Roadster Noise Issue

[twostring]

If you will be so kind...

http://www.youtube.com/watch?v=WAMQ8y1PEeo

Anyone have any ideas? I'll just paste what I've already outlined on the youtube posting.

A quick video to demonstrate a noise issue I'm having with my amp. Depending on how certain notes resonate in the amp, I get this horrible arcing sound. I'm curious to know if this is a sign my power tubes are going out, or if there is something far more serious going on within the amp. This problem just crept up on me one day about two months ago. Here's what I've done...

1. Isolate the amp by moving it off of and away from the speaker cabinet. The amp is also resting on a pillow to dampen as much of the vibration from the speaker as possible.

2. Check all channels and modes of operation. This problem occurs in both Bold and Spongy modes, 100 watt and 50 watt, rectifier or diode and no matter if the effects loop and reverb are on or off. The noise also occurs in all 4 channels.

3. I've done a brief "tap" test on each of the rectifier and power tubes. Tapping on the rectifier tubes does nothing. Tapping on each of the power tubes results in a brief "burp" noise similar to what you'll hear towards the end of this video. I haven't bothered to check any of the preamp tubes because at this point I don't believe they are the problem.

4. The noise sustains no matter if there is a signal going through the amp or not, meaning once this arcing starts, I can cut the volume on the guitar or even unplug it and the noise continues. I can sometimes turn down the volume on the amp and the noise will suddenly cut out, but at times I've had to switch the amp over to standby in order to get the noise to stop.

Here are the settings on the amp as played in the video...

Channel 1
Power - Bold/100 watt
Diode Rectifier
Effects Loop - Off
Voice - Clean
Master - 3 o'clock
Presence - 2:30
Bass - 2:30
Mid - 1 o'clock
Treble - 2:30
Gain - 8 o'clock
Reverb - noon

I'm playing a stock '60's reissue Strat (apologies for the background noise, I've got electronics in the room and I'm dealing with a single coil guitar through the amp at a pretty high volume).

Video shot with Nokia N95 8GB

 

[Bouncepogo]

Watched the vid, and read your account, it sounds pretty much identical to the problem I had with my rectoverb combo. After playing for a bit the power tubes started what i describe as 'droning' until i switched channels. Tap test on the power tubes elicited the same noise, sometimes ongoing, sometimes just a short burst.

I guessed at microphonic power tubes, got a new set of 6L6 tubes and i was sorted. That was a few months ago, played it at band practice volume many times since and no problems.

Hope this helps.

 

[twostring]

Watched the vid, and read your account, it sounds pretty much identical to the problem I had with my rectoverb combo. After playing for a bit the power tubes started what i describe as 'droning' until i switched channels. Tap test on the power tubes elicited the same noise, sometimes ongoing, sometimes just a short burst.

I guessed at microphonic power tubes, got a new set of 6L6 tubes and i was sorted. That was a few months ago, played it at band practice volume many times since and no problems.

Hope this helps.

Certainly does. I'd still like to get a few more opinions, but you backed up what I was thinking (and certainly hoping for).

 

[155]

do you have more tubes? if not take the 2 inside ones out and switch to 50w the outsides run in 50w mode, if it still happens try switching them out until you tried all 4 in different combos, its not likely 2 are bad but how old are the tubes? good luck

 

[twostring]

I don't have any extras laying about. The tubes are the same that shipped with the amp from Mesa...I would guess that they are about 2 years old.

 

[155]

start swapping them out

 

[twostring]

Will do as soon as I get home. I've ordered a replacement set as well...even if the tubes in the amp aren't bad, it seems like a good idea to have some tubes laying about to test.

 

[Fixxer6671]

Hey man, keep us posted, hope this works out.

 

[twostring]

swapped tubes around today (inside pair to outside, outside pair to inside) and the noise is still present in 50 watt mode. Ray of hope...switching to spongy and getting my tap on resulted in noise only on one tube (in either 50 or 100 watt mode). Replacement tubes will be here soon, so we'll see if that fixes it or not.

 

[twostring]

Update...new power tubes went in, dog-strangling went out. Seems like the tubes were the fault. I opened her up and zipped through the channels at nearly room-shaking volume and there was no hint that there were going to be any problems. Tap test resulted in no noise as well.

Thanks to all for the advice...it's appreciated.

Chad

 

[R_ADKINS80]

Watched and commented. I had a very simmilar sound, but chopped like toggle switch flipping with one volume off, when a STR454 power tube was acting up. Try some new power tubes bro. I would hope you keep a spare set on-hand anyways.

 

[Stratocaster]

Thanks for the update, twostring.
Glad everything worked out well.

From reading above, sounds like you swag the tubes to have been at around two years old, and that you are the original owner.

After you've had a little time to burn in the new tubes, let us know what you think of the difference between the old power tubes (before the death-buzz, of course) and the new ones.

Thanks,
Strat

 

[twostring]

Bear in mind that my main sound is pretty much what you heard on the video. Straight up clean blues tone with a Strat on channel 2. I tend to run a Blues Driver and a duo of tube screamers to bump up the gain in stages when needed. I rarely branch out from channel 2 (I run channel 4 high gain with a les paul for Alter Bridge type stuff at times).

I'd have to say with the new tubes, the character is still there, but the amp is much brighter. This isn't necessarily a good thing, since the amp was very bright to begin with. With the neck pickup, the bass strings have a meaty "klank" to them, while the highs are crisp but smoothe. When I kick on the BD-2 as a mild boost (tone straight up, gain at 9 o'clock, level at 3 o'clock), I bump the amp into a little grit when I dig in, but mostly just get more definition with large chords. The first tube screamer gives me a mid gain rhythm tone that still maintains good "klank" on the bass notes, but the high strings sing a bit more. The final tube screamer kicks it over the top for solos.

When I want to add a little bit of girth to my rhythms, I kick on my Deja Vibe with the volume around 2 o'clock, but the intensity just a hair above full down (the speed control doesn't really do much here, and the switches are set to modern and chorus). I thought of it while listening to Kenny Wayne Shepherd. If I'm not mistaken, for nearly all his rhythm work, there seems to be a very subtle modulation in his tone. This setting on the Deja pretty much nails it and gives me a great texas blues tone with just the BD-2. It's odd how some effects perform the unintened so well.

Anyone else using the Roadster for similar tones? I know it's not really the "intended" use for the amp (Re: hi-gain ripping), but I love channel 2 and it has a nice clean tone with some mass...something that I just couldn't get out of any of the Lonestars I've played.