advertisement


New (to me) A&R Cambridge A60

TonyScarlett

TonyScarlett

pfm Member
The A&R A60 I purchased off fleabay arrived on Wednesday. First off, thanks to Tony L for posting the link to the amp in the 'interesting eBay auctions" thread. I have had 1/2 an eye open for a nice clean, unmolested A60 for a couple of years now.
Had my first opportunity to properly evaluate what I've bought this morning so here are my initial thoughts.
Good news first; the amp is every bit as good in the flesh as it looked in the fleabay listing, it really is in stunning cosmetic shape with absolutely no scratches, dinks or worn lettering on the face plate. The teak case has a couple of tiny marks which you have to look for. Even the original box & polystyrene inserts are in excellent shape. It has obviously been cared for & come from a non smoking home. An easy 9.5/10.
The good news continues internally, the amp does indeed, to my untrained eye, look to be completely unmolested.
The bad news is obvious from taking one look at the pics. One of the smoothing caps has been leaking quite badly. I powered it up & after letting it warm up measured the DC offset. It's reading 3.6mv on the LH channel & 35.4mv on the RH channel. The voltage across R63 is 3.5v & R163 is 10.6v.
Not disastrous figures so I plugged in my trusty Grado SR80s for a quick listen. Apart from an obvious (& unsurprising) channel imbalance it sounds excellent which has me really impatient to find out how it will sound when fully restored back to health.
20210702-103053.jpg
20210702-102653.jpg
20210702-102836.jpg

I would be grateful for advice from fellow fishies on the best way forward, bearing in mind I am really not looking to "upgrade" the amp. I would like to keep it as original as possible replacing only the parts that need replacing. The obvious (to me) first step would be to replace the smoothing caps & see how it measures & sounds after that. Any advice on the best makes & types to go for?
I have read Roberts thread on the A60 in the reference section. Whilst useful, the example Robert was restoring is a later model which appears to have quite a lot of differences judging by the photos. I will need to do a bit of homework on the actual diffences before proceeding any further. Any links to useful threads or reliable resources would be appreciated.

Many thanks in advance

TS
 
gavreid said:
Good luck with the work but maybe it's worth paying someone to do as it's such a great example...
Click to expand...
An option i am seriously considering, this is far to nice an example to be ruined by an amateur!
Any fishies in the Midlands area want to take on the work? I would be happy to talk.

TS
 
Wonderful little integrated, one of the top 5 values for money in the hi-fi jungle no matter the year of fabrication IMO.

I still have mine and despite I have some much higher grade equipment now, I'm simply not able to get rid of it, it’s that good !

I would recommend replacing all the electrolytic capacitors with standard good quality. This amp doesn’t overheat so no need to be fussy with 105 degrees capacitors IMO.

I used some Elna Silmic II for the small ones as I wanted to give it some warmth but a good Nichicon would be fine.

For the large reservoir capacitors, I used the Nichicon KG (big brown ones) as the dimensions were exactly the same as the original ones and the solder lugs made it easy to install. Some Kemet ALT may also fit well.

I used a self clamping aluminum clip like this picture below to make sure the heat doesn’t transfer to the board when soldering the capacitor’s lugs :



A bit of Deoxit on contacts, speakers posts and some silicone based cleaner on all potentiometers and your should be good to go.

Mine had a scratchy volume pot so I replaced it with an ALPS Blue Velvet and it’s now perfect and the feeling when turning it up or down is great.

Hope this helps.
 
I've just half-upgraded my own late version A60 and have a few spare caps / voltage regs if you're interested.

I also have an ALPS Blue Velvet which I didn't bother with in the end if that's something you're interested in.

Ian
 
B-Ark-610873 said:
I've just half-upgraded my own late version A60 and have a few spare caps / voltage regs if you're interested.

I also have an ALPS Blue Velvet which I didn't bother with in the end if that's something you're interested in.

Ian
Click to expand...
Hi Ian

Welcome to PFM & thanks for the offer. Once I've decided which direction I am going to go I may well take you up.
My current thinking is to just replace the smoothing caps for now & see what difference it makes. I am entirely confident it's a job I can do myself with no issues. I like the look of those Nichicon KG type Gervais Cote mentioned, not cheap though!
Once I have the board out I can make an assessment on whether I am confident to carry out any further work. If replacing the smoothing caps allows me to bring the DC offset & bias measurements back to spec & restores the channel balance that will buy me some time to make a decision on any further work.
I seem to have got lucky with this one, all the pots are dead quiet in operation, no scratchiness or crackling from any of them.

TS
 
I put lots of info / photos and docs in a shared Google Drive here:-
https://drive.google.com/drive/folders/1XNnKH3W4y1hxG3aUwMVq9pqaMn3V3uK8

Hope the link works.
Big Plus 1 for doing the changes that Robert suggested. They keep the A60 sound and yet will ensure the amp "keeps on going".
There are slight differences in the parts required depending on the Serial Number/Issue of the PCB but it's not difficult to work out.
Like Gervais ( also in Canada ) I have used Parts Connexion but there are other suppliers probably nearer to you.

That looks a really nice one from an early date.

I have repaired ones with similar blown power supply caps and "crust" over the pcb.

Happy repairs & listening ahead.
Julian
 
Thanks for the responses so far, please keep them coming.
One question I have; where do UK customers get there Bourns multi turn trimpots? Farnell sell them but there handling & shipping charges makes them a ridiculous price. They don't appear to stock those Nichicon KG caps either so I couldn't add them to the order to bring the price down.
HiFi Collective stock the Nichicons but not the Bourns, same with Parts Connexion. Going to check out DigiKey next, I've used them successfully in the past.

TS
 
RS do indeed stock them, postage doubles the price but still much better than Farnell. Of course RS don't stock those Nichicons either. I did buy some of the Bourns last year for my Arcam Delta 60, I had to extend one of the legs on those as well. I was sure I bought them off Farnell but I don't recall the handling charge & postage cost being so high.
TS
 
There’s a thread where I rebuilt mine here waaaay back somewhere - it’s also an old one, so slightly different caps needed. I first did a simple rebuild as per Roberts guide, then a completely OTT one. Still have it, but it hasn’t been used for 10 years now.
 
TonyScarlett said:
I would like to keep it as original as possible replacing only the parts that need replacing.
Click to expand...

Agreed. If it was mine I’d do nothing more than a full like-for-like recap, Deoxit the pots and switches, and if the internal trim-pots are as corroded as the picture suggests replace them like-for-like too. Just don’t try to be clever, John Dawson knew exactly what he was doing and designed a classic amp, so restore as-is. My aim would simply to restore it to factory function and ensure it is good for another 20 years or more reliable service. It is way too nice an example to mod or alter IMO. I’d obviously use good quality Japanese or EU-made cap brands from a reliable trustworthy source, but beyond that I’d not over-think it.
 
For the trim pots I would use the Amphenol Piher, yours look like the PT10 range, and these would look asthetically similar to the original, I use these all the time in R2R machines
Piher trim pots - Google Search

Julian thanks for that link some great info in there :cool:

Alan
 
Quick update; I'd forgotten I had these Rubycon 10000uF/50v caps from the Delta 60 I recapped last year. The Delta 60 was operating perfectly before I recapped it so I figured they should be good to use just to get the A60 up & running.
Got the bias set to 8.5mv both channels, DC offset still a little high on the LH channel at 35.4mv but not speaker damagingly high. Channel balance has now been restored.
The upshot of which is, I've had an extremely enjoyable afternoon listening to my new toy. I can see why people still rate this amp. The terms I've been reading a lot in the Rega IO thread spring to mind; "musicality" & "just gets out of the way".
20210703-185113.jpg

I should clarify, the Rubycons are only a temporary solution. I am still formulating a plan of action but I remain keen to keep the amp as original as possible.
TS
 
You must log in or register to reply here.


advertisement


Back
Top