Sign in with
Sign up | Sign in
Your question

Arcam Alpha ('86) - integrated amplifier problem

Last response: in Home Audio
Share
Anonymous
December 15, 2004 10:55:23 PM

Archived from groups: rec.audio.tech (More info?)

My Arcam Alpha has recently developed a "balance" problem.

The left channel is noticebly softer than the right. Also, the high
freq. response of the left channel seems lower than the right.

The right channel also has a higher "idle" current than the left
channel.

When I power ON, the right channel "pops". When I power OFF, it also
"pops".

I have tested my speakers (Infinity RS6001) and my CD player
(Consolidated Electronics Broadcast CD Player) and have eliminated them
as problems.

Any ideas?
Anonymous
December 16, 2004 5:19:54 PM

Archived from groups: rec.audio.tech (More info?)

Hello,

Is this an original Arcam Alpha, or an Alpha 2 or 3? (The Alpha 5 and
up were not in production until after 1986.)

The correct bias voltage is 8mV across ONE of the 0.22 ohm emitter
resistors for an Alpha, Alpha Plus and Alpha 2, but only 4.5mV for an
Alpha 3. The adjustment should be made with the volume all the way
down, and the amp having been on for a half hour.

However, the bias adjustment is not likely to cause the problem you
have. It is more likely to be a problem in the tone control area, or,
less likely, a capacitor or bad stage in the power amp section.

Lastly, are you sure the power supply voltages are correct, and that
the speakers are OK?


Regards,
Tim Schwartz
Bristol Electronics


trouble wrote:
>
> My Arcam Alpha has recently developed a "balance" problem.
>
> The left channel is noticebly softer than the right. Also, the high
> freq. response of the left channel seems lower than the right.
>
> The right channel also has a higher "idle" current than the left
> channel.
>
> When I power ON, the right channel "pops". When I power OFF, it also
> "pops".
>
> I have tested my speakers (Infinity RS6001) and my CD player
> (Consolidated Electronics Broadcast CD Player) and have eliminated them
> as problems.
>
> Any ideas?
!