Amplifiers are a lot like cars.
Some like technical detail, some prefer vintage, some just need something to get from A-B, pun intended.
You can have a real aerodynamic car, but you start to lose sex appeal and you begin to look like (sound) like everyone else, just another boring beige Ford Contour.
So it depends on the persons needs.
I myself need a real visceral system, just the right blend of power to weight ratio.
It's also interesting how the real performers use the generally most "gas", relative to the application.
Lots of different cars out there with different options and colours. Your not going to find a single measurement to define them all.
You need a formula based on demographics and application. Then you can start to compare devices within a certain class or context.
Some like technical detail, some prefer vintage, some just need something to get from A-B, pun intended.
You can have a real aerodynamic car, but you start to lose sex appeal and you begin to look like (sound) like everyone else, just another boring beige Ford Contour.
So it depends on the persons needs.
I myself need a real visceral system, just the right blend of power to weight ratio.
It's also interesting how the real performers use the generally most "gas", relative to the application.
Lots of different cars out there with different options and colours. Your not going to find a single measurement to define them all.
You need a formula based on demographics and application. Then you can start to compare devices within a certain class or context.
Personally, I feel that the quest for audio perfection is a challenge all to itself, above and beyond just getting some sound to fill the room. Of course, like with high performance automobiles, you can't always use the potential that your 'super' audio system might have, and you might have to resort, sometimes, to test recordings just to show it off, even to yourself or others. Still, on the whole, a quality audio system, just like a quality automobile, will show itself even in the most mundane tasks, at times, like listening to FM radio and getting a quality transmission of a new (to you) female singer, who with the quality audio system, virtually 'melts your heart' and reminds you of special times in your past. This is what I work for, in audio. Heather Masse was my latest 'find' this week, on 'Prairie Home Companion'. I might buy her music when I can find it on a high enough quality format.
Speakers and there subsequent setup is the weakest link , especially with what is available to us today in the way of recordings and electronics .......
Audax used to be a trip to deal with , there was so much inconsistency's with their gf drivers they wanted us to pay Xtra just to have drivers not only of similar specs but same consistency's of colour and gel .....
It took a hell of time finding drivers that would have the same look from pr to pr credit to them we did not have reliability issues and could match to within 1 db. L/R .....
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I like my HD600's but they were a gift from a small vendor who used one of our xDSL drivers to make a USB headphone amp. One of my guys helped them with the application but did not want the headphones.
SoNic,
There was no getting used to the Grados for me, I really did try. Whatever they did, I could not adapt to it. I know some folks love Grados, but they are too piercing for me. My reference is real world sounds that I hear every day, music or other.
The Grados don't change, just the listener does. Some listeners find them wonderful, others awful. How does that relate to quality? (Not a rhetorical question.)
There was no getting used to the Grados for me, I really did try. Whatever they did, I could not adapt to it. I know some folks love Grados, but they are too piercing for me. My reference is real world sounds that I hear every day, music or other.
The Grados don't change, just the listener does. Some listeners find them wonderful, others awful. How does that relate to quality? (Not a rhetorical question.)
Careful with evaluating headphones. They are VERY tricky to evaluate precisely because they can be very revealing, but are much under the influence of what's driving them.
I've had headphones on my head for at least 3 hours every day since 1966, so I can honestly say I am well versed with them. In addition to which I always have a small collection at home ready to use.
Currently, this small collection consists of a pair of Grado SR-80, Koss Pro 4AATi and Sennheiser HD598.
The Grados were a gift out of the blue and my first meet with any Grado product. I found them to be very good in context of price, and much to my surprise, different from all other Grado cans I encountered, even the $1k ones. Different as in much better, far better voiced, other Grados are far too midrange for me, and well at the cost of bass and treble, colored so as to impress in the first 5 minutes at a dealer's place.
Koss ProAA4Ti keep all of the traditional Koss virtues, but are better tonally balanced than for example the older Koss Pro AAA from the 70ies - the same old profound bass is there, but it no longer dominates, it just participates with a quality mid and treble. Unfortunately, the headphone "housing", the frame the cans sit in, is of exemplary poor manufacture. It's robust, but is sqeals and sqeaks like a stuck pig, and I see Koss failed to notice that 35 years had gone by and today people prefer smaller and lighter cans. If you can live with the poor packaging, the sound is on the very good side, and for the money, it's a steal.
Sennheiser 598 finally do away with Senn's traditional brightish sound and give us a very well balanced sound at long last. The details you can catch with them is scary, but they manage to avoid being bright, pushy and "analytical" and go for just plain natural.
HOWEVER, much of what I've mentioned you will NOT hear using a typical setup, which is either thath !"#$%&/()= voltage divider in integrated amps and receivers, or even dedicated headphone amps in many devices, built around an op amp. You will need a quality headphone amplifier, in my case, my own:
True dual mono, custom 30 VA toroidal transformers, shunt regulated power supplies, fully complementary topology, SEPP output stage using 50W Motorola/ON Semi MJE 15030/15031 devices. Hand matched transistors throughout.
Since I am deeply convinced that much of the spatial information is lost through general system channel imbalance, I also installed a Stere/L+R switch - flick it to L+R position, use the balance control (Alps Blue) to adjust for the perfect middle on your head, which covers the entire signal path up to your ears and your ears, flick the mode switch back to stereo, and enjoy the world of pure class A sound. Hear what you never knew was there in all its glory, and you do not need those 1k phones for all the fun.
John, the general topology is very similar to your HCA-1205A amp, with two differences: 1) no input cascode stages, just simple differential pairs, albeit with very low noise Siemens BC 550/560 C trannies, and 2) no compensation caps at all, with some empty holes left over where they were supposed to be (RC for the first stage, C for the second). I assumed I'd need them, but it turned out that I don't need them at all, not one of them, and it's still hitting 1.6 MHz without the input filter at 10 V rms output, which is a first order with -3 dB at just over 400 kHz. Proper DC servo. Pure silver wiring for signal inside. 70 micron copper tracks. 20 dB overall NFB. The works.
I should also add that my above auditioning comments were made also using one of my own power line filters, which I use by default (surprise!), specifically this one:
All my audio, video and PC is hooked up via three of these.
I've had headphones on my head for at least 3 hours every day since 1966, so I can honestly say I am well versed with them. In addition to which I always have a small collection at home ready to use.
Currently, this small collection consists of a pair of Grado SR-80, Koss Pro 4AATi and Sennheiser HD598.
The Grados were a gift out of the blue and my first meet with any Grado product. I found them to be very good in context of price, and much to my surprise, different from all other Grado cans I encountered, even the $1k ones. Different as in much better, far better voiced, other Grados are far too midrange for me, and well at the cost of bass and treble, colored so as to impress in the first 5 minutes at a dealer's place.
Koss ProAA4Ti keep all of the traditional Koss virtues, but are better tonally balanced than for example the older Koss Pro AAA from the 70ies - the same old profound bass is there, but it no longer dominates, it just participates with a quality mid and treble. Unfortunately, the headphone "housing", the frame the cans sit in, is of exemplary poor manufacture. It's robust, but is sqeals and sqeaks like a stuck pig, and I see Koss failed to notice that 35 years had gone by and today people prefer smaller and lighter cans. If you can live with the poor packaging, the sound is on the very good side, and for the money, it's a steal.
Sennheiser 598 finally do away with Senn's traditional brightish sound and give us a very well balanced sound at long last. The details you can catch with them is scary, but they manage to avoid being bright, pushy and "analytical" and go for just plain natural.
HOWEVER, much of what I've mentioned you will NOT hear using a typical setup, which is either thath !"#$%&/()= voltage divider in integrated amps and receivers, or even dedicated headphone amps in many devices, built around an op amp. You will need a quality headphone amplifier, in my case, my own:
True dual mono, custom 30 VA toroidal transformers, shunt regulated power supplies, fully complementary topology, SEPP output stage using 50W Motorola/ON Semi MJE 15030/15031 devices. Hand matched transistors throughout.
Since I am deeply convinced that much of the spatial information is lost through general system channel imbalance, I also installed a Stere/L+R switch - flick it to L+R position, use the balance control (Alps Blue) to adjust for the perfect middle on your head, which covers the entire signal path up to your ears and your ears, flick the mode switch back to stereo, and enjoy the world of pure class A sound. Hear what you never knew was there in all its glory, and you do not need those 1k phones for all the fun.
John, the general topology is very similar to your HCA-1205A amp, with two differences: 1) no input cascode stages, just simple differential pairs, albeit with very low noise Siemens BC 550/560 C trannies, and 2) no compensation caps at all, with some empty holes left over where they were supposed to be (RC for the first stage, C for the second). I assumed I'd need them, but it turned out that I don't need them at all, not one of them, and it's still hitting 1.6 MHz without the input filter at 10 V rms output, which is a first order with -3 dB at just over 400 kHz. Proper DC servo. Pure silver wiring for signal inside. 70 micron copper tracks. 20 dB overall NFB. The works.
I should also add that my above auditioning comments were made also using one of my own power line filters, which I use by default (surprise!), specifically this one:
All my audio, video and PC is hooked up via three of these.
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Years ago a composer ex-friend said "I just don't understand why you don't get these AKG headphones. I'm going to get them (he hadn't heard them, merely read about them) because I like to get up in the middle of the night and work on music, and I don't want to disturb S___".
Now this man was famous for "I just don't understand why you don't..." sorts of challenges all the time. Since his technique for acquisition of anything expensive was to call his mother and wheedle out the necessary funds, he was often difficult to bear. As his ex-wife recently characterized him, "the most self-centered person in the world". I'd enlarge that classification to include "and probably this galaxy".
He mentioned that a particular mail-order retailer had them, discounted. I said OK I'll order a pair. There was a stunned silence on the line, and I got a call back later saying "make sure to tell them that I'm going to buy a pair right away as well!" So I called them up and ordered two pair of AKG K1000s, as the same man had sent me his Roland electronic harpsichord, having agreed to sell it to me, and I figured this would be tantamount to paying him most of what we'd agreed upon for it. The 'phones had been show samples, and initially they didn't come with the complete cabling, so I had to fabricate some of it initially (eventually they located them and sent).
When I told him I'd done this purchase for him, he was furious --- this wouldn't do at all, tax purposes, warranties, blah blah blah. So I canceled one of the orders. Then a while later he reneged on the sale of the harpsichord, which had by then become unavailable. No, this was not when he became an ex-friend, although it would have been one of many appropriate times.
I got the 'phones. Serial # 04255. They were remarkably good and remain so. A bit hungry for voltage but easy to drive from a small power amp. When I realized that there were some surface-mount resistors inside I contemplated taking them apart and "upgrading", but I saw a piece somewhere about the innards and their fragility, and thought better of it.
I also bought those Grados for a friend who's now in a rest home, along with a budget CD/MP3 player with a front panel level control. My expectations were not all that high, considering a total outlay of ~200$ US, but the phones seemed adequate at the price, and I hope the man figured out how to use the player, and that his granddaughter-in-law brought him some of his CDs --- I have to check back. Tupp deserves a system. He was classical A&R at Capitol/Angel for years, also as a very young man Alfred Wallenstein's personal assistant when Wally conducted the LA Phil.
Brad
Now this man was famous for "I just don't understand why you don't..." sorts of challenges all the time. Since his technique for acquisition of anything expensive was to call his mother and wheedle out the necessary funds, he was often difficult to bear. As his ex-wife recently characterized him, "the most self-centered person in the world". I'd enlarge that classification to include "and probably this galaxy".
He mentioned that a particular mail-order retailer had them, discounted. I said OK I'll order a pair. There was a stunned silence on the line, and I got a call back later saying "make sure to tell them that I'm going to buy a pair right away as well!" So I called them up and ordered two pair of AKG K1000s, as the same man had sent me his Roland electronic harpsichord, having agreed to sell it to me, and I figured this would be tantamount to paying him most of what we'd agreed upon for it. The 'phones had been show samples, and initially they didn't come with the complete cabling, so I had to fabricate some of it initially (eventually they located them and sent).
When I told him I'd done this purchase for him, he was furious --- this wouldn't do at all, tax purposes, warranties, blah blah blah. So I canceled one of the orders. Then a while later he reneged on the sale of the harpsichord, which had by then become unavailable. No, this was not when he became an ex-friend, although it would have been one of many appropriate times.
I got the 'phones. Serial # 04255. They were remarkably good and remain so. A bit hungry for voltage but easy to drive from a small power amp. When I realized that there were some surface-mount resistors inside I contemplated taking them apart and "upgrading", but I saw a piece somewhere about the innards and their fragility, and thought better of it.
I also bought those Grados for a friend who's now in a rest home, along with a budget CD/MP3 player with a front panel level control. My expectations were not all that high, considering a total outlay of ~200$ US, but the phones seemed adequate at the price, and I hope the man figured out how to use the player, and that his granddaughter-in-law brought him some of his CDs --- I have to check back. Tupp deserves a system. He was classical A&R at Capitol/Angel for years, also as a very young man Alfred Wallenstein's personal assistant when Wally conducted the LA Phil.
Brad
PS: Does anyone know the values for rbb' for the popular BC devices like the 560? I could work it out from noise figure plots. Very few manufacturers mention these values unless making a big deal about them, although I noticed ON Semi actually included it, even as a plot showing the weak dependence on operating point.
Agree that knowledge of the speaker s THD would be insightfull ,
but in this case it doesnt matter since the methodology i used
is to keep the output power constant and modify only the amp s
THD content.
So starting with no amp distorsion , there s only the speaker s
THD eventually.
Then the amp is trimed to produce higher levels of THD,
but still for the same output power, that will add to the speaker s THD.
As i said , whatever the speaker s THD , increasing the amp s
THD is audible at levels of 0.1%.
Glad to see DDV has hit on that what makes a great preamp just happens to look like a great can amp. Properly executed, it does both.
I like my Grado's , but I also like my 80s vintage Yamaha's. Grado's are relentless in detail, but the old Yamahammers are comfortable to listen to. Like an old sweater. The problem with good cans and an amp is it is really clear how poor the source material is.
I like my Grado's , but I also like my 80s vintage Yamaha's. Grado's are relentless in detail, but the old Yamahammers are comfortable to listen to. Like an old sweater. The problem with good cans and an amp is it is really clear how poor the source material is.
Hi,
As I said, your graph shows 0.5% THD not 0.1%, second your result is valid only at around 80dB SPL and only for a specific distribution of harmonics.
Change the variables and audibility changes.
Ciao T
As I said, your graph shows 0.5% THD not 0.1%, second your result is valid only at around 80dB SPL and only for a specific distribution of harmonics.
Change the variables and audibility changes.
Ciao T
Hmmm.
When I read things like that I just think "Peaky upper midrange" or possibly "An abundance of higher order harmonics". The former is what I think I hear in the Grados, I don't know if the later applies to dynamic transducers.
In that case it was while testing an amp before and after TMC
was implemented , to see if THD distribution was to change.
As already said the graph doesnt say that it was the audibility
threshold of THD , in fact it was audible at levels way below 0.5%.
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