I am having trouble with distortion in my system. I have a Sony
TA-E1000ESD pre-amp and an adcom 945 power amp. I am trying to drive
Magnepan 1.5's and I am getting a ton of distortion even at low volume.
The distortion LED is lighting up on the 945. I am running under
the assumption that the 945 is a 4ohm stable, which may or may not be
the case. I have tested the speakers with a different receiver, which
did not provide any distortion, but that receiver did not have the
power to adequately power the speakers. As a result, I am confident
that the speakers are not the source of the problem. The source I am
using is a cd/dvd player with an optical out. The 945 is new [to me] as
is the pre-amp. I am looking for a way to debug this problem. Any
advice would be appreciated. Oh, I am using relatively low end
interconnects between the amp and pre-amp, bought at Best Buy for ~$25,
and I am using a homegrown main cable, the specs of which I got he
http://www.tnt-audio.com/clinica/triple_t_e.html


Thanks,
Josh

wrote:
I am having trouble with distortion in my system. I have a Sony
TA-E1000ESD pre-amp and an adcom 945 power amp. I am trying to drive
Magnepan 1.5's and I am getting a ton of distortion even at low volume.
The distortion LED is lighting up on the 945. I am running under
the assumption that the 945 is a 4ohm stable, which may or may not be
the case. I have tested the speakers with a different receiver, which
did not provide any distortion, but that receiver did not have the
power to adequately power the speakers. As a result, I am confident
that the speakers are not the source of the problem. The source I am
using is a cd/dvd player with an optical out. The 945 is new [to me] as
is the pre-amp. I am looking for a way to debug this problem. Any
advice would be appreciated. Oh, I am using relatively low end
interconnects between the amp and pre-amp, bought at Best Buy for ~$25,
and I am using a homegrown main cable, the specs of which I got he
http://www.tnt-audio.com/clinica/triple_t_e.html


Thanks,
Josh

Someone else may know the answer immediately, but if you want to debug
this, the basic procedure (as you may know) is to test components
one-by-one to isolate the problem.

Does the 945 have a volume control?

Did you try the analog output of the cd/dvd into the preamp?

Can you substitute the components (different amp, different preamp,
different source)?

Which components have a volume control? Have you varied them?

Mike

If the distortion LED is lighting up then you most likely have a problem
with the amplifier. It could be an impedance mismatch with the speakers
or a defect in the amplifier. Cables would not cause this problem.
Their effect (if any) would be very subtle.


---MIKE---
In the White Mountains of New Hampshire
(44=B0 15' N - Elevation 1580')

wrote in message ...
I am having trouble with distortion in my system. I have a Sony
TA-E1000ESD pre-amp and an adcom 945 power amp. I am trying to drive
Magnepan 1.5's and I am getting a ton of distortion even at low volume.
The distortion LED is lighting up on the 945. I am running under
the assumption that the 945 is a 4ohm stable, which may or may not be
the case. I have tested the speakers with a different receiver, which
did not provide any distortion, but that receiver did not have the
power to adequately power the speakers. As a result, I am confident
that the speakers are not the source of the problem. The source I am
using is a cd/dvd player with an optical out. The 945 is new [to me] as
is the pre-amp. I am looking for a way to debug this problem. Any
advice would be appreciated. Oh, I am using relatively low end
interconnects between the amp and pre-amp, bought at Best Buy for ~$25,
and I am using a homegrown main cable, the specs of which I got he
http://www.tnt-audio.com/clinica/triple_t_e.html

I don't know anything about the 945 power amp, but Adcom usually makes
pretty potent amps. The wire described in the TNT article you referenced is
totally unsuited to connect an amp to Magnapan speakers. Use AWG 12 zip
cord. Unless you listen at unusually high levels, the equipment you have
should be satisfactory.

If I were presented with your problem, I'd start by measuring the roundtrip
resistance of the speaker cable. Anything over 1 ohm would be a red light;
I personally wouldn't tolerate anything over 0.25 ohms.

Norm Strong

Thanks to everyone for all of your pointers. I spent the weekend
swapping components in and out of the system trying figure out what was
wrong. Turns out the speaker cable was the culprit. I replaced it
with 12 gauge and it works wonderfully. Thanks again for all your
help.

Josh