I don't believe in the sound of rectifier tubes either, yet I offer this story.....
I was designing a custom headphone amp for a big $$$ customer that was based on a Tubelab SE. The customer drove 250 miles each way twice to be present while I performed the final "voicing" on the amp. This consisted of him listening to his CD's on his CD player through one of several pairs of his headphones while I swapped in different components some of which he provided. I had been using several rectifiers from my stash 5Y3's 5AR4's 6X5's and others mostly NOS, some new production. We had agreed on the 5AR4 and he said he would bring some on his return trip.
On the second session we got to swapping rectifiers while he listened. Even though I said there was no difference, he wanted to test some. He had brought 2 old European metal based 5AR4's, one Mullard, and the other had no name or printing at all. It was quite worn looking, but worked well (good voltage out). In about 2 hours of testing with me swapping tubes where he could not see which one I chose, he picked out the old Mullard EVERY time with his music! I fooled him once or twice with some rock music which he had never heard before. Even though he told me what to listen for and when, I could not tell the difference between any of the good 5AR4's. I could tell when he stuck in a 5Y3 or a weak 5AR4. Whazzup????
The B+ voltage was within 5 volts with all but the weak 5AR4. The Mullard was the highest voltage, but only by about half a volt. Could someone pick out a .5 volt difference in a 150 volt supply? Did the line voltage even hold steady for an hour of testing? In Florida, no way it changes by 2 or 3 volts as the AC units in the 8 houses on my pole transformer cycle. The power supply was CLCC. There was a 150 uF electrolytic and a 40 uf polyprop cap in parallel for the final cap. The current drain for the whole amp is less than 100 mA.
Note.....all testing was done with his fancy interconnects, but a cheap power cord from an old computer. The customer paid me a lot of $$$ for that amp and another amp. He also gave me that unmarked metal base European 5AR4. I still have it, and I still can't hear any difference between it and any cheap Chinese 5AR4.
That's too true. I have been fighting a middle ear disorder that causes dizzyness and hearing loss for 25 years (Menieres disease). Loud rock concerts haven't helped either. My hearing at low volume levels is screwed up by Tinitus.
I have played the rectifier game at audio events also using a Tubelab SE without the same results though. The results are statistically insignificant. Output tubes, OPT's, coupling caps and even power supply caps do show a stastically significant distribution, but the agreement on what is "good" is a different story.
But, just because there is a measurable difference between electronic components, it doesn't mean those differences are large enough to be audible to people with normal hearing. For example, speaker cables have different L, C, and R measurements but people can't tell them apart with their ears until the difference becomes extreme (at impractical conditions which no one in their right mind will attempt).
There's no such agreement, true. It's all in measurements, to some. Must defend their education costs of course.
I'm inclined to throw a switch and listen for offending tone, rattle & hum, peculiar distortion. Must not forget to enjoy listening every now and then. That it was all about in the first place, not?
I'm inclined to throw a switch and listen for offending tone, rattle & hum, peculiar distortion. Must not forget to enjoy listening every now and then. That it was all about in the first place, not?
We all know people who would argue that point for years!!!! My speaker wire came from Walmart, my power cable came off of a dead computer, and my interconnects came from Radio Shack. Most people who have heard my systems or built my amps tend to agree that they sound good.
It's all about putting your budget $$$ where it does the most good. If you have an unlimited budget and you believe that putting magic stones on the transformers and hanging crystals from the speakers make the system sound good, then by all means go for it. For the rest of us, the best bang for the buck can be found in the transformers. Speakers are also near the top of the list. Buy the best ones you can afford.
I would put the choice of rectifier tube pretty far down on the list PROVIDED that the power supply is properly designed.
Yes, my hearing is far from perfect. I can still tell the good stuff from the bad, it just takes a bit more SPL to get the dynamic range right. As with many audio nuts, my tastes keep changing, thats why I keep building amps. I still have a few standards that I keep returning to though. My first TSE with 45's and my KT88 powered SSE still see constant rotation. The 845SE hasn't seen power in several years, maybe it's time to fire it up.....No I'll wait till winter, it's too hot now.
Measurement techniques and equipment keep improving.....maybe they will get it right in a few hundred years.
My high school had a 3 year program in vocational electronics. It was 1967-1970, yess it was free AND taught vacuum tubes. That's where i learned to make em' glow!
20 years later I got to go to college paid for by my employer. I eventually got a masters degree in electrical engineering....no tubes this time. A formal engineering education and 40 years experience in an electronics design and manufacturing plant helps to understand the trade offs necessary to produce a manufacturable electronic device. Not all of those trade offs apply to a one off audio system we build for ourselves. It still helps to understand them.
One of the reasons for ridiculously high priced tubes, GZ34 being one of them, is that in addtion to "high end believers", a large number of guitar amp geeks seems to be willing to pay anything for the "mojo"...
even lots of 10s of bucks for "tropical fish", "orange drop", "mustard" caps, carbon comp. resistors etc, - all because of the "mojo".......
even lots of 10s of bucks for "tropical fish", "orange drop", "mustard" caps, carbon comp. resistors etc, - all because of the "mojo".......
Tropical fish and mustard caps were just run of the mill polyester caps in the late 1960s/early 1970s. Used by the bucket load in domestic radios, TVs etc. I now find it both amusing and annoying that they (especially mustards) are now so sought after and expensive. Its not as if polyester is even that good a dielectric for audio! OK for cheap stuff like radios and guitar amps but a bit non-linear so use with care in hi-fi.
Coming from an engineering background, I do find most of this mojo stuff rather hard to accept, but just maybe that is exactly what it's all about in guitar amps - non-linearities. It certainly does rhyme with tube compression, overdrive, crunch and whatever have you of names and expressions..... maybe there is some "mojo" in it after all ...
I have read this comment all over eBay, and kept wondering how a rectifier tube could, in any way possible, alter the sonics of an audio stage........unless you were selling tubes.
As mentioned here before by others where I first saw it, will help new production last while keeping the slow warmup feature 5AR4/GZ34 are noted for without hurting sonics. Protects those NOS as It will also help in power failures where it flashes back on quickly. UF4007 may be noticably preferable for a few cents more.
Randy
Randy
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It's simply supply and demand in action. There are very few old stock pieces left, so it is essentially inevitable that the price will rise. Whether you agree or not, as long as there are buyers for the tubes the price will stay high or climb higher.
I am a tube selller. I don't have any old stock 5AR4s to sell - but one reason I might recommend one - if I had one - would be (as Kevin Kennedy mentioned) the durability is really quite good.
I would also like to mention that I have a number of GREAT jazz players who get tubes from me - including Grammy Award winners, etc. They all seem to be able to hear things I can't - and as a result I have to trust them when they say a given tube/cap/etc. sounds best to them. So I'm a bit hesitant to say they don't have a basis for some of the preferences they express.
Finally - I really think it's inappropriate to paint all tube sellers with the same broad brush. I don't rip off my customers and I know some other sellers who don't either.
Yes, but not necessarily on the same equipment.
I enjoy my favourite music even on a cheap portable radio.
The reason I am here is solely for the VALVES - I love them - just the valves mind you. Of course I like to have fine transformers and so on and make nice-sounding amplifiers, and I know how important they are etc., etc., but it's the VALVES for me.
Paul
To some extent? Does that mean there are sounds we can hear but not measurable with contemporary measuring devices?
I would be delighted to read about the sound difference we can hear but could not be measured and presented in graphic form. What are those differences?
Guitar amps are different than audio(phile) amps, the power supplies are designed for overloading and severe abuse in our terms, the B+ ripple is high, whenever I see a long thread at an audiophile discussing the merits of rectifier swapping to me it just means a minimal B+ filtering is employed. Especially with headphones, you can hear different B+ ripple profiles (best is none of course.)
I do agree the modern GZ34 rectifiers are more prone to issues like mechanical buzzing, vibrating if the heater voltage isn't just right, maybe even radiating rfi.
The best bet I think are the 70's japanese GZ34's, well constructed with nearly the same dam tooling but not "fashionable", good value for the buck. I think I paid $60 for a pair of never used 70's hitatchi GZ34's last year, they didn't vibrate/mechanically buzz like the new JJ's they replaced.
I still believe that no matter the regulation, I chose a tube rectifier over SS, why introduce nasty high freq switching noise if we have an alternative with lesser of this evil?
I do agree the modern GZ34 rectifiers are more prone to issues like mechanical buzzing, vibrating if the heater voltage isn't just right, maybe even radiating rfi.
The best bet I think are the 70's japanese GZ34's, well constructed with nearly the same dam tooling but not "fashionable", good value for the buck. I think I paid $60 for a pair of never used 70's hitatchi GZ34's last year, they didn't vibrate/mechanically buzz like the new JJ's they replaced.
I still believe that no matter the regulation, I chose a tube rectifier over SS, why introduce nasty high freq switching noise if we have an alternative with lesser of this evil?
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