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I *might* be getting a 2nd cat, have a call with the breeder shortly:

A little T2 tube rolling goodness

Great time with Al & Steve! Good food, great friends, incredible fall scenery and I do believe the three of us wore Nitro out.

This old XRCD: Reiner and Chicago Symphony Orchestra, Tchaikovsky: 1812 Overture

Essential phone is only $299 ($499 without) with friends and family code from previous buyers until mid December. Very similar specs to the Pixel XL and they've fixed most of the original camera issues on release. 2560x1312 5.71" 504 ppi bezel-less edge to edge IPS display, unlockable bootloader, practically AOSP Android, Snapdragon 835, 128 gb storage, module compatibility, 7 hr on screen time before charging, Bluetooth 5, no branding on outside, certified working on all carriers. Savage good deal. Pixel 2 XL display is already having burn-in, bad angles, and grain/banding after 2 weeks. Ouch.

Time for some impressions of this rare beast. The Icelandic distributor has a set on loan and they carved an entire afternoon out of the schedule for me to try it and do some comparisons. I showed up with the HE90 I built from spare parts, Aristaeus, Carbon amp and a port modded SR-007Mk2. Since they were using the built in dac on the HE-1, I just plugged both amps into as well to equalize the comparison. Over all, I like the build quality of the headphones. Imagine a HD800 built properly and you are pretty much there. The leather earpads are super nice and the headband has nice extension to even fit my large melon. I don't think they are super comfy though as they are fucking heavy (550gr) and all of the pressure is on the top of the head. The Stax 4070 is just about as heavy but far more comfy due to the suspended headband design. The earcups get a bit warm due to the internal amps but only about 5-7°C above ambient. The cable is also pretty nice and not microphonic at all but more on the amps etc. later. Amp itself...well it is just fucked up. I get that they were trying to cater to some nouveau-riche people who just want something expensive but the wank factor is off the charts. I also have serious doubts about what's hiding in that nice marble shell... As for the headphones them selves... well the drivers look pretty much identical to the HE90 units and the few pictures of them that exist, point to that. I wanted to rip off the earpads to check further but people get antsy with something this expensive... One worrying thing I noticed though is that both sides of the drivers have porous dust covers. They look identical to the woven nylon found on the HE90 and well...I would expect solid covers. Now for some actual impressions. As I said above the HE-1 dac was the source for all the amps. To that you have to turn off the headphones so no direct comparisons were possible but I know how both systems should sound so not a big problem there. The source feeding the HE-1 was a Macbook Pro running itunes but I bypassed that with my own FLAC files and player. There are some major changes compared to the older system, this one can do bass and isn't as horribly colored either but over all...I was not impressed and the system never made me really interested in the music. It doesn't engage like a good 007 system can, where I sometimes just sit in awe even after owning a set for all these years. Here, it just doesn't pull me in. This is clearly a midrange issue as there just isn't enough presence there. First off the major issues are the bass, treble and the soundstage. Let's start with the bass, it has this annoying hump to it sort of like the old Lambdas. I'm not sure if this is the mosfet driver (could be, the Cavalli crap boxes have similar issues) or the headphones but it is a clear coloration and once you notice it, just annoys the fuck out of me. Now on some tracks it wasn't as noticeable but always lurking in the background none the less. Next up is the treble...which is both subdued and bright at the same time. I know plenty of people complain the 007's lack sparkle and with the Mk1 this was mostly true but they could be bright if the source called for it. The HE-1 manages something different, the treble is just flat and boring but then it suddenly bites hard. Now I was listening at higher levels but still nothing super loud, only about 12 o'clock on the dial. This also wasn't like the upper midrange bite of the 009's, more lower treble fizz but the source material didn't call for this. I'm so used to listening to SR-X Mk3 Pro drivers now (which are pretty much the gold standard for treble) as they are in my DIY headphones and nope, nothing like this. I suspect the amp is a huge influence here too but no way to verify that... Last major issue, the soundstage. Many will know my stance on the old HE90 where it sounds like you are listening to some people playing in dense fog and you can't quite make out where they are. This time around it is much improved but the lack of pin point accuracy is still apparent. The soundstage is also a bit too far away for my liking and it just doesn't throw the same huge headspace the 007's can. This also affects the midrange and the whole "disconnected" feeling I got from the whole system. I once reached for my phone as I was just a bit bored listening to it. Over all I like that Sennheiser built this but they really should have spent more time on the electronics. I don't think there are any improvements to moving the amps to the cups over something like the Carbon where I can burn 50+W as heat and overcome the small capacitance in the cable. Next post will discuss the tech specs of the system but I'll end with another picture of it all... It was really dark in there and I suck at taking pictures... Now for some technical discussion. I found the specs in the back of the manual and it turns out the bias is 650VDC and the amps run at +780VDC. This makes this more than compatible with Stax so I see no issue with removing the internal amps and rewiring one of these for Stax use. I have been asked to that before but I'm really hesitant to mess with something this expensive. That said, moving to proper amps which are not just the HEV70 rehashed can only be an improvement. I've never found any mosfet device with sufficiently low Cob to work in this role so I truly don't get what Senn were thinking. Some other info, the entire amp only consumes 40W per the user manual which doesn't leave a lot for the actual amps. So we have 8 tubes running with heaters plus all the motors in there. HV supply for the tubes, another for the output stage and well...not a whole lot of power to spare here. Compare that to the BHSE, Carbon or even the T2. All of them use far more power and it is just for one goal, to power the headphones. I also played around with the amp and I could swear that the volume control feels like a RK27. No way to know but how it felt when moving to the extremes...it was just like a RK27. Now as a proper volume control aficionado... ... they all feel a bit different. TKD feels nothing like a P+G or a RK50... Until somebody opens one of these up, take it how you will. It is also clearly a volume pot and not a chip or some other setup.

post the build sheet for your 911

Extension cord -- 1000 euro a meter. Paint job -- 5000 euro. Senn really testing what the market will bear ...

Dear friends, Amb.org is currently down due to a problem at the ISP. Unfortunately it is taking a long time for them to fix it. I’m very upset that it has taken so long without resolution, and it appears that it will be down for maybe another several days. The level of service I’m receiving from their customer support has been abysmal. Meanwhile please be patient as I work with the ISP to restore the connectivity. I apologize for any inconvenience this may have caused. -Ti

Yes, amb.org is back online.

HS

Thanks again, jose. I just wanted to document here the ground loop breaker circuit that I think you were referring to. It seems to have worked well for me.

I've copied BH zener regulated PS to use for a DTH 45 (ignore the B+ delay/FDA217, I got an unpleasant thump).

Thanks Birgir, that was an awesome impression and comparison for what efforts you went through.

Fish and chips @

A tale of two Als. Had a very nice dinner in the park with the Als. Al (Voltron) grilled sausages and asparagus, and we had my macaroni recipe. And Al (aimless1) brought his beautiful dog Nitro.

Finally found (Friday) a connector that leads directly from my local trails to my backyard. I am happy. Not that riding the 3/4's of a mile to the trailhead on the road was an imposition compared to having to drive but it's nice to be able to jump on the bike and hit the woods instantly.

Visiting Brits this weekend, so playing tourist. Went to the top of Mt. Tam, Saw San Francisco / Bay Area views I can see Skylark / rancho borago / Fairfax from here

a true balanced differential amplifier will have significant common mode rejection. For example there are a few well known diy dacs that have a bit of dc on their output. a differential amplifier will subtract the dc from the inputs and the output will be free of dc with respect to ground. a balanced amplifier made from 4 x unbalanced input amplifiers will have significant dc on the output. For headphones wired as balanced, no problem. For headphones wired as single ended, could be a big problem. supersymmetry dynalo and dynahi are true balanced differential amplifiers. So is the RSA darkstar (although it still sounds like shit) schiit joutenheim is a balanced differential amplifier (actually its an instrumentation amplifier) but has significant differential gain when used with a single ended input. liquid gold, liquid carbon, gsx are not balanced differential amplifiers. The first two have phase splitters to fix the problem. the gsx is balanced out only when you have a balanced input signal.

Test Tone @ Home live right now: http://mixlr.com/illuminator/chat

6c33 output tube for the win

Looks like significant price reductions on what is probably NOS. Nothing new from ray in a few years. also I really like this one, complete lie from day one. The amp is not differential. Its 4 x single ended amps same as liquid carbon. no common mode rejection... and one of the worst phase splitters ever

They have arrived! The builder got the color exactly what I wanted and was able to match the trapezoidal shape of the speakers perfectly.

I see, and thank you so very much for the quick respond and the confirmations. This explains the 7812 which supplies the relay load is regulating 12.1V and then drifting to 12.65V and down to 12.16V again I fired her up again and measured the HV together with the Bias, and ignore the -16.5V as I have no load to put it on. +12: 12.01-12.1V -12: -16.75V Low Bias: 276 High Bias:: 565 +500: +496V -560: -555V -260: -242V -500: -494V I also tapped into the Relay supply for the Led indicator to avoid tapping into the regulated from the output....but I guess it doesn’t matter since the LT7912 tends to overshoot without loads ? the Led is only an indicator and not a functioning switch