kevin gilmore

that is the seriously shrunk down version. The real thing costs a lot more. I would be happy to tell you the real cost, but as usual i don't have the faintest idea

pens?? Did someone say pens?? http://gilmore.chem.northwestern.edu/pens.jpg Including 2 vintage 14k solid gold cross pens (the fat boy and the one next to it) A sterling silver mont blanc, and 2 sterling silver watermans. Plus a whole bunch of 1940's vintage resin pens...

Board is 4.95 x 5.40 inches, 302 holes. I'll take 5 boards please...

The dynafet has that slightly sweet almost tube like sound that only fet outputs can have. But because of the drive circuit it has the balls of no other fet output amp i have listened to. If you want to buy one, you will have to find someone willing to build you one. And as usual there is a whole bunch of different ways to build this thing.

prototype works absolutely fantastic. Latest board layout at headwize.com in the thread. I have not had the time to verify that final layout completely yet. Sure would help if someone with much younger eyeballs would look at it and make sure it is correct before i spend $500 on boards.

the line outputs certainly go thru the tube and a pair of fet outputs so there will be a definite sound to those outputs. It is unclear from the schematic where the tape outputs are wired to http://gilmore.chem.northwestern.edu/melos.jpg

The $600 would be my price. You heathens would have to pay significantly more Its the reason god invented goy's. Someone has to pay retail...

Bet you all can't guess one of the things i'm going to do with this thing... http://gilmore.chem.northwestern.edu/bxrayn1.jpg http://gilmore.chem.northwestern.edu/bxrayn2.jpg http://gilmore.chem.northwestern.edu/bxrayn3.jpg http://gilmore.chem.northwestern.edu/bxrayn4.jpg 3 times the flux and 16 times the resolution. At this point i'm pretty sure i can take pictures right thru the outside case without ever taking the thing apart

The ground channel as used in the aria is very different from the ground channel used in all of the other 3 channel versions. It actually has -(L+R) as the signal as opposed to a buffered ground. Very different kind of thing. Think of it as an attempt to boost output voltage from a lower voltage power supply. A bridge amp of sorts. Of course if you do balanced all the way you don't need an active ground channel. Some believe that the ground channel shunts power to the other power supply rail instead of poluting ground. My opinion is that the 3rd channel just decreases the damping factor and really offers no other benefits. So 4 channels is the way to go. I've never seen a set of real headphones that cannot be wired for balanced. (iem's don't count)

I evlauated this exact circuit almost 4 years ago when i was trying to do a portable on a lower voltage power source. It just can't cut it. Especially for music where there is a lot of in phase mono present. (like a single female voice) The ground channel works even harder, and since it drive 2 loads at the same time, it work worse, not better.

Lets see, $5000 phono preamp, no painted over chips here Lets see $2900 apache balanced headphone amp, no painted over chips here either $900 HR2. nope, no painted over chips. XP7..... why only the sr71,hornet and tomahawk? Maybe ray was pulling a headphonia?? seems like you have to spend at least $500 to get honest product. I got this brand new apex2 xray coming in less than 2 weeks. 16 times the resolution of my old unit. You get me ray's permission and i'll post the metalization pictures...

no billy you are just plain fucked up. A high res Xray of the metalization layer complete with the manufacturer identification is all that is needed to identify a chip. And when ray says it ain't so he is just a fucking liar. pardon me, i have to go to my best friends funeral tomorrow. Not going to take shit from billy today.

With respect to the second quote, there was a lot there that i left unsaid. The people who know what i'm talking about obviously know what i'm getting at, and the people who don't are going to have a hard time figuring it out. That way the hammer is not so obvious. I have never had a problem with commercialization. For a 15 year period i was an exhibitor as part of quad electroacoustic at the CES show. I know more about the politics of that kind of thing than you will ever know.

those are heatsinks for the output transistors.

Krell made a wonderful headphone amp about 10 years ago. It was called the ksa25. Very few were made, it was something like $4k then. Atma-sphere makes some truely wonderful amps that drive headphones very well, kind of pricy. Don't see levinson (as in harman international) ever coming up with a headphone amp, they have enough trouble selling their current stuff. Conrad-johnson, vtl, rowland... that would be some nice stuff.

quoting granodemostasa Example 1: The B52 was one amazing product. I didn't like it to start with, but after hearing it on Billy's system I grew to have much respect for it as one of the top headphone amps out there. The apache wasn't the same. On the same piece of music, on the same headphones, the apache sounded like it had some amount of glare and "TV" around the music that seemed so clean and pure on the B52. Is anyone surprised at this. Ray said it himself numerous times. The thing is 2 x HR2 in one box. So he took a 10 year old headwize design with a class AB output stage and cramed it in one box for a price of somewhere between 2400 and 2900. Then he added a 1 opamp buffer as the preamp output. Its not a preamp, no remote control and no tape loop. And as a balanced headphone amp it has to be god awful. Evidently ray is aiming at the cordoba crowd. Corinthian leather. Its all about looks and the marvelous build quality. Screw the sound. Example 2: The new singlepower SS amp. For 1700 dollars i sort of expected an amplifier in the same performance range as the 1600$ zana deux, but instead i got something less than that. it was more or less equal to a balanced desktop and an apache, as opposed to belonging to the B52, dynamight, and Max balanced crowd. Surprise Surprise. At least it is supposed to be all discrete and mosfet output stage. But who knows... Example 4: the gold plated Maestro XLR- I really expected to hear the world lifted to a new level. instead i got fuzzy imaging, big power, and a particularly "singlepower" tube sound. It was good, just not the upgrade i'm looking for. mikhail needs to give up on the white cathode follower with put put tubes thing. For something that is that much money it could at least have been turned into an extreme with real output tubes. Then mikhail produces this miniature thing with no ventilation holes and people are telling me that it runs 30 degrees hotter than a raptor. THIS IS NOT A GOOD THING. Where is that talking heads album... burning down the house This commercialization thing is producing some amazing high priced junk.

One of the biggest and emerging problems is the head-fi international meet. Vendors are now virtually required to have new products at this show and are now driven by this yearly thing. So instead of coming out with rational new products when they are ready, many things are hurried along, sometimes putting current customers on the slow track so that more time can be spent coming up with new product that may or may not make any kind of financial sense...

time for a flyback line switcher i think

Now if we can just get those old high voltage mercury batteries, then the thing truely would be portable...

finally someone with a brain and the correct answer. However on some directly heated triodes the thoriated material on the fillament is actually quite toxic and known to cause cancer. Getter material is not very good for you either.

One will be a commercial amp, can't speak any more... The other is a bamaslama, you gotta build it yourself. (evidently a number of people have done so) Seeing the latest pictures you should be able to build a mcalister yourself. Its not possible to do any worse of a job....

My guess is that jason would like the singlepower extreme with 6as7's a lot. In which case there would be 2 more amplifiers that he would like even more.

first of all for completeness the numbers above are for unbalanced output. balanced output numbers slightly higher. Just for comparison (actual real numbers tested by me and i'll put my money where my mouth is) All numbers are 1 volt rms output. raptor 120 ohm load 106 ohm raptor 32 ohm load 32 ohm B52 (balanced) 120 ohm load 101 ohm B52 (balanced) 32 ohm load 30.6 ohm (this was a surprise as i thought it would be higher) singlepower white cathode follower with 5687's (can't keep track of model numbers) 120 ohm load 103 ohm 32 0hm load 31 ohm singlepower cathode follower with 6as7 (called the extreme) 120 ohm load 29 ohm 32 ohm load 18.2 ohm dynalo .3 ohm output impedance, 16 to 300 ohm load dynahi .13 ohm output impedance, 16 to 300 ohm load

Into 32 ohms the output impedance is 28.5 ohms Into 400 ohms the output impedance is 150 ohms

With a 120 ohm impedance headphone the small signal spice calculates the output impedance as 79.9 ohms.