help: integrated amp shutdown

[chancholik]

Hi there.

I am using Arcam av50 as the processor and some of its power
amp section. I also have an Arcam delta 290 that I am using
as power amp. So, the av50 and delta 290 are used to passively
biamping a pair Newform Research speakers (front).

Problem: Recently, the delta 290 would shutdown suddenly and
come back on in a second or two. I leave the amps on all the
time. Sometime the delta 290 would shutdown while we are
watching movie. Other times it would shutdown while not in
use. The shutdown causes a popping sound in the speakers.

Questions: What is wrong with the amplifier? Is the amplifier
dying? Is the popping sound damaging to the speakers?

[Mr Peabody]

Arcam does well with driving difficult loads so if you are sure your wiring is correct and the amps have proper ventilation, I'd say the 290 needs to be taken in for a check up. I'd also be afraid of speaker damage with a pop depending on how loud it is and what is causing it.

[RGA]

maybe the caps need replacing - fairly cheap repair I should think but you should get it looked at..

[chancholik]

Thank you very much for the responses.

There is no Arcam dealer in Tucson AZ. I will call
Audiophile Systems, Ltd and see what they suggest.

But why does it shutdown suddenly and come back on.

[RGA]

That is strange because the only other thing would be if the amp was overheating -- is it well ventilated? Are you running the amp heavily with a 4 ohm speaker?

Any good repair shop should be able to make diagnstic and repairs -- I had the Delta 290 integrated. There was a 290p power amp as well. Try running it as just an integrated and not as a power amp and see what happens.

The 290 integrated to be run as a power amp requires that you open up the amplifier and switch an internal switch to make it run as a power amp (a pain in the ass) -- but if yuo have not done this then this may be the problem -- my manual didn;t state this -- but some later 290 integrated's did.

[chancholik]

Hi there.

Yesterday, it shutdown and did not come back on.
I don't it is overheat, not thing is on top of it, it does feel
hot, the speakers it driving is Newform Research R630, I
think rated at 8 ohm.

Yes I did open it up and switched to EXT INPUT.

Thank you very much.

[chancholik]

Hi there.

Yesterday, it shutdown and did not come back on.
I don't THINK it is overheat, NOTHING is on top of it, it does NOT feel
hot, the speakers it IS driving is Newform Research R630, I
think rated at 8 ohm.

Yes I did open it up and switched to EXT INPUT.

Thank you very much.

[chancholik]

Hi there.

I think it is an overheat problem.

I took the top cover off and found that the insulation, a thin square
sheet glued to the underside of the cover, fell off. In fact, the
insulation is clearly burned. I did not feel the heat because
the insulation is on top covering couple heat sinks. So, the heat
never got to the cover.

I will test it tonight.

Thank you very much.

[MGFalc]

yikes, not good thats not meant to happen! what you've done is like the analogy of putting a cd player into a phono stage. the power will have went through the preamp rather than going straight into the power amp and kind of tried to amplify and control again! good idea to get that checked out straight away. good luck!

[poneal]

with the volume turned all the way down, bass/treble knobs centered or defeated and speakers disconnected. Put leads into speaker a or b and measure. You should get a prettly low number. If it's 100mA or greater you have a problem.