Hi,
Dejan, the above reply wasn't addressed to you but nonetheless....
I can assure you that designing a tube preamp or amp with THD well down to 0.001% is perfectly doable.
The preamps can even be designed without resorting to a global feedback loop.
No distortion, no colouration or am I wrong?
But of course, everyone is free to his or her personal preferences. I'm not defending valves per se, it's just that I know it's not the valves that are to blame.
Best,
Sorry I popped in uninvited, Frank, but I did and that's that.
My personal ideal is maximum linearity. By linearity, I also mean neutrality. Theoretically, most people will say that's their ideal as well, but they lie, mostly unintentionally.
A lot of time and effort was spent on linearizing my speakers. This was eventually achieved to very great extent - not perfect, but way nearer to that ideal thanthe vast majority of speakers I have ever heard, at any price, by anyone. On top of that, just as great attention was dedicated to making them an easy load to drive, and again, I don't know of any speaker commercially available which is as easy to drive as mine (but obviously, I haven't heard all the speakers available, so the previous statement is naturally relative). This was done on purpose, to enable each and every amp to dop its best with them. Thus, it is the cornerstone for my own opinion making.
For load tolerance, I use my old but refreshed AR94 floorstanders, which are not very easy on loads, although there were speakers which were way worse. And lastly, there are my wife's JBL Ti600 speakers.
For me to have an informed opinion, anything that comes along will be tested on all three, in three romms and three different acoustics, using three tuners, two CD players, one cassette deck and one TT. If it's a tuner, or CD player, there are thee preamps, three power amps and five integrated amps so drive it with.
The point is, I do not qualify anything lightly at all, I tuly and really give it the whole shebang. I feel that's the only way I can honestly say what I think of it. The lab measurements I do for my own sake, just because I am curious. My lab is relatively modest, consisting of a dual trace oscilloscope good up to 50 MHz, a dedicated, low distortion function generator good up to 100 kHz, a wide bandwidth function generator good to 50 MHz but not particularly low THD, plus a few multimeters. Good enough to yield some basic information and resolve basic issues, for finer work I go to a friend with a better lab setup.
I am NOT a measurement freak and do NOT insist on wild results, like a THD of les than 0.0001%; I feel that as long as THD is below 0.1%, albeit under full stress, more important is the harmonics decay than their absolute value.
So, trust me, when I say I feel tube audio, by and large, is oloured in my view, I have both the time, method and means to back it up with specifics. Again, I have heard some tube items I feel were very good indeed, just as I have run across some SS audio I felt was very good to excellent.
I agree with you that it's not simply the tubes themselves but how they are used; with transistors, it's exactly the same thing, with loudspeaker drivers also the same thing, etc.
When I refer to tube audio, I mean the things which are commercially available, not literally ALL of them; ulimately, I haven't heard all of them and cannot have an opinion of the sonics of something I've never even seen, let alone auditioned.
OK?
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That's what I thought, but I wanted to make sure I got it right. Thank you, Demian.
That you design by using measurements is easy enough to understand, but the question is do you also listen by measurements?
A retorical question in you case John, as well as in my case, but there's an awful lot of people out there who equate low THD measurements with good sound. Far too many, in fact. That's how a lot of junk is sold.
Agreed.
But I don't hink too much listening is done in big corporations, budget goals are the most important issue there.
And there's the question of auditioning - listening is a natural process, but hearing is an art. Frankly, I doubt most of the modern day audio designers have much of a musical education.
Being a professional musician is a completely different thing from being a trained listener. They have nothing to do with each other jet people here seem to think they do. Its complete and utter nonsense!
AES E-Library Selection and Training of Subjects for Listening Tests on Sound-Reproducing Equipment
AES E-Library Subjective Measurements of Loudspeaker Sound Quality and Listener Performance
AES E-Library Differences in Performance and Preference of Trained versus Untrained Listeners in Loudspeaker Tests: A Case Study
And there are manufacturers that do scientific listening tests with their products. Behind Harman's speaker testing labs - YouTube
AES E-Library Selection and Training of Subjects for Listening Tests on Sound-Reproducing Equipment
AES E-Library Subjective Measurements of Loudspeaker Sound Quality and Listener Performance
AES E-Library Differences in Performance and Preference of Trained versus Untrained Listeners in Loudspeaker Tests: A Case Study
And there are manufacturers that do scientific listening tests with their products. Behind Harman's speaker testing labs - YouTube
SY, don't be so literal. Instead, go out there and try some budget models, then come back and preach how they all listen. Ultimately, if they do, they should change their panel members.
Specifically. Harman has always been a company apart. Their company history shows that pretty clearly. And telling me that Harman does that is a bit silly, don't you think, me, who owns two of their integrated amps, from 1993 and 1999, plus their up market Citation models (preamp and amp)?
Remember, they are the most obvious proponent of low global NFB circuitry, they were the ones who emplyed Matti Otala for years (late 70ies to early 80ies), and so forth. What are the chances of me not knowing the basics of that company, what with my views?
They probably all LISTEN, the question is what and how do they HEAR their products?
Specifically. Harman has always been a company apart. Their company history shows that pretty clearly. And telling me that Harman does that is a bit silly, don't you think, me, who owns two of their integrated amps, from 1993 and 1999, plus their up market Citation models (preamp and amp)?
Remember, they are the most obvious proponent of low global NFB circuitry, they were the ones who emplyed Matti Otala for years (late 70ies to early 80ies), and so forth. What are the chances of me not knowing the basics of that company, what with my views?
They probably all LISTEN, the question is what and how do they HEAR their products?
Are you suggesting that a "golden eared" panelist will know better how an instrument sounds than the man playing that instrument?
Are you also suggesting that EVERYBODY takes listening results as seriously as Harman does? If so, how do you explain quite a lot of rather poor sounding products on the market?
Thank you Demian.
In my urge to p**s off Pavel and Dejan (Scott too?), I forgot to mention here
that the tubed amp was open loop (how else could that have happened?).
I am fully satisfied with TAS5704 chips. When you’ll engineer something with such chips (I2S input, Class D Out) let us know. I am in.
George
I accept your "oops".
On Infinity - the two US companies which have always been represented in my country, ever since the late 60ies and early 70ies, were Acoustic Rsearch and Infinity. Consequently, I have had many an opportunity to hear alot of their models over the years. I still do.
Like in just about every lineup you care to mention, there were models I liked and there were models I would never buy myself. As it happens, a fair share of my friends and acquaintainces did buy Infinity speakers, I suspect more of them did so than those who bought an AR model. One guy actually had an Infinity Reference, the model which comes in several parts and needs a fork lifter to position in a room. That was a great speaker however you look at it, but it was an evil load which at the time, only Krell, Mark Levinson and the likes of them could drive. They justified the exitence of high power, high load tolerance amps.
Personally, I was more of an AR man, although they had their at best mediocre models, like everybody else. AR5 served me from 1973 to 1986, thereafter it was AR94 until 2003.
Overall, I'd say Infinity did better than AR on entry level and more inexpensive models, but at the time, they faced some stiff competition from the UK speaker industry, and to a lesser extent, from the German loudspeaker industry. In my view, Rogers, who made 3 (I think?) BBC monitor models, the largest being a fully blown 3 way speaker, were in my view better.
What I always liked about Infinity is their immediacey, their presence, whereas AR had a slightly less presence (as being there) sound, they were more laid back.
On Infinity - the two US companies which have always been represented in my country, ever since the late 60ies and early 70ies, were Acoustic Rsearch and Infinity. Consequently, I have had many an opportunity to hear alot of their models over the years. I still do.
Like in just about every lineup you care to mention, there were models I liked and there were models I would never buy myself. As it happens, a fair share of my friends and acquaintainces did buy Infinity speakers, I suspect more of them did so than those who bought an AR model. One guy actually had an Infinity Reference, the model which comes in several parts and needs a fork lifter to position in a room. That was a great speaker however you look at it, but it was an evil load which at the time, only Krell, Mark Levinson and the likes of them could drive. They justified the exitence of high power, high load tolerance amps.
Personally, I was more of an AR man, although they had their at best mediocre models, like everybody else. AR5 served me from 1973 to 1986, thereafter it was AR94 until 2003.
Overall, I'd say Infinity did better than AR on entry level and more inexpensive models, but at the time, they faced some stiff competition from the UK speaker industry, and to a lesser extent, from the German loudspeaker industry. In my view, Rogers, who made 3 (I think?) BBC monitor models, the largest being a fully blown 3 way speaker, were in my view better.
What I always liked about Infinity is their immediacey, their presence, whereas AR had a slightly less presence (as being there) sound, they were more laid back.
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