How much hum is normal in a Dual Rec (Roadster)?

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crockett

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I've been taking a Roadster combo for band rehearsals lately, it's one of the few places where I can crank the volume up. I've been using Ch 4 Modern set to just about the Modern Recto manual preset along with a TS808 out front to boost the amp. The guitar I'm using has EMGs. With the output set at about noon and Ch 4 master at 10 o' clock, there is a very audible hum from the amp (TS808 set to 9:00 and 3:00 for overdrive/level). I thought that this could be a pickup problem, but the other guitarist also uses EMGs, so I swapped guitars and his showed the same issue. His also comes with EMGs stock, so there's less to suspect on any ground loop issues from within the guitar. On clean channels there is no hum, it's only on the higher gain stuff and it's amplified with the tube screamer on. It's loud enough where the guitar volume needs to be rolled off in between parts to avoid annoying everyone else. I have to turn up the volume an instant before my part begins, especially from when starting out of silence.

Is this the typical response/behavior of the amp? I haven't changed tubes in almost 2 years, so could that be the issue?
 
Wow, do you really need all that gain? EMG's are super hot pups (too hot IMHO) and you're running the Recto Modern setting from the manual which is very gainy and then you're boosting it as well. I would be shocked if you didn't have a ton of noise :shock:

If you must have that much gain you can either get an ISP Decimator pedal and run it after the OD pedal (they work VERY well) or you can try running EL34's in the amp which give a more aggressive and saturated sound so you don't have to run the OD pedal.
 
crockett said:
I've been taking a Roadster combo for band rehearsals lately, it's one of the few places where I can crank the volume up. I've been using Ch 4 Modern set to just about the Modern Recto manual preset along with a TS808 out front to boost the amp. The guitar I'm using has EMGs. With the output set at about noon and Ch 4 master at 10 o' clock, there is a very audible hum from the amp (TS808 set to 9:00 and 3:00 for overdrive/level). I thought that this could be a pickup problem, but the other guitarist also uses EMGs, so I swapped guitars and his showed the same issue. His also comes with EMGs stock, so there's less to suspect on any ground loop issues from within the guitar. On clean channels there is no hum, it's only on the higher gain stuff and it's amplified with the tube screamer on. It's loud enough where the guitar volume needs to be rolled off in between parts to avoid annoying everyone else. I have to turn up the volume an instant before my part begins, especially from when starting out of silence.

Is this the typical response/behavior of the amp? I haven't changed tubes in almost 2 years, so could that be the issue?

I would suspect a microphonic preamp tube, but having noise isn't at all suspicious from an EMG loaded guitar with a tubescreamer and modern mode. If it's really bad, you probably have a tube going microphonic.
 
It actually doesn't sound like all that much gain in the final output. Gain is at about 1-1:30 dialed in on the amp. I'll see if I dial down the gain and re-balance the output what it'll sound like, but I'm guessing the hum will still be there. I'll check out the preamp tubes just for sanity, but it sounds like it's probably working how it should.
 
It could be noisier valves and/or not conditioning the power that is fed into your rig. Nevertheless, under normal condition, there should only be a faint hum in the background when you stop playing, or at least that's what I've found. IME, inserting a Mesa SPAX7 preamp valve in V1, and using a power condtioner for the amp brought the noise down fairly significantly...
 
The SPAX7 does help a bit but I still think that the combo of EMG's, Tubescreamer and higher gain settings is the problem. You should really try the ISP Decimator. They are really great at eliminating the noise without killing your tone or dynamics.
 
Whats it sound like without the TS in front of it? Any hum? How about when the guitar is turned down? Just trying to eleminate or narrow down the culprit.
 
There's less hum without the TS engaged, but it's still there. Rolling the volume down will kill the hum, about half way does it; going from about 7 to 10 on volume is where it really shows it's face. I'm going to try some stuff out at practice tomorrow night regarding the settings on the amp, if all else fails, the noise gate may be the answer.
 
Watch out for fluorescent lights, they wreak havoc on active pickups. My buddies' Jackson with active pickups (Dimarzios I think) hums like crazy, but depending on where he's positioned himself in relation to the lights, the hum goes away.
 
If possible, try a different guitar that has passive or lower output pups and see if that's an issue as well. Mine makes some noise on Channel 4 if I dial the gain way up but nothing out of the ordinary for a high gain amp.
 
LithiumZero said:
If possible, try a different guitar that has passive or lower output pups and see if that's an issue as well. Mine makes some noise on Channel 4 if I dial the gain way up but nothing out of the ordinary for a high gain amp.


I play with a Telecaster and neon lights and fluorescent lights will make a gig unenjoyable for me. I've definitly learned to be quick with the volume knob on my guitar though! I've also learned what direction I need to face to keep the hum down.
 
tele_jas said:
LithiumZero said:
If possible, try a different guitar that has passive or lower output pups and see if that's an issue as well. Mine makes some noise on Channel 4 if I dial the gain way up but nothing out of the ordinary for a high gain amp.


I play with a Telecaster and neon lights and fluorescent lights will make a gig unenjoyable for me. I've definitly learned to be quick with the volume knob on my guitar though! I've also learned what direction I need to face to keep the hum down.


Single coils..... love the tone, HATE the noise!
 
TFridgen said:
Watch out for fluorescent lights, they wreak havoc on active pickups. My buddies' Jackson with active pickups (Dimarzios I think) hums like crazy, but depending on where he's positioned himself in relation to the lights, the hum goes away.

Interesting. They are suppose to be less susceptible to hums than passive, which I found to be true in my case...
 
KH Guitar Freak said:
TFridgen said:
Watch out for fluorescent lights, they wreak havoc on active pickups. My buddies' Jackson with active pickups (Dimarzios I think) hums like crazy, but depending on where he's positioned himself in relation to the lights, the hum goes away.

Interesting. They are suppose to be less susceptible to hums than passive, which I found to be true in my case...

Maybe there is a problem with his wiring? He installed them himself so a bad ground could be the culprit I guess. His solution is just to turn away from the lights, not the best but works in a jiff!
 
Turns out that it does have to do with positioning. I got to practice early (on time) and was able to try out a lot of things. Turning the lights on or off made no difference, it's at a practice studio with lots of other bands playing as well, so the light in only my room might not do much. But facing about 90 degrees to the amp eliminated just about all noise, moving further away from the amp or in certain spots helped as well. This time I noticed the hum on all 4 channels when it was present, and when it wasn't, the noise was low with the tube screamer on in Ch 4.

It could be poor wiring in the EMGs, but I checked the schematic and it's right. There are two patch jobs that a tech did, soldering extra leads to the cap which is too short to reach across from the volume to tone pots and one of the grounds come from a long braid extension piece. But I'm convinced nothing is suspect with the amp except for maybe an aging tube. A power conditioner or noise gate might be the answer if I don't want to deal with it at all.
 
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