Amp Noise Problems!

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chromeboy

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I have used tube amps for years most of which were high gain amps. Marshall, Mesa, Fender, Peavey to name a few. Currently I am playing through Jet City amps. I wanted a Soldano but didn't have the funds so I went with Jet City. I have jca 50h and just bought the 100hdm. Love these amps and the price was great. My only issue is the amp noise I am getting. Louder than the normal hiss or hum although my old marshalls were pretty noisy. Now I went through my signal chain and added a noise suppressor which helped but when not playing there is still noise. My 50h is about a year old but the 100hdm I have only had for about a week. So is there a better way to cut the noise down than just a noise suppressor. I mean both amps are pretty new so the tubes shouldn't be bad. Anyone have either of these amps and had the same problem? If so how did you fix it?
 

chromeboy

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It's before my compressor and overdrive pedal. My boss ns 2 has it's own loop so I loop those pedals. My other effects like delay , chorus and flanger are going through the amp loop. My amp makes noise even if the is nothing plugged into it so I don't think its my pedal board. I had read it could just be ill seated pre amp tubes but I don't know. It's a new amp so not sure if I should mess with it or just send it back for a refund or a replacement.
 

Len

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There's a known problem with the JCAs where the tube heater PCB traces in the amp pick up noise. It results in a loud hum.

There's a link here about how to mod the amp for lower noise:
http://www.guitarampboard.com/forum/viewtopic.php?t=1615

I did the mod to my JCA50 head and it worked well. Before the mod I used an an MXR Noise Clamp with the amp's preamp section in the noise gate loop to reduce the noise.
 
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ampmadscientist

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I have used tube amps for years most of which were high gain amps. Marshall, Mesa, Fender, Peavey to name a few. Currently I am playing through Jet City amps. I wanted a Soldano but didn't have the funds so I went with Jet City. I have jca 50h and just bought the 100hdm. Love these amps and the price was great. My only issue is the amp noise I am getting. Louder than the normal hiss or hum although my old marshalls were pretty noisy. Now I went through my signal chain and added a noise suppressor which helped but when not playing there is still noise. My 50h is about a year old but the 100hdm I have only had for about a week. So is there a better way to cut the noise down than just a noise suppressor. I mean both amps are pretty new so the tubes shouldn't be bad. Anyone have either of these amps and had the same problem? If so how did you fix it?

The noise gate won't help you if you use it at the input...
but it will help you if you use it at the effects loop. This is because it will shut off the noise from the preamp, before it reaches the power amp.
(the noise is coming from your preamp...)

What type of "noise?" Hiss or hum or buzzing? Post a recording...
"Noise," with or without the guitar plugged in? This is an important part of the solution.
"Noise," with or without effects pedals? this is also important.

Noise comes from more than one source.
Then it adds together in the final output.
Each source of noise must be identified / tackled separately, and eliminated one at a time. (or you will get nowhere)

Now what would help a lot...is to get a schematic to your amp.
And what else helps quite a bit is to list all the stuff you are plugging into the amp.
 

chromeboy

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I tried putting my ns2 in the loop which helped but I had the threshhold all the way up and there was still noise when I turned up my guitar. The pedals I am using is a sure pedalboard wireless, a Morley mini volume, a morely bad horsey wah, a compressor, an ocd overdrive, a super chorus and a dd3 delay. The delay and chorus are going through the effects loop of the amp. Originally I was using the noise gate before the compressor and the odd using in in the ns2's loop. I'm gonna try a ground lift to see if that may help as the home I live in is over a hundred years old and the electrical is not very good. If nothing works then I will be forced into sending it in for warrenty service.
 

ampmadscientist

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Oh boy.....

A. Amp plugged into speaker - no guitar, no effects pedals...

Turn the amp up loud.
IS the noise still there? Yes or no? What kind of noise is there NOW? (post the sound clip)

B. Amp plugged into speaker, JUST the guitar ONLY plugged in, no effects. Stand 10 feet from the amp.

Turn the amp up loud. Turn the guitar up loud.
What kind of noise is there NOW? (post the sound clip)

C. Lesson one:
there is NO such thing as a noiseless effects pedal.
Don't blame your amp, for the noise from effects pedals. (this is a really common mistake)

Just because the amp is noisy----with effects pedals----does NOT mean there is something wrong with the amp.

D. Connect effects pedals ONE at a time.
Which effects pedals cause the NOISE? Identify this, ONE pedal at a time.
Identify which pedal is the noisy-est...
Identify which pedal is the least noisy.
 
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chromeboy

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When the amp is on with nothing plugged onto it it is noisy. I don't stand right in front of my amp and use a wireless so I walked away over 30 feet and still the noise. I have been playing for over 30 years so I know standing facing the speakers will give you more noise. I returned the amp and had GC order me another one. Also I looked on some jet city forums and apparently the jca line has this issue. Now my 50h is noisy as well but not near the level of the 100hdm. I used a ground lift on my 50h and it did cut the noise down to a very acceptable level. When I get my new 100hdm I will try using the ground lift to see if it cuts down the hiss/hum. If not then I just may return the head and get another 50h head. On another forum I saw that the tube heater goes right past the ac picking up hum. At least I think that's what was said. Not sure. I really like the sound of this head so I hope my new one will be a little better otherwise back ot goes.
 

Len

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When the amp is on with nothing plugged onto it it is noisy. I don't stand right in front of my amp and use a wireless so I walked away over 30 feet and still the noise. I have been playing for over 30 years so I know standing facing the speakers will give you more noise. I returned the amp and had GC order me another one. Also I looked on some jet city forums and apparently the jca line has this issue. Now my 50h is noisy as well but not near the level of the 100hdm. I used a ground lift on my 50h and it did cut the noise down to a very acceptable level. When I get my new 100hdm I will try using the ground lift to see if it cuts down the hiss/hum. If not then I just may return the head and get another 50h head. On another forum I saw that the tube heater goes right past the ac picking up hum. At least I think that's what was said. Not sure. I really like the sound of this head so I hope my new one will be a little better otherwise back ot goes.
Yeah, that's definitely what you're hearing. Have you considered contacting Doug at Jet City? He's usually very helpful.
 

chromeboy

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I have contacted him. Sent him three emails but have yet to hear from him. What I don't understand is that if this is an issue possibly in production then why is the problem not being fixed. This amp sounds awesome but I have read many posts on forums where people complain of the excessive noise with these amps. Surely Doug has had to have heard of this. So I don't know if anyone at Jet City is addressing this issue.
 

Len

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I have contacted him. Sent him three emails but have yet to hear from him. What I don't understand is that if this is an issue possibly in production then why is the problem not being fixed. This amp sounds awesome but I have read many posts on forums where people complain of the excessive noise with these amps. Surely Doug has had to have heard of this. So I don'tt know if anyone at Jet City is addressing this issue.
Maybe to cut corners, since the amp is so low priced? I usually don't expect too much out of an amp that cheap.
 

chromeboy

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Yeah maybe but from what I heard, Mike Soldano himself did a mod that reduced the noise significantly. And from what was said it was a pretty easy fix . I don't know enough about amps to attemp to work on them. Maybe I will run the amp by my amp guy to see what he would charge me to do the mod.
 

SG~GUY

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-best solution is to find the source of the noise and eliminate it, otherwise your creating one problem to compensate for the first problem.

-it sounds like you have something causing interference, dirty power of some other issue like florescent light fixtures, a rheostat, neon lights, or in fact dirty power, try it in other rooms that are on a different circuit than the current circuit, see if that helps.
 

ampmadscientist

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I found basically 2 problems which I corrected:

Hiss:
just like Marshall / Fender, I installed a 7pf 1000V cap between plate and grid of the first preamp stage.

Buzzing: it's filament noise.
You have to change the layout or use the "cancellation method," to stop the AC heater voltage from bleeding into the audio path.

These 2 sources of noise are "typical" for high gain guitar amps. There is nothing unusual about it.
Hiss, buzzing, hum, oscillations, microphonic ringing...

Even many experienced techs don't understand where the noise comes from or how to get rid of it...

On a PC board, it's more challenging to get rid of noise because there is little you can do to change the layout.
But you can still use cancellation methods...

On a HW amp, you can re-arrange the wires (especially the filament wires).

Guitar noise /effects noise : these are different problems.
The noise does not come from 1 single source.

The noise from several sources adds together...that is reality.
you need to identify each source of noise - and tackle each source separately.
 
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chromeboy

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Thanks for all of your suggestion s guys. I will mention some of them in my next email to doug at jet city.
 

chromeboy

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Finally heard back from Doug at Jet City and he said he had heard of the noise problem and the fix that Soldano did but said that the mod was on a 50h and not the 100hdm. He did mention that better quality tubes may help but that noise is just the nature of high gain amps. So I am picking up my new 100hdm on Saturday. I will try using an ground lift and plugging it into a different outlet and moving the amp to a different area of the room it is in. I'll let you all know what happens.
 

ampmadscientist

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Finally heard back from Doug at Jet City and he said he had heard of the noise problem and the fix that Soldano did but said that the mod was on a 50h and not the 100hdm. He did mention that better quality tubes may help but that noise is just the nature of high gain amps. So I am picking up my new 100hdm on Saturday. I will try using an ground lift and plugging it into a different outlet and moving the amp to a different area of the room it is in. I'll let you all know what happens.

Ground lift:
it should not get better with the ground lifted, it should get worse.

Which indicates the electricity may be wired wrong.

Pick up a tester at the hardware store:
61-501-orig.jpg


This will tell you if the power is wired wrong, if the ground is missing, etc...
Everybody should carry one in the gutar case.

So -- take the amp to a different loaction where the power is good, and test it again.
If your power checks bad, then get an electrician to correct the miswiring.
 

chromeboy

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Update:. I got my new 100hdm and also bought a furman power conditioner and now the amp has what I would call a normal amount of hiss. I also found that turning down the overdrive pre amp cuts down the hiss. Luckily the 100hdm still gives you plenty drive even with it turned down to about 2 1/2 to 3. I then just use an ocd pedal as a clean boost for solos. If I need a little more saturation I use my compressor and I get all the saturation I need. I am also trying out using the crunch channel for rhythm and the overdrive for solos. Anyway so far so good. Power onfotioner is working and plus I always use a noise supressor so it's pretty quiet now. The amp sounds great!
 

ampmadscientist

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You should not need a power conditioner at all...ever.

If the electricity is really bad, a power conditioner does not fix that.

If the electricity is really bad, call an electrician and get it fixed the right way.

Bad power can be a shock hazard, and the power conditioner does NOT make it safe to use.
 

chromeboy

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Pros use them all the time. I have worked shows with nationally touring acts and they always use them especially when playing smaller venues and large clubs. In a perfect world maybe you wouldn't need one ever but we don't live in that world. There is a reason pros are using them and it's because they work. Just sayin. Doug from jet city didn't seem to have a problem with it.
 
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