Help amp distortion on output

[Guest]

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

Hello all,

I happen to pickup an amc 3050A integrated amp recently for cheap ($50)
but it has a problem and I wanted to know if it could be an easy/cheap
fix or should I just return it. When turned on it begins to hum loudly
once an output is selected the music comes out but it is very
distorted. I tried it with cd and phono with the same results.

Any thoughts? should I keep it try to get it fixed or should I just
return it?

Thank you for your comments, daniel

 

[Guest]

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

In article <1102617358.087838.46030@c13g2000cwb.googlegroups.com>,
danielmmtz@yahoo.com says...

>Hello all,
>I happen to pickup an amc 3050A integrated amp recently for cheap ($50)
>but it has a problem and I wanted to know if it could be an easy/cheap
>fix or should I just return it. When turned on it begins to hum loudly
>once an output is selected the music comes out but it is very
>distorted. I tried it with cd and phono with the same results.
>Any thoughts? should I keep it try to get it fixed or should I just
>return it?
>Thank you for your comments, daniel

I would do the easiest thing and check for a blown fuse. I had an old
Phase Linear amp that would sound very distorted when one of the fuses
blew.
-----------
Alex

 

[Guest]

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

"Alex Rodriguez" <adr5@columbia.edu> wrote in message
news:cpag60$fop$4@newsmaster.cc.columbia.edu...
> In article <1102617358.087838.46030@c13g2000cwb.googlegroups.com>,
> danielmmtz@yahoo.com says...
>
>>Hello all,
>>I happen to pickup an amc 3050A integrated amp recently for cheap ($50)
>>but it has a problem and I wanted to know if it could be an easy/cheap
>>fix or should I just return it. When turned on it begins to hum loudly
>>once an output is selected the music comes out but it is very
>>distorted. I tried it with cd and phono with the same results.
>>Any thoughts? should I keep it try to get it fixed or should I just
>>return it?
>>Thank you for your comments, daniel
>
> I would do the easiest thing and check for a blown fuse. I had an old
> Phase Linear amp that would sound very distorted when one of the fuses
> blew.
> -----------
> Alex
>
>
The hum indicates a more serious problem and could very well damage his
speaker(s).

Take it back.

Mark Z.

 

[Guest]

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

It sounds like a power supply capacitor is either dead or has become
disconnected. If so it is not a particularly difficult repair and so
shouldn't be that expensive. Get some quotes or an asessment of the
problem.


Gareth.


<danielmmtz@yahoo.com> wrote in message
news:1102617358.087838.46030@c13g2000cwb.googlegroups.com...
> Hello all,
>
> I happen to pickup an amc 3050A integrated amp recently for cheap ($50)
> but it has a problem and I wanted to know if it could be an easy/cheap
> fix or should I just return it. When turned on it begins to hum loudly
> once an output is selected the music comes out but it is very
> distorted. I tried it with cd and phono with the same results.
>
> Any thoughts? should I keep it try to get it fixed or should I just
> return it?
>
> Thank you for your comments, daniel
>

 

[Guest]

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

I may have misread your post. If the loud hum is physical, i.e. not coming
through the speakers, it sounds like there is a big problem taking a lot of
current. Take it back.




"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:cpc0in$3kf$1@sparta.btinternet.com...
> It sounds like a power supply capacitor is either dead or has become
> disconnected. If so it is not a particularly difficult repair and so
> shouldn't be that expensive. Get some quotes or an asessment of the
> problem.
>
>
> Gareth.
>
>
> <danielmmtz@yahoo.com> wrote in message
> news:1102617358.087838.46030@c13g2000cwb.googlegroups.com...
>> Hello all,
>>
>> I happen to pickup an amc 3050A integrated amp recently for cheap ($50)
>> but it has a problem and I wanted to know if it could be an easy/cheap
>> fix or should I just return it. When turned on it begins to hum loudly
>> once an output is selected the music comes out but it is very
>> distorted. I tried it with cd and phono with the same results.
>>
>> Any thoughts? should I keep it try to get it fixed or should I just
>> return it?
>>
>> Thank you for your comments, daniel
>>
>
>

 

[Guest]

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

Hi, ok I cannot return it the guy sold it "as is" untested, oh well. I
have tried using it as an amp and as a preamp with another integrated I
have and it works both ways. Still it does not work on its own!!

My assumption is that the problem is in the pre out main in. I have
tried with an interconnect but the noise humming is still there.
Anything I could do to fix it easily?

Thanks

 

[Guest]

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

At this point it sounds like an open ground connection somewhere. Possibly
associated with the pre-out jacks, like bad solder connections. I assume
you're using good cables or jumpers, or there's a switch to connect or
separate the pre-main.

Mark Z.


<danielmmtz@yahoo.com> wrote in message
news:1102813892.237716.284910@c13g2000cwb.googlegroups.com...
> Hi, ok I cannot return it the guy sold it "as is" untested, oh well. I
> have tried using it as an amp and as a preamp with another integrated I
> have and it works both ways. Still it does not work on its own!!
>
> My assumption is that the problem is in the pre out main in. I have
> tried with an interconnect but the noise humming is still there.
> Anything I could do to fix it easily?
>
> Thanks
>

 

[Guest]

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

I'm no expert by any means, but since folks laughed at me when I brough in old
stuff, that's when I decided to subscribe to these newsgroups over four years
ago. Boy, what a difference! You folks are awesome, and I have printed
hundreds of pages stuffed into several large notebooks and bought many books on
electronic repair. Truly an educational experience in here.

Anyway, I'm sitting here with a mono "classroom" reel-to-reel from the late
70s/early 80s with a distortion. It even distorts when you have it on pause
and monitor the input signal from an outside source.

Hum and distortion can come from bad caps or a power transitor gone out of
tolerance and a few shaky resistors. My last "hum" experience was from a bad
output transitor (part of a pair).
The tape recorder is no big deal, and I'm sure the fix will be relatively easy.
Other than the time commitment, the parts have been very inexpensive. I've
repaired at least 15 console stereos, numerous reel-to-reels, cassette decks,
answering machines, amps, cd players. Just having a ball!

If you like the set, start testing some of the components and check for cold
solder joints and bad connections. It's good therapy, too. . It's a great
hobby and a good way to take your mind off drama at work.

Sorry for all the rambling, just my $.02.

BobbyB
Tucson, AZ