I just recommended what I personally preferred. Most of the time New Old Stock (NOS) tubes will sound better than New/Current Production tubes.
NOS tubes all were designed with stricter specifications due to them being used in more things at the time. Also, many tubes were also made for the military and those had even higher grade specifications and requirements.
New/Current production tubes aren’t as high in demand, so the assembly process and specifications aren’t as tightly followed or enforcd. Also, 95% of current tubes are made in Russia (New Censor Corp), China (Shuguang, PSVane), and Slovakia (JJ Electronics).
These new/current tubes normally require an extremely lengthy burn-in process to sound decent. Most of them tend to have 1 note bass, and have soundstage, depth and textural deficiencies IMO.
A very good price to performance recommendation would be grabbing a pair of RFT 12AX7 and a pair of Ei EL84 tubes. Both of those are available at upscaleaudio.com at very fair prices.
I agree with the conclusion for most tubes NOS are a better choice unless premium new production are available, but I don’t think this is the reason.
I’ve seen a lot of speculation around why, most of it seems to be that old tubes were produced with components that had better metallurgy.
The is a bit of a generalization, I’m not sure you can attribute a particular sound quality to all new production tubes.
I do agree NOS tubes generally sound better until you start to spend similar amounts on new tubes, PSVanes 2A3’s for example are very good, a lot feel they are better than almost all of the available NOS tubes, but they also cost about the same.
In NOS I generally prefer the Chinese made tubes to the JJ tubes to the current Russian production tubes, but again it’s a gross generalization, there are lots of new production tubes I haven’t tried.
I also agree on the Ei recommendation for El84’s, and good new production El84 will likely cost more than the NOS tube in this case, and though I liked the PSVane El84, it wasn’t “better” than the Ei or Tungsram.
This is why I said most do, not all. PSvane are a good example of new production tubes that sound pretty good.
An article I read a while ago (link below) actually cited what I said as 1 of a multitude of reasons. It is a very interesting read.
The main takeaway quote from that article:
“Today there aren’t the same forces driving up tube quality—none of the stringent demands of the military or scientific research communities, nor is there the industrial infrastructure and pool of expertise: the boffins, chemists, physicists, metallurgists, skilled workers, etc required to make tubes to the same exacting standards, even if there was the will to do so. Tube manufacturers no longer jointly engage in serious research and development efforts with the academic community or military to refine and improve thermionic technology.”
So I can only guestimate on the vc and the hekse since I haven’t tried that exact pairing, but for the utopia it pairs actually pretty well, enjoyable experience but there is much more to get out of the utopia later on with a higher end amp. With the utopia the quicksilver keeps it fairly neutral overall with great control, impact, density, and reasonable amount of detail. Stage is larger than normal although slightly less accurate. Overall for 1k it’s not a bad choice for a utopia. Regarding the zmf, I feel like it would also be a great pairing if you wanted something neutral but pretty organic given how my vc reacted to amps. For the 1000se I can’t really say too much with confidence here since I don’t have as much time with it when it comes to pairing with other similar tube amps in this range, but I would bet it drives them decently well if you wanted something tube
They are good enough as the amp still sounds great with stock, but you can get better with nicer nos or new production tubes, overall upgrade but the stock tubes don’t feel like they are limiting it either, I would still be very happy even if I could only run stock
Just realized I haven’t posted here since I received the Quicksilver. I am really enjoying it with my Bifrost 2 and Verite Closed. I bought some replacement tubes based on a few recommendations I’ve seen, EI 6BQ5 and Gold Lion 12AX7. In my mind they sound better than the stock tubes, but I don’t know that I would be able to tell in a blind test because both setups sound great!
My Verite Closed has never sounded so good. I also have the SW51+, and it also pairs really well. If I’d gotten the SW51+ earlier, I may have never ordered the Quicksilver. When listening to either amp, I feel like I could be perfectly content if it was the only tube amp I owned. In that regard, it is quite silly to have both, but I may eventually have to create two listening spots. Might keep the Bifrost 2 with the Quicksilver and stick a Modi 3+ with the SW51+.
Sorry there aren’t many detailed sound descriptions. If anyone has specific questions in regard to sound characteristics, feel free to ask.
If you are interested in tube rolling further with the QS, I can definitely recommend the Matsushita 12AX7 or RFT 12AX7. Both of those go extremely well with the Ei EL84/6BQ5 tubes.
I actually settled on the Ei EL84 and RFT 12AX7 for my Quicksilver and my Auteur sound excellent off of it.
So how do you normally go about tube rolling? With op amp rolling, I can generally immediately hear a difference, but with the Quicksilver (and I’m assuming tubes in general?), I bought some Tunsgram tubes, and it wasn’t until like a week later that I was really impressed by them. (I assume it was actual burn-in, but it could just be my brain or whatever other factors.)
Well, it does depend on the tubes. Burn-in is definitely a real thing with tubes…and although many tubes are marketed/listed as New Old Stock, the majority of the time they are actually lightly used and already burnt in. But if the tubes are truly New Old Stock and never been used, then you will need to burn them in. That is even more true of new production tubes as they seem to need a much longer burn in period.
Here is a good explanation of tube burn-in that I bookmarked a while ago when reading some audio forum that I can’t remember the name of at the moment…
"When a vacuum tube is subjected to high temperatures and voltages, the physical properties of certain metals and substrates can be altered slightly over time. This phenomenon could cause subtle changes to occur with the performance and sound of a given tube, which can be desirable, depending on the listener’s preferences. Once the tube initially stabilizes, it should perform predictably and consistently for a period of time before entering into a gradual decline in performance and tone.
Similarly, when a tube is subjected to high temperatures and voltages, the chemical properties of certain materials can be altered as well; e.g. chemical oxidation and/or reduction, sequestering impurities, etc.
A good tube manufacturer takes all of this (and more) into account when designing and building a vacuum tube. Nominal physical and chemical changes in a tube’s materials are consequences of normal operation and should be expected. I just wished they made them like they used to."
The Matsushita are a bit more linear and balanced. The RFT tubes add some weight to the bass and the mids while being much more tame in the treble. The RFT tubes add some width to the soundstage as well, which I really like. I also have a pair of RCA 12AX7 tubes but I tend not to recommend those due to the high price and rarity of finding a matched pair.
I listened to the stock tubes for about 2 to 3 weeks. The fact the stock new production tubes sounded pretty good on the QS tells you a lot about the quality of the amplifier. That was one of the 1st things that impressed me.
Agreed. That is the consensus from most owners of the amp. The fact that it can sound so good with the cheap stock tubes is certainly a testament to the amp’s design. I was hesitant to change from the stock setup, but I’m digging the tubes I’ve got in at the moment.
I’m new to tube amps in general. I have a simple question regarding my Quicksilver. Which tubes affect the sound more, the input or output? I’m considering getting some NOS Mullard CV4004/12AX7 from Upscale Audio to go alongside my EI 6BQ5 output tubes. Will this make a bigger difference than switching out the EI’s for NOS tubes?
I have the Gold Lion 12AX7’s in the amp currently, and they sound great already in my opinion. I’m just wondering if the NOS Mullards will take things to the next level.
Hello,
It’s all subjective, unfortunately.
While you might like it, others hate it.
It’s very very different.
There is only one way around it buy, install, give enough time to burn in then judge.
That’s the only downside to the process.
On my Feliks Euforia, the input tube had the most influence.
I can’t say whether it’s the same with the Quicksilver.
But I would also be interested to know if this is due to the design or if it is a general rule.
Otherwise, tube rolling is fun but can also be expensive.
Especially if you are not satisfied.
Nos tubes are generally good and better if the price fits.
But don’t be afraid to try out the new variants of the manufacturers.
With the 12ax7 there are some that have been cryonised, so it can’t be wrong.
Your project with the mentioned tube set had advantages on the new Macintosh mha200.
With the disadvantage that the sound was a little more forward and the treble was peaked.
But it’s all a matter of taste at the end of the day.
My tip would be rather what are you missing, what do you want and try to find the tube that can do it by googling or asking the dealer or community.
That saves a bit of money.
I’m interested in doing some more tube rolling in my Quicksilver. For NOS 12AX7’s, I’m considering the RCA black plate, Tungsram, Telefunken smooth or ribbed plate, and Mullard long plate. Suggestions here have made me consider the Matsushita and RFT as well.
I think I’ll stick with my EI EL84 output tubes since those seem widely liked.
I’m interested to hear impressions from more owners that had rolled any of these tubes in their Quicksilver.
I bought a few vintage 12AX7 tubes to roll in my Quicksilver. I’ve got some Tungsram and some Amperex on the way. I may try a few Tungsram EL84 tubes before it’s all said and done, but the Ei’s are holding their own for now.