Marshall VS100

NovTech · 09-27-2009, 06:07 AM

My Marshall VS100 head has a problem...

Here are the symptoms;

Clean channel is fine, although it does have a slight hum at high volumes. When I run the overdrive channels there is a load squeel when the volume is above 1. With the volume below 1 the sound is great (there is a load buzz), but when I try to play at higher volumes there is a real bad feedback type sound. This happens in both overdrive channels but not in the clean channel.

I have tried to replace the tube and it is the same problem. I've tried different guitars, speaker cabs, cables and it is the same problem.

I have also tried to plug the guitar into the effects loop and there is no squeel at high volumes when in the overdrive channels, although there is very little overdrive also.

One note: When I got the amp I had to resolder the main power switch. It was not turning on so I resoldered it.

NovTech · 09-29-2009, 06:52 PM

Anyone have any ideas on this??? It is driving me crazy trying to figure this out...

NovTech · 10-01-2009, 11:39 PM

Sorry, I meant to say LOUD not load in my explanation...it was late when I posted this...

Enzo · 10-02-2009, 03:48 AM

Check that control. Is the solder to it 100% or are there cracks? Also important, make sure the control is not cracked or open.

NovTech · 10-02-2009, 05:24 PM

By control do you mean the on/off switch that I resoldered???

Enzo · 10-03-2009, 05:09 AM

No.

I mean volume control.

COntrol = pot = potentiometer

NovTech · 10-03-2009, 06:38 AM

Problem Solved....

After resoldering most of the board...the noise was still there...

I then tried a different cable from my head to my cab and the noise was gone....grrrrrrrr, i tried different patch cables and they all made the noise, then I used a cable that is made for the connection from the head to a cab and wala...problem solved.

Thanks to everyone for their help...

gbono · 10-03-2009, 08:07 AM

Quote:

Originally Posted by NovTech

Problem Solved....

I used a cable that is made for the connection from the head to a cab and wala...problem solved.

do not use a shielded cable, normally used for low level audo signals, to connect an amplifier to a speaker enclosure. you probably had an oscillation(good for you that you can still hear high frequencies) set up in the output of your amplifier - this situation can damage components.

Enzo · 10-03-2009, 02:04 PM

That is why they make speaker cables and signal cables. Each use has its own needs.

09-27-2009, 06:07 AM	#1
NovTech Junior Member Join Date: Sep 2009 Posts: 15	Marshall VS100 - high pitched squeel My Marshall VS100 head has a problem... Here are the symptoms; Clean channel is fine, although it does have a slight hum at high volumes. When I run the overdrive channels there is a load squeel when the volume is above 1. With the volume below 1 the sound is great (there is a load buzz), but when I try to play at higher volumes there is a real bad feedback type sound. This happens in both overdrive channels but not in the clean channel. I have tried to replace the tube and it is the same problem. I've tried different guitars, speaker cabs, cables and it is the same problem. I have also tried to plug the guitar into the effects loop and there is no squeel at high volumes when in the overdrive channels, although there is very little overdrive also. One note: When I got the amp I had to resolder the main power switch. It was not turning on so I resoldered it.

10-02-2009, 03:48 AM	#4
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,366	Check that control. Is the solder to it 100% or are there cracks? Also important, make sure the control is not cracked or open. __________________ Education is what you're left with after you have forgotten what you have learned.

10-03-2009, 05:09 AM	#6
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,366	No. I mean volume control. COntrol = pot = potentiometer __________________ Education is what you're left with after you have forgotten what you have learned.

10-03-2009, 02:04 PM	#9
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,366	That is why they make speaker cables and signal cables. Each use has its own needs. __________________ Education is what you're left with after you have forgotten what you have learned.

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09-29-2009, 06:52 PM	#2
NovTech Junior Member Join Date: Sep 2009 Posts: 15	Anyone have any ideas on this??? It is driving me crazy trying to figure this out...

10-01-2009, 11:39 PM	#3
NovTech Junior Member Join Date: Sep 2009 Posts: 15	Sorry, I meant to say LOUD not load in my explanation...it was late when I posted this...

10-02-2009, 05:24 PM	#5
NovTech Junior Member Join Date: Sep 2009 Posts: 15	By control do you mean the on/off switch that I resoldered???

10-03-2009, 06:38 AM	#7
NovTech Junior Member Join Date: Sep 2009 Posts: 15	Problem Solved.... After resoldering most of the board...the noise was still there... I then tried a different cable from my head to my cab and the noise was gone....grrrrrrrr, i tried different patch cables and they all made the noise, then I used a cable that is made for the connection from the head to a cab and wala...problem solved. Thanks to everyone for their help...

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