dirty channel hum/hiss

[mavrick12x]

i have no idea how long this has been going on but there is a hiss coming out from the dirty channel on my rockerverb. i didnt think too much of it because i've been playing a lot through my cheap highway one tele. but last night we put a prs custom 22 on it and same issue. then i noticed the hiss with no guitars into it at all. one test i'll do when i get to my amp will be to turn it on with nothing plugged into it. just the internal 16ohm jack. its not there from the clean channel so i dont think its my pedals.. possibly preamp tubes going bad? any suggestions?

[brianr0131]

How high up is your gain? My Rocker hisses a bit at 3 o clock or higher. Normal if you ask me.......

[mavrick12x]

only around 1:30 ish

[Icarus]

I recently noticed the hum on my RV50's dirty channel. With the gain anywhere over 1-2 o'clock it was noticeable, over 3 and it was annoying. I put a noise gate in the loop and it totally killed all hum but i needed the treshold so high to stop guitar feedback that I didnt want it in there. Next I changed out the EH preamps for JJ's and the hum was reduced by enough to satisfy. Not sure if it was worn preamps or the change of brand that helped but I would try replacing your preamps after trying a gate in the loop as it may work for you. If you don't use noise gates, I would go get an isp decimator g-string which goes in the loop and in front.

[jason41224]

hum is normal with tube amps. however, if you have nothing plugged into the input jack, then it should be dead silent. with my rocker 30, it gets pretty noisy with the gain above noon, and higher if the volume is above 9'oclock.

[mavrick12x]

hum is normal with tube amps.

to clarify its more of a hiss than a hum. but im aware that this is common with tube amps. but i need to check out if its there with no input

[Tamayo]

I had the same problem with my RV50. I believe it was a few things. Both of the tubes for the clean channel were bad and some of the connections were dirty/dusty. Weird. The reason you hear it most with the dirty channel is from the amount of gain through the channel. I took mine to a solid amp tech and he took care of it with some troubleshooting. Albeit tube amps are a bit noisy it should only be the typical amount "fuzz".

[a.hun]

hum is normal with tube amps.

to clarify its more of a hiss than a hum. but im aware that this is common with tube amps. but i need to check out if its there with no input

A bit of hiss is pretty normal with valve amps, and at higher gains will only get louder. If annoyingly loud try some valve swapping. Start with the preamp valves for that channel.

I realise your problem isn't hum mavrick12x, but since it has been mentioned...

Hum shouldn't be more than barely noticable in a well sorted amp design. Oranges are generally particularly well sorted designs on that score so I wouldn't expect any significant amount of hum to be normal at all.

You may get some acoustic hum from some transformers which you'll hear with your head close to the amp. That is sometimes the case and not usually a problem at all. But electronic circuit hum coming through the speaker is a different matter. Can be due to valves, either individual ones getting noisy or badly matched power valve sets where the imbalance will allow hum. Or it can be due to various other things like failing filter capacitors, poor grounding, and various others listed here:
http://www.geofex.com/ampdbug/hum.htm" onclick="window.open(this.href);return false;

So while a little hiss can be normal hum generally isn't normal. None of my amps hum more than very slightly and if one started to I'd be getting it checked.


Andy.

[mavrick12x]

I've done a little troubleshooting and this is what i've found:

I turned on the amp with no input plugged in and it was completely silent on both clean and dirty channels.

I plugged in my pedal rig and the hiss was there...

I unplugged the effects loop thinking something in there was the cause but the hiss was still there..

I unplugged my tele from in front of the amp and there was still a hiss...

I started unplugging pedals until the only thing in was the output from my eventide timefactor...

so either that the TF is faulty or maybe there are some settings on the TF I don't know about..

anyone have any ideas?

thanks...

marcus

[indianDYsummer]

Take the timefactor out and put other pedals in and see if its still there? Replace the f/x loop driver tube?

[mavrick12x]

okay heres an update...

I took my Eventide home to work on some new patches and to my suprise the hiss is in my vox too....

dead silence without the pedal.... hiss with it... so maybe a time for a buffer pedal and or noise gate?

i've been doing some reading on the eventide forums and it sounds like this is a fairly common problem and no really "follow these steps" solutions...

its a hiss i can live with on the clean channels but recording makes me nervous. but the hiss on the dirty channel is almost unbearable when im not actively playing...

other option will be to put it back into the effects loop and see if it improves.

[Icarus]

....Or...... throw the pedal away and get one that doesnt hiss

[mavrick12x]

I don't really feel like throwing 300 dollars away

[Icarus]

Or sell it, or is it good enough that the pro's outweigh the con's?

[mavrick12x]

It's good enough that I'm gonna find a fix