Creek 4040 S2 integrated amplifier

[TD]

I have just been given a 4040 S2 amplifier. Unfortunately, the left
output channel is somewhat distorted. At quiet volumes it sounds fine, then
as the volume is turned up, the distortion kicks in.

As the volume is further increased, it is only the distortion that increases -
the overall volume of the sound eminating is still relatively quiet. I would
describe the distortion itself as sounding a little like white noise, or
digital saturation.

Anything that stands out as a possible culprit here? I don't have a schematic
- I have emailed Creek but who knows if they'll reply.

--
TD

 

[Jerry G.]

For this type of fault the output stage and related driver circuits
will have to be troubleshooted. It is very possible that one or more
of the output or driver transistors are defective, or any of the
support components. It is impossible to take a guess at this. An
experienced tech who is used to troubleshooting these amplifiers can
service this for you.

Jerry G.

--


On Sep 2, 4:57 pm, TD <topper.dog...@googlemail.com> wrote:

I have just been given a 4040 S2 amplifier.  Unfortunately, the left

output channel is somewhat distorted.  At quiet volumes it sounds fine, then
as the volume is turned up, the distortion kicks in.

As the volume is further increased, it is only the distortion that increases -
the overall volume of the sound eminating is still relatively quiet.  I would
describe the distortion itself as sounding a little like white noise, or
digital saturation.

Anything that stands out as a possible culprit here?  I don't have a schematic
- I have emailed Creek but who knows if they'll reply.

--
TD

 

[Dave]

"TD" <topper.doggle@googlemail.com> wrote in message
news:g9m7qn$t12$1@registered.motzarella.org...

Well yes, but this is sci.electronics.repair hence I thought someone here
might give me some advice on how to troubleshoot and repair it myself.

--

What is your level of skill with regards to servicing electronic equipment?
Do you know how to identify the various components found within the
amplifier? Do you have the proper tools to do the work? Do you have a
basic understanding of the way in which a DC-coupled solid state amplifier
works?

If you don't have a basic understanding of how this stuff works, your
likelihood of success in repairing it without assistance is very low.

Also, your chance of causing more damage is fairly high.

If the amp has pre-out/main-in jumpers on the back remove them. Replace
them with a patch cord so that the left pre-amp out goes to the right main
in channel. Does the distortion move to the other channel? If it does, the
problem is in the pre-amp (unlikely but possible). If it does not, the
problem is in the amp.

If the problem is in the amp, I'd pull the output transistors and test them.
Given that the amp (and thus the transistors under test) seems to work fine
at low volume, this might be easier said than done without some specific
test equipment. If the outputs test OK, get a schematic. Inject a sine
wave into the amp's input, and use your oscilloscope to trace the signal
path. You'll get to a particular component or group of components or
integrated circuit where the signal looks good going in, and distorted
coming out. You've found your problem area. Depending on what type of
component, what its' function is, where it's located, you may need to test
various other components in order to determine what's actually broken.
Also, realize that if the outputs are failed, there's a possibility that
another fault elsewhere in the amp took them down, and that new ones may
blow immediately upon installation.

FWIW, it's an expensive amp that you got for free. I'd pay somebody to fix
it rather than take the chance I'd butcher it as my first foray into
electronics repair.

Good luck.

Dave

I'd say there's a good chance that it's either an output transistor or a
driver/pre-driver on the main amp board, but I'm often wrong.

 

[TD]

On 2008-09-03, Jerry G. <jerryg50@hotmail.com> wrote:

For this type of fault the output stage and related driver circuits
will have to be troubleshooted. It is very possible that one or more
of the output or driver transistors are defective, or any of the
support components. It is impossible to take a guess at this. An
experienced tech who is used to troubleshooting these amplifiers can
service this for you.

Well yes, but this is sci.electronics.repair hence I thought someone here
might give me some advice on how to troubleshoot and repair it myself.

--
TD

 

[TD]

On 2008-09-03, Dave <dspear99ca@yahoo.com> wrote:

"TD" <topper.doggle@googlemail.com> wrote in message
news:g9m7qn$t12$1@registered.motzarella.org...

Well yes, but this is sci.electronics.repair hence I thought someone here
might give me some advice on how to troubleshoot and repair it myself.

--

What is your level of skill with regards to servicing electronic equipment?
Do you know how to identify the various components found within the
amplifier? Do you have the proper tools to do the work? Do you have a
basic understanding of the way in which a DC-coupled solid state amplifier
works?

Low, yes, some of them, and little but I'm willing to read up on it.

If you don't have a basic understanding of how this stuff works, your
likelihood of success in repairing it without assistance is very low.

I don't disagree, but it was worth finding out for sure.

Also, your chance of causing more damage is fairly high.

If the amp has pre-out/main-in jumpers on the back remove them. Replace
them with a patch cord so that the left pre-amp out goes to the right main
in channel. Does the distortion move to the other channel? If it does, the
problem is in the pre-amp (unlikely but possible). If it does not, the
problem is in the amp.

If the problem is in the amp, I'd pull the output transistors and test them.
Given that the amp (and thus the transistors under test) seems to work fine
at low volume, this might be easier said than done without some specific
test equipment. If the outputs test OK, get a schematic. Inject a sine
wave into the amp's input, and use your oscilloscope to trace the signal
path. You'll get to a particular component or group of components or
integrated circuit where the signal looks good going in, and distorted
coming out. You've found your problem area. Depending on what type of
component, what its' function is, where it's located, you may need to test
various other components in order to determine what's actually broken.
Also, realize that if the outputs are failed, there's a possibility that
another fault elsewhere in the amp took them down, and that new ones may
blow immediately upon installation.

You, sir, are a true legend. Thanks for the advice.

FWIW, it's an expensive amp that you got for free. I'd pay somebody to fix
it rather than take the chance I'd butcher it as my first foray into
electronics repair.

Yes, it sounds more than good enough as computer speakers with some
JPW mini-monitors that I also got for free.

Good luck.

Dave

I'd say there's a good chance that it's either an output transistor or a
driver/pre-driver on the main amp board, but I'm often wrong.

Noted.

--
TD