Modern Amps with Vintage Tubes

[DocNrock]

Hey all, does anyone here have any experience with putting NOS vintage tubes into modern amps?  I thought I would share my experience, as it is all in the quest for the holy grail of "that tone," right?

I have a Peavey JSX 2x12 combo that I got back in 2008.  After getting it, because of the open back it was missing some of the bottom end that I like.  Soon after getting the amp, Satriani left his endorsement deal with Peavey and the JSX line was discontinue.  I then found a new JSX 4x12 cabinet on clearance at GC for like $298.  Sold!  Now I just run into a THD Hot Plate into the cabinet, using the combo as a head only.

I loved the tone, but tone is a never-ending quest, right?  I started researching tubes and learned that many people love Eurotubes' JJs.  There are those that hate them, as well, but I thought I would give them a try.  When they arrived, I went to swap them out.  Only to find out that the amp came stock with JJs in V1-V3.  There was a Sovtek LPS in V4 (Phase Inverter).  Going back to research, I learned that the PI has little to no effect on tone.  It just drives the power amp section.  Indeed, it is part of the power amp section.  I also learned that the Sovtek LPS is almost unanimously thought of as the perfect tube for the PI slot, even though it is also widely thought of as having a horrible tone in the preamp tube positions.  Other modern tubes I tried are Mullards, and Tung-Sols.  The Mullards sounded pretty good in all the slots.  The Tung-Sol sounded good in V1, only.  The gain was a bit thin and sharp in the Crunch and Ultra channels.

Further research led me to want to try some NOS vintage tubes.  Although difficult to find and pricey, I learned that Telefunken made some of the most sought after 12AX7s on the planet.  I had some Groove Tube 7025Ys in my parts bin.  These are discontinued, but were made in (then) Yugoslavia on the original Telefunken equipment.  I tried them, but they were a bit brittle on top, although the rest of the range sounded great.  Online reviews compared to Telefunkens said that the 7025Y sounded similar, but the Telefunken did not have the high end brittleness, but had more of a singing quality.  I decided to give them a try.

I found a reputable online source and got three lightly used Telefunken 12AX7.  They were about 70% the cost of NOS and came with a 90 day guarantee, to include microphonics.  These literally transformed the amp.  Honestly, I liked the clean channel better with the JJs, although it is not at all horrible with the Telefunken in V1.  With the Telefunkens in V1-V3, the amp has a great midrange growl on the crunch channel, the gain has a definite singing quality when playing lead lines, and the nasal midrange "honk" this amp is known for was gone.  Also, the Ultra channel, which is incredibly high gain, sounded fizzy with the JJs.  With the Telefunkens, it also has a nice singing quality.

I tried a Telefunken in V4, but there was a definite "balance," that was missing compared to the Sovtek LPS.  I don't know how to put it into words.  Suffice to say, the Sovtek stayed in the PI slot.

A unique feature of this amp is that it has a switch so that, with proper biasing, you can use EL34s or 6L6GCs for the power tubes.  KT77s will also work.  The amp came stock with JJ EL34s.  I tried the JJ KT77s, are supposed to be kind of a hybrid between EL34s and 6L6GCs.  They were a nice change.  There was a bit more bottom end "beef," but the amp did not lose the midrange punch that EL34s are known for.  Since I went for the Telefunkens in V1-V3, I figured I go for broke (YOLO) and see what I could find for vintage 6L6GCs.  It would seem the holy grail for these are RCA "blackplates."  The same guy who sold me the Telefunkens also had a matched quad of NOS RCA blackplates. 

After putting these in and rebiasing, I must say I was expecting more.  I haven't tried any modern 6L6GCs, but these are supposed to have a lot more bottom end beef than the EL34s.  The blackplates did not deliver in that department.  The tone was great, but not what I was looking for.  I ultimately went back to the EL34s, but probably will try out a modern set of 6L6GCs to see what they sound like.  Alternatively, it does bug me that these four pricey tubes are sitting on a shelf not being used.  I may put them back in, as well, and see if they develop more of that beefy bottom end after they burn-in.  Unlike the Telefunken's they were not lightly-used.  They were truly NOS. 

Has anyone else tried vintage tubes in a modern amp?  What were your experiences?

On a side note, I remember being a kid going into Radio Shack and seeing shelves of vacuum tubes they sold and an RCA tube tester, as well.  Had I known what I know now, I would have bought up their supply of EL34s, 6L6GCs, and 12AX7s with the money I made mowing lawns and stored them away.  At what these sell for currently, I could have sold them in current times and probably made enough to retire!  :laughing7:  I'm sure many of you know what I'm talking about, at least Cagey. 

 

[mayfly]

I've done this.  My experience is that NOS tubes, even those you could get 10 years ago, were very inconsistent.  They varied wildly in tone, mU, gain, transconductance, and just general guts.  I had a good run of some phillips 12ax7's, but they ran out after 50 or so.  I also ran into many counterfeit tubes (like bugle boys with sovtek internals).  My advice: Always go to some one reputable for these old tubes (Tube Store or Antique Electronic Supply).  If it sounds too good to be true, it likely is.

Anyway, after the good NOS ran out I investigated every tube on the market.  JJs were the most consistent and generally best sounding.  After that I just voiced the amps to sound great with JJs.  Done.

BTW, regarding the PI section tube, if you're using the dual master volume in your amp this tube has a huge impact on tone.   

 

[DocNrock]

I've done this.  My experience is that NOS tubes, even those you could get 10 years ago, were very inconsistent.  They varied wildly in tone, mU, gain, transconductance, and just general guts.  I had a good run of some phillips 12ax7's, but they ran out after 50 or so.  I also ran into many counterfeit tubes (like bugle boys with sovtek internals).  My advice: Always go to some one reputable for these old tubes (Tube Store or Antique Electronic Supply).  If it sounds too good to be true, it likely is.

Anyway, after the good NOS ran out I investigated every tube on the market.  JJs were the most consistent and generally best sounding.  After that I just voiced the amps to sound great with JJs.  Done.

BTW, regarding the PI section tube, if you're using the dual master volume in your amp this tube has a huge impact on tone. 

Very interesting about the variability.  I have seen similar reviews.  I've also read to be aware of counterfeits.  The Telefunkens and RCA blackplates have tell-tale markings that are difficult to, if not impossible to, counterfeit.  Also, as you mentioned, a reputable dealer is a must.  That is where reviews came in handy, as well.  The tubes that I got are all marked as far as their numbers go.  Within the batches that I got, they are relatively balanced. 

My amp doesn't have a dual master, so not a problem here. 

 

[Cagey]

Consider this. All tubes are only made in the 2 or 3 plants that are left in the entire world, and have been for quite some time now. They're made by political prisoners in communist countries where there is no profit motive to speak of. As a result, quality control is not exactly what you'd call "Job One", per se. Mullard, RCA, Sylvania, JJ, Mesa, et al don't make tubes. They're all private labelled.

While tubes are electronic devices, they're complex mechanical constructs with myriad production variables. As a result, consistency in performance is difficult to achieve. But, most tube circuit designs are sloppy enough to tolerate a surprising amount of variation in component tolerance, not just from tubes but resistors, capacitors, etc. They have to be when you consider the radical variations in environment they live in. Temperature, vibration, voltage and current levels/changes alone can range from non-existent to extreme in very little time. Still, there's only so much variation you can have before it affects circuit performance, and it usually comes from the tubes.

I saw a video once where an amp manufacturer (Bugera) was loading testers with 6L6 tubes to check their performance before installation in an amp. Apparently, they bought the tubes in bulk and tested them on the spot, I imagine to save money. In any case, they got something like a 25% yield out of those tubes. In other words, they'd test an average of 8 tubes to populate one 50watt amp, which takes 2. I'll leave it to your imagination how close a tube needed to be to proper spec to pass the test, but bear in mind that they're another company peopled by political prisoners in a communist country working for scratch without a profit motive to speak of.

I doubt the numbers were always that bad. During the vacuum tube's heyday when competition existed and all things electronic used them so production was high, I'm sure the machinery and people used to produce them were newer and better maintained. Today, I'd be afraid to look at what the Chinese are using for machine tools and labor. But, tube's heyday was a long time ago. I'm quite skeptical of the number of "NOS" tubes that seem to be available today. Kinda like the number of "Vintage" Strats that are floating around. To look at it, you'd think Leo was building half a million Strats a year in 1961. To look at how many NOS tubes are available, it would appear that tube production in the '60s outstripped demand by several orders of magnitude, and distributors just bought them up and inventoried them anyway. I know the military has a tendency to stock spare parts as if they were free, but even they have their limits.

So, bottom line is, tubes are inconsistent and all bets are off. Modelling is where it's at now. Good modelling is expensive, but so are "good" tube amps. But, at least with modellers you get the same thing every day, no surprises (other than catastrophic failure) and little or no maintenance.

 

[Tonar8352]

At what these sell for currently, I could have sold them in current times and probably made enough to retire! 

Oh there are a few things from our childhood days that we should have purchased multiples of and held on to for retirement. 

 

[DocNrock]

Consider this. All tubes are only made in the 2 or 3 plants that are left in the entire world, and have been for quite some time now. They're made by political prisoners in communist countries where there is no profit motive to speak of. As a result, quality control is not exactly what you'd call "Job One", per se. Mullard, RCA, Sylvania, JJ, Mesa, et al don't make tubes. They're all private labelled.

While tubes are electronic devices, they're complex mechanical constructs with myriad production variables. As a result, consistency in performance is difficult to achieve. But, most tube circuit designs are sloppy enough to tolerate a surprising amount of variation in component tolerance, not just from tubes but resistors, capacitors, etc. They have to be when you consider the radical variations in environment they live in. Temperature, vibration, voltage and current levels/changes alone can range from non-existent to extreme in very little time. Still, there's only so much variation you can have before it affects circuit performance, and it usually comes from the tubes.

I saw a video once where an amp manufacturer (Bugera) was loading testers with 6L6 tubes to check their performance before installation in an amp. Apparently, they bought the tubes in bulk and tested them on the spot, I imagine to save money. In any case, they got something like a 25% yield out of those tubes. In other words, they'd test an average of 8 tubes to populate one 50watt amp, which takes 2. I'll leave it to your imagination how close a tube needed to be to proper spec to pass the test, but bear in mind that they're another company peopled by political prisoners in a communist country working for scratch without a profit motive to speak of.

I doubt the numbers were always that bad. During the vacuum tube's heyday when competition existed and all things electronic used them so production was high, I'm sure the machinery and people used to produce them were newer and better maintained. Today, I'd be afraid to look at what the Chinese are using for machine tools and labor. But, tube's heyday was a long time ago. I'm quite skeptical of the number of "NOS" tubes that seem to be available today. Kinda like the number of "Vintage" Strats that are floating around. To look at it, you'd think Leo was building half a million Strats a year in 1961. To look at how many NOS tubes are available, it would appear that tube production in the '60s outstripped demand by several orders of magnitude, and distributors just bought them up and inventoried them anyway. I know the military has a tendency to stock spare parts as if they were free, but even they have their limits.

So, bottom line is, tubes are inconsistent and all bets are off. Modelling is where it's at now. Good modelling is expensive, but so are "good" tube amps. But, at least with modellers you get the same thing every day, no surprises (other than catastrophic failure) and little or no maintenance.

Pretty sure that when you can get ones that are genuine and tested for the variables Mayfly mentioned, that this is why the NOS ones sound better and last longer.  They were made during an era when QC existed in this industry. 

Modern day tubes are exactly as you describe. Branded ones have been screened like the process you mentioned at Bugera after being bought from one or more of those current sources you describe.  Underperforming tubes are scrapped..  Eurotubes even mentions this on their website about JJs.  It is clear that neither JJ nor Eurotubes actually makes the tubes they brand and sell.  The same goes for Mullard, Tung-Sol, etc.  Likely the reason the different brands sound different is because they have different source manufacturers. 

It took me quite some time to find the vintage tubes that I did.  I personally didn't find many out there. But, I did my homework ahead of time about which dealers are reputable and how to identify counterfeits. I'm pretty satisfied that I got the real deal.  Consistent with what you said about modern tubes, even the 7025Y, made on original Telefunken equipment, does not have the same tone as an original Telefunken. Those were made in communist Yugoslavia.  And this is after they were bought in bulk from somewhere in Yugoslavia and Groove Tubes branded the ones they liked the best.

Modeling is getting better, but I still prefer the sound of a tube amp and a set of pedals.

YMMV

 

[DocNrock]

At what these sell for currently, I could have sold them in current times and probably made enough to retire! 

Oh there are a few things from our childhood days that we should have purchased multiples of and held on to for retirement.

Isn't that the truth!

 

[Kostas]

I've always wanted to experiment with NOS valves but when I see the prices I let it go... I have a quartet of Sylvania 12XA7 and I can't say I heard night and day differences in my amps. They have been working great for three years so that's something. The most impressive result I had it was when I completely retubed my friends mid 90's Laney with TAD tubes, stock tubes were Sovtek and they had been worked hard for 15 years. It's not only that the noise stopped but the tone improved, I could hear that from the first notes.

I hear more differences with speakers, they can really shape the sound of an instrument.

 

[Logrinn]

I hear more differences with speakers, they can really shape the sound of an instrument.

This!
If I were to put it in numbers I'm thinking that 60-70% of the sound comes from the speakers.

 

[DocNrock]

I hear more differences with speakers, they can really shape the sound of an instrument.

This!
If I were to put it in numbers I'm thinking that 60-70% of the sound comes from the speakers.

No doubt the speakers shape the sound, but with amps, everything shapes the sound, I think.  If I used my JSX 4x12 cabinet with different heads, every one is going to sound different.  Say, a Randall solid state head, a Marshall tube head, and my JSX tube combo, they are all going to sound different through the same set of speakers.  The corollary is also true, if you run an amp through different cabinets (speakers).  It will sound mostly like the amp, but the speakers will color the tone differently. 

I believe that what I hear when I changed out the tubes was a different coloration of the tone.  The overall sound of the amp did not change, like night and day, but the coloration of the sound became more pleasing to me.

Again, YMMV.  :icon_thumright: 

 

[Logrinn]

The overall sound of the amp did not change, like night and day, but the coloration of the sound became more pleasing to me.

And in the end that's all that matters. Having a sound that is good for you. Everything that goes between the fingers and ears doesn't really matter as long as you like what you hear.  :icon_thumright:

 

[fdesalvo]

In my exp, using vintage preamp valves in multiple gain stage amps is lost when the gain is poured on.  The power section is another story - vintage tunes (in good condition) can suffer great abuse and offer lifespans that typically far exceed modern production examples.

 

[DocNrock]

In my exp, using vintage preamp valves in multiple gain stage amps is lost when the gain is poured on.  The power section is another story - vintage tunes (in good condition) can suffer great abuse and offer lifespans that typically far exceed modern production examples.

Thanks for the comment, Frank.  It is an interesting one. 

I actually experienced the opposite.  The vintage tube did not give me such a great clean tone in V1, clean, but common to all three channels.  But in V2 and V3, I found the gain to be much more harmonically rich and "singing," as opposed to "fizzy."  It may have to do with different amps.  I have read that some modern amps do better with modern tubes. 

 

[DocNrock]

The overall sound of the amp did not change, like night and day, but the coloration of the sound became more pleasing to me.

And in the end that's all that matters. Having a sound that is good for you. Everything that goes between the fingers and ears doesn't really matter as long as you like what you hear.  :icon_thumright:

On that, I think we can all agree!  :icon_thumright:

 

[Tonar8352]

I think Doug and Pat make a great attempt to demonstrate the impact of many of the things already discussed in this thread.
Personally I get a kick out of them, I hope you enjoy. For me; I'll take the vintage amp but the modern one sounds way better
with the original tubes and speaker. 
https://www.youtube.com/watch?v=kZny2dV9V58

 

[DocNrock]

I think Doug and Pat make a great attempt to demonstrate the impact of many of the things already discussed in this thread.
Personally I get a kick out of them, I hope you enjoy. For me; I'll take the vintage amp but the modern one sounds way better
with the original tubes and speaker. 
https://www.youtube.com/watch?v=kZny2dV9V58

Thanks for that, Tonar.

One thing I would have liked to have seen was for them to have played the old amp with the new tubes.  My takeaway was that the vintage tubes definitely had a different tone in the new amp, but they also played through the old speaker/cabinet.  It also would have been nice to have heard the new amp with the old tubes played through the new cab/speakers.

On a different note, I had never heard of these guys before.  Great YouTube show!

Really, to be clear, what I was going for was to see what vintage tubes would sound like in my amp.  Clearly, there is no vintage Peavey JSX.  There is definitely a different tone with the vintage tubes.  One that I really like.  I wanted my JSX to sound different than any other out there, but in a way that I liked.  With that as the goal, I got what I wanted.  :icon_thumright: