s-petersen
Scott
So you did these tests,with the Yaqin connected to s solid state preamp?
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Yaqin MC-100B - not as powerful as advertised, but still a good value. Part 1.
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XJS_V12
New Member
I know the manual says between 50 & 60 mA, but whan I replaced the standard KT88 tubes in my MC-100B for JJ's, my tech who has been working on tube gear since the days of black & white tv's said that 50/60 mA is too high and biased mine in at 36 mA and said the tubes will last longer. Will it make much difference to sound and tube longevity if I wind the bias up?
If you read my notes above further, you will find that best results (lowest distortion numbers) were at 85 mA. If you care about power tubes life, this amplifier is not for you. I do not care what someone says unless he confirms it with measurements. KT88s are designed for 50 mA and 500 V at plate. In this amplifier they only see 400-410 V.
ChopperChas
Super Member
Shortly after I got the Yaqin, and rolled the tubes to the JJ Teslas, Sylvania Chrome Dome, and at the time Mullard AX7s, my bud and I did a A/B comparison between the Yaqin and a Rogueaudio Tempest II.
There honestly wasn't a lot of difference, at least at the volume levels we were listening at. One was a little brighter, one had a little more bass, but they were so close I don't even recall which was which. His amp was a couple grand, mine $700 bucks, plus a $250 for some new tubes, and the difference in the sound was negligible.
Do note that my speakers are Cerwin Vega VS-150s, which are extremely (101dB) efficient, so that may have something to do with my good luck with this amplifier. I've had it five years now, and have made no modifications to it. The *only* problem i had was the blue LED burned out after a couple of years.... and honestly that damn thing was so bright, I had put electrical tape over it anyhow.
Charles.
I wouldn't run those at 85mv.
Look at what other amp users are running KT88's at as a guide.
Always have the tubes in, when powered on.
You can safely run it up to a 100. This amp uses unusually low plate voltage for KT-88, so you can't compare it with others. The whole idea is to bias it into class A for most of useful power range.
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ChopperChas
Super Member
interestingly enough, I did notice that an increased bias gave better sound with the JJ Tesla tubes. The higher the bias, the harder the bass hit. I was running at 70ma, but the tube life was right around 6 months before one of the Teslas met an unfortunate demise. Replaced two of the tubes with the original Chinese tubes (2 Tesla, 2 Chinese), and biased down to 55ma and they've been going strong ever since. But... the bass was considerably better with the higher bias.
Charles.
Charles.
MasterHiFi
Adrift In a Sea of Info
I saw this post quite a while ago, and then for some reason I landed on it again today. Then as now, I just sat there shaking my head. You really have to wonder if it is worth it to bother to respond when you read a statement like this:
Nothing personal about "for_p1", but you say to yourself, "what an idiot". And the OP is wholly responsible for this unflattering statement. No one should be judged when they lack experience or education. But it is obvious from the OP's profound testing and modification skills that he has plenty of education which must come with considerable experience. That's why, when the OP draws a conclusion that ALL tube amps (at least moderately priced) are deficient as compared to solid state, he reveals himself to be, well... an idiot.
He mentions some unknown massive 250wpc amp to be his reference, though we know nothing about it, no brand, no model, nothing. Furthermore, there is no mention of the speakers on which he performs his listening tests. Isn't that rather important? Maybe your speakers are a terrible match for this particular tube amp. Maybe the Yaqin is just a lousy product? That's not to discount all of the users who found this amp to be delightful. I have no doubt that users coming from mass produced low or mid-fi equipment hear a big improvement with this unit. But we have no idea what the OP is comparing it to.
And since there was no mention of a preamp, we have to assume that he was using the Yaqin as an integrated amp. If not, what preamp drives his 250wpc amp? Maybe the Yaqin is terribly matched to your preamp? Anyone with your experience should be cognizant of impedance matching. But if you used the Yaqin as an integrated, did you try a Fisher 500B or 500C? You can get one fully restored for $700 - $1000. You can get a Scott 340B for even less. They sound FANTASTIC. If you used the Yaqin as an amp, did you try one of the beautiful sounding SET amps? They will literally take your breath away. Again, we don't know your speakers, so we have no idea what might even be appropriate or practical.
Then, after significant testing and modification, the OP comes to an equally ignorant/stupid conclusion:
No, you can't say that. Aside from a myriad of other reasons, simply for the fact that it is not true. Anyone with such prodigious testing and electrical skills - far beyond any skills that I possess - has no excuse. That person should be educated enough to know that such a universal conclusion cannot be drawn from a single comparison. Guess what? Good tube audio blows away solid state, hands down. Granted, in the "new" market, it takes a much larger investment to yield the positive results for which tube audio is known. That is because good tube equipment is seldom mass produced like most solid state equipment. Good tube amps are hand-wired and do not use circuit boards as found in the Yaqin and other lower-end Chinese products. But if you have "moderately easy to rive speakers", then there are any number of small boutique tube amps, 8 - 15wpc (more comparable to 15 - 30wpc for most solid state pieces), that are very affordable and sound absolutely amazing. If you have inefficient speakers that require lots of power then things can quickly get much more expensive.
The point is, you have a guy who is unarguably a very skilled technician, which seems to give his account added authority, making sweeping statements that are patently false based on a single listening experience on a single amp, with no idea how this amp pairs with his speakers and or preamp, or compares to his reference amp - and then he extrapolates this experience to be representative for ALL tube equipment. It is just idiotic. Should I base a conclusion for ALL manual transmission automobiles based on my frustrating experience driving a garbage truck? I bet BMW owners might have a thing or two to say about that. And they'd be right - ESPECIALLY if I were an auto mechanic. Although he possesses electrical skills that I will never have, what I DO have is listening experience, and that is precisely what he lacks. His comments would be less damaging were he not making huge generalizations based on his lack of listening experience, drawn from a sample of one. single. piece. Stupid.
Tube audio rocks, and it blows the doors off of solid state. It took me 30 years to figure this out, but the evidence is undeniable. And that evidence is not based solely on the Yaqin MC-100B.
By the way, if you have a very modest system, say a Pioneer or Sony receiver and other, similar levels of equipment, I'm confident that even the Yaqin MC-100B will represent a huge step up in sound quality over what you are used to. So, in spite of what the monkey-brained OP said about it, don't be afraid to give it a try. And if you have very efficient speakers, check out some of the SET amps out there, like the Creek, etc. that will rock your world.
MasterHiFi
Nothing personal about "for_p1", but you say to yourself, "what an idiot". And the OP is wholly responsible for this unflattering statement. No one should be judged when they lack experience or education. But it is obvious from the OP's profound testing and modification skills that he has plenty of education which must come with considerable experience. That's why, when the OP draws a conclusion that ALL tube amps (at least moderately priced) are deficient as compared to solid state, he reveals himself to be, well... an idiot.
He mentions some unknown massive 250wpc amp to be his reference, though we know nothing about it, no brand, no model, nothing. Furthermore, there is no mention of the speakers on which he performs his listening tests. Isn't that rather important? Maybe your speakers are a terrible match for this particular tube amp. Maybe the Yaqin is just a lousy product? That's not to discount all of the users who found this amp to be delightful. I have no doubt that users coming from mass produced low or mid-fi equipment hear a big improvement with this unit. But we have no idea what the OP is comparing it to.
And since there was no mention of a preamp, we have to assume that he was using the Yaqin as an integrated amp. If not, what preamp drives his 250wpc amp? Maybe the Yaqin is terribly matched to your preamp? Anyone with your experience should be cognizant of impedance matching. But if you used the Yaqin as an integrated, did you try a Fisher 500B or 500C? You can get one fully restored for $700 - $1000. You can get a Scott 340B for even less. They sound FANTASTIC. If you used the Yaqin as an amp, did you try one of the beautiful sounding SET amps? They will literally take your breath away. Again, we don't know your speakers, so we have no idea what might even be appropriate or practical.
Then, after significant testing and modification, the OP comes to an equally ignorant/stupid conclusion:
No, you can't say that. Aside from a myriad of other reasons, simply for the fact that it is not true. Anyone with such prodigious testing and electrical skills - far beyond any skills that I possess - has no excuse. That person should be educated enough to know that such a universal conclusion cannot be drawn from a single comparison. Guess what? Good tube audio blows away solid state, hands down. Granted, in the "new" market, it takes a much larger investment to yield the positive results for which tube audio is known. That is because good tube equipment is seldom mass produced like most solid state equipment. Good tube amps are hand-wired and do not use circuit boards as found in the Yaqin and other lower-end Chinese products. But if you have "moderately easy to rive speakers", then there are any number of small boutique tube amps, 8 - 15wpc (more comparable to 15 - 30wpc for most solid state pieces), that are very affordable and sound absolutely amazing. If you have inefficient speakers that require lots of power then things can quickly get much more expensive.
The point is, you have a guy who is unarguably a very skilled technician, which seems to give his account added authority, making sweeping statements that are patently false based on a single listening experience on a single amp, with no idea how this amp pairs with his speakers and or preamp, or compares to his reference amp - and then he extrapolates this experience to be representative for ALL tube equipment. It is just idiotic. Should I base a conclusion for ALL manual transmission automobiles based on my frustrating experience driving a garbage truck? I bet BMW owners might have a thing or two to say about that. And they'd be right - ESPECIALLY if I were an auto mechanic. Although he possesses electrical skills that I will never have, what I DO have is listening experience, and that is precisely what he lacks. His comments would be less damaging were he not making huge generalizations based on his lack of listening experience, drawn from a sample of one. single. piece. Stupid.
Tube audio rocks, and it blows the doors off of solid state. It took me 30 years to figure this out, but the evidence is undeniable. And that evidence is not based solely on the Yaqin MC-100B.
By the way, if you have a very modest system, say a Pioneer or Sony receiver and other, similar levels of equipment, I'm confident that even the Yaqin MC-100B will represent a huge step up in sound quality over what you are used to. So, in spite of what the monkey-brained OP said about it, don't be afraid to give it a try. And if you have very efficient speakers, check out some of the SET amps out there, like the Creek, etc. that will rock your world.
MasterHiFi
MasterHiFi
Adrift In a Sea of Info
More profound statements from you, it seems. 100 dB is rock concert level. Only the most extreme concerts go up to 120 dB, and sustained exposure to anything above 85 - 90 is damaging to our hearing.
ChopperChas
Super Member
Speaking of volume, when I blew some resistors in my 100B (tube failed and took out a bunch of parts), I swapped in a Phase Linear Series II Model 200... and it's a LOT quieter for the same input level from my preamp. The Phase Linears, even the 200s, were supposed to be the "LOUD" amps of their era, but the Yaqin produces more volume with the same input.
Charles.
Charles.
You mix output power with gain. Amplifier can have low power and high gain, or opposite - high power and low gain. Gain is usually a non-issue with modern preamplifiers. Power is what allows music to play louder.
100 dB is NOT concert level. I talk about peak levels here. Average is 10 to 20dB lower. Amd average is what is perceived as loudness. Amplifier should have power reserve of 20dB to avoid clipping on ANY type of music.
Human Error
New Member
I saw no data in your rant attacking the OP, except for this 30 years bit. That suggests that a significant portion of the 'research' could be related to the effects of presbycusis (likely with one or more of the following as well: sociocusis, nosocusis).
If you believe the OP is guilty of overgeneralization it's your responsibility to post hard data to rebut the claim(s) you do not believe are accurate. Tirades are not adequate.
I happened upon this thread after reading the same material posted at the DIY forum. There were no attacks on the OP there, including the post someone else made here claiming that the OP's effort is a "disservice". Ugly behavior and false, too.
Sure, it strikes me as overconfident to use one data point (a single tube amp) to claim that tube amps sound the same as solid state. But, the bigger point is that amps shouldn't sound like anything at all. They should not color the original sound. If they do sound like something that's bad, as long as it's a significant change to the reproduction. The worse one's hearing is, the less difference it makes. The worse one's speakers and other equipment/setup are... The more ambient noise... Etc.
Theoretically, the only reasons to have an amp alter the source sound are to correct a problem with the source material (e.g. too peaky at 1K) or with other parts of the reproduction chain (the person's hearing, the room, the other audio equipment pieces—generally the speakers). But, that kind of correction is, as a practical matter, handled by things like EQ/room correction. To keep things simple, amps should be able to reproduce the full range of the source material without affecting it—distorting it.
If added coloration (distortion) is desired then, in my view, the amp should have a switch to turn that on or adjust it. It should also have a default mode of being as faithful to the source material as it can within its budgetary limitations. Amps should get out of the way and let various EQ solutions (e.g. DSP with microphone-measured correction points, speaker choice/placement, room treatments) take care of whatever happens after the sound is merely amplified. The main reason for this is so the only variable that is really important is how well the amp is capable of driving the speakers in the room (amp power profile — watts and ohms).
I don't recall seeing the term presbycusis in Stereophile and Absolute Sound reviews (or the related terms). Older men tend to have more disposable income so it would be bad for business to point out that paying a lot for small quality differences that one can't hear because of age isn't objectively worthwhile.Wikipedia said:
Audio enthusiasts tend to look at audio as if it's like most forms of experience (knowledge is cumulative). However, given the realities of hearing degradation (including that which comes from aging alone) — a person can become less accurate as an arbiter of sound quality over time.
As for tubes vs. solid state... The only value that I know of that tubes have over solid state is aesthetic. It is my understanding that everything that they can do (including their different distortion profiles) can be implemented with solid state designs. Moreover, solid state is more efficient, not only in power usage but in terms of not having to replace parts as often. I believe visual aesthetics are important and am willing to pay extra to replace tubes (and deal with the heat) but visual beauty and nostalgia are not sound improvement. Since I have age-related and exposure-related hearing degradation the fact that affordable tube amps don't measure well is less of a worry for me — as long as they can cover enough of the sound spectrum in a reasonably-clear manner. I also can't tolerate loud volume levels due to tinnitus so the low power of budget tube setups is not as much of a drawback. I could not care less about how much "slam" an amp provides unless I am setting one up for a live rock concert.
All that said, though... I do not like the idea of paying for products that deceive customers about their specs and I don't like the idea of paying for shoddy designs. An example of a shoddy design (in my view) is a tube amp that costs thousands of dollars and uses small noisy fans for cooling. This amp apparently not only doesn't meet its claimed specs it runs some of its parts out of spec. Someone in the other forum said their guess is that the output transformer isn't very good (a place where corners are cut on very budget tube amps) and there isn't data on it. I think the data for the parts used should be published information so buyers can know they're buying something that meets their expectations.
I can thank my father for forcing me to shoot guns and attend drag races for a lot of my hearing loss. I can also thank Siouxsie Sioux for the one and only rock concert I attended that caused my ears to ring for a year and a half. Aspirin, which I need for back pain, also aggravates things. Etc. Young people are suffering from exposure-type hearing damage at a high rate due to the popularity of listening to music with headphones/earbuds in noisy environments. Every time I read a review on a site like Stereophile and the reviewer says he turned up the volume so loud that it was painful I have to shake my head. How are we supposed to take that reviewer's word when the reviewer apparently exposes himself to dangerous decibel levels routinely (in addition to not being young)? Environmental noise is also a huge problem for a lot of people, such as people who use New York mass transit:
To see some of the difference between males' hearing and females':Environmental Science Tech journal said:
Acoustic Society of America journal said:
People really need to post the results of their current hearing tests (conducted by independent audiologists) when they review audio equipment, especially professional reviewers.
Wikipedia said:
Poultrygeist
Lunatic Member
A lot of effort responding to a dead thread.