Which preamp tube would you choose?

[coreyfyfe]

I always heard how awesome JJ's were. So I got some for my Electric. Never again. I still have them in there now but when they need to be replaced, I'm going Sovtek all the way. Or Gold Lions. The first time I replaced my power tube set (with the JJ's in there now), 1 of them went bad on my 2 days after. It was such a hassle. Then I learned that a lot of people have been having issues with JJ's for a while now.

I'm pretty down in JJ's in general but I also tend to shy away from the Gold Lion branded New Sensor stuff. I've only tried a handful of 12AX7 but the first batch I got were microphonic, bad enough to be sent back for replacements, some were fine. Total opposite of the JJ, very bright and crisp. I got a set of GL KT88 more recently and they were noisy in my amp, lots of pop and crackle when and noise. Didn't bother mixing and matching to try to find the noisy one just swapped in a different set of KT88 I had available. Very small sample size there but just saying you can have problems with any new production "brand".

 

[roller]

Hey there,

I'm re-tubing my Mesa Bass 400 (6550) soon and am sold on Tung Sol for the power section.

Just wondering what you guys think of these that are in the poll and why you'd choose them for the pre-amp section.

Currently, it has the Mesa brand pre-amp tubes which I heard are just re-branded Sovtek's or something and Sovtek power tubes. It was last re-tubed in 2009 by the previous owner and I've it for over a year now and have used it a ton and think it'd about time for some new tube goodness.

Thank in advance!

TubeDepot.com is a great resource.

 

[beans-on-toast]

I always heard how awesome JJ's were. So I got some for my Electric. Never again. I still have them in there now but when they need to be replaced, I'm going Sovtek all the way. Or Gold Lions. The first time I replaced my power tube set (with the JJ's in there now), 1 of them went bad on my 2 days after. It was such a hassle. Then I learned that a lot of people have been having issues with JJ's for a while now.

Tubes are getting better than they were a few years ago. That's good for the industry.

No question that there are some bad products out there. I've found JJ's that were microphonic, the mica spacers that are supposed to be pushing up gainst the glass envelope and supporting the structure were not even in contact with the glass. On the other hand I have seem some JJ's that were very good. The same with some Sovtek tubes, they can have issues.

I think that it's important to buy tubes from a good reseller. One that burns the tubes in, then test them to a high standard to weed out the bad ones. Hopefully this will avoid issues like you had with your power tube.

 

[Stumbo]

Sometimes that's better than knowing too much about them, and getting too caught up in the minutia of the specs.

Hey! We live for minutia!

Normal is as normal does.

 

[blubass]

Double blind testing could straighten out this debacle real quick

You don't really know how much you don't know until you know it.

 

[twinfallsbass]

I found the Chinese 12ax7's to work best in my 400+. Mesa designed the 400/400+ around those tubes.

 

[Stumbo]

Double blind testing could straighten out this debacle real quick

You don't really know how much you don't know until you know it.

What's really the problem is to find two blind guys to do the testing.

 

[somebrains]

I always heard how awesome JJ's were. So I got some for my Electric. Never again. I still have them in there now but when they need to be replaced, I'm going Sovtek all the way. Or Gold Lions. The first time I replaced my power tube set (with the JJ's in there now), 1 of them went bad on my 2 days after. It was such a hassle. Then I learned that a lot of people have been having issues with JJ's for a while now.

That's how I feel about JJ's in my blackline SVT and Buster 200.
Last "amp tech" was realy pushing them, I was fine with my existing whatever is in there.

 

[Wasnex]

I had the opposite impression from the tung sol and mullard RI tubes I've tried - the mullards seem a bit brighter and the tung sols more well rounded in the low mids, but I also only tried them in the first position in a few amps. I would take either over JJ any day of the week just because of the issues I've had with JJ branded tubes over the years (many early failures and poor stability), but also agree with the assessment that standard JJ 12AX7/ECC83 tubes tend to sound a bit muted in the highs/darker compared to most new sensor/Chinese production.

It could be the tubes are operating differently in your amps than mine. IMHO more likely our descriptions vary because of context. I agree the Mullard ECC83 and CV4004 have more extended highs than the Tung Sol. I would call this bright in Hi Fi terms but not for a bass amp. The Tung Sol seems to have a strong upper mid range peek in comparison to both Mullards. I would call this bright for a bass amp as the peak extends into the frequency range of many treble controls. I found the bass and low mids of the Tung Sol slightly stronger than the Mullard CV4004, but weak in comparison to the Mullard ECC83.

My only failure with new 12AX7s has been a Tung Sol 12AX7. The used JJ ECC83S I have all tend to hum a bit, but none have failed. I have read that JJ has a tendency to put out bad batches from time to time, so I believe your bad experience with the brand. I have installed around 10 JJ ECC803S over the last year and all of them sound great and have similar performance. One of them is in a circuit with over 200V on the cathode. I am also running 42 KT88s in various amps. More than half are JJs. The highest failure rate of current production tubes has been Electro Harmonix KT88EH. One shorted, three stopped conducting, and one has low emissions. I didn't buy any of the tubes, they came with a couple of amps. They could have been thrashed by the previous owners.

I've not had any issues with new sensor tubes in regards to the cathode voltage. I know new sensor tends to just reproduce the old data sheets online, but if we believe them as their specs the datasheet does show 180V for the Link Removed, same as the standard JJ 12AX7. The 803S that you recommended actually lists 100V heater to cathode as a limiting value.

IMHO, the old datasheets are not relevant because the current designs are not based upon the old designs and do not use the same materials. I am certain New Sensor has admitted some of their tubes with spiral wound heaters have problems with elevated cathode voltages and the true cathode to heater limit is believed to be around 80V. As New Sensor hasn't provided a list of good and bad, I avoid their tubes with spiral wound heaters in cathode followers and some phase inverters. IMHO New Sensor tubes are often my first choice for V1 in bass and guitar amps and I trust them anywhere that doesn't have elevated cathode voltages.

There are two data sheets floating around for the JJECC803S with different heater to cathode limits. One lists 100V the other 200V. I hadn't seen the one that lists 100V.

In threads that focus on concerns with elevated cathode voltage, NOS, JJ, and Chinese tubes are generally recommended and assumed safe. The older Sovtek 12AX7WA, WB, WC are also supposed to be safe but IMHO tend to be very dark and lack detail. I saw an official response from New Sensor that their Svetlana 12AX7 was safe, but I am suspect because it uses the spiral wound heater design of other New Sensor tubes. The Svetlana is one of my favorite V1 tubes for guitar amps.

 

[Wasnex]

There was a Telefunken copy made on the original machines. I think it was in the 1990's and made somewhere is eastern Europe.

I believe the Telefunken copy you mention was made by Ei. NOS are still available of this tube.

 

[Wasnex]

I tried all 3 of the poll choices in my Demeter VTBP-M-800D amp but the winner for me in V1 was the long plate Sovtek 12ax7LPS.

I tried the LPS in multiple amps. It had a similar tonal profile to the Mullard ECC83. Both tubes have the soft upper mids I like and also boost the lows. The biggest difference was the Mullard had tight deep bass with a lot of fundamental, while the LPS sounded woolly/loose. YMMV

 

[bassbooty]

I tried the LPS in multiple amps. It had a similar tonal profile to the Mullard ECC83. Both tubes have the soft upper mids I like and also boost the lows. The biggest difference was the Mullard had tight deep bass with a lot of fundamental, while the LPS sounded woolly/loose. YMMV

and it varied..... my experience comparing it to a Mullard 12ax7 was the opposite...but different bass, different cabs, different ears, etc.

 

[Wasnex]

Well, you know what they say about everyone having opinions. Here's mine.

None of the currently produced tubes sound great to me. Some sound better than others and both the JJ and Ruby fall in the better sounding category.

I use older USA or European tubes in my bass preamps. I have used tubes by G.E., RCA, Sylvania, Mullard and Telefunken. They each have a sonic flavor to them so one that I love may not be your cup of tea. Also, just to muddy the waters, Tube manufacturers used to buy tubes from each other and put their own label on them so the label does not always tell the whole story. I will still give you my take on some of the more common types that are still available. I bought most of my supply off Ebay, by the way.

Telefunken ECC83(European designation for 12AX7) A fantastic sounding tube with low noise. Very transparent with sweet sounding highs that are never harsh like some of the current tubes. This is a really great tube for folks that dig a very clean tone. Available in the more coveted Smooth Plate design or Ribbed Plate. Both versions sound lovely to me.

English made Mullard ECC83. A fine sounding tube with a buttery warmth to the lows. Clean highs.

RCA 7025 (low noise 12AX7) Sounds similar to the Mullard. A little more hi fi to my ears. Not a lot of coloration.

G.E. short plate 12AX7A Another great sounding tube. A little brighter sounding than the RCA.

Sylvania 12AX7A/7025 Lots of tube warmth in this design. One of my favorite tubes in SWR preamps.

Of course, YMMV. My hearing is damaged so I am working with a handicap. I will say, however, that I frequently get compliments on my tone so I must be doing something right.

One other thought....many of the older tubes have pins that can get corroded and most of them are. I clean them with one of the rectangular erasers or very fine sandpaper or steel wool. Cleaning can save some problems.

I can't argue with this at all, but I generally won't pay more that $40 for a single preamp tube. Unfortunately the desirable NOS 12AX7 types tend to be significantly more expensive from trusted vendors, so most of my 12AX7s purchases are current production. I do buy primarily NOS for a bunch of other tube types such as 12AU7, 12AT7, 12BH7, 12DW7, 6C4, 6N1P, etc.

 

[Wasnex]

I'm pretty down in JJ's in general but I also tend to shy away from the Gold Lion branded New Sensor stuff. I've only tried a handful of 12AX7 but the first batch I got were microphonic, bad enough to be sent back for replacements, some were fine. Total opposite of the JJ, very bright and crisp. I got a set of GL KT88 more recently and they were noisy in my amp, lots of pop and crackle when and noise. Didn't bother mixing and matching to try to find the noisy one just swapped in a different set of KT88 I had available. Very small sample size there but just saying you can have problems with any new production "brand".

Curious where you buy tubes. Most of the tube vendors cull out bad tubes. Music stores and some other online sources don't do this.

A known problem with JJs is their pins tend to be smaller than other tubes. This can cause erratic behavior and noise. I have experienced this multiple times with the JJ 12DW7s in my Ashdown CTM300. Reseating the tubes has always fixed the problem, but it tends to come back after several months. I don't think the preamp tube sockets used in the amp can be retensioned, so I will eventually install NOS tubes with bigger pins. I have already purchased GE and a Raytheon 12DW7s for the occasion.

 

[gregmon79]

That's how I feel about JJ's in my blackline SVT and Buster 200.
Last "amp tech" was realy pushing them, I was fine with my existing whatever is in there.

Yeah that's why I'm going with Sovtek next time. That's what was in there when I got it and it was a mean, LOUD, machine. Not that it's not now. But it seemed to me that a lil something was lost when I swapped tubes out.

 

[Wasnex]

Yeah that's why I'm going with Sovtek next time. That's what was in there when I got it and it was a mean, LOUD, machine. Not that it's not now. But it seemed to me that a lil something was lost when I swapped tubes out.

Every tech I have ever used offered to give me any parts pulled from my amp. With tubes I ask them to toss the bad ones and return any that have remaining life. Even dual triods with a bad section can be useful. I pulled a vintage US made 7025 from my Fender Showman Reverb because it was noisy. The tube found a new home in V2 of a Hiwatt DR201. The circuit only uses the good half the tube.

 

[gregmon79]

Every tech I have ever used offered to give me any parts pulled from my amp. With tubes I ask them to toss the bad ones and return any that have remaining life. Even dual triods with a bad section can be useful. I pulled a vintage US made 7025 from my Fender Showman Reverb because it was noisy. The tube found a new home in V2 of a Hiwatt DR201. The circuit only uses the good half the tube.

Oh I kept my old tubes too. They were toast for the most part though.

 

[Johnflo]

Tubes age and don't always sound the same. Try as many as you can!

 

[coreyfyfe]

Curious where you buy tubes. Most of the tube vendors cull out bad tubes. Music stores and some other online sources don't do this.

A known problem with JJs is their pins tend to be smaller than other tubes. This can cause erratic behavior and noise. I have experienced this multiple times with the JJ 12DW7s in my Ashdown CTM300. Reseating the tubes has always fixed the problem, but it tends to come back after several months. I don't think the preamp tube sockets used in the amp can be retensioned, so I will eventually install NOS tubes with bigger pins. I have already purchased GE and a Raytheon 12DW7s for the occasion.

I've bought tubes from a lot of online and physical vendors. The microphonic gold lion 12AX7s I got from the tube store dot com. In my experience they do minimal testing at best and their matching has been pretty spotty.

Ive always had good luck with AES, TC tubes, and a few others and tend to favor those vendors.

 

[popcat]

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