Tony said:
Sorry, my question was not too clear. I was assuming the operating voltages that Darius referred to was the rectified DC - the B+. If the B+ varies, not ripple, just different voltage (e.g 300VDC and 320VDC), then I can see why a particular circuit will sound differently because the change in voltage can move the operating points of the tubes. I have tried Mullard, JJ, Sovtek, GE 5AR4's in my Eico st-70, I really couldn't hear any different that I notice right the way. FWIW, the measuring devices were my ears that probably can't notice 5% thd
I am an engineer, and I tend to agree with the above statements, especially in a SE amp with nearly constant current drain. Some audible differences can be expected when using rectifiers with grossly different voltage drops.
I have made, and sold a few amplifiers based on the Tubelab SE. Several years ago I sold one of the first ones to a well to do individual for use as a bedroom amp. He already had a high dollar 300B amp for his main system. After he figured out that the Tubelab SE kicked his expensive amplifier's butt, he asked me if I would build him a custom version just for headphones. He made two 500 mile trips to my location and stayed in a hotel for the weekend so he could be present during the build and "select" the "special" components to be used in this amp.
We tried a zillion tubes, transformers, and component combinations that eventually provided him with his personal audio nirvana. He had brought with him a collection of very expensive tubes which were rolled through the amp several times, and he purchased several more during the build. His collection included a few Mullard 5AR4's. My collection includes Shuguang, Sovtek, National, and RCA 5AR4's. Note the opposite ends of the price spectrum.
The Tubelab SE with a choke and a motor run cap added to it is a very quiet amp. All tubes are DC heated. We were connecting headphones directly to a 600 ohm OPT with no attenuation, and using a 30 or an 01A for the output tube. No hum could be heard. The hum and its IMD products were very low on the FFT analyzer, regardless of the rectifier tube being used.
Twice during the build I played rectifier tube roulette. The customer was NOT able to see which tube I was installing, and was listening only to one of 3 pairs of expensive headphones that he brought. He could identify his Mullard 5AR4's EVERY TIME! I could not.
We postulated that I was just a mere mortal audiophile, and he was special
. At any rate I was well paid for the experience. He also left me one of the "special" Mullard rectifiers. I have it stashed in a safe place, and my amplifiers use Shuguangs.No "Shakti Stones" of other implements of "magic" were used or present during the build. I did notice some expensive power cords, interconnects, and speaker wire in his setup when I visited him about a year after the build.
You guys have it all wrong. The pebbles MUST be cryo treated for them to work at all. The crystal structures need to be aligned!
tubelab.
I enjoyed that story, took me back to when I and a friend were constantly rolling rects.
On him being able to pick his tube, reminds me of an article slamming DBTs. It was about codecs for broadcastng and the DBTs indicated no audible problems could be heard. However some expert listened and could hear a problem that was verified. Once this was pointed out everyone had no trouble hearing it.
So Mr rectifier was probably homing in on something real subtle. He knew what to listen for. How this ability helps him enjoy the music I don't know, it would seem like a distraction to me.
If he keeps practicing he should eventually be able to catalog his tube recorded albums by the rectifiers used in the mixing and cutting gear.
I enjoyed that story, took me back to when I and a friend were constantly rolling rects.
On him being able to pick his tube, reminds me of an article slamming DBTs. It was about codecs for broadcastng and the DBTs indicated no audible problems could be heard. However some expert listened and could hear a problem that was verified. Once this was pointed out everyone had no trouble hearing it.
So Mr rectifier was probably homing in on something real subtle. He knew what to listen for. How this ability helps him enjoy the music I don't know, it would seem like a distraction to me.
If he keeps practicing he should eventually be able to catalog his tube recorded albums by the rectifiers used in the mixing and cutting gear.
Wellllll... fwiw.... there is a pretty noticeable difference between Sovtek and Mullard rectifiers in both my Simple SE and my Anthem Pre1 Preamp. You can get a used, but testing new (better than any currently produced 5ar4) re-branded Mullard for about $50. With the failure rate of JJ and Sovtek 5ar4 tubes combined with their dismal life expectancy, the $50 Mullard is also a better value over time. The fact that it sounds better in my gear is icing on the cake.
I will say that my Simple SE with choke and motor run caps is less sensitive to "tweaks" than any other piece of gear I've ever had, to the point where I'm not interested. Many digital amps react VERY strongly to small changes made upstream, and to their power supplies.
And as far as dielectric grease with silver added... I tried it on the tube pins in my preamp and Simple SE, and it made a bigger difference than changing rectifier tubes Also, it keeps copper from corroding. If you think this stuff doesn't work, you should look up dielectric grease and figure out why its used.
Dave
I will say that my Simple SE with choke and motor run caps is less sensitive to "tweaks" than any other piece of gear I've ever had, to the point where I'm not interested. Many digital amps react VERY strongly to small changes made upstream, and to their power supplies.
And as far as dielectric grease with silver added... I tried it on the tube pins in my preamp and Simple SE, and it made a bigger difference than changing rectifier tubes
Also, it keeps copper from corroding. If you think this stuff doesn't work, you should look up dielectric grease and figure out why its used. Dave
oldeurope said:
Darius;
different voltages will change differently "sound" of each and every particular amplifier. One will "sound" better, another will "sound" worse, the same about different time constants caused by different rectifiers. So, you can not say that the tube "sounds". It does not. When the amp was well designed for some ranges of parameters of rectifiers probably other tubes out of ranges will give worse "sound", but without knowing what the designer of the amp assumed you can't tell if the tube "sounds" better or not.
Speaking of 12AX7, some amps designed for Chinese tubes will sound horribly with NOS 12AX7s because of HF oscillations.
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