I was trying to come up with an analogous situation elsewhere in audio reviewing. Reviewing an amplifier with a third-party power cord? … This sort of thing is done all the time and nobody seems to be particularly upset by it. But a power cord (at least in my experience) doesn’t really have the same fundamental level of impact as tube rolling. And in any case, a power cord is more of an external add-on than anything else. Tube rolling is more akin to swapping the Caps in the power supply! I think a reviewer should stick to the tubes as delivered. The only exception is if the manufacturer somehow has an acknowledged policy of using multiple tube sources.
My own experience with tube rolling in my BHK300s has left me with mixed emotions. One one hand, there is no doubt that changing out the tubes has a dramatic, transformative impact on the amplifier. There can be an element of pleasure to be had from the exploratory aspects of the process. On the other hand, the downside is the seriously limited tube life, and the insidious nature of tube degradation where you can’t really tell it’s going off until either it goes so far off as to make itself obvious, or you swap in another set of tubes by way of a comparison.
Even then, when I bought a set of the much-lauded Tungsram tubes, I had to contend with the radically different nature of the sound they produce. I didn’t really enjoy them as much as I had been led to believe. Was this due to a need for break-in? … no, a hundred hours or so didn’t make that much of a difference. Were they just a bad set of Tungsrams? … who knows. I’m currently using Golden Lions. Not sure which direction I’ll take when they wear out sometime during the coming year.
For complex reasons that aren’t worth going into, I originally used some JAN Phillips “low noise” tubes whose provenance remains murky. They were audibly noisy from day one, but that didn’t practically bother me. The sound was just great. I was very sad when they wore out.
FWIW for me I have been a fan of the Golden Lion 6922’s (And the KT88’s in other amps) I did use the Tungsrams for awhile but I had two tubes fail in six months and went back to the Golden Lions. All I can say is they work for me. Tube rolling is fun and I have done a lot of it between speaker and Headphone amps. But as I said, for reviewing it is simply too time consuming.
One one hand, there is no doubt that changing out the tubes has a dramatic, transformative impact on the amplifier… On the other hand, the downside is the seriously limited tube life…
Do others have a similar experience with seriously-limited tube life when continuously swapping them? Or is this just a fact particular to tube-rolling with the BHK monos? And why would switching tubes impact their life?
Do others have a similar experience with seriously-limited tube life when continuously swapping them? Or is this just a fact particular to tube-rolling with the BHK monos? And why would switching tubes impact their life?
I didn’t want to imply that changing tubes shortens their life. it’s using tubes that shortens their life.
Someone else should step in here, but I also believe that different types of tubes have different lifespans. Maybe it also depends on how the tube is biased, etc.
Remember too that some of these tubes might be over 50 years old. I have not had any more fail with the Monos than other amps too. Swapping has not been an issue except when someone uses a tube variety that is not completely in spec with an amp they try them in. Sometimes you need a specific variant with a particular amp. You can shorten their life or burn them out if they are not compliant to the circuit.
Let’s start with where we agree. PS Audio must ship its Signature Amps with new tubes. The Golden Lion 6922 are excellent tubes and the amps sound great with them.
Most agree that rolling the tubes to some 50-old NOS tubes improves the sound of these amps.
All I proposed was that PS Audio could ship the BHK Signature Amp with the stock Golden Lion 6922 to a reviewer, and include a pair of NOS tubes, suggesting they may wish to roll them. A reviewer should be able to roll one pair of tubes with little trouble.
Sorry, No reviewer I know does this with any regularity unless they have a lot of time and an extensive NOS collection. Regardless, very few manufacturers send alternate tubes. I had one send some to me and then needed them back. It was a friend though and He was interested in my opinion regarding the differences I experienced rather than suggesting one was “Better”.
I am not saying it is a bad idea, just that it is hard to devote essentially twice the time (With one additional tube type) to spend on a single review.
Usually manufacturers don’t use NOS tubes because there is a constraint in the industry that every amp you sell must produce the exact same sound. This is possible with industrially produced tubes, and this also garantees that you will have enough spares for the life of the amplifier.
Using NOS tubes is difficult for a manufacturer because there is no way to produce these tubes anymore, and it is difficult to obtain a sufficient amount of tubes having the same characteristics in order to sell the same amp to each customer.
That said, it is up to every end user to perform the tube swapping if desired. To my opinion there is no doubt that NOS tubes sound from better to far better than the one provided with the amp.
We agree. Manufacturers cannot ship with NOS, and in this particular case, NOS sounds better, whether a little or a lot. Also, just my SWAG, the demographics of buyers of BHK Signature 300s are experienced audiophiles, who are replacing solid state amps, not beginners and not die-hard tube fans.
Rolling the tubes is easy and as Paul McGowan says, “this is a 10 second listen.” I am not suggesting a full-blown review with NOS tubes: it, however, is worthy of a footnote to bring this advantage of the hybrid v. only solid state amps to potential buyer’s attention.
I had no idea that swapping tubes would make this kind of difference. I have rolled tubes on tube amps, but did not hear this level of difference. Also, all of my other tweaks cumulatively have not improved the sound as much as tube rolling, so yes I think it is worth a footnote.
For the first 29 years in this hobby, much like Paul, I used solid state based equipment. Decided to give tubes a try 2 and half years ago with the introduction of PS Audio’s BHK amps. I didn’t initially considered swapping out the tubes. It was only after seeing Bascom weigh in on the great sound of Tungsrams tubes, in these forums,which inspired me to take the plunge. Educating the masses Isn’t a bad idea as some old dogs can use a new trick or two
Here is my review of the BHK 250 from last May. I do briefly mention tube rolling. I have returned to the Golden Lions with the Mono’s at home since I have had two Tungsram’s fail.
Elk, prior to the my BHK purchase and reading the PS Audio form, I knew little to nothing about tubes and tube rolling. The little I did know was total happen stance 15 years ago when, ironically, I was buying a PS Audio HCA-2 amp from Kevin Deal at Upscale Audio. While there buying my amp he gave me a tour of his operation, in his house at that time, and he showed me his tube selection as well as his testing and burn in equipment.
Eric, a comment and a question for you. First the comment, I purchased 4 pairs of Tungsram tubes from Upscale Audio. 15 months and 3000 hours later, they are still dead quiet and great sounding. One of these days I am going to install my next set and will order 2 more pairs. Now the question, since you tested the BHK 250 and own the BHK 300s, what do you feel is the benefit of the 300s in terms of sound quality? And, do you have subs in your system?
Norton, firstly, I did not buy my Tungsram’s from Kevin. I will next time. I have ordered others from him and they are all still working.
As far as the 250 vs the 300’s I get a better low end grip from the 300’s that is likely due to twice the damping factor. I am running my Vandersteen Treo CT’s without a sub and there are some musical passages that make think I have a sub because of the power and clarity of the bass. The 250 is no slouch there either. The 300’s simply drive the lowest levels with more authority. I recently finished a review for the new Focal Kanta N°2’s and it is the same fantastic low end definition. Mid’s and highs are pretty much the same, as in excellent! I am a big fan of these amps.
The little I did know was total happen stance 15 years ago when, ironically, I was buying a PS Audio HCA-2 amp from Kevin Deal at Upscale Audio. While there buying my amp he gave me a tour of his operation, in his house at that time, and he showed me his tube selection as well as his testing and burn in equipment.
Which is exactly my point: prior to buying the BHK you were generally aware that people with tube equipment swapped tubes. As with cables, power upgrades, acoustic treatments we, as audiophiles, know of these things at least generally.
Thus, there is no need to mention in each review that the equipment under review may sound better with a different interconnect or tubes, or that a speaker will sound its best in a treated room, etc.
Elk, we can agree to disagree. You apparently have not rolled your tubes. Without doing so, you may underestimate the overall impact. Eric mentioned tube rolling in his review of the 250. Nice review, BTW.
I thought once I found a set of quads I liked in my system, tube rolling came to an end. With the Redcloud update, the Siemens ECC88 and the Tungstram sounded shrill. The top end was too hot. I am back to the Amperex (Holland PQ).
