spritzer

I don't think anything is going to fail but things to look out for, noise in the headphones with nothing playing, bad connection where the cable meets the earcups as that is a known failure spot on the early Mk1's and the condition of the earpads and the headpads as the earpads wear out and on the really early Mk1's the headpad disintegrates. As for the amp, take the top off and look at the silver getters on the tubes, if they aren't nice and silver I'd swap out the tubes and if one is milky white...you need new tubes. I would also blow all the dust out of the amp as it can short out the amp but that's about it.

....so I bought one of these. They popped up on Massdrop while I was talking to Kevin who immediately called BS on this. My curiosity peaked, I had to get one. Here is the product page: https://www.bursonaudio.com/products/supreme-sound-opamp-v5i/ BS meter is tingling so I waited for it to arrive: Nice enough box and here are the internals: I forgot to take a picture of the top but it looks exactly as it did on the page. Here is the bottom though: The potting compound is pretty soft so here is what I found: So... the only thing in there is an opamp with the top markings sanded off and one small cap. There is nothing on the bottom, just this. We have no idea what opamp that is but it would be pretty simple to dissolve the resin and look at the die. I very much doubt this is some custom one off unit, why would they sand off the top if it was some custom device? Also, why is that cap there? I mean this is a dual opamp so two channels and two power rails...why one cap? This reminds me of the Single Power tube adapters, they had parts for just one section of the dual triodes...why I just don't know.

I'm running mine right now off a Carbon so no issues.

Hifi+ and Absolute sound, same company and the same level of utter garbage. I buy them from time to time just to laugh at all the inaccurate shit they print. They don't check anything so they might as well be the PR agents for the manufacturers.

Yes, I think that was the first one. I can't find the schematic with a quick search but it should be here somewhere. Then we had the SRM-1 Mk2 first version in 1982 but in reality, most of that improvement had already been done to the later SRM-1 amps. It's fun to open those up... you never know what you are going to find.

Well it is a Hifiplus review so not even useful as toilet paper...

Other than laughing at his badly made crap for years, nope. I was the first one to take the original Jade apart and reveal the crap it was but that hardly counts as it was over a decade ago. Funny enough, the cable used on the original Jade is superior to the one they use now, gotta love "progress".

You can't look at the bias in a vacuum as it's the max potential of the entire system. Here, there is a certain range but it always depends on the drive voltages. If they go to high, you will arc the system. You can tell in the extreme cases but not really. Maybe with an electron microscope or something like that...

Shit... it's close to a decade... The imbalance on those sets is usually just due to the age of the phones and/or possible damage over the years from the SRD boxes. Basically, the normal bias sets could be easily overloaded by the transformers which caused arcing. Also sunshine is ultimate enemy of electrostatics as it breaks down the diaphragms over time.

They are ok and pretty well built. You can easily use them with an adapter though the cable is pretty short as they foresaw some sort of portable usage I suppose. The bass is pretty limited due to the small drivers. If you are keen on one, I have mine for sale on my site with a Stax adapter... Shameless plug but my better half really wants me to have a "sane" number of headphones...what ever that is.

I do wonder how many of these would be plugged into normal amps and short them out if they hadn't reversed the plugs...

It just means Stax are sneaky fuckers...

Happy to help.

I have a rather large oak bookshelf modified for audio use (i.e. liberal cutting of holes in the back) but I've used some Ikea ones in the past. They all seem to be out of production though...

What a hackjob of a cable!! Anyway... attached is the correct wiring from Sennheiser with one caveat, they wired them backwards with the - to the front stators. Stax do it the other way around. With a Stax cable, the line is the + pin, the middle wire is the bias and the last one is the -. So what I would do is take the line to the front stator (closer to the ear). Middle is the middle one and then the last one. he60pinout.pdf

That looks a lot like Ikea stuff to me....

Is tomato8 coming out of the woodwork? Clearly some shilling is needing to be done! Not a problem. I'll ask Kevin if he wants to rip this one apart...

I spot a Terminator dac...

I also don't think Fang really understands what is going to happen now. I'm going to track down a Shangri-la jr. amp no matter the cost just to rip it apart.

Lol!! Does he seriously think it works like that? Wow...just wow...

It's on Head-fi so I don't care

It's 100% stock and they are very bass light and diffuse sounding. I still like them though but I do wonder about the new Dekoni earpads for the HD series. Those might help but I haven't picked up a set yet.

That stuff is just too funny. So let's start at the beginning, 1k in series with the output is better than nothing (Cavalli, Woo, Kingsound etc.) but it should be around 5K. How 1K is similar to 5K and offer the same protection is beyond me. Does anybody at Hifiman understand Ohm's law? There are indeed two 2M resistors on that board. When I initially wrote that I had only looked at the amp board and was still trying to untangle the mess of this build. Still that should be 4.7M but 4M is close enough. Also, while the amp is very reminiscent of the SRA-10S... it does have the opamp input. You know what amp is based off the SRA-10S and has an opamp inputstage? The SRM-001... aka the 1995 portable amp. Yup there are some similarities there as well. So the output stage uses FQPF4N90C's as can be seen here: ...and the datasheet is here: http://www.mouser.com/ds/2/149/FQPF4N90C-195517.pdf Go down into Dynamic characteristics and there we have output capacitance, typical 65pf. So the headphones are roughly 130pf or so and you have two of these per driver. Yup, stellar job of keeping the Cob low. For reference, the 2SC4686A used in the KGSS and KGSSHV, 2.2pf. So the output capacitance here is just about 30 times higher. Same goes for what Stax have used for years. Also, notice the black cans on the source pins, those are inductors for some reason. Inductance and capacitive loads don't really mix, just look at the train wreck that is the Woo WES. For any laymen reading this, many know about the 10 times rule when matching sources to amps. The goal there is for the input impedance of the amp to be at least 10 times higher than the output impedance of the source. Same goes for preamps into poweramps etc. Same thing applies here, how do you think the amp likes driving the capacitance of the headphones when it first has to overcome its own output Cob? Bottom line, if anybody like JimL wants to take a look at the Jade2 amp, I'll send it to you for free. The only things I did to it was simplify the input wiring, as it makes no sense to go from the sockets to the amp PCB, then to the volume control, then back again. I also redid the earthing of the amp as it was very lacking for CE safety requirements. One more thing that amuses me endlessly with Hifiman is that familiar Chinese trait... victim hood. I still remember it well at Canjam 2010 when somebody gave Tyll a set of HE-5's (I think) to measure and Fang freaked out. It was his own personal set so he could do what ever he wanted with it but Fang did not approve. That speaks volumes about his character. I'm all for right being right but what about addressing the flat out lies in the specs, that a few parts were not properly soldered to the boards or that I'm sure the same crap applies to the 50K$ Shangri-La. They certainly use the same cable...

So I guess blue is the new black? I broke down and got a 009BK... I know I'm weak but we all knew this would happen. What's funny is that after 6 sets of 009's that have gone through here, these are a bit different. They are still bright and the bass is mehhh but they are not as bright as my other set and the bass is improved. Could be unit to unit variation but that's not the norm with Stax so I'm curios if they have updated the 009's a bit. More listening to come...

For me there is no comparison between Stax and Hifiman, I have my issues with the Stax amps as they desperately need to modernize them and for me, some of the headphones just sound "off" but there no denying the quality. Now the new Stax amps from China, D10 and D50, don't really fall under this as they are experiencing major issues.