I too thought that DK's official explanation of Class A versus Class A/B looked , at best murkey or at least somewhat confusing, as I even in light of this 'misinformation trail', purchased the DK itegrated amplifier.
Most audiophiles recognize that Class A is the description presumably, of an amplifier, running 'full out' which is to say, full power output, in order to eliminate the negative action, known as 'switching distortion'(from class A to class B circuitry) transistors.
Without getting into a major dispute here, the 'former regime' at DK, says that this amp, the Mark III, 'eliminates the issue of switching distortion'through proprietary circuitry, doing away with the switching distortion, therefore, it behaves like a Class A amplifier, without having the byproduct, too much heat.
Does this really happen?
Great question! I am an unabashed audiophile, who believes in 'potential versus measured greatness', so I am biased toward capability when measured against actual bench tested measurements. To explain, "If it sounds good, it's good, regardless of the measurements" and vice versa. I only know, in looking at the measurements, that without an empically complete scientific evaluation, that the 'square wave' input versus output for the Reference amp, looks 'almost perfect', if not actually perfect.
There is, as one looks at the ocilliscope reproductions of the amp, that it has, no 'time domain' signal delay, issues, as the amp reacts to the input signal instantly--also, no ringing, seen as 'overshoot' of the input signal. This is, perhaps the 'best' square wave representation that I have ever seen. Even the reviewer of the DK amplifier (Australlian Hi'fi") was non plussed, to the degree that he thought the amp signal was a 'null'or no actual signal, or the ocilliscope at 'idle', as what he saw, was perfect from a bench technician's evaluation standpoint.
This kind of 'square wave' replication is the 'holy grail' insofar as science meets sound is concerned.
I know that many, if not most amps don't recreate this kind of square wave from an input signal.
So, time function and amplitude function look perfect.
What does this portend,as it relates to output versus input?
The 'whole idea' of sound revolves around that very complex issue--which is, 'does the output 'look' like the input'?
In this instance, at one fequency, at least, the DK is, from a scientific, and measurement standpoint, with today's technology, 'perfect'.
Does it sound 'perfect'. Well, no. Nothing is absolutely perfect. But, does it sound really good? Yes! It does !
More important, it sounds 'musical', again one of those non scientifically graded, but all important, 'ear measurements' for the listener. This is a real chance to 'forget' the world of measurements, an area where the audiophile aready places his or her ears above the fray of measurements versus the so-called scientific data, and therefore 'above' absolute 'bench measure' testing.
Again, our ears out measure the bench.
I LOVE this site!
Larry R. Staples
DK Design/President/LSA Group |
Ctchen,
I would think that, owning a DK, with a tube preamp section--you may miss the 'warmth' that tubes offer in the overall sound.
To realize the value of tubes in the preamp section, one needs only to 'switch' the tubes for another brand or design to realize how much of the sound is dependent on the preamp section. The DK amp, depending on the tubes used, sounds completely different when the tubes are changed. If you can audition the Tact, you may, in fact, like it better. This is the point at which 'personal taste' enters the picture.
We have heard the Tact under non audition conditions, and recognize it as being a fine product--though very different than the DK.
I would again, recommend that, since we have tubes vs. a digital amp, you audition the TACT carefully-as the sound probably doesn't get much different than these two.
I prefer the warmth of having Telefunken Tubes in my unit--that doesn't mean that everyone will.
Thanks for buying a DK. Please, let us know what happens, and how this turns out.
Best,
Larry R Staples
DK Design |
Thanks for the kind words everyone.
All we want is a chance to prove that our company will do everything possible to make buying a piece of audio gear, a pleasant experience.
Mumum, I have been answering emails sent to the old home office during our transition. You would be surprised at how many people are searching for a real helping hand. Frankly it is gratifying to help the people writing in--and it's helpful to both of us. I get to see what people are asking, and saying, since it helps DK to move in the direction the customers want.
One of my first offical decisions, was to 'kill' the home theater piece which was close to production. Before you yell and scream, its not that I don't want the Surround Sound piece in our line--that is a very big market, and we want to have a product in that arena. It was, that the product in question did not make sense to me from a DK perspective.
The unit was 'all solid state'--and I think that people look to DK for 'Hybrid' electronics.
So now our engineers are working to make a 6 channel unit, with 6 channels of tube preamplification.
This will put us back some 3 additional months, and create additional expense. Am I being Polyanna? Was this a bad decision?
Time will tell. But my thinking was that, we have to remain true to our 'roots', and continually improve on the company, but not stray from our core competence and identity, which began as hybrid.
I have polled several of our larger dealers in an informal way--and they have supported that decision--don't think that some weren't disappointed about the delay. they were. But all of them agreed that the philosopy 'must' be maintained.
Any input from you guys on this?
We want to build what the select few audiophile/moviefiles want us to build.
I look forward to your comments--thanks again for the kind words.
Larry R. Staples
DK Design Group |
Mumum,
That was my thinking, a unit that would excel in both multi channel, or two channel music, as well as movies.
Plus again, being true to our identity.
Making a six channel pre stage will take some doing, and perhaps, because of it's physical size, two units, as in a pre and amp separates.
Whichever way we go, it will be a worthy successor to our Integrated, or we won't do it at all.
Switching is planned, as well as 'plenty of inputs'.
Send me your preferences on a unit like this, as we will try to hit 'most' of the preferences of our customers.
As I mentioned earlier, we exist to create what our customer base wants and expects from us, and at a reasonable price.
Best,
Larry
PS Send it to the DK site, and I will address any questions or suggestions that anty of you might have. |
Artmaltman,
We have two rooms at the WCES in Las Vegas, Room 2002 and 2004 at the St. Tropez Hotel, which is next door to the Alexis Park.
We have new products that we are introducing at the show, so it should be an exciting time for all of us at DK.
Thanks for your interest.
Larry |
No,
I have been in random contact with him.
His primary business interests were out of the Audio realm--he recently married, and I believe he consolidated his business efforts in an effort to lessen his work load.
Larry |
Dabarrie,
I switched the stock tubes in my first MK II, to the Telefunken. That is a good tube, but somewhat lean in the bass for my taste. (Let's face it--tubes allow us to revoice the system, allowing for speaker differentials). For example, a THIEL owner would most likely have a different tube in mind than a Vandersteen owner.
The Telefunkens I used when I had the Sound Lab A-1's, again were good, but not as musical as the Amperex ECC88/6DJ8, circa 8/1962, New Old Stock, and probably about $250.per pair. (Jim Dillon who works for Toys from the Attic, one GREAT STORE) sent me a pair as a wonderful surprise gift! They are really magic--nice sweet musical bass, space within space, great vocal presence, really nice tubes. Hard to find probably, but, again terrific.
We are breaking in an amplifier for an upcomming review,(at the reviewer's request), and he further asked for a second set of tubes, for comparison's sake. So this week end, Shari at the office, asked me to try the Siemens, of course ECC88/6DJ8, (she estimated that they were from the 1970's) priced at $110. MSRP. I am not impressed yet.
Everything sounds congested, with less space rendered. The bass doesn't go as deep as with the Amperex, and the midbass is disproportionately loud. Sounds strange, but that's what it's doing.
This is all on my LSA2's, (Standard, not Signature Speakers), which have output at 10Hz (down 14db but not cut off). The bass is peculiar sounding, again too loud in the mid bass, but less deep bass.
Overall, I would say that, if you can get the Amperex, you'll love them, (if your speakers are fairly neutral). Again, this can be thought of as a voicing tool, with everyone having a somewhat different 'flavor' in mind.
If you would like more info, call me 888 671 8607--I'll be glad to discuss your whole system.One other note--in Las Vegas, we switched to the Electroharmonix which cost about $10. or so a pair, MSRP. They are pretty good for that money--respectable midrange, no zing on the top (at least with our LSASE Amp, and it's active loads).
Tube 'sound' has to be weighed against the circuit it's in as well as the speakers--the whole system. So again, if you want to discuss, just call me--it's probably worth while.
Thanks, |
Dabarrie,
The Amperex allow my system to sound very organic. This is system specific though. As I mentioned, tubes will be viewed differently by listeners experiencing various interconnets, sources, cables, and most certainly loudspeakers.
To me, the most exciting aspect of tubes varying presentations, is that, depending on choice, some may be able to 'tame' one loudspeaker while another could even liven up another which may be too polite--therefore a potentially great 'tuning aid' for one's system.
Again, I prefer the Amperex for my system, even though they're somewhat expensive.
Good luck.
Best,
Larry R. Staples
LSA Group
President/Designer |
Actually saying that 'paying $250 a pair is unnecessary' is somewhat misleading.
Of course one can get poor quality, or what I consider to be throw away Bugle Boy tubes for the prices mentioned, from ebay or many other private sellers.
When buying from an individual, for example, on an ebay sale, one runs the risk of buying from someone who does not have measuring equipment. This could mean that the buyer could easily end up with sub standard tubes.
For example, to be considered an NOS tube, the MCDT must measure at least 65. This, I believe, is the minimum scale measurement to allow them to still qualify as NOS.
I am afraid that some audophiles may think that NOS (new old stock) actually means that the tubes are old but have never been used, which of course is not correct. Tubes can have gone through many hands yet still be worthy of the NOS rating, as calculated from the MCDT. These Amperex I was referring to in my post, in which I was addressing the question of which tubes I like, actually measure at 110/108 respectively. They are 6DGA While Label Tubes, and sound just terrific--that is what I was referring to when I said it was such a wonderful gift, and further that they were worth in the neighborhood of $250. Given their measurements, they could easily sell for that price, and be well worth that amount of money for a discriminating listener. |
Dabarrie,
Please be careful.
First bleed the amp down, (playing it softly, turning it off, to drain the power from the output).
Then turn off the rear rocker unplug it--remove the top plate--in the rear you will see two tubes, surrounded by 'rings'. Try to not touch anything but the tube itself!!!
Wearing gloves or using something to keep the oil from your hands from transferring to the tubes, gently, gently rock the tubes front to back, while pulling up gently. It will seem stuck, but will pull lose. Note the bottom pattern of the tube.
Take both tubes out--then put the tubes back in matching the patterns. Be careful, as the tubes are somewhat delicate-if you misalign the bottom you can bend them-worst case, break the tube.
This shouldn't happen though, just be gentle.
Plug the amp back in--let it stablize, by turning on the rear rocker switch, then wait about a minute.
Hit the front 'on' switch, and the tubes will cycle to power in about 30 seconds.
Don't make any evalutations for 24 hours--and I would leave the amp on constantly for the first day.
With our circuit, we feel that the tubes should have a life of about 10,000 hours playing hours.
Let me know if I can be of any further service.
As to the question of "how can they be called new".
I suppose that it depends on which 'expert' you wish to believe.
Recently, I have spoken to several 'experts' and each time was given different information about this.
The most compelling of the experts, meaning the one who appeared to know the most, (how can I know for sure)--told me that the definition of NOS was not that New Old Stock means New in the classic sense, but New as it relates to measured performance. He indicated that, if the tube,(regardless of ownership or use) measures at least 65, and it's old stock it can be considered to be NOS. This sounds counterintuitive to me also, but that was his explanation.
I welcome any 'experts' who sell or trade in tubes to give their definitions, as I don't pretend to know the right answer. Heck, I'm the guy who said that Amperex circa 8/62 NOS tubes retail for about $250. because that is what another 'expert' told me--and he's a tube dealer.
TVAD says they can be had for less than half that at virtually any time on ebay. While I would personally feel more comfortable buying from a tube dealer, (maybe that's who is selling on ebay), that's a choice for everyone to make on their own.
Caveat Emptor, as always.
Best,
Larry R. Staples
LSA Group
President/Designer |
Dabarrie,
Herein lies the reason the tube nay sayers exist (I guess for other reasons too)they can be delicate. Surprisingly, I have dropped tubes,just the other day, clunked them together and so on with no issues. Just bad luck.
As to Shari--what a jewel.
Shari worked for THIEL when I was with them--I knew of her terrific work. When I found out she was moving seventy two miles west from Lexington to Louisville, I asked her to work for LSA. SHE IS TERRIFIC!!
"...prefers THIEL or LSA speakers". You guys are evil!HA!
She's in Florida right now, her father is having health issues..she'll be back Monday.
Best,
Larry |
