Arcam Alpha 8 voltage issues

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Thank you all very much for your help.

I am pleased to know that it seems nothing is wrong with the amp, its just the 110v circuit has not been installed.

I had to purchase a step up transformer for my wifes sowing machine recently (rated 200w) and when it comes I will use that when she is not sowing! If alls well I can then get another one for my amp.

Is there such thing as a noisy transformer I should avoid? Or is this not going to make much difference to the sound?

Many thanks again for all your inputs, I really appreciate your help.

Simon
 
The problem is very simple...
You got the amp from the UK right ? So transformer is a 230/240V unit.

It is not that simple. Arcam used to design these units with a dual 115/230V primary. I have serviced an Alpha 8R with such a transformer. It appears they decided at some point to save costs or something, and switched to 230V primary only. However, the fuse holder and terminals are still installed on the board, which can be misleading.

The original poster is therefore right to have thought the amp can be converted by simply changing fuse - this is the original intention of the design. This is also indicated in the service manual.
 
The main supply capacitors are rated for 50V, but I would be concerned about exceeding the SOA of the output MOSFETs with +/-42V supplies from a 30-0-30 transformer.

The power loss in going from +/-37V to +/-35V supplies is so minimal, you really wont notice. The original transformer has an electrostatic screen (which is what the green/yellow wire from it is for) but I dont believe there will be a problem with a regular toroid.

Simon, where have you moved to ? That would help narrow down a supplier for a suitable transformer if you want to go that route. A stepup transformer will also work of course.
 
Jaycee,

I have moved to Moose Jaw, a small town in Southern Saskatchewan Canada. After the Harrier demise in 2010 I was offered a job with the Canadian Airforce. Moose Jaw is located in the Prairies, it is MILES from anywhere, mostly inhabited with Moose (as the name implies) and does not have much in the way of Hifi servicing!

I would be interested in attempting a Transformer transplant if I could find the right part, is this the right idea?

On the other hand I could quite easily get a step up transformer and not run the risk of damaging my beloved amp with my basic soldering skills.

Again I appreciate all your help.

Simon
 
Easy mistake to make i guess... the alpha 8 is an integrated amp, and it sounds like he has an alpha 8P power amp - bi amplification I guess...

The 8P is basically the same as the 8, just without the preamp. It's even the same PCB, without the preamp parts stuffed.
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.