[rcag_ils]

If it's electrical signal, it can be measured. Unless you are hearing something that's not there. I see dead people......

[MarkM]

We most certainly can indeed hear differences between different tube brands used in our equipment.


A tube is an elector-mechanical device and the way the plates are arranged and supported internally will make differences in their transfer characteristics, as will other changes appear as they age.  They do have a short break in period from new out of the box to the time they provide consistent performance over their service life.


There is no difference we can measure on the test bench.

Its bad karma to poo-poo these clients of ours.  It gains nothing and makes you look pretty radical.  We very much appreciate your long time support, but you need to understand that people hear what they hear, and browbeating them will not change things.

We can hear differences in tubes that we cannot measure. 

Best regards,

Frank Van Alstine

If it's electrical signal, it can be measured. Unless you are hearing something that's not there. I see dead people......

Very well put for the non tube rolling believer Frank.  Electrical measurements on the bench is critical, listening to the design with the ear is the next set of measurements for any product.   

A speaker will pretty sound as it measures, tube gear has a lot of leeway. This is well documented by many of the top designers of high end gear over the last 40+ years!

Of course, some of you don't want to be bothered with facts, you just run with what you believe and don't let up.  Lame.

[rcag_ils]

Of course, some of you don't want to be bothered with facts, you just run with what you believe and don't let up.  Lame.

I believe different tubes will make different sound, when you stick a tube with different transfer curve in the same circuit, you will hear the differences, and I believe those differences can be measured.

I don't believe the so-called "tube rolling" should be a ritual of making a piece of audio eq. to sound better, it's like saying the designer didn't do a good enough job.

[dminches]

I don't believe the so-called "tube rolling" should be a ritual of making a piece of audio eq. to sound better, it's like saying the designer didn't do a good enough job.

Why do you care that others enjoy doing this?  You keep saying the same thing.  We know your perspective.  This is a tube rolling thread.  If you don't believe in this practice then why are you here?

Seriously, many of us DO feel like we can alter the sound for the better with a change in tubes.  Why do you need to try to negate that?

[I.Greyhound Fan]

I don't believe the so-called "tube rolling" should be a ritual of making a piece of audio eq. to sound better, it's like saying the designer didn't do a good enough job.
[/
Who said any thing about making tube rolling a ritual.  In my situation, I was curious.  In addition, I found that I could change some of the fatiguing sound of my DAC that was bothering me on some music.  If I had not tube rolled, then I probably would have sold my $2000 DAC.  Along the way I found that some tubes produced deeper punchier bass along with a wider sound stage and warmer sound.  This is not any slight to the designer.  I happen to use a Parasound amp and different speakers than the designer. If I had all AVA gear it would be a different story.

Tube rolling is not for every one and you can drive yourself nuts with the many tubes out there.

I can tell you this.  If I was able to buy Franks new amp, preamp and DAC, I would not be tube rolling.

[rcag_ils]

Sorry for raising the blood pressure for some of you, I am certainly not against "tube rolling". If that's what makes you happy, by all mean, get the best sound out of your eq.

[jackman]

I'm not going to get in the middle of this but can only comment on my personal experience.  Audio playback is imperfect.  Even the best system is an approximation of a live event or an event in which someone performed music and had it recorded so we can play it back on our systems.  There are several "flavors" and countless approaches to "the best sound", including flea powered SET amps and big horn speakers, class A, B, D, etc., big electrostats or ribbon speakers, tubed gear, SS mixed with tubes and so on. 

Everyone is trying to achieve a sound they feel is good, or as good as we can afford (or are willing to spend).  Many of us spend lots of time trying different gear and different combos of gear.  We mess with placement, room treatments possibly, active crossovers, fancy caps, cables, etc.  Those of us with tubes even delve into the mysterious and dark world of NOS tube rolling or new tube rolling for that matter. 

I've done some tube rolling with positive, negative and somewhat mixed results.  Calling tube rolling "EQ'ing" is arrogant in my opinion.  It assumes the original tubes are "perfect" and that any non-stock tubes are imparting a flavor.  The problem is, there are so many variables (speakers, room, amplifier choice, etc.) it's impossible to know if the stock tubes are going to sound best.  Also, sometimes manufacturers spec their products with tubes that meet a pricepoint, or because of availability.  They are not making any more NOS tubes, and some rare types are getting very expensive.  Heck, some of the higher grade new tubes are very expensive (Psvane, Genelex Gold Lion, etc.).  Spec'ing these in an amp or preamp could raise the cost of entry and lead to lost sales.  This is not good for business, especially in today's economic climate. 

I've owned AVA tubed gear (Fetvalve amps and preamp) and the stock tubes sounded best.  Tried several NOS tubes from eBAY and none sounded better than the stock tubes (I think they were JJ's).  Some of the aftermarket tubes I tried sounded dark, some were very noisy or microphonic.  I was kind've happy to find this out because the cheapest ones sounded best.  Not sure if the NOS tubes were fakes because I bought them on ebay but none sounded better than the stock ones and all were more expensive than the ones Frank supplies.  Score!

In my Modwright CDP, the stock tubes were NOS.  I don't know if they make a new 5687 tube so you have to use NOS.  I tried several NOS tubes and found there was a MAJOR difference in sound quality.  Some tubes are more dynamic, some are more laid back, some have more detail, some are dull and lifeless.  Several (GE, Tung Sol, Raytheon, etc.) sounded excellent but each brand, and even some from different eras sound different.  It's not night and day but there is a subtle difference.  I'm really digging the Raytheon's I bought from Rob in the AC classifieds.  They are slightly different (more dynamic, stronger bass) than the GE's and Tung Sol tubes I tried but I could easily live with GE or Tung Sol tubes if they are quiet and in good operating condition. 

Calling tubes EQ is just not accurate.  It assumes there is a "right" answer or perfect tube for every piece of gear or every system.  There are too many differences in systems, music preferences, rooms, and individual preferences to assume there is a "perfect" sound and that anything that veers away from that sound is "flavored".

[I.Greyhound Fan]

Well said Jackman.  In my case, I found that many NOS tubes sounded better than the stock 6CG7's.  Some were worse too.

[jackman]

Another problem with NOS tubes is dealing with fakes.  I see lots of NOS tubes on eBay coming from China.  If they can make realistic Tag and Rolex watches, how hard can it be to relabel a tube with silk screen writing?  Also, I've read about guys in Germany buying big lots of old tubes that were low quality and relabeling them as high $$$ NOS tubes.  Who knows, maybe the bad NOS tubes I got from the Bay years ago were fakes.  They said they were matched and tested but I don't have the ability to verify! 

Sorry for my wordy former post.  To me, tube rolling is not like EQ'ing, it's like positioning speakers and selecting proper cables to get the best sound in my system.  The results are often subtle and I'm not sure I could tell the difference in many cases in a blind test.  I have not tried any of the big buck tubes or cables for that matter.  It's amazing to see guys spending up to $1000 on small signal tubes.  My Genelex tubes, the most expensive ones I own, were only $90, and they were guaranteed and tested by Jim McShane, a guy I trust.  They sound better than the $12 stock JJ tubes that came with my preamp but the difference is subtle.  The JJ's sounded very good and I could easily live with them. 

[rcag_ils]

To me, tube rolling is not like EQ'ing, it's like positioning speakers and selecting proper cables to get the best sound in my system.

Anytime you alter the audio freq. response of your audio eq. is EQing, some may achieve this by replacing the tubes with the same type but different brand, or by changing out their speaker cable and patch cable, or by changing out the cap, or put a notch up or down on the bass and treble controls, or go all out and use a 12 band equalizer, or in my case, using an active crossover. They all achieve the same thing, and they all can be measured with the proper test eq.

[MarkM]

I've owned AVA tubed gear (Fetvalve amps and preamp) and the stock tubes sounded best.  Tried several NOS tubes from eBAY and none sounded better than the stock tubes (I think they were JJ's).  Some of the aftermarket tubes I tried sounded dark, some were very noisy or microphonic.  I was kind've happy to find this out because the cheapest ones sounded best.  Not sure if the NOS tubes were fakes because I bought them on ebay but none sounded better than the stock ones and all were more expensive than the ones Frank supplies.  Score!

I agree with that statement.  I owned one of the early T8 preamps & Ultra 550 amp that used the 12AT7 tube.  I tried two NOS types and found that in those designs, the stock tubes were excellent and felt I wasn't getting a good return for my $$ invested in NOS tubes.

The Fet Valve Ultra+ preamp is transparent to tube changes in my system. 

[dminches]

Anytime you alter the audio freq. response of your audio eq. is EQing, some may achieve this by replacing the tubes with the same type but different brand, or by changing out their speaker cable and patch cable, or by changing out the cap, or put a notch up or down on the bass and treble controls, or go all out and use a 12 band equalizer, or in my case, using an active crossover. They all achieve the same thing, and they all can be measured with the proper test eq.

I am not sure why you keep referring to measuring things. It is all about what you hear.

I have been working with an acoustic engineer who has a great reputation in this space and he has warned me that a lot of what I hear in terms of changes to the acoustics of the room as a result of adding treatments cannot be measured or will not necessarily align with the revised measurements.  I assume he knows what he is talking about.

[rcag_ils]

I have been working with an acoustic engineer who has a great reputation in this space and he has warned me that a lot of what I hear in terms of changes to the acoustics of the room as a result of adding treatments cannot be measured or will not necessarily align with the revised measurements.

I think you can still measure the response of the rooms that have different acoustical properties. But we are talking about altering your audio eq. by substituting different parts in it.

[jackman]

I have a Rat Shack spl meter but don't have sensitive or sophisticated equipment to measure with high sensitivity in my room.  Most people probably do not.  Also, I'm not sure some of the subtle differences we experience with tube rolling can be measured.  My system is highly adjustable, my bass is active up to 150 hz, and my passive xovers have a contour switch to adjust upper frequencies.  Actively changing the settings in passive or active xover is EQ'ing but changing tubes is very subtle in many cases. 

Either way, when I try different tubes, I'm more concerned about what sounds better to me than what an analytical piece of equipment coule potentially tell me. My objective is to design a system that is good sounding to me.   If this is EQ'ing, so be it! 

One last thing.  I tested some in line high pass filters on my monitors to attenuate the sound below 150 hz.  It helped integrate my subs in the system but did something strange to the sound of the monitors.  Something was missing in the mids and high frequencies and it was not a positive change.  It was relatively subtle but the sound quality was diminished.   I now run the monitors full range and I'm working to dial in the subs.  I also tried running the monitors active through a DCX2496 but the passive, external xovers, sound much more natural to me.  Through the years, I even ran active eq on the monitors and always liked the sound of no EQ on the monitors and minimal EQ on the subs. 

[dminches]

Either way, when I try different tubes, I'm more concerned about what sounds better to me than what an analytical piece of equipment coule potentially tell me. My objective is to design a system that is good sounding to me.   If this is EQ'ing, so be it! 

Bingo.  That's all that matters.

[modular747]

If it's electrical signal, it can be measured. Unless you are hearing something that's not there. I see dead people......

So, tell us exactly what the measurements actually do show, and just  how to go about measuring them, in detail. It's not enough to name a device (i.e. "spectrum analyzer) without saying how you would use it. You also need to be able to relate a particular measurement with a specific audible effect.

Your idle speculation that it "can" or "should" be measurable with available equipment and techniques  is just that.

[avahifi]

One test we do when playing with tubes is to put a different tube brand in each channel of a preamp or amp.  They we look at the square wave performance on the scope.  Unless one of the tubes is really way off base, the scope traces look exactly the same.

Finally we switch the scope to the invert and add mode, which adds the output of both channels to each other, with one channel out of phase with the other one.  The results are a straight line, no obvious differences even with the scope set to a high resolution.  The scope output is nulled, even if we use mono digital white noise as a signal.

Its hard to think that changing tubes is changing frequency response by any audible amount.  What is happening is more subtle than that.  We still can hear what we can't yet measure.

Regards,

Frank Van Alstine 

[rcag_ils]

Music is nothing more than harmonic freq. if not, all musical instruments would sound the same, to find the differences in sound that are produced by the same type of part but manufactured with different methods, we need to look into the harmonic structure that each part produced. I no longer have access to a high $ spectrum analyzer, nor I have the time to haul everything there (where I work) and test it for hours, but I bet it can be measured.

[I.Greyhound Fan]

Well I finally reached tube Nirvana!

I received a pair of Vinatage 1950's Sylvania Black Plate 6CG7's with the internal shield between the plates and horshoe or D getter today and they have transformed my system along with the vintage 1950's Raytheon Black Plates that I am running in my Ultra II preamp.  The Sylvania's are in my Ultra II DAC.

The sound is warm, liquid and very analog sounding.  Its very musical, with deep bass, and lush midrange while keeping high frequency detail.  Imaging is very good and sound stage is fairly wide but I have to admit that it is not as wide as some of the other tubes that I have tried-RCA clear tops and black plates, GE black plates as well as the EH's.  But the trade off is well worth it.  It cost me about $300 in tube rolling but I will make some of that back in selling the tubes that I don't like.

[I.Greyhound Fan]

After just a few hours of play time the sound stage and transparency just opened up.