Tube Rolling: Friend or Foe?

Since you live in Holland, I would think you would have a good stash of European tubes including Amperex (made in Holland).

But back to my point; many people with no knowledge of electronics and certainly no knowledge of the circuit they want to roll tubes into somehow think they are smarter than the designer and know what combo of tubes will elicit the best sound. This stands a distant second to people who proposed that Wilson should just wire their drivers to binding posts on the rear of the speakers and let genius audiophiles figure out how to connect and set up electronic crossovers and obtain a better sound than Wilson does with their passive crossovers.

mep said:

Since you live in Holland, I would think you would have a good stash of European tubes including Amperex (made in Holland).

But back to my point; many people with no knowledge of electronics and certainly no knowledge of the circuit they want to roll tubes into somehow think they are smarter than the designer and know what combo of tubes will elicit the best sound. This stands a distant second to people who proposed that Wilson should just wire their drivers to binding posts on the rear of the speakers and let genius audiophiles figure out how to connect and set up electronic crossovers and obtain a better sound than Wilson does with their passive crossovers.

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Mark: I don't think that's exactly accurate. Today's most manufacturers choose the best tube available since they must have an adequate supply both now and down the road for their customers. It's a rare manufacturer who choose to design using a relatively unknown NOS tube (like cj with the Mullard 8080 or Allnic for instance) that is still available in large quantities. Also, there aren't enough NOS tubes to make a run of gear really anymore. So I think (and most manufacturers know I encourage it unless there's an electrical issue) that there is validity to the concept that a better tube exists out there. Plus the tube rolling (it is swapping colorations in some instances and a manufacturer can't know your system) is in part, matching the component's sound to your system. Or take BAT which offers a "standard" 6H30 and also a "superduper" 6H30-DR --and gets a good premium for them too!

Tube swapping can be a dangerous activity - if you get this addiction and start trying every tube you can get in your expensive preamplifier you are increasing the risk of picking a faulty tube. As far as I know, the CAT preamplifier uses semiconductors in the circuit, mixed with the tubes - if you get a short circuited tube, you can damage the preamplifier.

My advice - get a tube tester and never put a new tube in the preamplifier before checking it. Even tested tubes can become damaged during shipping.

microstrip said:

Tube swapping can be a dangerous activity - if you get this addiction and start trying every tube you can get in your expensive preamplifier you are increasing the risk of picking a faulty tube. As far as I know, the CAT preamplifier uses semiconductors in the circuit, mixed with the tubes - if you get a short circuited tube, you can damage the preamplifier.

My advice - get a tube tester and never put a new tube in the preamplifier before checking it. Even tested tubes can become damaged during shipping.

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And I've had some tubes that must have been made in someone's garage. I put them in, heard a crack, and then no sound. Looked inside the preamp and the tube had literally cracked and lost vacuum. Luckily no damage. So a good tube tester is a must or having someone test before they sell it to you.

MylesBAstor said:

Mark: I don't think that's exactly accurate. Today's most manufacturers choose the best tube available since they must have an adequate supply both now and down the road for their customers. It's a rare manufacturer who choose to design using a relatively unknown NOS tube (like cj with the Mullard 8080 or Allnic for instance) that is still available in large quantities. Also, there aren't enough NOS tubes to make a run of gear really anymore. So I think (and most manufacturers know I encourage it unless there's an electrical issue) that there is validity to the concept that a better tube exists out there. Plus the tube rolling (it is swapping colorations in some instances and a manufacturer can't know your system) is in part, matching the component's sound to your system. Or take BAT which offers a "standard" 6H30 and also a "superduper" 6H30-DR --and gets a good premium for them too!

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Myles-I hear what you are saying and I do believe you are right with some caveats. With a simple line stage that uses a pair of common tubes such as 12AU7s for example, it would be hard to screw anything up. Now let’s throw in a tube phono stage with the line stage and now we have to worry about the grading of the tubes for noise. You can get away with nosier tubes in the line stage than you can in the phono stage. Now let’s start throwing some variants of the original tube in the mix that possibly draw more heater current than the original tubes did and more than the circuit can safely provide because some guru said the variants sound so much better. Some people think that as long as the replacement tube will plug into the tube socket it must be ok. It doesn’t take but a few missteps and you have a preamp or power amp that will no longer function correctly and/or will be noisy.

Most sellers of tubes on the internet have no way of grading their tubes for noise or microphonics. Who has a curve tracer like Mike Sanders to match their output tubes? Who else has the tube burn-in and matching capabilities that Kevin Deal does? Buying premium NOS tubes from Eddie Ebay doesn’t guarantee you a damn thing in terms of performance. I have a box full of NOS 6922 premium tubes that are either noisy, microphonic, or both for proof.

Can you possibly improve the performance of your preamp or amp with premium NOS tubes? Sure you can. Can you also waste a bunch of money and get worse performance if you bought a tube set from the manufacturer of your amp or preamp that were selected and graded for your gear? You sure can. If you are going to throw the dice and go with NOS tubes, you need to be careful and you need to be willing to gamble some money away.

mep said:

Myles-I hear what you are saying and I do believe you are right with some caveats. With a simple line stage that uses a pair of common tubes such as 12AU7s for example, it would be hard to screw anything up. Now let’s throw in a tube phono stage with the line stage and now we have to worry about the grading of the tubes for noise. You can get away with nosier tubes in the line stage than you can in the phono stage. Now let’s start throwing some variants of the original tube in the mix that possibly draw more heater current than the original tubes did and more than the circuit can safely provide because some guru said the variants sound so much better. Some people think that as long as the replacement tube will plug into the tube socket it must be ok. It doesn’t take but a few missteps and you have a preamp or power amp that will no longer function correctly and/or will be noisy.

Most sellers of tubes on the internet have no way of grading their tubes for noise or microphonics. Who has a curve tracer like Mike Sanders to match their output tubes? Who else has the tube burn-in and matching capabilities that Kevin Deal does? Buying premium NOS tubes from Eddie Ebay doesn’t guarantee you a damn thing in terms of performance. I have a box full of NOS 6922 premium tubes that are either noisy, microphonic, or both for proof.

Can you possibly improve the performance of your preamp or amp with premium NOS tubes? Sure you can. Can you also waste a bunch of money and get worse performance if you bought a tube set from the manufacturer of your amp or preamp that were selected and graded for your gear? You sure can. If you are going to throw the dice and go with NOS tubes, you need to be careful and you need to be willing to gamble some money away.

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Personally think this topic deserves its own thread. Maybe Steve or Amir could transfer over the last couple of posts?

mep said:

Davey-Jim McShane is a good guy who happens to specialize in Harmon Kardon restorations. Is Jim passing out recommendations for how to retube a CAT preamp? Trying to outsmart the designer is always a tricky business.

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Mark, I suspect that you are missing my point about tube rolling. No one is suggesting changing out one kind of tube for another i.e. a 6DJ8 for a 6FQ7 or a KT88 for a EL34 or ??

Instead, I am suggesting that a different brand/design of the same tube type be tried. In my instance, the stock tubes that Ken spec'ed for my CAT were Ei's. I replaced the Ei 12ax7 with a NOS GE long plate 12ax7.
The difference in sound wasn't subtle. Kevin Deal and Jim McShane are both very capable of suggesting what NOS tube will be an upgrade for any of the stock tubes in the CAT.

I know you didn't like your CAT preamp that much....my question to you is did you ever really hear what it could do??

Why Davey, maybe if I would have substituted those lousy EI 12AX7s that everyone in the tube industry thinks were dead ringers for the Telefunken 12AX7 and replaced them with some NOS GE 12AX7s all would have been right in the world. Seriously, how old were your EI 12AX7s when you swapped them out for some NOS GE 12AX7s? Maybe the not so subtle differences you heard were due to replacing old, tired 12AX7s with NOS 12AX7s more than it was the magic GE 12AX7s. I don't think I ever heard any tube freaks getting lathered up over some GE 12AX7s.

Hopefully Amir will transfer over part of the thread from the CAT forum where we discussing the pros and cons of tube rolling. I'd hope everyone would lend their thoughts and experiences on this subject esp. as far as testing, are NOS really NOS, can the use of NOS tubes make a unit sound better or does the manufacturer have it right to begin with, etc!

MylesBAstor said:

Hopefully Amir will transfer over part of the thread from the CAT forum where we discussing the pros and cons of tube rolling. I'd hope everyone would lend their thoughts and experiences on this subject esp. as far as testing, are NOS really NOS, can the use of NOS tubes make a unit sound better or does the manufacturer have it right to begin with, etc!

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done

Tube rolling can change a lot in tube equipment sound quality.

However, any conclusion needs for a long time listening. Most tube equipment needs typically between 15 and 60 minutes warm up time to sound its best and stable, and any immediate conclusions taken after two minutes listening can be erroneous. This excludes any direct comparison with the old tubes, unless you have a similar spare unit and can switch between the two.

My VTL750 has a 12AT7 input tube - the difference between a Telefunken and a Mullard was large. My preference would depend on the balance of the speaker and cables I was using with them.

treitz3 said:

Hello, mep. I have been rolling tubes in my CDP and I'm finding the Ei12AX7 gold pins a tough tube to beat and I've had some rather well regarded tubes in and out. To the OP, I am most definitely a friend of tube rolling. Oh, yeah.....definitely a friend. To microstrip and MylesBAstor, that was sage advice [tube tester]. No tube roller should be caught without one, IMO.

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Mark and Treitz, the Ei's in my CAT were Not gold pins and had about 700 hrs on them when I replaced them. The tubes that Kevin Deal suggested to me were the NOS 1963 GE 12ax7 long plates from his reserve. Rolling this tube into the phono section in place of the stock Ei 12ax7 was an eye opener!
Kevin told me that the 1963 NOS GE long plates are some of the best sounding 12ax7's ever made , frankly I believe him.
Mark, are you saying that Kevin Deal doesn't know his stuff in regards to these tubes? Or maybe you have more experience in these matters than he does....., or what?
I have talked to Jim McShane about tubes on numerous occasions as well, BTW do you believe the same about him?
I guess when it comes to the CAT and tubes, YMMV.

Kevin is the real "deal"

Steve Williams said:

Kevin is the real "deal"

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LOL, Steve that's a good one

I think tube equipment and tube rolling just go together hand in hand. I'm sure the manufacturer knows that a better tube of the same type will improve the sound but given the prohibitive costs and scarcity of better tubes, the manufacturer has to settle on whatever is readily available and reasonably priced. When I bring home a piece of tube equipment, I definitely change the stock tubes. In my experience, there are certain synergies between tubes and the vintage of the parts used in the equipment. I have an Audio Research SP 3 that still has the original parts and a factory updated Audio Research SP 3. For my own tastes, I like Telefunkens on the Audio Research with the original parts, while for the factory updated version, I like using Amperex in the phono stage and Mullard in the line stage.

DaveyF said:

Mark and Treitz, the Ei's in my CAT were Not gold pins and had about 700 hrs on them when I replaced them. The tubes that Kevin Deal suggested to me were the NOS 1963 GE 12ax7 long plates from his reserve. Rolling this tube into the phono section in place of the stock Ei 12ax7 was an eye opener!
Kevin told me that the 1963 NOS GE long plates are some of the best sounding 12ax7's ever made , frankly I believe him.
Mark, are you saying that Kevin Deal doesn't know his stuff in regards to these tubes? Or maybe you have more experience in these matters than he does....., or what?
I have talked to Jim McShane about tubes on numerous occasions as well, BTW do you believe the same about him?
I guess when it comes to the CAT and tubes, YMMV.

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Davey-How many times have I recommended Kevin Deal to people on this forum??? I wouldn’t recommend him if I didn’t believe in him.

Now I’m going to say something else with regard to TU-BE or not TU-BE tube rolling. If a piece of tube gear doesn’t sound great with the tubes the manufacture ships it with, something is wrong with it. Manufacturers have to design their tube gear based on currently available tubes. No *large* manufacturer of tube gear can design their product based on expectations that their customer base is going to chase the same shrinking pile of NOS tubes. It has to be able to sound great with currently available tubes that everyone can buy. You can ask Mike Sanders about that.

The original Quicksilver monos were designed to use the 8417 output tube which went out of production. Mike bought up as many of them as he could and he still couldn’t keep his customers supplied with 8417s and he had to change the amp to use EL-34s. Mike also designed the MS-190 (of which I owned two) to use only Mullard EL-34s because Mike was running these tubes so hard in his amp that only the Mullard EL-34 could stand up to the punishment. Good luck with finding 8 NOS MATCHED Mullard EL-34s to keep this amp running. Mike couldn’t find enough at sane prices to keep the 75 MS-190 amps running that he sold.

And that is why I got rid of the McIntosh C2300 preamp. I didn’t think it was a great sounding preamp. McIntosh did a great job of selecting low noise 12AX7s, but the preamp just didn’t cut the onions for me. All of the knowledgeable audiophiles said you “have to” change out those nasty Chinese 12AX7s and replace them with six NOS Telefunken 12AX7s and then and only then will you hear what this preamp can really do. Horse chit. The purpose of tube rolling should be to make an already great sounding product sound even greater. It shouldn’t be about trying to make a mediocre product sound great.

If you want to read something from someone who is an expert on tubes and tube grading and matching, wander on over to the RAM website and read some of the papers written by Roger Modjeski. It might just shatter some of your dearly held beliefs. You may feel dumber than a box full of Amperex pinch waist microphonic 6922 tubes after you bask in the wisdom of Roger Modjeski.

And one final thought that Myles sort of touched on before, and that would be counterfeit *NOS* tubes. Yep, there are plenty of them out there and there has been for quite some time. Kevin Deal has a page on his website that talks about them and he used to have some pictures of counterfeit tubes. The ARC D-70MKII amp that you know and love Davey is also an amp that I owned at one time. I bought mine from the original owner and it had a counterfeit Telefunken 12AX7 in it (the one that sits right next to the 6550 voltage regulator). It wasn’t even a good counterfeit because the logo didn’t even match. Some counterfeiters are much more clever and unless you are a tube expert, you might not know that you have been taken. And of course that begs the question of how many people are running counterfeit *NOS* tubes in their gear and are gushing over how much better they sound than those crappy new available tubes?

If a piece of tube gear doesn’t sound great with the tubes the manufacture ships it with, something is wrong with it. Manufacturers have to design their tube gear based on currently available tubes. No *large* manufacturer of tube gear can design their product based on expectations that their customer base is going to chase the same shrinking pile of NOS tubes. It has to be able to sound great with currently available tubes that everyone can buy.

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I totally agree Mark