Matchless Question

[sniffyduke]

Have a Clubman 35.

Think I am going to send it to Matchless and have them take
a look at it.

Just want to lay out some symptoms and see what you guy's think.

1) Amp is very loud, louder than my Plexi.

2) Amp was sent in for repair once already
because when you pluged into the input
you would get no sound
(this was after a friend used it at a concert
and ran two amps together through
effects send and return.

3) It does not break up well at all.

4) When I pluged it into a new 4ohm 2x12 cab
When powered on, the amp made a very loud
buzz. Turned it back on and it still buzzed.
So, the next morning when Iturned it
on, the buzz was gone.

5) Very loud hiss when pre is turned up above 12:00

Tried switching out all the tubes and it made no difference.

[rp]

1) Amp is very loud, louder than my Plexi.

That's a symptom?

Doesn't sound like there's much wrong w/ it. It's going to cost a lot to send it to Matchless. Why not have a local tech at least give it an evaluation first. If he's a good guy it may not even cost you anything.

[selloutrr]

number 3 and number 5 can be preamp tubes.

what is the age of the amp? do you live in an overly hot or wet climate?

Number 4 - what other appliances share that power? florensent lights, microwave.. - dirty power.

[sniffyduke]

4) yes there was a florensent light pluged into the same socket.

I know a florensent light will cause amp noise if it is on
but I did not know than even with it off sharing the same
outlet could cause an issue.

Can you not use florensent light when working on an amp?
If the amp is being built in the chassis, I have a florensent artist light
above where I am working and soldering. This is ok right?

I mean, a florensent light is not going to damage circuts
when just working on an amp?

[sniffyduke]

No more buzz. But the amp has been super loud.
It has two volumes full blast and off.
When you turn the master past 9:00
It just is loud (really loud) and turning
the master up past this 9:00 setting
the volume does not get louder
Its like right after 9:00... BOOM LOUD

Like I was saying, It went in for repair once, because
after a friend used it at a show (he ran it through the effect loop
with another amp) when I got it back, the front inputs did
not work.

Could this be Output Transformer related.

What are the symptons of a bad Output transformer.

[selloutrr]

http://www.geofex.com/ampdbug/outtrans.htm

[selloutrr]

if the amp has an fx loop it should split the the preamp and power setion. do you have a preamp you could plug into just the return and test the power section? and vise versa the matchless preamp into another amps power section to determine where the issue is.

If you are not trained in amp repair and safety.. send the amp in for repair.

[sniffyduke]

pre-amp?

I have a trident channel strip I use in my studio for recording.

What would this test determine?

[Normster]

It may just be a bad volume pot. If the carbon strip is burnt at the ground side (9:00 o'clock) it can't bleed any signal to ground.

[sniffyduke]

How do you burn a carbon strip?

I know the amp runs so hot, that when you pull the cable
out of the 4ohm jack onthe guitar amp its real hot.
lots of heat.

[sniffyduke]

I will have a local guy look at it.

If he does not know, I will send it to matchless again.

[selloutrr]

are the transformer getting hot when the amp is running?

preamp....

The amplifier can be divided into 2 parts
first the preamp, second the power
at the end of the preamp is the FX out (send) at the front of the power section is the FX in (return)

you could make the trident ch strip work but you will need to make sure you have the correct impedance and don't over load the section under test. it's easier to use another amplifier.

I agree the pot could be bad but the heat is a concern. Matchless are usually very well built amps, but even good amps can have a bad part.

[sniffyduke]

So, if this was the case.

Here is what he did at the concert.....

He had his matchless as the main amp, ran
(Dont know if its send or return) his main amp
into a fultone tape echo, then out the tape
echo into my amp. I think it was just hitting my power section
there were no cords going into the input of my amp.

The amp did not blow out on him on stage.

But when I got it back home, when I pluged into
the input there was no sound.

I know I had mullard output tubes in it.
and the amp ran so hot that there were clamps
around the EL34's and It melted all the felt inside
the clamps.

But I sent it to matchless and they fixed my input
but it still just seems real loud.

I guess I will send it in again, Phil isa nice guy and
has always taken care of me.

[sniffyduke]

I did remove the amp from the chassis and
I think they replaced a filter cap, because one is
diff than the others, do not know what this would have to
do with anything.

I will let them handle things, but I like to learn
about trouble shooting as well.

Thank you guy's

[tweedeluxe]

what you are describing doesn't seem unusual to me, if it has the "crossline" 1MΩ master volume circuit used in most matchless amps. replace it with a 500k pot and you'll have more control. IMO a better (but more involved) option would be to replace it with a different PPIMV circuit altogether.