12ax7 Preamp tube test (VIDEO)

[Rilke]

Hi fellow MTS'ers!
Recently I undertook a tubetest (6 different tubes) for my V1 position in my rm100 to see how it reacted. As I am a recording engineer I naturally recorded the test to see what the differences were (also to eliminate ANY bias I had towards one tube or another).
The test was through a foglifted Rm100 and a Jaded Faith Erect module, you can check it out here:
https://www.youtube.com/watch?v=YxmhdtAFYPE&feature=youtu.be

The result is a bit interesting, and much smaller than I had expected. The test was made through reamping a DI to eliminate difference in play from take to take (etc.) Anyways, check it out if you're interested and let me know what you think

Btw, the test is pretty documented in the Info under Youtube if you wanna read more

Best regards
Christian

 

[Mattfig]

That was awesome.....I would like to say I heard differences but, if there are any at all, they are subtle in forms of compression and brightness???

IDK, but GREAT JOB! Thanks for sharing!

 

[Rilke]

Hi Matt!
Thanks a lot!! Yeah, I wholeheartedly agree, VERY subtle differences!! I had expected a more significant change, which might be achieved by changing more tubes than just the V1. Apparently the general thinking (just reiterating here, so don't take my word for it hehe) is that in a tube amp with lots of tubes (a la the rm100), changing one tube yields a smaller degree of sonic change, than for example in a 2 tube 12ax7 amp. Which seems to make some sort of sense at least to me

In this case I agree, the amount of compression, gain and brightness (or lack thereof) separates the different tubes by a hairwidth. I can distinguish the differences in a good listening environment, but even there the difference is very minor indeed.
I took great care setting up the experiment so that it should be as biasfree as possible, but it might be interesting to repeat it with a less gainy sound and see what changes might possibly come from that
Best regards
Christian

PS.
Thanks Matt for all the good advice regarding my amp elsewhere on this forum, you're really an asset!

 

[galao]

Great comparison, thanks for your work! A few weeks ago I´ve posted a comparison between the RM4 and SYN-2 with similar results. The difference is very subtle and can be reduced to tube V1. With headphones the 7025 and Sovtek 12AX7 sounded slightly different from the rest. I can just refer to Rob´s recommendation to go for a 5751 in the PI position of the RM100, which is really a great improvement.

 

[Rilke]

Hi Galao! I actually saw that one (great comparison aswell!), I agree that the changes between the RM4 and the SYN-2 was very negligible aswell. I agree that the 7025 and the LPS was slightly different, and both were among my favorites (ended up with the LPS).
I've been thinking of making a test (same style) with the PI, and should probably drop a 5751 tube in the test aswell, although the slightly lower gain of that tube, makes it a bit more difficult to make a 1:1 test

 

[galao]

Yes, a tube comparison in the PI position would also be great.
You will likely have to elevate the volume of the 5751-recording.

 

[tnjazz]

I didn't hear any noticeable difference between any of them myself. I'd love to hear this test done with a clean channel - that's typically where I can hear differences between tubes.

 

[Rilke]

Tnjazz; Yeah, I think the tone (high-gain) in some way masks the characteristics of the tube, also I think that for one to hear the full flavor of each tube it would require more changes than 'just' the V1, even though it is considered the tube with most impact. Rob (Jaded Faith) suggests that the complexity of the amp is so high that the tube in itself plays a minor role cause it simply is a smaller part of the circuitry than in a simpler amp.

My amp is out for the moment for a transformerchange (MM-output + mm choke), but when it comes back I'd be happy to make a repeat of the test with a cleaner sound, I would imagine it might yield a bigger difference.

As it stands the expensive NOS tube doesn't sound markedly better than the new sensor russian counterparts. And the difference is exactly so minor that it's not of any issue, at least with that particular tone

 

[tnjazz]

Yes, that makes sense. I have changed out V1 in all my units and a number of my modules to nice NOS tubes and I *think* I hear a slightly smoother tone overall but that could just be what I want to hear, knowing I have replaced a Chinese made tube with a vintage one.

I've always been told that every tube plays a role in the overall sound, including the power tubes. I'm starting to realize it's not a night and day kind of difference though, and in a live setting it isn't likely to be noticed at all. Certainly not by the audience.

 

[Rilke]

I have done the exact same thing with another of my amps, a 71 Fender twin reverb, where I changed to NOS tubes over JJ's. The difference there was greater (I felt that it was much more musical and 3d sounding), but I did not record the differences so it very well might be imagined.
The brain is kinda the enemy here, because we just want/wish the sound to be better with the NOS tubes, it is easy to 'hear' a big difference, especially without a pre/post recording.

However I've been through a couple of powertube combinations with the RM100 (recorded), and there is a markedly different sound with EL34/6l6/KT88's. I have promised a video documenting these differences but never got around to making it. I will probably get around to it soon though.

With the high-gain sound I would have loved the NOS tube to shine through, and it does sound a very small bit different (a bit darker/warm). As you say, though the diffence, at least what this particular sound is concerned, is so small that nobody would notice it, when I listen to it, I would say the sound is basically unchanged.

 

[ricky]

I don’t trust my ears after playing loud music for years. However, I may have noticed a slight increase in presence in the Soviet and Svetlana. However, I may be biase a little and that may be because there is a golden shower video of my from a visit to Russia a couple of years back.

 

[Spencer4hire]

I don’t trust my ears after playing loud music for years. However, I may have noticed a slight increase in presence in the Soviet and Svetlana. However, I may be biase a little and that may be because there is a golden shower video of my from a visit to Russia a couple of years back.

:lol: Thanks that was funny!!