Arcam A85/90 fit for purpose?

[friendly1uk]

I quite fancied an A85 but they're all broke? Today on eBay, both 85s and 90s are listed, but only broke. I have been watching a while. It seems about half of them have failed. Many are sold just as power amps as it seems it's issues with input selection that's most common. Almost a theme. Such that you could argue that under the sale of goods act, Arcam have fouled.



Has anyone got the drawings, or hands on experience from fixing these things? I'm obviously concerned that anything I buy will be broke within the year. So I'm interested in whats been used, as I have to expect very limited life from one now. If it's not off the shelf parts, I need to start my 10 year long process of amp choosing, all over again.



I have found similar posts on other forums, but no answers. Though drawings were shared privately, ending the discussions.

 

[Mooly]

HiFi Engine have the A85 manual I believe.

 

[JonSnell Electronic]

They have a digital switch for selecting inputs and rarely fail. Check the 5v supply to the uProcessor.

 

[friendly1uk]

I don't actually have one Jon, I'm just quaking at the thought of owning one. I want it... but the number of broken one's is truly outstanding. I thought perhaps they had used something like a micro controller, running their own logic. If that makes sense.





I will have a look Mooly. Thank you.

 

[friendly1uk]

Well that's that then. A microprocessor with 100 legs. I will keep my Alpha 8r

 

[RM]

As I used to repair these in Norway way back I still have complete motherboards, inputboards and even frontboards for A85. All new and unused.

Maybe also 1-2 RIAA upgrade kits for A85

Also several mainboards for CD players, including DAC boards.

3-4 unused channels for the P1000, 2-4 transformers, and even new Controlboard for same.

Regards
RMalmin

 

[jaycee]

The microcontroller is extremely unlikely to fail in itself, and is likely not the cause of the failure of the units youre seeing.

Define "not working". There's probably a lot of dicks blowing them up with party usage, putting a bigger fuse in to "get it working" and causing further damage in the process.

The amp does use the SAP15 output transistor, which is known to suffer from blown emitter resistors if pushed too hard. The STD03 + external emitter resistor could easily be fitted if this was a problem.

 

[RM]

One major problem with the front boards were the socket for the flat cable going to the input board. It was a bit on the "soft" side and would "bulge" out in the middle section causing the wires in the center of the cable to loose contact. Either change the socket, or easier; insert a little piece of plastic between the cable and socket. Maybe only 0,5 mm thick?

Regards
RMalmin

 

[friendly1uk]

Hi RM. I bet you have PM's for these upgrade boards already It's very interesting to hear about this plug. Perhaps thermal cycling is the cause of quite a few failures.


Jaycee, it's always front end. Many are sold as power amp only.

 

[RM]

This particular problem`s root were solely due to a low quality connector.

You are correct, first come - first served.

RMalmin

 

[jaycee]

I guess then it is the problem RM mentioned - with a bad connection to the microcontroller/display board, neither the analogue switching muxes nor the volume control IC would get any commands, resulting in silence.

I guess if you can replace a flatflex connector, its an easy fix

 

[Ian Finch]

It's an unusual type of fault that you could waste a lot of time looking for. If it was common in that model, we could expect Arcam to be aware and to have responded with at least a service notice and an offer or recommendations for a replacement part.

 

[friendly1uk]

Arcam stick their hand out for £200. If it's fixed with a big finger, that's disgusting behavior.

 

[Ian Finch]

Not quite. I understand that like a number of UK manufacturers now, Arcam simply don't do repairs as that undermines service agreements and they would have to employ repair techs. They just do a factory refurb by fitting a complete and working new board, often a later version if that's all they have. For example, before I bought it, Cyrus repaired what was a Cyrus 5 amplifier by effectively turning it into a Cyrus 6 and that's what I have now, with new paint finish, remote control and all but the cost? Well, I understood it was considerably more than Arcam are asking and that was 7 years ago. Hence the sale.

 

[Bare]

IMO Arcam is a Joke. Doesn't deserve to be purchased.. let alone listened to
Owned since '96 much to my shame.
Their service Is a sparse network of iffy little shops who consented to patch Arcam gear for an erm.. Reduced cost.. to the factory.
Having had to deal with this lovely scenario it took the local small time inept "Authourized Arcam Repair Centre" 4 !! separate attempts and $200 to patch My Arcam.
It was a (1) failed diode . Imagine just how pleased I was.
Incidental to this repair fiasco.. my Arcam was shortly after.... totally outclassed/performed by a whim buy ~100$ (albeit "murican") Lm 3886 Amp gizmo.
Couldn't believe the sheer audio improvement differences .
Acoustic Research ? My Butt.

 

[friendly1uk]

Acoustic Research were a 'murican' company.



AR Cambridge, Massachusetts. Speakers.
A&R Cambridge, UK. Electronics.


Very easy to think of them as related, but I can't find a connection.



I'm guessing your amp was an A&R, and that would make it very dated. I have spent time with one and agree it's easy to beat, and that was in the 90s. When it already looked dated.



Hello Ian. I understand the board swapping thing. I've been forced to do this many times. Knowing I could fix the board with less bother and enjoy doing so. I cringe thinking they wound swap a board in this instance though. I'm tempted to pick up one of the broken ones just to have a look. In fact... I'm bidding but it's early days.

 

[jaycee]

Arcam is now part of the Harman Group, which in itself is part of Samsung