[jimbobuk]

I've been trying to find some information on the frequency response of the HE60/HEV70 system, along with any reviews.. Just for something to read about whilst i listen to my new set. Google didn't throw up much but it did bring up this review

http://www.hifichoice.co.uk/archive/...rintreview.htm

from the mid 90s i think. One bit in particular interests/concerns me

Quote:

It's the treble that betrays this Sennheiser, being less refined than that of Sony and Stax rivals in this comparison. There's clear evidence of a very-high-frequency in-band resonance revealed as vocal sibilance with some performances, and as a phasey edge that can be detected with many recordings - rapid phase shifts are associated with high-Q resonances, and the audible effect can be a comb-filter type of phasiness. The effect lent an uncomfortable edge to Jennifer Warnes's voice, and a squeaky, slightly metallic overlay to orchestral strings. Percussion suffered most, sounding coloured and coarse.

What do people think of this, could they even try to explain it a bit clearer as i don't really know what rapid phase shifts or high-Q resonances are

I've not heard anything untoward as yet.. if there is such a problem had bad is it, what recordings (CDs?) show this up, and is it a physical resonance or an issue with the HEV70 doing the driving?

Cheers

 

[Hirsch]

Essentially, the review is describing the flaws in the HEV70 amp. It's got a bit of grain in the highs, and can sound sibilant. That edginess doesn't happen if the HE60 headphone is used with a different electrostatic amp.

 

[jimbobuk]

thanks, the current combo will definately keep me happy for now, but i will have to look into alternative amps for it sometime perhaps. If there are any floating around for people to test/compare/review i'd definately appreciate a chance to try one out

 

[Edwood]

The HEV70 definitely has phase issues.

-Ed

 

[sgrossklass]

I'd also have found it strange if the rather large HE60s exhibited a fairly strong resonance in the highs. The Q factor can be defined over which percentage of energy is lost during a cycle, thus a high-Q resonance would be a hardly dampened one. In open headphones, for example, you try to make the back as permeable to sound as possible, to reduce the Q factor of any resonances that might build up inside the enclosure behind the driver. Metal mesh seems to work better than plastic grilles here. (Remember the HD500 mod? OK, these cans were intended to be semi-closed - i.e. closed only for bass -, which kinda failed, at least if you look at sonic balance in stock form.)

 

[jimbobuk]

Quote:

Originally Posted by Edwood The HEV70 definitely has phase issues. -Ed

How so, and what does this mean?

What type of music creates this phase issue problem so that i may try it out myself.. is a particular tone required, a particular instrument or frequency range.. I know of phase from wave theory (in and out of phase for constructive and deconstructive interference) along with the whole burn in speaker solution by switching the polarities of two speakers so one is "out of phase" with the other in theory canceling each other out (with deconstructive interference) and meaning you can burn in speakers (strictly i guess only with a mono source) loudly without creating loud volumes.. I understand the theory of that but its never worked out whenever i've tried it (with stereo material, perhaps that was the problem)

sgrossklass thanks for your answer, it helps a little but i still don't GET it beyond the idea that you're agreeing with Hirsch that such a problem shouldn't be a feature of the headphone, rather the amp..

Another thread and more headfi searching is needed but hearing what the best alternative HE60 amps are will be something to try sometime. I know i found a thread where i think lan was saying that he had modded his HEV70, but he didn't use his HE60's at the moment, also that he'd heard the popular amp alternatives and none agreed with him.

 

[jimbobuk]

eeek when you quote a thread it puts the thread nested with the thread you quoted.. don't know whether i like that as its made my post's comment about sgrossklass's reply a bit funny, coming before the actual post.

Is the forum being upgraded to this new system, in theory i dont mind the view at the top of the post.. if it didn't do this nesting it'd be fine, is there a way to disable it on a per user settings basis?

 

[sgrossklass]

Quote:

Originally Posted by jimbobuk eeek when you quote a thread it puts the thread nested with the thread you quoted.. don't know whether i like that as its made my post's comment about sgrossklass's reply a bit funny, coming before the actual post.

Choose "Linear Mode" under "Display Modes" - better?

 

[jimbobuk]

yes, thanks

 

[Zanth]

Quote:

Originally Posted by Hirsch Essentially, the review is describing the flaws in the HEV70 amp. It's got a bit of grain in the highs, and can sound sibilant. That edginess doesn't happen if the HE60 headphone is used with a different electrostatic amp.

Yep I agree. In fact, with the KGSS, I find the Omega II's can have more sibilance than the HE60's using the same amp.

 

[jimbobuk]

What are the options for getting a HE60->stax adapter so that you can use the KGSS, or Stax SRM-007t amps?

There the only two options for driving a HE60 really aren't they?! The KGSS confuses me a little.. can you only buy them from one place or is that a type of amp (like meta42) that is built by many people?

What's the best place to buy the KGSS and Stax amps from?

 

[Hirsch]

Quote:

Originally Posted by jimbobuk There the only two options for driving a HE60 really aren't they?! The KGSS confuses me a little.. can you only buy them from one place or is that a type of amp (like meta42) that is built by many people?

Any of the Stax amps can drive an HE60. The KGSS is a design that's open to anyone to build. www.headamp.com is probably best known for a reliable and good sounding implementation of the design. SinglePower has an electrostatic amp available, and I believe a company called McAllister builds one, although I've never heard either (somebody correct me if I've got the name wrong for McAllister, or whoever makes that amp). So, there are several options for an aftermarket amp for the HE60.

Eric343 made some HE60 adapters, although I don't know if he has them anymore.

 

[cosmopragma]

Quote:

Originally Posted by Hirsch (somebody correct me if I've got the name wrong for McAllister, or whoever makes that amp)

Mcalister.

 

[Veto]

Rudistor (Italy) also makes electrostat amps, although not that many people
have heard them.
They seem to have an office in the UK maybe handy for you.

http://www.rudistor.com/soundsystems/electrost.htm

 

[jimbobuk]

Thanks guys for the linkage.

I don't think Eric343 is making adapters any more.. he was selling off some of the parts needed to make them i'm sure in one thread.

So everyone who talks about their KGSS is talking about the standard solid state amp, or the hybrid one??! Again they have two knobs for left and right channels.. the HEV70 has something like that to a point, i've yet to try altering it as i think it sounds about right already.. at least it turns both at the same time in normal use, seperate dials would frustrate a little bit, though i know most people manage easily enough.

I've heard of Rudistor amps.. never heard anything about their electrostatic range.

To be honest the SRM-007t amp has one thing going for it, that its formfactor looks a lot smaller than all the others.. i like that the HEV70 is small too as i dont think i have the rack space for the bigger (and heavier?) amps, where as the 007t doesn't look that much wider than the HEV70, if a bit taller.