[Gariver]

Thank you very, very much, Pete! It's just fantastic to have one of America's finest tube-amp designers helping out a bunch of newbies. We really appreciate your input here! The same goes for Mr Joseph Lau, designer/manufacturer of ASL amps. His input here is also appreciated very, very much.

 

[88Sound]

This thread is Great! IMO the RKV Mark II sounds excellent with the K1000, full bass, like a great pair of speakers so.......

These are the applicable RKV spec's, based on the previous posts could you tell from looking at these specs alone that the RKV would be a good candidate to power the K1000's?

power output: each channel 3 watt SINUS, ( between 100 and 400 ohm loads ), bandwidth: 15 - 100 000 hz, damping factor: 3600 !, distortion 0,002 % at 1 Watt-200 Ohm load, maximum output voltage 80V, IC - fullautomatically - controlled bias, class-A


Regardless of the answer I sure like what I hear!

 

[Gariver]

You left something out: The RKV's output impedance is 0.06 Ohms. That's an extremely low Zo! So when you use the K1000s with the RKV, the bass is full, not thin. So there's no need to use a subwoofer next to you.

I got that figure by using a damping power of 3,400, and I used it at 200 Ohms. So the right way to state output impedance is...

RKV's output impedance = 0.06 Ohms at 200 Ohms.

You can do your own calculations with the info in this link...

http://www.transcendentsound.com/am...t_impedance.htm

Mr Millett's quoteo on source impedance...

"Part of the confusion here is understanding that source impedance is NOT the same as the rated load impedance. Almost all amplifiers designed to drive speaklers have rated load impedances of 8 ohms (and sometimes 4 or 16 ohms), but that is NOT their output impedance. Their output impedance varies between damn near 0 for many SS amps to 8 ohms or so for some tube amp circuits."

"This also relates to the term "damping factor", which is a ratio of the load impedance to the source impedance. A high damping factor, at a given load impedance, means a lower source impedance."

*

 

[Orpheus]

Pete,

hey... thanks there. i sent your map design to several people already!--can't get anyone to build me one though.

but your response was very helpful. i had a talk with my amp's engineer about all the info i got from this thread. he was starting get pissy at my though... so i might just tell him to shove his amp up his donkey now. i personally hate to buy equipment from people who think they're doing you a favor, but since they are selling to you at too low of a cost think that they can yell at you, as if you're not one of their higher-paying customers. bad attitude.

anyway... i am sure Pete's response was helpful to many.

 

[mikeg]

Pete - Thank you for your wonderful explanation. Although I'm not yet technically knowledgeable enought to understand most of it, I will retain it, and restudy it as I learn more. For now I'm enjoying my K1000 connected to the 16 ohm speaker terminals of my ASL AQ-1005DT, and the sound is rich, and the base seems sufficient, and appropriate to the music.

 

[Joe Lau]

Quote:

Originally posted by mikeg In accordance with advice from techical reps at Divergent Technologies Corp., and at HeadRoom Corp., I connected the K1000 headphone to the 16 ohm speaker terminals of my ASL AQ-1005DT amp. The sound is wonderful, but really no better than when connecting this headphone to the 8 ohm speaker terminals of the ASL Wave monoblock amps.

Try connect to 4 Ohm or 8 Ohm not 16 Ohm. May be K1000 need more lower impedance not Voltage Swing.

 

[Gariver]

Hey, Mike: What don't you understand? I'll give you another view.

Part of the confusion around here is this: Some people confuse output impedance with the speaker output impedance (4, 8, 16 Ohms etc.). Mr Millett made the difference clear. When he says that amps that work well with the K1000s must be under 7 Ohms, that's an amp related specification stated as Zo (output impedance), not a speaker related specification.

This problem indicates that we need other, different words to make the difference readily apparent. It's like having a Bulldog and a Poodle, but not having the word Bulldog and Poodle to show the difference. So they are just dog and dog. Hmm...no wonder it's so it's hard to understand.

I got rid of some of my doubts and misunderstandings with Pete Millett's post. I was not sure about 300B SET amps. I mean, I thought they did NOT have enough power for the K1000s. Pete cleared my doubts. He said 300B amps with 8 watts per channel can power the K1000s. He actually recommends them. Great!

Here's a super-duper Ohm's Law Calculator...

http://www.markhannahsurplus.com/ohmslaw.htm

*

 

[mikeg]

Thank you Joe Lau and Gariver.

 

[Orpheus]

got the Tube City 300BC today:

http://www.tubecity.net/amplifier.htm

and oh my god... this thing is huge!!!... weighs in about 48 lbs. though size isn't necessarily a measure of performance, i'd say you'd definately be getting your money's worth with this baby! it's so big for my desk that i had to turn it sideways to fit! (my friends are gonna laugh... this amp is almost 2x as big as my 1000 watt Hafler amp... and it's only being used to drive some headphones!)

...and it has the coolest indicator lights. the front two tubes that glow green in the picture are actually some kind of strange level meter! the green light actually moves around while the music plays. so cool!

how does it sound?--well, what can i say--it sounds like what a $2500 amp should sound like. the noise level is very low... there is an infinitely small amount that you could barely barely hear if in a dead quiet room witht he k1000's.... but otherwise i'd say they are pretty much silent. compared to my solid state Monarchy SM-70, it does take a little harshness out. sounds beautiful. i was expecting some roll-off of the bass and treble compared to the sm-70, but the bass is if anything louder and more full. the treble isn't missing either... but the harshness is gone. awesome.

...there are some little things that make this unit even more cool: it has a switch that lets you use 300b or 300bxls tubes (though i dunno how they compare.) also, the volume knob is huge!--it's stepped... though since this unit outputs 15wpc, the volume stepping is perfect for the k1000s. and it's really solid, you gotta really put some strength in that thing to turn it. the front panel looks wood in the picture, but is actually marble!

everything about this amp seems very high quality and heavy. definately worth a listening.

...the seller also included some Sophia 300B mesh plates, and a bunch of NOS tubes, including a Valvo rectifier. i'll try them out later after i've used the original tubes for a while.

orpheus

 

[darkclouds]

congrats Orpheus!!!

I saw that on Audigon for a very nice price. With the Sophia, you will not be looking for a tube upgrade, which is an excellent bonus.

 

[msjjr]

I fully agree with the Sophia mesh plates.
Check out this shootout for the review.


http://www.enjoythemusic.com/magazin...ent/1201/300b/

 

[wallijonn]

The Crown D60 lists Nominal Output Impedance (Zo) of 0.01 from 1Hz to 200 Hz, 0.02@1KHz, 0.16@10KHz and 0.2@20KHz. The damping factor is listed as 800 from 1Hz to 100 Hz, 350@1KHZ and 23@20KHz. The input impedance is 25K ohms. Hum and noise is 106 dB below rated output. Harmonic Distortion is less than 0.001% from 20Hz - 400Hz, and increasing to 0.05% at 20 KHz at 28wpc into 8 ohms. Slew rate is 6 volts per microsecond. The manual states that the output impedance is less than 15 milliohms in series with less than 3 microhenries.

all I know is that I like the way it sounds on my AKG K501 and K1000. (Greg says he doesn't want me to compare it to his SAC. And I told him that that is fine with me as this is one case where I want to remain in ignorant bliss). And, yes, I have heard his SAC. To me, this sounds better. (I keep repeating this to myself about a million times a day. Eventually I'll really start to believe it

).

 

[mikeg]

Quote:

Originally posted by Joe Lau AV-8 and AQ1005 DT is design in difference topologies and have fifference type of sound. AQ1005 DT - More detail , better mid range due to it is SET , Zero feed back. AV-8 - Push/Pull design - More Dynamic and more extend High but it is get by more over all feed back , So it mid range can not compare with AQ1005 DT. AV-8 have high over all feed back and it benifite on lower output impedance and better damping. It may be good for AKG1000. Rem : You should use 4 Ohm Tap on AQ1005 DT to drive AKG1000. It will get better performance. It is hard to sell AV-8 in low cost due to parts cost increase in the past. EI 6BM8/ECL82 price increase to double due to it stock is not much now. May be We use too much EI tube in the past.

I respectfully disagree that the AQ1005DT is superior to the AV-8 for AKG K1000 headphones. My tests show no difference in sound quality. Although there may be a difference in sound quality heard through speakers, this difference is not apparent to me with with the K1000. As for using the 4 ohm speaker terminals of the AQ1005DT for driving the K1000, I tried it tonight. I found the sound quality to be very inferior to that obtained when connecting the K1000 to the 16 ohm speaker terminals of this amp. Connecting to the 8 ohm terminals yielded a sound quality that was better than that obtained from connecting to the 4 ohm terminals, but somewhat inferior to that obtained from connecting to the 16 ohm speaker terminals. The contrast between the sound produced from connecting to the 4 ohm terminals versus the 16 ohm terminals is as follows: the sound from the 4 ohm terminals lacked fullness, was excessively laid back, unpleasantly analytical, and somewhat disjointed; the sound from the 16 ohm terminals was rich and full, more forward, wonderfully warm and musical, and with beautiful tonal balance. I hope that these descriptors, which I got from a recent Head-Fi note submitted by Vertigo-1, are helpful. Throughout my previous comparisons of the AQ1005DT to the AV-8, which I reported at the beginning of this thread, I connected the K1000 headphone to the 16 ohm speaker terminals of the AQ1005DT.

 

[mikeg]

Quote:

Originally posted by Joe Lau Try connect to 4 Ohm or 8 Ohm not 16 Ohm. May be K1000 need more lower impedance not Voltage Swing.

Connecting the K1000 to the 4 ohm speaker terminals of the AQ-1005DT produced much inferior sound, as compared to using the 16 ohm speaker terminals. Please see my detailed response that I submitted at 11:13 PM today in this thread.

 

[mikeg]

Quote:

Originally posted by msjjr Mine is the Antique Sound Labs AQ1005 300B DTI. I'll have to check the exact impedance. My AKG's don't connect to the speaker binding posts but through a separate circuit into a balanced output. I have heard them through the same amp at 120 ohms and they don't sound as nice at all. Much improved soundstage and imaging with the correct impedance.

How or who adjusts this impedence? How does one get this separate curcuit?