A&R A60

[retrospective]

I don't know whether this is ok.

I picked up a Boxed A60ap a while back, it sounds great but has a slight pop on shutdown the consensus being the smoothing caps were discharging at slightly different rates and that it was nothing to worry about.If the Din shorting plug is removed prior to shutdown there's no pop.
Anyway i happened upon a Rotel rx600a which just sounds So right with my speakers and Cd player.
Anyway i've lost the motivation to change the smoothing caps and the A60's just sat gathering dust surplus to requirements.

 

[Hazelberry]

My A60 has a small pop on powering off. It has always done this, even since it got new smoothing caps just a few years ago. I replaced them when one channel began to fade in and out. Otherwise the amplifier sounded fine. Both caps (originals) had begun to leak.

The A60's performance is much improved by bypassing the speaker output fuses. Other amplifiers can sound as good as or better than the A60, but I like it for its appearance as much as anything. I like its slim elegance and it matches my Rega 3 with wood surround. I also revived it from being very ill.

 

[Arne]

Hi Julian,
thanks for your replies and don't worry about sounding a bit pessimistic. I'd rather trust someone with experience on my topics than having someone clueless telling me what to do not knowing it wouldn't change anything for the better. those sa 200 amps are not exactly cheap, so I thought 2 a60's would do as well. In regards to the pre out it's just bothering me to have a sub sitting here doing nothing except wasting lovely space. Have you tried some of the decibel dungeon mods like a bigger transformer in a separate casing or the rc filter to isolate the driver/output? Except the amplified diode mod those 2 are the only mods not tried yet and I'd love to know if worth the trouble as its quite a bit of a surgery to do so. Also can you tell me where the preamp power supply ends and where the phono pre begins as I dont listen to vinyl atm but would like to have the whole powewr supply chain recapped.
thanks a lot!
Arne

 

[Operajulian]

Hi Julian,
thanks for your replies and don't worry about sounding a bit pessimistic. I'd rather trust someone with experience on my topics than having someone clueless telling me what to do not knowing it wouldn't change anything for the better. those sa 200 amps are not exactly cheap, so I thought 2 a60's would do as well. In regards to the pre out it's just bothering me to have a sub sitting here doing nothing except wasting lovely space. Have you tried some of the decibel dungeon mods like a bigger transformer in a separate casing or the rc filter to isolate the driver/output? Except the amplified diode mod those 2 are the only mods not tried yet and I'd love to know if worth the trouble as its quite a bit of a surgery to do so. Also can you tell me where the preamp power supply ends and where the phono pre begins as I dont listen to vinyl atm but would like to have the whole powewr supply chain recapped.
thanks a lot!
Arne

Hi again

I have an SA200 sitting in a box here in Toronto ! But given the size and weight of the ( transformer ) beast it would be expensive to post to you.
Though nothing like the numbers of A60 amps that were built, I do see them from time to time on Ebay and Canuck Audio Mart. Keep an eye out.

The first A60 I did mods to was based on Decibel Dungeon's suggestions. I even had a local firm make a higher VA transformer that would fit inside the original case rather than go outboard. I did the RC filter change made a wee difference I think. The amplified diode mod - was a fail for me. No discernable improvement and a pain to set the IQ.

All further upgrade have been based on Robert's list and to be frank thats all I think one needs to do. There is a limit to improving what is already pretty darn good for its price/age.
IMO the value of upgrades are first the power supply caps, then other e-caps, then the volume pot ( change to Alps ), then the change the IQ pots to Bourns multi-turns.
Once all that is done and working Ok - do as Arkless and others suggest by pass the speaker fuses.

May I also suggest , once the cover is off and the circuit board accessible - just replace all the e-caps as the price of the components is minimal compared to one's time.

Happy listening.

Julian