Tube holder for Peavey Classic 30? Hmm, I wonder if there is suc a beast??

[Jared Purdy]

No, I've only had the amp since Dec 25th, and one of the tubes went microphonic after about 2 weeks. Now, to be fair, the staff at the store that I bought it from told me that roughly 2% of all stock is defective, and I may have just gotten a bad tube or two. They are going to warranty it/them (they said that they'd replace all 7 actually, just to be sure).

The amp came with a full set of JJs, so being new to this, I don't know if JJs are more prone to microphonics than others? The store is going to replace them with Groove Tubes, which I have been told by thetubestore.com, are made by the lowest builder, and then restamped with "Groove Tube" (the store said that they are usually made in China). That info, coupled with what Enzo said regard the construction difference bewteen the C30 and the C50 (offering a better and more solid socket mount for the tubes) has just got me wondering.

[Steve Conner]

Oh, well see if they'll let you keep the old JJs, they could be useful as spares. They might need to keep them for the warranty claim, though.

Groove Tubes are indeed rebranded, I believe they can be either Sovtek or Chinese. JJ are made in Eastern Europe and seem to have a decent reputation for quality.

Combo amps are notorious for shaking their tubes to pieces, but there are a lot of combos in the world that work fine without any shock mounts. I don't know of any commercial amp that used them: I got the idea from looking at military tube equipment used in aircraft.

If you just play the amp at low or medium volume in your home, the vibrations won't be so violent and the tubes may last fine. Enzo sees a lot of amps belonging to working musicians, that get cranked up full in a bar several nights a week.

[Mars Amp Repair]

Attza verry nah-sah enzo! g

[Jared Purdy]

I teach at a college, so my hours are kind of all over the place. For example, Tuesdays and Wednesdays I'm home, alone, all day , that means playing with the volume, when I'm playing. I have had it cranked a couple of times! Generally, I have channel one turned up to 4/5, but I control the volume from the guitar (I vary the tone controls, usually with the bass at around 9, mids at 7/8 and the treble at 6/7 - the louder its cranked, the more the tones get dialed down). I woudl say that on channel one, its usually running around 2/3. On the gain channel, I keep both the pre and post at 6 (with the tone controls the same as on channel 1), and dial in the volume from the guitar. Now, when the wife and kid are home, thats a whole new ball game! Generally, they let me keep it around 1.5/2 during "normal hours", and then I'm down around one or less during their sleep time.

[tedmich]

FYI the "orange heat resistant foam rubber" is silicone rubber foam available at ....where else

Mcmaster Carr

5109K54
Extreme-Temperature Silicone Foam Adhesive-Backed,
1/4" Thick, 3/4" Width, 36" L
In stock at $8.95 Each

[Jared Purdy]

Thanks, and where is mcmaster carr?? I's in TO

[olddawg]

You know, my 18 watt Marshall clone is meant to hang upside down in a combo. It just has spring wire with a little loop in the middle that goes over the top tip of the EL84s. The spring wire attaches to the mounting screws for the tube sockets. I know this unit probably has a PCB, but you might be able to fashion and mount some springs to do the same job for pennies.

[Jared Purdy]

The C30 has a wire type of securement system, to hold the tubes in place, I presume. They do the job. However, the vibrations coming from every sq. inch of the amp when it is cranked have a different effect, I suspect. I hope to have my EL84s replaced by tomorrow, and I will mark on the calender how long they last! I suspect that I just got a bumb batch. The amp is only a month old, and though I have cranked it to 12 once (for a bout five minutes) and to 6 for about 10 minutes, its not generally above 2-3 90% of the time.

[Jared Purdy]

Old Dawg, by any chance to do play Jerry Garcia with Grisman, Saunders et al stuff?

[Enzo]

If your rear grille already has a strip of foam, by all means, double it up if it doesn't hold the tubes tight enough. You can buy the foam tape from PV direct, they sell it by the foot.

I suspect that a great deal of the vibration that those tubes are encountering comes right through the circuit board (where the sockets are screwed to), and right down through the entire tube. If the socket was mounted to something more secure, and away from the relatively flimsy circuit board, say the chassis, that would offer a more solid foundation, and possibly reduce some of the vibrations.

No, the vibration comes from the chassis, to which the circuit board is mounted. What kills the tubes is the shaking caused buy the vibration.The circuit board is actually fairly securely mounted to the chassis. The chassis is relatively thin sheet steel. The chassis can flex. So really, the tubes are already mounted to the chassis.

I have no idea what the good folks over at Peavey have tried, nor do I know if they read any of this stuff, or if any of it gets reported back to them.

Why do you think the latest rear grille is shaped to fit under the tubes and has the foam strip added?

Keep in mind that not all tubes rattle, not everyone plays loud enough to make loose tubes rattle, and many people are not bothered by some vibration sound coming from the back. Set this amp on a stage next to the drum kit, and the ssound from the speaker will make a lot more racket vibrating the snares on the drum kit than from tube rattle. When this bugs someone, it really bugs someone, but most C30 owners are not tuned into it as a "problem."

The person who initially wrote that comment, was talking about the poor build of the circuit boards on the Fender BDRI (and similar Fender amps) and wondered how much more it would cost to make smething that only lasts 5 years, last longedr, like 10 or 20 (he was specifically speaking about the Fender BDRI, which according to him and others starts to show all kinds of problems at the 5 year mark, or sooner, a reason why they don't offer extended warranties, according to him at least).

What baloney. The tube rattle problem in the PV is not due to cheap boards. And for that matter, just what is wrong with the Fender boards? The Fender problem with the dropping resistors overheating is not due to cheap boards, it is due to a marginal design. After all, the rest of the resistors on it don;t fall off. And to say they don;t offer extended warranties is silly. Fender offers 5 years right out of the box. That is a long darn warranty, and the sort of stuff I will be repairing in that amp during that 5 years is going to be reverb pans, those two resistors, jacks, channel switching circuit components, solder on the power tube sockets.

Not much of that is the board's fault for being to thin. Those resistors should have had larger copper pads, yes, but a heavier board wouldn;t have helped. What ther really should have done us used three-terminal regulators instead of the zeners. And the solder to the tube sockets? it cracks away from th socket legs, not the circuit board.

The C30 does have some design weaknesses. The fold around board layout is tremendously inconvenient. And the little jumper wires connecting the board sections are vulnerable to breaking. Again, that is caused by the board sections moving relative to each opther, not the board thickness. The wires are what breaks, not the circuit boards.

The C30 has been in production for some 16 years now, I don;t think to has to prove itself against claims it will only last 5 years - the length of its warranty.

I shock-mount all of the tubes on rubber bobbins

I would imagine that would be a difficult and possibly expensive mod on the C30,

I don't see any reason why you couldn't shockmount the tube socket board, maybe extending the jumper wires to it a little.

Probably could. it is the whole row of tubes. It is riveted to the center board with angles for rigidity. Hell, the jumpers would probably flex enough.

But a large problem is the shaking rather than the vibration. The whole thing vibrates, any combo amp does. Think about the radio antenna on your car. When you drive over a bump, you feel the vibration comiong through the car body. Now look out the wiondow at that antenna. Notice how the end of the antenna is swinging back and forth wildly? The vibrational energy is amplified by the length of the antenna whip. In the C30, the tube sockets are screwed to the center of the chassis. As it vibrates naturally, right behind that speaker, the motion is amplified by the tubes sticking out from it. They shake around like that antenna.

If you clamp the tubes to the chassis, with something like my brute force retainer, or with something spring loaded like Tom's Tamer, you don;t stop the vibration, that chassis will vibrate no matter what. But what it does do is prevent the tube itself from swinging around.

And by the way, the bent-wire forms that come with the original amp are only there to prevent the tubes from falling out, they are not there to prevent motion.


Groove tube sells tubes from all the factories, not just one or two. "Low bidder" is not fair. Whether it is Groove, or an OEM like PV, they want a tube that will work, but they also want production quantities. When PV need 10,000 12AX7s, it does them no good to get 500 super-top-quality, hand made by Tibettan monks and their virgin daughters 12AX7s. That leaves them 9,500 short for production.

That is why you will see the C30 come from the factory with JJs at one time, with a Ruby tube another, and so on.

You can take a brand new tube from the box, hold it up and rap on the glass, you will hear whether it will be a rattler right there. Brand new tubes can rattle. The tube is still perfectly good, as a tube, it will just be rattling in this particular amp.


PLEASE learn the distinction between microphonic and rattling. A microphonic tine will make noises come out the speaker. It may or may not rattle. A rattling tube makes physical noises you hear through the air. It may or may not be microphonic.

[Jared Purdy]

I don't know Enzo, you had my full support and attention until those Monk's Virgin dauhgters. Seriously, I was under the obviously delusional impression, that there were in fact Monk's gorgeous, hot-bade daughters in skimpy robes, dedicating their lives to Muse by lending their other worldly beauty, and nimble talents with circuit boardetry, to the sounds that we create. Its all so mundane now .

Thanks for the reply. I think that I, and likely others, not having seen the inside of the chassis itself, combined with short handing info, mistakenly refer to the circuit board as "flimsy" when, as you point out, its not so much the board (a case of mistaken identity) but is either the chassis, or a combination of things. Mind you, someone on another forum, I think it was telecaster.com, who has a BDRI and and HDRx did infer that the Fender board was poorly made and weak/delicate (I'm trying to capture the right adjectives) as he had tried to do some mods to it. I don't know, maybe he's all thumbs, or has gorilla hands (no slight to gorillas).

So, I feel compelled to ask, is there a home made solution to that? I will see about getting that foam, its an easy mod. Thanks for the link.

I was over at Trinity Amps last night, they are a boutique amp company in Toronto producing some really, really fine heads and combos. Mostly smaller stuff in the range of 15-18 watts. Largely Marshall based, but also one VOX design,one Fender Tweed and one HiWatt version. He uses both EL84s and 6V6s, and in the heads he uses both tube types so that you can switich between them for different sounds.

His amps really are beautiful, and are made extremely well. However, as I wrote in a post last night (on this form) the C30 more or less stood up to his variants of a Marshal, VOX and a Fender Tweed all of which used a Tone Tuby Alnico. Seriously, I was amazed at how well it stood up to his amps in overall tonal quality. His held the cleans a bit better at a higher volume (over 6/12), but not by much. Conversly, the Peavey delivered better gain in the 2nd channel (which the Tweed didn't have). If a person was to go in there, sight unseen, hell bent on buying and realized if was just too much money, they need not be dissapointed at the Peavey C30. In fact, they would be more or less perfectly content.

As far as gain goes, the C30 delivered exceptionally good gain against his Marshall variant, and the tone was also remarkably good, though admittedly, when the volume really got cranked on his, the tone was defiantley cleaner, but then again, his speaker is better, and there is likely something in the overall build process. One thing that he uses that I know I also want to try are silicone (red in colour) O rings. He puts them around the 12AX7s and the EL84s in the combo amps. He said he uses two per tube, and buts them roughly in the middle of each tube to help reduce vibrations. Have you seen these? before?

Well, as far as microphonic and rattling, I'm only going by what two service techs have told me. They have not heard my amp in front of them, though at least one of the them will today. I was told to tap on the tube (lightly with the earser end of a pencil) and if the tube rattles its gone microphonic. I'm in no place to argue here. I was also told that if I strumbed the guitar (with the cage off the back of the amp) and held the tips of the tubes that I thought were microphonic, the vibration would go away. Most of it did, though not all of it. I was also told that for the tube to be microphonic the sound does not have to come through the speaker?????

When I was going around and trying all of these amps, Mesa 5:25, Soldano (?), Epiphone, Traynor, C30, HRDx, BDRI, Reverbe Deluxe, Twins, Marshall Class 5, MA series, Orange, Blues Junior, Dleta Blues, C50, not one of them produced a rattling or microphonic tube. And, from the looks of it, and from the questions I asked (I always wanted to know how long the amp had been on the floor so as to determine if the speaker was broken in), those floor amps had been there a considerable amount of time.

When mine comes out of the box, and onto my living room floor, and within two weeks, at least one of the tubes is "rattling" i.e., producing a rattling type of sound out the back, not through the front, I figure that there must be something wrong with the tubes. So I explain the sound and the circumstances, and they all say microphonic. Maybe they are short forming the terminology, whch obviously doesn't help to educate people. I can't imagine people who play electric guitar for a living, or even as a hobby would live with this sound. Its obnoxious, and very noticeable, to the point where it interferes with the listening. I'm going to be replacing the tubes today (the EL84s and the 12AX7s), and I'll be doing it with a tech. I'll let you know what they say about them, if in fact they are just rattling, or if they have gone microphonic.

Thanks again for all of the time you put into addressing our comments.

Regards, Jared.

[Steve Conner]

I was also told that for the tube to be microphonic the sound does not have to come through the speaker?????

Well, I would say that it's only "microphonic" if the unwanted noises come through the speaker. Microphonic means the tube is acting as a microphone, turning vibrations into an unwanted electrical signal that gets amplified along with the wanted one.

If you hear rattles, but not through the speaker, then it's just "rattly".

Either way, rattles in an amp are annoying and need to be fixed. But the distinction is important, because if the rattles don't come through the speaker, then you've no proof that they even come from the tubes! It could be a loose screw, loose wire or anything.

[Jared Purdy]

So, what causes the rattles, and why so fast?? Faulty, poorly constructed tubes?? Luck of the draw??

[Enzo]

The EL84/6BQ5 was designed as a nice little tube, intended to sit in a table radio or maybe a TV set, and politely deliver sound to a little speaker for a long while. It was never a mechanically robust tube. The internal supports are good enough for something that sits on your bedside table or on the TV shelf.

But when we start using it in guitar amps, it sounds fine, but is really mechanically marginal for the task.

You can have a brand new NEVER been used tibe, right out of the box that rattles. In many amps it doesn;t matter, but in the C30, the tubes are in a circumstance that if the innards are not real tight, you will hear the rattle. SO before I stick a set into a C30, I always rap on the glass to see if the innards are loose. If they rattle in my hand, they most assuredly will rattle in teh amp. And if the set is loose, I just save it for some other amp that won;t care, like the C50.


SO I'd pick "luck of the draw."