[discretesound]

discretesound - do you mean the transformer hums?

Im not to sure. But the hum comes from the amp itself and the longer it runs the louder it gets.

 

[discretesound]

Mine is very quiet, did you check the tubes to see if they are working properly?

I've tried reconfigure the tubes and change some of the tubes and the outcome still the same

 

[SleepyOne]

Likely the transformers - check your main voltage (using small electric meter), if it is too low or too high it can cause the transformer to make the buzzing sound. My DAC too buzz depending on time of day (voltage veries). Best give Craig an email to double check nothing amiss.

 

[Anathallo]

Mine hums as well - it's subtle, but definitely audible.  I was going to shoot Craig an e-mail if it continues, or if it is a voltage issue coming out of the mains.

 

[discretesound]

I send my amp back to craig so he can do all the check. I measured my voltage and it doesn't seem to fluctuate much. The hum gets pretty loud after a while and it tends to get very annoying.

 

[LindseyTopper]

I like to use powered "near-field" speakers.  I like the Dynaudio which are about $1,300.00 for the pair.  If I was limited to $1,000.00 or less, I would get the NHT Mini 100.  They are not being produced anymore.  You could probably get them for under $600.00 and even less used.
 
Lastly, you could get Audio Engine speakers which could be had for under $500.00 per pair.  The NHT speakers are really great.  The Audio Engines are incredibly popular.  They look good and sound good.  The best in this group are the Dynaudio's, but you pay for it.

 

[tme110]

I finally got to see (and hear) a S7 a week or so ago.  Very nice.  Even after looking at all the pictures over and over, it was much larger than I was thinking and man was it heavy!  Nice amp.  too bad it was at a meet though so I couldn't do any real listening with it.
 

 

[ctemkin]

tme110's posting reminded me that I hadn't posted some observations of my own.  It was my S7 he saw and listened to, and it was nice meeting him and the others at the DC area meet.
 
Some of the people there had brought an HE-6 and and AKG1000, neither of which I had ever listened to previously.  We tried them both on the S7 out of the speaker terminals.  I listened to each briefly. 
 
I thought that the HE-6 sounded excellent; I did not pick up on any of the flaws, such as a shrill treble, that others have said occur when this headphone is underpowered.  Of course this may have been in part because the tube set I have was designed to bring out the bass and take the treble down a notch on my HD800s.  The owner of the HE-6 said that he liked the sound, but did not think that volume through the S7 was sufficient.  He obviously likes to listen a lot louder than I do. 
 
I wasn't that keen on the AKG1000, but perhaps that was because the listening experience is different with speakers that distance from your ears, and I am not sure that I had them adjusted optimally. 
 
I also got to hear stats for the first time, and they were not too shabby.  Justin was there and brought 3 BHSEs, along with, I believe, one 007 and two 009s!  I thought they were great.  I got to listen to Grumiaux's Tchaikovsky's violin concerto (which I brought) and to Di Meola and others in Friday Night in San Francisco (which Justin brought).  Great air, great tone of the instruments, absolute quiet background.  I unfortunately did not have an opportunity to A/B the stats with my HD800 on the S7, because whichever I listened to, there was always someone using the other.  I have to admit that I am very intrigued by the stats, and I would like to follow up further.  However, while there may indeed be sonic differences that I could easily pick up on if I listened to one phone and amp and then the other combination immediately afterwards, each playing the same passage, I did not get the impression that there were major sonic differences or that there was a huge difference in how enjoyable it was to listen to one versus the other.  I think that is an excellent showing for the S7.

 

[kiertijai]

@ctemkin  My S7 is coming and I would like to know the tubes that you are using for the HD800
any recommendations of the tubes for LCD3 and other?
Is it also good for the high sensitive phones like Grado and Fostex TH900?

 

[tme110]

I can say that I loved the S7 and his tubes with my Grados.  I liked it with my grados better than I liked it with my lcd-2 but I'm sure that was the tubes.
 

 

[ctemkin]

kiertijai,
 
For the driver and four output tubes I am using Sylvanias that are marked JAN-CHS-6SN7W in green lettering on a black plastic base.  The bottom mica is below the top of the base.  The remaining two output tubes are KEN-RADs that are marked JAN-CKR-6SN7GT in sort of gold lettering on a black base.  They have staggered plates.  I first tried all Sylvanias, but using the two KEN-RADs added a little more bass to the HD800s ( even with all Sylvanias, the bass was very considerably improved in comparison with the Apache) and took a little edge off the treble.  I found this combination to be just what I wanted, and so I didn't feel the need to try other tubes.  I also have not gotten around to finding a set of tubes that will work well with the LCD-2.  I like the LCD-2 better on the Apache than on the S7 with my current set of tubes, which is not to say that the right set of tubes would't change this.  If I were to get tubes for the S7 for the LCD-2, it would be to boost the treble (it is rev 1) and in effect make it sound more like an HD800, but since I have an HD800, and since I doubt that different tubes would provide the LCD-2 with the HD800's soundstage, I haven't seen the point in continued experimentation.  Much earlier in this thread, as I recall, Anaxilus and others have made specific recommendations for LCD-2 and maybe other phones.
 
Best of luck.
 
ctemkin

 

[kiertijai]

@ctemkin   thanks so much for your valuable suggestions.
    I may not have all those tubes but I do have similar tubes.  I think I will try the Sylvania 6SN7W metal base
and KenRad VT231 for the HD800 as you suggested, I think they should be similar except the bass may be
a little more.  For the LCD2 I think I will use the Tungsol 6SU7GTY or the Tungsol BGRP to improve the treble,
any suggestions would be much appreciated.

 

[minimus]

I have done a fair amount of tube rolling in my Super 7 to dial in the LCD-2s. I highly recommend using a 6F8G with an adaptor (readily available on eBay) in the front position. National Union, Raytheon, RCA all sound very good. My top pick is the National Union. I have tried Tung Sol round plates, but don't like that tube as much as the others, which are much cheaper than Tung Sol. By the way, Craig "blessed" the 6F8G when I asked him for tube recommendations...and I think he uses the LCD-2s to voice his amps.

In the other positions, I like RCA 6SN7s better than Sylvania. The RCA's seem to have better bass and transparency. That said, rolling the 6 output tubes has much less effect on SQ than rolling the front position input tube.

 

[LindseyTopper]

Try using Dynaudio or NHT mini-moo powered speakers.  I love the Dynaudios and am even considering another pair.  They have dual 50 watt amps in each speaker cabinet for woofer and tweeter.  I currently use a Peachtree I-Decco to regulate the volume out of the preamp and get the use of a very cost effective DAC.

 

[Anaxilus]

Quote:

That said, rolling the 6 output tubes has much less effect on SQ than rolling the front position input tube.

 
That's correct.  Think of the three tubes per channel as one big 6SN7.  Each tube change will only effect the output stage to a minimal degree.  If the input tube is the engine, think of the output tubes as the intake, headers, exhaust, etc.