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View Full Version : How to stop Tube Vibrations and Microphonics in combo amps?


D-Nastee11
12-30-2011, 02:30 PM
I just order new tubes because after having my amps shipped from tone merchants cross country to Missouri I have been noticing a lot of rattles and noises. I know UPS and Fed EX aren't nice about tossing around boxes that are heavy so I figure my best bet is to just start fresh. Now that I have the tubes ordered I wanted to look into any methods people are using to minimize such issues. I have heard about a few different ones. Just wanted to see what people here are doing. Thanks

D-Nastee11
12-30-2011, 06:14 PM
bump

supergenius365
12-30-2011, 08:11 PM
I use tube dampers - those rubber ring things. Seem to work well.

chervokas
12-30-2011, 09:22 PM
I just order new tubes because after having my amps shipped from tone merchants cross country to Missouri I have been noticing a lot of rattles and noises. I know UPS and Fed EX aren't nice about tossing around boxes that are heavy so I figure my best bet is to just start fresh. Now that I have the tubes ordered I wanted to look into any methods people are using to minimize such issues. I have heard about a few different ones. Just wanted to see what people here are doing. Thanks


Well, when amps are shipped it's a good idea to pull the tubes and wrap 'em in bubble wrap and secure 'em somehow in the amp or in a separate box. No good reason to ship amps with tube in the sockets.

As for tube dampers my experience has been that simple silicone o-rings don't do much. I have found that these can work: http://herbiesaudiolab.net/tube.htm, but they're not going to make a howlingly microphonic tube like a good one.

Toneseeker361
12-30-2011, 11:08 PM
I have heard of people using soft rubber washers on the amp mount screws to minimize tube rattle.

Standard 64
12-31-2011, 03:18 AM
good luck,I hate combo amps for their rattle capabilities

chervokas
12-31-2011, 09:51 AM
I have heard of people using soft rubber washers on the amp mount screws to minimize tube rattle.

Yeah, I never found that to be very effective.

falconer
12-31-2011, 10:05 AM
good luck,I hate combo amps for their rattle capabilities

:agree As many times as I've been tempted...I'll never buy another combo.

DeaconBlues
12-31-2011, 10:26 AM
It's a matter of isolating issues(if any) to minimize/eliminate any rattles. I seldom have these issues with combos, but when I do it's usually a simple quick fix. I like combos for their portability. I hate heads and cabs for their lack there of.

I've had good luck with the red silicone(?) washers for quieting tube rattles, btw.

tele_jas
12-31-2011, 10:37 AM
I use tube dampers - those rubber ring things. Seem to work well.


This...... Works really good.

I've been playing combo's for a long time, rarely do I have a problem with tube rattle.... but the few times I have, I used these tube dampers and they worked wonders, even on an EF86.

chervokas
12-31-2011, 11:13 AM
I use tube dampers - those rubber ring things. Seem to work well.

Just FYI, be careful about rubber....tubes get freakin' hot, some upwards of 300 degrees and will melt rubber washers. Silicone is the most common material you see for tube dampers (which are often just silicone o-rings repurposed), because silicone can handle the heat.

D-Nastee11
12-31-2011, 11:51 AM
Well, when amps are shipped it's a good idea to pull the tubes and wrap 'em in bubble wrap and secure 'em somehow in the amp or in a separate box. No good reason to ship amps with tube in the sockets.


I agree 100%, but for whatever reason they left them in the sockets so that's why I decided to start from zero and just re tube both amps. I would like to try those herbielabs dampeners, but at $23 and up per tube I really need to know they work WELL.

tbblues
12-31-2011, 11:55 AM
+1 for Herbie's Audio Lab. The one listed for guitar can take the heat. In my case, it tamed an ef86 pre-amp tube in a combo.

Baxtercat
12-31-2011, 02:16 PM
Don't replace the whole batch. Tap on 'em [w/ the amp on] to isolate which tubes are causing the most noise.
Re. preamp bottles, if you can find them, the Russian '90s 12AX7WBs are really low-noise.

Toneseeker361
01-01-2012, 08:50 PM
Yeah, I never found that to be very effective.
Thanks!

dughaze
01-02-2012, 12:42 AM
Between the tube noise, the heavy weight, the chassis rattles, the inevitable boxy sound, and the lack of a good sounding low end I gave up on combos also.

falconer
01-02-2012, 09:00 AM
Between the tube noise, the heavy weight, the chassis rattles, the inevitable boxy sound, and the lack of a good sounding low end I gave up on combos also.

I've been through any combination of cab, chassis, and tube rattles in every single combo I've owned. I've experienced perfectly good, and expensive, NOS tubes that played well for a few weeks, then turned microphonic. No more.

As one tube vendor here told me via email: Combos are excellent devices for turning good NOS tubes into microphonic junk.

Ed Reed
01-02-2012, 09:08 AM
Mesa sells a noise dampened 12AX7 and it has a piece of heat shrink tubing on the OD. This would be easy to do. Power tubes are another thing.

cxx
01-02-2012, 09:37 AM
I haven't had any luck with any remedies. The combos with horizontal tube mounts are worse, but I've had problems with both. Mostly power tubes in my experience. It probably depends on how loud you play but if you go with a combo you just have to live with shorter tube life. I'd keep a replacement set around and swap when questionable.

Rambergwest
01-02-2012, 09:38 AM
The speaker is the vibration source obviously but the main reactive surface for the pickup effect is the chassis. The larger surface area gets energized and feeds the electronic components. One trick to reduce this source is to use the self adhesive vibration matt that is available from car stereo shops on the outside of the chassis. This will significantly quiet the metal and if you use tube covers on your pre-amp tubes you should be quite a ways down the road to a usable amp. As always FWIW and I am sure that a lot of folks see just the tube itself as the problem.

MT Buckaroo
01-02-2012, 11:14 AM
Question for the previous poster: Why do tube shields help with this issue? Is it simply that the spring loaded aluminum covers secure the preamp tube in its socket better, minimizing vibration?

I've always run all my amps, heads and cabs (and none of mine have to suffer load out and travel regularly) with those shields removed, under the impression that heat disperses better and that tone is improved. Maybe I should think about putting the shields back on in my combos...

Rambergwest
01-03-2012, 11:39 AM
I have two types one that just has a spring to hold the tube in place the other type is older and has wool felt that goes between the spring and tube. This type is a bit more dead than the spring only type. Both do very little but sometimes it's enough depending on the tube. Some tubes seem to fit a little looser in the pins and it's those that benefit the most from my observation.