Anders

I am also skeptical of cryo treatment but now remember something I have read about it. It is an accepted method to increase the strength of metal but of course this is not the same as better sound. Another use of cryo treatment is to increase the durability of thin synthetic materials. According to the article, some women leave expensive brand stocking for cryo treatment because they last 2 - 3 times longer after treatment. So treating electrostatic film could possibly be an advantage.

I am not sure we are talking about the same thing. I bent the metal arc above the headband so the distance between the earcups decreased and the pressure against the ears/head increased (similar on what you do on a Grado). Rotating the earcups is something I have done all the time.

Wow, it helps to bend the arcs! Tighter bass and more presence.

Thanks spritzer, I will try to bend the arcs. I am not negative to the 007 at all, I think it is an excellent headphone and the best I have. Only some minor flaws that could at least party depend on user ignorance. It is not a headphone that is easy to use - a ten page user manual wanted. I have a 15 W tube amplifier (25 W in pentode mode). It has three huge transformer but the weight is only about 40 pounds. I understand that weight is necessary and positive but I have difficulty grasping that a headphone amplifiers has the double weight. Headamps BH is considerably lighter.

What is written in the threads is not audible. I was a little careless regarding model number, I have the 007 Mk 1. I don't mean that bass is insufficient in volume but it is sometimes a little uncontrolled and not tight enough. That is not easy to evaluate because the reproduction from most headphone / amp combos understate the deep and round content of bass and that is very well reproduced by the 007 Mk 1. But I still think that it lacks some control, tightness and could be more hard-hitting. I believe that the weak point is primarily on the amplification side and feel not sure if Mk 1 is the best alternative just now because amplifiers that are better than 717 are not available for the moment. But I have not heard Mk 2 (007A). My reluctance of headphone amplifiers with a weight of 80 pounds is philosophical rather than technological, but I am skeptical of the necessity.

It was just a glimpse of hope, it is always possible to fuck up with a design. An a second thought, it might weight 40 + 40 pound like WA5 and then I am probably not interested. Oops, it was only 35 + 40 pound lbs, at least for the light edition (LE).

I think the 717 is a very good amp, especially at used price. It is a neutral amp without any harshness or other treble artifacts . It has a very slight warmth but does not add any artificial warmth (with my Reimyo DAC). It will reveal source weakness but that must not necessarily sound bad if there is some synergy! My main complaint with the 717 is that it has somewhat limited output power and does not drive the O2 to its full potential. It drives HE60 and the 404's much better than the 007t amp and I think the 717 has fully adequate driving power for these headphones. But I still think that the 717 is very good with O2's but it is a little lacking in bass that is not hitting hard enough and too soft and uncontrolled. That also makes the overall presentation lacking some impact. I don't like the O2 with 007t although it works more or less well depending on type of music (hint: bass content). I think that 007t with Electro-Harmonix tubes sounded better with O2 than with 404 and HE60. The tube brightness was not so apparent with O2 as with the other headphones but I finally swithched back to Raytheon because the EH are too bright with the lesser headphones and to the extent I will use the 007t it will be with HE60 and Lambda type headphones. The somewhat eyuphonic character of the Raytheons can also be a nice complement to the much more netral 717. Both 007t and 717 sound better with the balanced input. I don't know if it depends on the amplifier design or that the balanced output on the DAC is better (my unbalanced cables should be at least as good as my balanced). The new Woo offering is interesting indeeed. The same output tubes as the Blue Hawaii should give it adequate driving power. Headamp electrostatic amps are currently unavailable (at least for most of us) and I hope Woo will make a really good amplifier. But the 717 should definitely be the best value for money.

Thanks, I have saved it with pictures for future needs, need not worry so much about my Mk I and can sleep a little better

I second that, you get used to the measurement and adjustments after a few times. But you can't do the same type of fast tube switching as in a self-biasing amp with tubes open on the top.

It can also be necessary to check and readjust the biasing after a while for new tubes because the can "drift like crazy" as spritzer said. So tube comparisons are tedious with 007t.

We may agree to some extent. I don't know how similar these two EH tubes are but there could be similarities. The 6CG7 lacks finesse and it is not silky smooth or something like that but it has a neutral tone and good extension. I like it much more on the SR-404 than on the HE60 where it sounds too harsh. The SR-007 could be better to use as a reference but I haven't got it yet. I have no definite idea of how long time it takes for tubes to burn-in and in some cases I have had other equipment that burned-in also and it is hard or impossible to isolate the effects. Maybe I have confounded and overestimated it but I have heard differences after 50 hours. There is a psychological aspect too but this also applies to other aspects of evaluating audio gear.

I just wanted to share my personal experience of the tubes, based on rather much listening with varying types of music, and not on a meet or something like that. Very shortly, that EH tubes are quite good and Raytheon lack in some aspects, in my experience and my system. In the beginning I was more positive to Raytheon, but still think it is very good. dvse, you want proof! I have never seen any proof on Head-Case but tons of opinions. Duggeh, you tweak it in quite another way. You say I am rude and therefore wrong. Next time I will be meek as a lamb and you have to accept the truth!

Becoming rude and bashing "wrong" opinions is not what I strive for.

You are probably right that this is the wrong forum for me, but for quite other reasons than you state!

I have those rebranded Raytheons and they are very good tubes with good dynamics and smooth and elegant sound. Much better than the GEs that came with the 007t. They are very smooth and warm from the upper midrange and up. Excellent tubes if you like that sound. I was also very pleased with for a time but the problem is that they tend to smooth out the music in a romantic way that not always comply wiht the essence of the music. My EH gold pin tubes are probably not fully burned-in (about 50 hours with music) and I don't know yet if I like them better or less than the Rayteons. They are more extended in the top and probably also a little in the bottom (the latter is not easy because I simultanously installed tube dampers). They need much burn in and sound very harsh and unforgiving during a phase. EH are more nutral than Raytheon but still a little to the bright side. If they calm down a little more I think I prefer them to the Raytheon. Tested with 007t, SR-404 and HE60.

Would that mean that SR-007 A/Mk2 is the the best buy now? I haven't heard them and it is possible that I would like the sucking stock A/Mk2 best. If not, I can mod it into a good sounding headphone.

Advertising has increased over the years so there is not much hope. If they withdraw this something else will come instead. My only question is if advertising is for supporting the site or if users are necessary for the advertising revenue.

Nice clarification, thanks!

Lately? So has it been for some years at least in the headphone forum, and it has spread over to other forums as well.

I wondered if really ALL references to Head-Case are deleted from Head-Fi so a while ago I mentioned Head-Case in a thread, in adequate context and not at as a flame war. It took only a few minutes until the post was edited and Head-Case deleted. I can understand that Jude dislikes this site but this taboo is going too far. I have some questions about amplifier design. I have very little knowledge in the field except some understanding of common terms. I am surprised about all the discussions on inferior design because amplifier design should be a well developed field of knowledge - at least as long as we restrict as too mid-fi and a bit up - maybe not the state of art. Could it really be a problem to make a good design of an amplifier for an engineer with expertise in the field? I thought that the real problem in manufacturing and business is to implement the design i a way that is cost-effective and develop effective marketing and distribution. Of course it takes time, but not really a technological problem. It seems that design and manufacturing of headphone amplifiers often are poor with bad principal design, low production standard and problems with reliability. Experienced DIYers can be more knowledgeable than commercial designers. Is the problem that production of headphone amplifiers to a major extent is an outgrowth of DIY and that not always the most suitable choose to start a business? Is headphone amplifiers a profitable market or are there simply too many enthusiasts? In my experience, it is very difficult to find adequate information as a ground for decisions on purchase. This situation is not unique for headphone amplifiers but I think it is worse than for other audio components.