Finding V1 Tubes that don't rattle

[jjang1993]

Hey everyone, I've been enjoying my Vintage Sound 35SC amp a lot. Rick Hayes is a great amp builder and his customer service is top notch. This knocks the Fender Reissues out of the park. I do have some problems finding a good V1 tube. Out of the 4 Groove Tube 12AX7Cs I have, one didn't rattle, all of the stock TAD 12AX7Cs rattled the worst, two of the three tungsol one's didn't rattle, 4 Sino 12AX7Bs rattled, two TAD 12AT7s rattled, one of the two Sino 12AT7s did not rattle. The tubes that rattle in the V1 position of this amp don't rattle in the V1 position on my Super Champ, but I'm pretty sure the 12AX7 in the Super Champ is a phase inverter.

 

My gut is telling me to go with the Tung-Sols and steer clear of chinese made tubes, as two of the last three TS have been rattle free, and the one that rattled wasn't even that bad. Also, the TS 6V6 set is pretty rattle free in my Super Champ XD. The chinese tubes seem more prone to rattling in this amp.

 

Is this type of dilemma in search of a rattle free V1 12AX7 normal for new production tubes in Fender styled amps? I don't think the tube socket is bad or loose, as it takes a good amount of effort to remove and install a 12AX7.

 

I've removed the spring loaded preamp tube shields. I do use two of the silicon O rings on all my preamp tubes, and 4 of them on each power tube, and I swapped out the tube rectifier for a solid state rectifier for a punchier tone (yes I rebiased the power tubes, it's extremely easy with the external bias points Rick puts in these amps). I was able to get a good V2-V5 combination preamp wise that doesn't make any rattles when I use any of the non rattling V1 tubes. I've ruled out the power tubes, as the rattle still occurs with the rattling tubes in V1 even with different power tubes..

[WRGKMC]

Mentioned this in one of your other Posts. Groove tubes is a branding company. They don't manufacture tubes. They buy from China, Russia and Yugoslavia, test, match pairs and rate their power levels then stamp their name on the tubes. They were bought by Fender several years ago and like many major companies fender has been known for buying at bargain basement prices.

 

JJ's make some of the most physically and electrically durable tubes out there and still sound very good in most amps including Fenders.

This will depend on transport too. The tubes come from half way around the world and that are like transporting light bulbs. The elements can always get beat up in the process.

 

JJ JJ ECC83G (G for gold pins) or JJ ECC83s (S for standard pins) (12AX7) have very low noise ratings as does Electro Harmonix. If you go to this page https://www.google.com/search?q=Vacuum+Tube+Comparison+chart&biw=1680&bih=977&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiZhcuWuLTPAhVk9YMKHeC1A_sQsAQILg#imgrc=CcAFinMfhgL4VM%3A and open up the comparison chart you'll a ratings chart like this. The bottom rating is for Noise and Microphonics. Some of this is electrical noise and some is microphonics caused by physical vibration. The higher the rating the lower the noise.

 

These charts don't tell you how long they might remain noise free in a combo that rattles them to death, but its better to start with a rating of 5 and work down.

 

 

 

This Chinese tube for example is at best a 3.5 rating on noise so even new you're beginning with a handicap. You will also want to look at the other factors including Tonality, Gain, Headroom and Sensitivity and pricing when comparing. This tube is $9 so you get what you pay for and not all high cost tubes have great ratings but the tone may be good. The EH above is only a couple dollars more and from my experience is a killer tube for most applications.

 

 

Power tubes don't have these ratings unfortunately but the reviews they post are fairly accurate. There are several other tube vendors that also have reviews for the products they sell. like the Tube store here. http://www.thetubestore.com/Resources/Product-Reviews/6L6-Tube-Reviews and Antique Electronic Supply. https://www.tubesandmore.com/tech-corner/12ax7-comparison-current-made-tubes

 

Once you find the best reviews you can shop for price between them.

 

I also suggest you even contact the company and ask what they advise. They been in business a long time and get inquiries regularly about what tubes are best for specific amps. No doubt they can tell you what tubes to stay away from because they get failed tubes back from customers when they don't work out.

 

 

[jjang1993]

Does low noise floor translate to a less likelihood of mechanical rattle? Apparently the Tube Amp Doctor 12AX7Cs are selected for very low noise but they rattle like crazy. I'm beginning to be skeptical of companies like Tube Amp Doctor and Groove Tubes. It sounds like they just buy tubes and put their own label on them. I doubt they actually test their tubes except when they need to match power tubes.

 

Has anyone tried the more expensive eurotubes or Herbie's Audio dampers?

[Les Paul Lover]

Whilst microphonic do happen, I find it unlikely that your amp would show them so badly???

 

Something else, if you compared their microphonics to a PI slot in another amp, we still don't know if they are for sure microphonics

 

Furthermore microphonics fault can express themselves in many ways, I find it again unlikely they would all rattle rather than some pop, squeal, squash or make random rocket noises.

 

Can you describe that rattle in more detail? Is it volume dependant ? Does it stop at low or high volume ?

If the valve is actually amplifying an outside rattle (a sign of slight microphonic , I would look to sort out the amp rattle in the 1St place.

 

I hope that makes sense?

[jjang1993]

It sounds like a glassy ring. With all of the rattling tubes it happens at low volumes and high volumes. They sound make any popping or squealing noises. Thankfully I have 3 12AX7s that do not rattle but I would like to have 3 more that are good V1 tubes.

[Les Paul Lover]

OK, so the rattle you described isn't a rattling noise at all, is that right?

 

A pinging ring noise sounds like a microphonic issue, and if you have bought that many tubes that are all microphonic, you can count yourself unlucky.

 

I hope you bought new and recently, from a reputable dealer, and would send them back within the 90 days warranty that is usually provided with valves.

 

As WRGKMC was saying, JJ valves are pretty rugged and i've had good luck with them in the past, even though some people disregard them.

 

Their 6V6 valve is one of the best modern produced 6V6 valve too, capable of taking punishing voltages without complaints. I've had a set of those in my Orange RV50 since 2009, and they're still going strong (it isn't my main amp, but I've still played it quite a bit!!!!).

 

I've had JJ preamp valves in my Orange AD15 combo, really good sound, bright, full, and microphonic free. They replaced a TAD set, sounded a bit better, but I don't known how old the TAD set was, so cannot they were an improvement on new for new basis.

[jjang1993]

I did buy the Groove Tubes new, two of which I had to send back to get replacements because one died in my Super Champ and the other one rattled like crazy in my Super Champ. I won't even bother with Groove Tubes, the ones they end sending me could be worse than the ones I would ship to them. I doubt they screen their preamp tubes.

 

Knowing that the issue is microphonics, I'll likely order some Tung-Sols or EHXs from tubedepot and pay the extra 4 dollars to get one that has low microphonics. I'm considering getting one of the small preamp tube dampers from Herbie's Audio Lab. They're pretty pricey, but part of me thinks those tube dampers are just band aids and the real long term solution are to get quality tubes.

[jjang1993]

The glassy ringing doesn't sustain like in this video.

[WRGKMC]

All tubes rattle. Its a matter of how much and whether that mechanical vibration translates to worse things like microphonics and electrical noise.

 

You can even have two matching tubes from the same manufacturer and one will begin to rattle and the other doesn't. Its simply how tight the glass is to the element inside. If the element is tight against the glass or completely clears it, you wont hear any rattle.(but you can still have microphonics and electrical noise) If the element is barely touching the glass, its most likely to rattle the most.

 

Rattle may or may not affect the tubes functionality, but as I said, you start with tubes rated with the lowest likelihood of producing microphonics and you'll have the less likelihood of rattle.

 

In order to understand why, you have to know how microphonics are caused. A mic diaphragm is made to vibrate because the air vibrates. Its coil and magnet generate an AC signal. If the diaphragm is too rigid or dampened so cant vibrate with the air, the coil and magnet cant generate a current

 

A tube can vibrate from the speaker and the element inside can vary the signal inside causing unwanted electrical noise and even act like a microphone reproducing a thumping noise when you tap them and cause a feedback loop like a mic pointed at a speaker.

 

How do you get rid of microphonics???? You build a sturdier tube more resistant to mechanical vibrations.

 

This doesn't stop the element from vibrating of course.

 

If you have one person shaking their head back and forth in the air and another doing the same banging it against a wall, the second will rattle the wall and do more damage to the brain inside.

Same with the tube elements banging against the inside of the glass tube. It is more likely to become microphonic and noisy.

 

The question is how sturdy can you make a tube before it begins to affect the audio quality. The manufacturers used to make tubes that had aluminum casings instead of glass. They were often used in field military applications like field radios so the tubes were less likely to break. Some military tubes can still be found, but the popular ones used in amps are ungodly rare and expensive so we have to use what's available today.

 

Tube manufacturers would have made tubes highly durable and free of microphonics a hundred years ago if it were possible to do so without influencing the sound. Unfortunately the delicate parts made of thin metals are wants needed to give you the best sound quality.

 

Like the old filament light bulbs, there is only so far you can go because of the technology with that design. They instead moved to making the fluorescent and LED bulbs we use today.

 

With amps, the tube vibration issue was solved already. Its called Solid State as in the word Solid. You may not like the tone as much but it does solve the issues that plagued tube amps, fragile elements and high electrical consumption, just like the new LED bulbs solve the issues with the older carbon filament bulbs.

 

The chart I posted is your best bet to use as a guide. The only other alternative is to pull the head from the combo and build a separate can, thus eliminating the source of the vibration making the tubes rattle.

 

By the way, there are other versions of JJ tubes that aren't as good so stick with the JJ JJ ECC83G (G for gold pins) or JJ ECC83s do not buy the 803's which have a low microphonic rating.

[1001gear]

Those low noise AX7s (I believe they're all "low noise") might be more appropriate for hifi preamps and maybe that's why you got microphonic ones. Try Mesa Boogie 12AX7s instead. Specify that they're going into a combo amp. They have those beefy plate/cage structures and your chances of microphonic specimens should be greatly reduced.