What difference would that make?
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How to Test Objectively Test Tube Rolling?
- Thread starter watchnerd
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So you believe you can actually hear such differences in measurements generally, that most of ASR is just waiting to catch up with your golden ears?
So set up an appropriate test with number of trials and report back. Could be a PIA
Sorry, think the whole subject is entirely subjective and limited to a very small subset of audio gear users.
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I think this is the key point. Microphony is underestimated. To illustrate, I remember a couple of places where big-envelope tube amps were used as microphones, to provide a wispy, ethereal track to mix into the reverb. Nowadays you would use a plug-in, but back then it was a sensational effect. I think it's always present to a degree, even in domestic replay situations. Thus an objective test of tube rolling should include the acoustic, not just the electronic.
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That exact thing was half of the TT magic that tried to preempt digital in the late 1970s and early eighties. The other half was the sudden fashion for stiff MC suspensions, which bounced energy back into the record, into the platter, into the record again, and back to the needle. Audiophiles took the various feedbacks as one, and called it ambience.
Galliardist
Major Contributor
What are you trying to achieve? If you are choosing your preferred tube, just do the job sighted. There is no problem with that process.
If you want to verify your result, or show what I'd say would be some expected differences, choose the preferred tube sighted, randomly choose one other tube, compare just those two by measurement and then use the FLAC/ABX method to check blind - both with and without level matching. If there's something to be found, you can go further with other tubes if you want.
But getting the right one for listening to music is probably the most important step here.
If you have measurements or specifications for some of the tubes, you can of course do the maths for your system and see which ones match the expected specification for the amp and start objectively testing from the closest match instead. which is a more objective route - but you still have to listen to them all anyway and choose at the end regardless, if what you are saying is true.
Seriously, I'd say you are in audible measurement land here rather than sub-audible.
There's an easy way to avoid the 'blind' issue, namely have a friend do the swapping. However, tube amps can take something like 15 minutes to get to their final sound, that is probably far too long for a listening comparison test to be meaningful.
This is going to sound goofy, but what about using extremely linear recording equipment to take recordings of something off the amp, do this for all the tube variations, then do a blind comparison listen of the files? It might not tell you which tubes you'd prefer to listen to live, but might help you decide if you can hear a difference.
My dad sold tubes in the 60s. They were treated as a commodity; I think his customers replaced them one at a time as they blew, without even worrying if they were the same brand.
This is going to sound goofy, but what about using extremely linear recording equipment to take recordings of something off the amp, do this for all the tube variations, then do a blind comparison listen of the files? It might not tell you which tubes you'd prefer to listen to live, but might help you decide if you can hear a difference.
My dad sold tubes in the 60s. They were treated as a commodity; I think his customers replaced them one at a time as they blew, without even worrying if they were the same brand.
That's exactly what I said upthread about ripping to FLAC and using software ABX testing tools.
I'm finding the comments hilarious...
Sorry, I missed that you were talking about ripping from the amp output.
As an agnostic on the subjective/objective debate, I find the religious level of absolute certainty from which each side argues their case - regardless of the merits of the argument - equally hilarious. I'm a mathematician, and like numbers and believe in metrology. For me, while I've looked at the literature on canine intelligence tests, and wouldn't consider a breed which measures in the bottom quartile, I also wouldn't choose between two dogs strictly on the basis of a high score on the test.
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