[NotoriousBIG_PJ]

At the first toronto meet we listened to a highly moddifed ASL AQ-1005DT power amp with k1000's and a bunch of other headphones. I don't think anyone thought it was the best can used with the amp. I know my friend and I really liked the rs-1's with the amp and some liked it best with the r-10. ZZZ complained about the harsh highs of the k1000 with the amp, which was certainly smoother then the stock version. All I know is I felt like a serious dork with them on.

Biggie.

 

[mikeg]

According to Mikhail, the SDS is not appropriate for powering a K1000 directly. So, I have not, and will not try it. My observation of improvement was based on contrasting the use of a powered preamp (the SDS) for driving my power amp., versus my previous use of a high quality passive preamp. It's possible, of course, that use any powered preamp. will result in a dramatic improvement in the fullness of sound of the K1000. But, I have not tried any other powered preamp.

Quote:

Originally Posted by mikeg When I first encountered the improvement of using the SDS as powered preamp, I contacted Mikhail and asked for his opinion. From what I recall, his explanation was that the improvement in base, clarity, fullness, etc., were to be fully expected contributions of the SDS unit. As I understood Mikhail's explantion, the fine qualities of the SDS that accrue to any headphone that's connected directly to it, are also "passed through" to units connected to it, when it's used at the preamp. that drives these units. I should add that the Passive preamp. that I previously used (i.e., the ASL Passive T2) is really a high quality one, and yet, it's performance does not match what I get by using the SDS as powered preamp. Mikeg, would you say that it's the SDS that's really making the difference in what you're hearing and if it were possible to use the SDS as direct amplification to the K1 you might get the same results?

 

[mikeg]

As for possible impedance-matching issues when connecting the ASL Passive T2 preamp. to the ASL AQ-1005DT power amp., I don't think that there are any. I conclude this because the technical rep. at Divergent Technologies (which are the North American outlet for ASL) told me that the Passive T2 unit was a perfect unit for driving the AQ-1005DT power amp. He said that use of this combo is even superior to the latest ASL integrated AQ-1005DT unit. Since I'm taking his word for it, I assume that use of the SDS to control the power amp is as good as I'm likely to get from the K1000, which of course is outstanding sound.


Quote:

Originally Posted by jpelg Perhaps Mikhail (or anyone else familiar with the SDS topology) can elaborate more specifically on what the SDS is doing when acting as only a preamp, as in this case? What tubes are in the preamp-only chain? What/How much amplification is taking place to the signal when passed thru the preamp-only chain? Also, are there impedance-matching issues with the "passive" ASL preamp that are being corrected using the "active" SDS instead? (anyone?)

 

[mikeg]

It would be interesting to know what kind of preamp was connected to the AQ-1005DT power amp. at the meet. As for driving an R10, and an RS-1 with the AQ-1005DT, I have done so routinely with the RS-1, and more recently with the R10. Although these cans sounded fine when connected to the AQ-1005DT, they sound better when connected to the SinglePower SDS. BTW, the RS-1 sounded somewhat better when powered by the AQ-1005DT, than when driven by an RA-1. One more thing. A special ASL transformer unit needs to be connected between the AQ-1005DT and the R10 and RS-1; i.e., these headphones should not to be connected directly to the speaker terminals of the power amp.

Quote:

Originally Posted by NotoriousBIG_PJ At the first toronto meet we listened to a highly moddifed ASL AQ-1005DT power amp with k1000's and a bunch of other headphones. I don't think anyone thought it was the best can used with the amp. I know my friend and I really liked the rs-1's with the amp and some liked it best with the r-10. ZZZ complained about the harsh highs of the k1000 with the amp, which was certainly smoother then the stock version. All I know is I felt like a serious dork with them on. Biggie.

 

[Mastergill]

mikeg, I'm not surprised. IMO/E a "powered" preamp as you said will always be better than a passive one. IMO again, passive preamp sucks. You may think the signal path is simpler, cleaner and more transparent, but you need the high gain, the headroom, only active preamp can give to achieve a full bodied* and punchy sound.

Everything is important in an audio chain, but i like thinking of a preamp as the heart of the audio system and not only because it switches different sources.


*Is that an English word?, not sure lol.

 

[NotoriousBIG_PJ]

Quote:

Originally Posted by mikeg It would be interesting to know what kind of preamp was connected to the AQ-1005DT power amp. at the meet. As for driving an R10, and an RS-1 with the AQ-1005DT, I have done so routinely with the RS-1, and more recently with the R10. Although these cans sounded fine when connected to the AQ-1005DT, they sound better when connected to the SinglePower SDS. BTW, the RS-1 sounded somewhat better when powered by the AQ-1005DT, than when driven by an RA-1. One more thing. A special ASL transformer unit needs to be connected between the AQ-1005DT and the R10 and RS-1; i.e., these headphones should not to be connected directly to the speaker terminals of the power amp.

The aq-1005dt I am talking about was moddifed into a headphone amp. No preamp was used.

Biggie.

 

[mikeg]

The only way that I was able to power regular headphones (e.g., the R10 and RS-1) with my AQ-1005DT power amp. was by using an ASL UHC-Signature headphone adapter with it. This device is connected to the 8 ohm speaker terminals of the power amp., and these regular headphones are then plugged into it. The K1000 is simultaneously powered by connecting it to the 16 ohm speaker terminals of the power amp. As for the modification that you describe, I have no idea what was done to that AQ-1005DT. It could be that the modification enabled it to somehow drive the regular headphones, but it may have detracted from its performance when powering the K1000.

Quote:

Originally Posted by NotoriousBIG_PJ The aq-1005dt I am talking about was moddifed into a headphone amp. No preamp was used. Biggie.

 

[mikeg]

Your observation regarding the use of a powered preamp. is exactly the same as mine. And, your description of the result as a "full bodied and punchy sound" is very apt.

Quote:

Originally Posted by Mastergill mikeg, I'm not surprised. IMO/E a "powered" preamp as you said will always be better than a passive one. IMO again, passive preamp sucks. You may think the signal path is simpler, cleaner and more transparent, but you need the high gain, the headroom, only active preamp can give to achieve a full bodied* and punchy sound. Everything is important in an audio chain, but i like thinking of a preamp as the heart of the audio system and not only because it switches different sources. *Is that an English word?, not sure lol.

 

[meech]

Mikeg,

Does the AQ1005 have 4 ohm taps? Stevieo said that he got better results using the 4 ohm taps than the 8 ohm taps of his Dared amp.

 

[NotoriousBIG_PJ]

Quote:

Originally Posted by mikeg The only way that I was able to power regular headphones (e.g., the R10 and RS-1) with my AQ-1005DT power amp. was by using an ASL UHC-Signature headphone adapter with it. This device is connected to the 8 ohm speaker terminals of the power amp., and these regular headphones are then plugged into it. The K1000 is simultaneously powered by connecting it to the 16 ohm speaker terminals of the power amp. As for the modification that you describe, I have no idea what was done to that AQ-1005DT. It could be that the modification enabled it to somehow drive the regular headphones, but it may have detracted from its performance when powering the K1000.

I happen to own a aq-1003 moddified to a headphone amp the same way as the aq1005 was. That amp had a special connector just for the k1000 so if anything there was a performance gain vs. tapping the speaker outs. I know my amp does not detract in anyway from driving speakers.

Biggie.

 

[Soundbuff]

I'm really intrigued by the K1000. I am hesitant to order one because it does look like it might be uncomfortable for long sessions. I've read it's heavier than most phones. To those who have one, is it a headphone you can wear for hours, and does it press hard on your temples? Can you lay down on a pillow with it or is that just impossible?

I wonder if you can get the same great results using it with a regular headphone amp like the MG HEAD OTL 32 or Grace 901 (both of which I have read can handle the AKG K1000) - or do you really need something truly huge to get the best results from the K1000s?

 

[mikeg]

Yes, it does.
Quote:

Originally Posted by meech Mikeg, Does the AQ1005 have 4 ohm taps? Stevieo said that he got better results using the 4 ohm taps than the 8 ohm taps of his Dared amp.

 

[mikeg]

I've got some distressing news. For the first time, a few hours ago, I connected my K1000 to a $15 (yes, fifteen dollar) Portable T-Amp. I powered this little amp with a Radio Shack 13.8 volt 3 amp. power supply that cost about $38. The signal (i.e., music) that I fed this amp. was from the pass-through loop of the SinglePower SDS amp. Well, the result is amazing. The sound produced by the K1000, when driven by this little inexpensive amp., is amazing. The difference is very slight, as compared to the sound produced when the K1000 is connected to the AQ-1005DT. I need to do more testing, however, and I'll get a good chance to do so tomorrow morning. Guru (i.e., gsferrari) will visit me, and will do some critical listening to my various systems. I'll leave this hookup to the $15 amp. as is, for Guru to test when he get here. I'm sure that he'll produce some interesting comments for our Head-Fi group. As for questions of comfort when wearing a K1000, I can wear it for several hours without undue discomfort. But, I don't think that it's practical to lie down with it. IMO, it fits too loosely for that.


Quote:

Originally Posted by Soundbuff I'm really intrigued by the K1000. I am hesitant to order one because it does look like it might be uncomfortable for long sessions. I've read it's heavier than most phones. To those who have one, is it a headphone you can wear for hours, and does it press hard on your temples? Can you lay down on a pillow with it or is that just impossible? I wonder if you can get the same great results using it with a regular headphone amp like the MG HEAD OTL 32 or Grace 901 (both of which I have read can handle the AKG K1000) - or do you really need something truly huge to get the best results from the K1000s?

 

[Yikes]

K1000’s RULE!!

Comfort: I find them the most comfortable phones that I have ever used. The fact that they don’t touch my ears is a huge factor. I do not find the pads on my temples to be a problem. The one down side is that you have to be upright to listen. With the K1000’s they’ll be no lying about, that’s why I have my HD-600’s.

They don’t absolutely need a megabuck amplifier to drive them. My choice is the affordable ASL MG Head OTL/32. The combination works extremely well together. I would however not consider using an inexpensive solid-state amp. When I tried using an inexpensive Rotel or NAD amplifier the results were a little less than satisfactory.

I’m not a fan of passive line stages. One issue with passive line stages is that the capacitance of the interconnect cables interacts with the input impedance of the power amplifier, basically becoming a tone control. A passive line stage (no such animal as a passive preamp) tends to sacrifice dynamic drive power and pacing. It’s why the best systems always use a separate preamp. Even when using a source that includes an integrated volume control I would still use a high quality preamp.

IMHO

 

[Edwood]

Quote:

Originally Posted by gsferrari I agree that they are sensational headphones. But not too many people can fork out $700.00 for a pair. Also - finding the right amplifier is an ordeal.

Holy crap! The price of K1000's has gone up quite a bit lately.

-Ed