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Thread: Footers under tube amp

  1. #1
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    Footers under tube amp

    This is a continuation from the discussion on the thread:

    Review: Reference 3A Reflector monitors

    The discussion had been about perceived deleterious affects of Herbie's Tenderfirm rubber feet under my amp on imaging and timbre.

    Yesterday I tested the footers again. I started with Alfred Brendel's rendition of Beethoven's Diabelli Variations for piano op. 120 (Philips). This is the recording that I had started with when Peter A. came over for a listening session a few days ago.

    First, without footers:
    I noticed an anomaly in the image that I hadn't noticed before, since I only had paid attention to the sound, which I loved, and never paid attention to the image of the piano. While most of the piano sound was relatively centered, there were sporadic low notes that jumped out quite close to the left edge of the soundstage. This may have caused Peter's impression that the sound came from everywhere. Then I played the same Beethoven piece in Solokov's recording, where some of the high notes were off center. Instruments on the Janaki string trio CD were well focused, with only the violin on the left channel moving around a bit at times (in this case this can be real since the player may move and with her the instrument). Finally I played "Blue Moon" by Art Blakey and the Jazz Messengers, with Freddie Hubbard on trumpet, because I had been concerned about a timbre change with footers. The trumpet was just above the speakers as I had heard it last time. Peter hears it much more elevated in height.

    With footers:
    Everything sounded more or less identical (!). Imaging was the same on all recordings, including the exact location of slight changes in violin position on the Janaki as the music is played. At first I thought the centering of piano on the Brendel was actually better, but taking out the footers again seemed to show that this was not the case. The timbre of the trumpet on "Blue Moon" seemed changed a bit, but going back and forth with and without footers suggested that also this was an illusion (or the going back and forth numbed me to actual differences, I don't know). The voices briefly heard around 2:30 were audible the same either way. Height of the trumpet also did not change, or the tight center focus of the trumpet.

    Still concerned about the piano imaging, I turned to a CD which I know should give rock solid center imaging: Maurizio Pollini's rendition of Beethoven's piano sonatas Op. 109, 110 and 111. I played a bit of Op.109, and the imaging was indeed tightly focused around the center throughout all registers of the piano, from high to low. The same held without footers.

    The good imaging with footers also held for non-centered instruments. In track 3 of Rihm's Jagden & Formen, an English horn plays half left, straight between center and left speaker, and a viola plays half right. Both had the rock solid, locked-in imaging that I had heard many times before.

    Conclusion:
    There is no clear difference in imaging or sound between the situations with or without footers on all the music played.

    I did keep the footers under the amp after I could reproducibly hear less distortion and grain on massed violins in the Adagio of Beethoven's Ninth (Blomstedt/Staatskapelle Dresden). I could not reproduce the stronger timbral differences that both Ian and I thought to hear when he came over last time.

    ***

    So what to make out of all this? My experience with the footers is the same as before Peter came over to listen. What could have changed Peter's impression so drastically when I removed the footers? One possibility is that the footers settle (as suggested by DaveC) and only then show deleterious effects, which would explain why I didn't hear those yesterday with switching them in and out. Yet I had never heard problems with imaging, and the great imaging that I focused on in my speaker review was with footers having been in place for several weeks. Another intriguing possibility suggested by Francisco is that there is an instability in terms of tube microphonics, and perhaps removing the footers took care of the problem when Peter was here. However, I cannot reproduce any problem that might exist. With switching in and out the footers the amp sounded pretty much the same throughout, which might not be the case if there was an intermittent problem with tube microphonics, which you would expect to show up with the constant slight movements of the amp under switching back and forth. I cannot rule out any problem, but at this point it does not seem likely to me there is one. In any case, it is unfortunate that inadvertently I made Peter focus on a problem with piano imaging on the Beethoven/Brendel at the beginning of our session, a problem that I had never paid attention to. It seems to have set the tone for the evening.

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    Addicted to Best! DaveyF's Avatar
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    Al, when changing out the footers, I am assuming that you powered down...is that correct? If so, did you allow the amp to settle for an equal amount of time once you resumed? Tubes amps, at least IME, take some amount of time to settle, usually on the order of 45+ minutes. This settling time makes it more difficult to determine the changes in SQ from one parameter to another....( our audio related memory just isn't that great).

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    Quote Originally Posted by DaveyF View Post
    Al, when changing out the footers, I am assuming that you powered down...is that correct? If so, did you allow the amp to settle for an equal amount of time once you resumed? Tubes amps, at least IME, take some amount of time to settle, usually on the order of 45+ minutes. This settling time makes it more difficult to determine the changes in SQ from one parameter to another....( our audio related memory just isn't that great).
    No, amp is on all the time. I do the switching out gently, aided by convenient handles on the amp.

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    Addicted to Best! DaveyF's Avatar
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    Quote Originally Posted by Al M. View Post
    No, amp is on all the time. I do the switching out gently, aided by convenient handles on the amp.
    Interesting, that's not something I personally would feel comfortable doing.

    I presume all of your connections are not disturbed by the movement?

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    Quote Originally Posted by DaveyF View Post
    Interesting, that's not something I personally would feel comfortable doing.
    Well, there's never any "bump" or something.

    I presume all of your connections are not disturbed by the movement?
    Correct, they shouldn't be. The angle under which the cables move with the changes is negligible.

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    Shun Mook footers under tube amps are just fantastic. Better than HRS, symposium, still points, finite elemente
    Audition recordings: Zero Distortion Link; Reference Components: Zero Distortion Link; Own: Lampi GG One-day-to-get: Apogee Scintilla, or a horn (with Tenor 75 OTL ), Preamp to be fit in to suit the gain and drive the power amp. Analog: TBD

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    Quote Originally Posted by Al M. View Post
    In any case, it is unfortunate that inadvertently I made Peter focus on a problem with piano imaging on the Beethoven/Brendel at the beginning of our session, a problem that I had never paid attention to. It seems to have set the tone for the evening.
    Al, thanks for taking the time to revisit this. I am not that surprised that you did not hear much difference because you did not seem to hear much difference the other night either. What is surprising is that you had before described the imaging, or perhaps tonal, issues that both you and Ian had heard before and that prompted you to insert the footers in the first place. Ian told me that the sound improved quite dramatically with the insertion of the footers when he was there.

    I am at a loss to explain why the footers made such a sonic impression on me. Perhaps the next time I hear your system I will not notice a difference, or I will. Many things in this hobby are difficult to explain.
    My system link on WBF: http://www.whatsbestforum.com/showth...-Sublime-Sound
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    Member Sponsor [WBF Founding Member] Mike Lavigne's Avatar
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    Quote Originally Posted by PeterA View Post
    Al, thanks for taking the time to revisit this. I am not that surprised that you did not hear much difference because you did not seem to hear much difference the other night either. What is surprising is that you had before described the imaging, or perhaps tonal, issues that both you and Ian had heard before and that prompted you to insert the footers in the first place. Ian told me that the sound improved quite dramatically with the insertion of the footers when he was there.

    I am at a loss to explain why the footers made such a sonic impression on me. Perhaps the next time I hear your system I will not notice a difference, or I will. Many things in this hobby are difficult to explain.
    I've been under the radar lately, mostly listening to digital and loving it......and not really talking about it. just listening. and much of that digital listening has been piano. while things were already very, very fine sounding, when I moved a pair of Taiko Tana TS-140 active isolation units under my dart 458's 2 months ago now, I crossed some threshold.

    this stuff is fully holding my attention, and it's touching all the bases for me. I'm not claiming any superiority over any other approach, it's more I could care less about any other approach.....and I don't care to try and convince anyone. I have no idea whether my experience has relevance to anyone else.

    loving my digital piano. a lot. I don't want to threaten anyone's dogma or comfort zone so i'll stop there.
    Wave Kin. NVS tt, AS-2000 ord. (2) Durand Telos (1-Sapphire) arms, CA Gold Stat, Ort Anna carts, -2- Studer A-820 RTR (1/4" + 1/2").*MSB Select II dac w/33 Femto clock + mono powerbases, SGM serv + (2x) 30 tb NAS. *darT NHB-18NS w/2 phonos, King-Cello. *dart 458 mono blocks. EA MM7. *Equi=tech 10WQ, (10) Abso Fid PC & (2) Evo Acou PC. *Evo Acou 12' TRSC and 8m + 1.25m 'zeel' ic's, *Tripoint Troy Sig + Elite, Entreq Sil Tel + Pos, *Herzan TS-140 & TS-150, Wave Kin. A10 U8's + 2NS, Adona GTX.

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    Quote Originally Posted by PeterA View Post
    Al, thanks for taking the time to revisit this. I am not that surprised that you did not hear much difference because you did not seem to hear much difference the other night either. What is surprising is that you had before described the imaging, or perhaps tonal, issues that both you and Ian had heard before and that prompted you to insert the footers in the first place. Ian told me that the sound improved quite dramatically with the insertion of the footers when he was there.

    I am at a loss to explain why the footers made such a sonic impression on me. Perhaps the next time I hear your system I will not notice a difference, or I will. Many things in this hobby are difficult to explain.
    You're welcome, Peter. I also thought that evening there were differences in the trumpet as you described, and differences in the presence of the band, but I couldn't replicate that. Just as I couldn't replicate the rather prominent differences in timbre that both Ian and myself thought to hear when we first tried the footers. Perhaps what you heard was real, but from experience I also know that initial impressions can be deceiving.

    The differences between my new and old speakers were usually quite obvious, but I nonetheless made sure to double and triple check all differences that I described in my review (I wonder if other reviewers go to the same lengths, frankly). Mostly first impressions held up because the differences were not subtle, but in one case that initially I found a slam dunk I had to let it go, because the differences were just not big enough. A juicy detail that I had to drop, for truth's sake.

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