"Tim Schwartz" wrote in message
...
On 2/18/2011 7:32 AM, N_Cook wrote:
Arfa wrote in message
...


wrote in message
...
Arfa wrote in message
...
Anyone by any chance got schematics for an Arcam Alpha 10 amplifier ?

TIA

Arfa


Not motorized function sw prob I hope.



No, it's not. But why do you ask, I wonder ? I did one of those on an
Alpha
9 just yesterday. It was no particular problem, as has been the case
with
a
few I've done in the past.

Arfa


Too much back-torque with all those multiway wafers - stripped plastic
gearbox cogs - indexing/alignment problems


Funny,

I've done DOZENS of those Alps switches. They must be taken apart and
cleaned, as spraying them does not seem to last, but I've never had a
stripped gear drive.

Regards,
Tim Schwartz
Bristol Electronics

P.S. These switches were used in the Arcam Delta 290, Xeta 1 and Alpha 9
integrated amps, along with the Creek 5350 and some Yamaha products. I'd
guess along with many others I don't know about.

Yes, that's exactly what I did. You remove the switch from the board, and
unbend the three tags on the front. that allows you to withdraw the shaft
from the wafers. There are index marks on the wafer rotors, and the shaft is
flattened on two sides, so you can't get the indexing wrong, if you pay
attention in the first place. The only one that you have to watch a bit, is
the front-most wafer that controls the motor stop, because that one is
driven differently via two tabs. The wafers themselves are easily 'sprung'
from the frames, and the rotors easily unclip from the bodies - like a VCR
mode switch. I have some very very fine wet and dry paper - something like
1000 grade - and I use a tiny piece held in needle point tweezers to burnish
the contact pads and central ring back to bright metal. I clean the rotating
contacts with a pencil rubber, and re-tension them. Finally, I add in a drop
of high quality switch cleaner / lubricant, before clipping the rotor back
in. The individual wafers can then be clipped back into the frame, and the
index marks used to realign them, before refitting the shaft. They run like
silk after they have been thus refurbished, and are electrically silent. I
have never had any mechanical problems caused as a result of doing this, nor
have I ever had one bounce. I haven't done as many as Tim, but probably
still twenty or more, over the years.

Arfa