connectors in back are just spring clips--pins should work fine, tho i'd personally use bare fire for 'em
Thanks.  Will consider that.  Right now my primary concern is trying to find a way to get cables to connect the speakers to the amp.  Want to Biwire and would like to avoid spades or bare wire.
Actually any electrolytic capacitor can be replaced for an improvement.  Nichicon KZ Muse or Nichicon KW are the best I have used.
Just got the A 500 up and running.  Seems to be fine.  True to form it has a more neutral sound than the Denon PMA 520 that I also have.

Question.  Does anyone know where to find a manual for the A 500?  Can't seem to find one online that I can download.

Also, I am trying to determine what kind of speaker connection to use with the amp.  Won't take Banana's and I am not sure Pin's will work either.  Weird shape to the speaker connectors.
Thanks for the detailed info.  Very helpful.  I noted the THD on the old unit is incredibly low compared to the newer amps.  Should still be a very quiet amp.  But I would have to agree that it is probably not wise to drop a lot of money into it considering the age.  But will be sure to have all the parts that might be close to failing or are failing replaced.  Capacitors included.
Power supply capacitors do indeed degrade, and if they fail (as they will) they can destroy your speakers. Since modern ones are often physically smaller, you may be able to fit modern ones with a higher capacity into the same case, for more dynamic headroom. Avoid audiophile caps: those from mainstream manufacturers are often better quality and cheaper.
Price is relevant here, because at least in Europe you can buy this amplifier’s modern successor, the Yamaha AS 501, for only about 350 euro. It is more powerful, measures better, and also has digital inputs. See here for a test of the previous model, the AS500 without the digital inputs but otherwise identical: http://www.avhub.com.au/product-reviews/hi-fi/yamaha-a-s500-amplifier-review-test-395710
It measures better than many audiophile amplifiers costing sometimes ten times more. In particular, frequency response under varying realistic load is stunning (within 0.05 dB). This is a perfect straight wire with gain. So don’t spend too much on refurbishing the old amplifier.
I forgot switches very important Elna Swiss Silver contacts  And get a much better  volume attenuator and nee on off switches.
 This is a true rebuild  for just a few areas would not do .a lot of cheap parts 
For sure in original model.  If it is something  you want forever.
Personally  if you could afford it by s nice used Through Reno hifi ,or online
The excellent Pass labs integrated amps .all depending on Loudspeaker demand.
Much much better coupling capacitors are available, as well power capacitors 4pole caps by Jensen,or Mundorf ,increase suzes by 50% in microfareds if room.are the best,as well  are better resistors, 
NEOTECH 6-9S copper Wiring   all connectors to  Copper Gold Type. Fuses and holders get rid of cheap steel fuses. Much better diodes, bridge rectifiers
Torroidal transformer  Piltron  Black double potted type . 
This is if it is worth it . This is probably over $ 1200, to do this depending on prices and labor st $75 an hour.
Thanks Erik.  Yes, I liked it as it was previously.  Wasn't sure if there could be anything else done to improve it further.  

Power caps are Capacitors, correct?
Time for new power caps.

Otherwise, either love it as is, or swap it. :) 

Best,

E