The Stax thread (New) - Page 1371

There have also been QC issues with a few units here.

Yeah, I'll be auditioning it again before buying (more closely next time)...but to me it sounds pretty great. Should be hearing it's headphone amp again as well next time with HD800s and LCD 2.2s. 

 

Unfortunately the Line Magnetic has no headphone section. The wife isn't a fan looks wise of the Leben, but she likes the 'all in one' idea of it having a headphone amp. 

 

There were some new tubes in the 218 so that could've been part of the problem. We'll see. 

 

whenever I compare components I try to level match them.  For headphones I normally I play pink noise, place a sound pressure meter approx where my ear would be, and adjust gain until the headphones produce the same reading.  After I have done this the headphones have sounded subjectively at the same level except one case, when comparing SR-007 to HD800.  The SR007 always sounds significantly louder.  It seems my perception is  that SR-007 are 4-5db louder.  My theory is that the SR-007 seals more tightly though I don't remember this being a problem with closed headphones I tried a while ago. Any suggestions about how to do a better job without getting a manakin head and/or why my subjective is very different from my attempt at being analytical.

 

Random side note... wherever I place the mic inside the SR-007 I see a normal distribution of pink noise, within the HD800 depending on the position I see frequency bands that seem quite suppressed.

 

--Mark

 

 

I told a lady friend about this and she responded:

 

 

I wonder what that means?

It's not necessarily about 'listening' to her...It's about wanting her to enjoy music as much as I do. The 009s have made me feel a bit selfish over the last few months because the more head time they get, the more isolated I was being towards spending time with her. 

 

Also, it's sold already. Official once the wire come through. Didn't expect someone to drop that kind of cash this fast. lol

What kind of issues? I've heard nothing but good things about them build wise.

 

http://www.head-fi.org/t/575746/lebens-owners-request-what-i-found-inside-my-leben-cs-300x-limited

 

A few people had varying issues on this thread, the most striking is mwilson had serious problems with two separate units from his dealer.  If you're dealing direct with a dealer, they shouldn't be an issue to return if there is a problem, but it does say something about the state of their build quality/QC/what have you.  

This is a bit troubling, but I will be buying from a local dealer so any issues will go straight to him. He popped the hood for me last time I went and showed me the craftsmanship and it looked top notch to me. If I end up with one the first thing I might do because of this is pop the hood and make sure all is well. 

 

It's always hard to judge with companies that do small things like this because you get a few people with issues a year ago and there's no telling what's changed since then (for better or worse).

 

I also think mwilson just has really terrible karma in general. :D Clayton SF seems to like his experiences enough to have upgraded to the CS600 at this point. 

 

Thanks for bringing this my attention though. Any chance you have info on Line Magnetic's QC? :)

 

All I've heard about Line Magnetic is that its fairly priced and has surprisingly good build for a Chinese product, but I've never heard one of their amps myself. Its one of those things that just hasn't had enough exposure yet to hear both the good and the bad, you're still just hearing the great show reports and people who went to their dealers and were impressed, etc.  That doesn't mean its not good, but with new speaker amp companies I personally like to wait around until the company has gestated enough in the public's intestinal tract to have a goodly amount of "real world" impressions.  Just my personal preference though.

 

They should be using better soldering irons.

Leben sounded better first go round but I'll be giving the LM another shot. 

 

The 218i is 80lbs or so so build quality seems great after handling one myself. It fits a ton of tubes as well which is nice...but the Leben is a good headamp along with the rest. 

 

I'd like to give the LM a little more time to hear back from new owners, but it and the Leben are really my only options at this point and I'll be ordering fairly soon. 

 

Thanks for helping even though it's the Stax thread. :D 

 

Because of wild variations between headphones frequency response, it's no surprise you run into such issues Mark. Tyll and other headphone testers have similar issue with overlaying various phones response curves.

From a conversation in a different forum, I was told about new standards coming into place for the estimation of audio program loudness: http://tech.ebu.ch/loudness

Although I haven't checked in detail, from the conversation we had on this french audio forum, it would boil down to measuring the B-weigthed SPL (maybe your meter has this function?) with a pink noise input. I have listed the norms below:

This one has additional processing accounting for diffraction effects from the head (in order to estimate the perceived loudness from the multichannel audio programme), which you can ignore, but appendix 1, section 2 is interesting: http://www.itu.int/rec/R-REC-BS.1770-3-201208-I/en

This one relates to non-stationary signals (audio programmes) so it can be ignored I assume:
http://tech.ebu.ch/docs/tech/tech3342.pdf

In summary, I would attempt to measure B-weigthed loudness using pink noise input, which would be miles better than matching SPL for single tone (like 1kHz or 250Hz), as this absolutely does not take care of level matching.

This seems quite instructive, the first pages give a background about perceived loudness. Figure 7 illustrates the various weighting curves, including the Reveised B Weighting curve recommended above: http://www.speech.kth.se/prod/publications/files/3098.pdf

Personally, I would try B or A weighted SPL, probably A-weighted is available on any sound level meter. I have a gut feeling A-weighting would be much more useful than the other (my understanding is that B and C weightings were defined for louder than normal stimuli) for normalizing headphone response. I wonder if you've tried it Mark?

Note: not really appropriate for the Stax thread, just following up on MorbidToaster question...

 

I have a Leben CS600 driving Devore O/96 and I am very happy with the sound quality on the speakers. The headphone output is also excellent, but I have had an issue with the HD800 due to its high sensitivity. There is a slightly perceptible buzz on the right channel which is audible only when no music is playing (not volume dependent).This buzz can also be heard on the right speaker one or two inches from the speaker (but not from a normal listening position). I don't think you would hear it on the Harbeth HL5 which are much less sensitive than the O/96. It does not show up on less sensitive headphones (e.g. AKG K702). It is most likely an output transformer wire going too close to one of the power transformers or the power supply tube, but I have been too lazy to open up the CS600 to check on this theory  - the beast is quite heavy.

 

I solved the problem by putting a small resistor dividing bridge inside the TRS plug of an extension cord to reduce the headphone sensitivity by about 8-10 dB - buzz is completely gone without affecting the very nice sound tonality. This also give a better volume knob level for normal listening on the HD800, which is the only headphone I use on the Leben. Some people have been complaining of the same buzz issue on the CS300, and I assume a similar approach would work just fine. Various versions of the Leben have used different series termination on the headphone outputs, so the buzz issue may or may not be perceivable on current CS300 production units. You may also hear it on the HD800 and not the LCD-2 (different sensitivity & impedance).

Edited by tiberiuspv - 1/6/13 at 3:21pm

Thanks again for the info...That's quite the system you've got there. Those O/96s are real beauties. 

 

I think I'll be okay if I decide to go with the 300XS since I'm buying from a dealer no more than 10 minutes from where I live right now. 

 

Thanks guys.

 

EDIT: On topic...I'm giving the 009 + LL one more listen (well, a few more) before it goes to it's new home in a few days. I'm not much of a Jazz guy, but this album really is something special. 

 

 

I picked it up last night at my local record store (owned the HD Tracks version before). It's just beautiful on vinyl. Well recorded stuff really does just shine on a 'stat system.

Edited by MorbidToaster - 1/6/13 at 3:46pm