Headphone CSD waterfall plots
Nov 27, 2011 at 4:47 PM Post #526 of 937
 
Quote:
Just curious, purrin, what volume do you measure at?  I'm not sure if it's a product of the Burson HA160D amp or the LCD2 R2s but when going to VERY high volumes, the upper mids become intollerable, and it spikes quickly.  I'm almost wondering if this is the resonance at 5k even more pronounced at high volumes.  Then again, could be the Burson as well, but something gets out of control pretty quickly past a certain volume (thankfully a very high one).



Doubt it's the Burson, I never noticed that from it before.  Never noticed the spike either w/ the two r2s I liked and I'm really sensitive to spikes around 5k.  Not sure if it's your phones or some source issue w/ your synergy.
 
Nov 27, 2011 at 5:26 PM Post #527 of 937
Yeah but you noticed the spike on the bad R2 (at the OC meet) you heard right? And you also noticed the spike (small) on one of the good R2s before we switched to a certain rare super rare PX25 tube?
 
Nov 27, 2011 at 11:08 PM Post #528 of 937
The thing that led me to believe it is the r2s is the fact it doesn't sound like 'clipping' to me, more a harshness.  I could see it being resonance, though most of the resonance I've heard and identified (not headphone listening) was at bass frequencies, so it's difficult for me to really conclude.  One thing I did notice is that this review of the HA160 (not D) seems to touch on it:
 
excerpt from http://www.digitalaudioreview.net.au/index.php/audio-reviews/desktop-audio-reviews/item/293-burson-ha-160-headphone-amplifier
 
"Out front, we have two quater-inch headphone output sockets:  the left is for tougher customers (15 - 150 Ohms), the right for more amiable cans (150 to 500 Ohms).  At 62 Ohms, one might presume the AKG 702 to find appropriate drive with the left-hand drive. Well yes.  And no.  There's just too much drive - the AKGs sound overcooked/burnt.  Comfortable listening levels disappear a shade after 9pm on the volume dial - ok - but there's a brittleness that starts among the midrange reeds and then spreads in either direction as volume levels are pushed.  It's toast that requires scraping.  It's sitting on a hard chair for too long - the discomfort only apparent after fifteen or so minutes.  Switching to right-hand socket drive and the Burson/AKG finds comfy couch repose.  Craig Finn's Hold Steady relaxes into the guitar-chugging "Stuck Between Stations" and things never get as overtly strident as with the horsepower of the left-hand hole."
 
Again, this doesn't come into play until ridiculous volumes (nothing I would listen at longer than to see what they can do).  I brought it up more out of curiosity and to potentially help validate the resonance.  That said, after the reading the review, I'm left wondering if it's the same thing that the reviewer mentions, and if so, it appears to be the Burson.  On the other hand, the HD650s can be pushed to ear bleeding levels with no sense of this, but they're a completely different impedance, too.  Hmmmm...
 
Nov 27, 2011 at 11:59 PM Post #529 of 937


Quote:
Yeah but you noticed the spike on the bad R2 (at the OC meet) you heard right? And you also noticed the spike (small) on one of the good R2s before we switched to a certain rare super rare PX25 tube?



The OC one was such an anomoly.  That thing was like a totally different/broken phone.  An upper mid spike on the second?  Not anything severe that I recall, I thought there was some peakier, disconcerting stuff up a bit higher if i recall.  I just don't remember the upper mids on the (good) R2 to be murderous like some other phones.  If you are asking me if everything was flat and smooth then that's easy to answer.
 
Nov 28, 2011 at 12:14 AM Post #530 of 937
The harshness you are describing sounds like the amp is running out of steam - that is it can't provide enough current - since the LCD2's impedance is what? 50ohms? It doesn't necessarily have to hard clip. Audible strain / distortion is already a good sign.
 
I can't say for sure since I've only heard the Burson (with LCD2) two times very briefly (and only at reasonable listening levels) in my life. I know the LCD2r2 resonance is fairly high up in the treble (I suspect 9kHz++). The treble response is a bit rough. But these behaviors should be consistent (that is not get any worse) throughout the volume range of a amp.
 
Nov 28, 2011 at 12:20 AM Post #531 of 937
Thanks for the insight, purrin...!
 
Dec 4, 2011 at 6:24 PM Post #533 of 937
Dec 4, 2011 at 6:33 PM Post #534 of 937


Quote:
I like the new graphic/animation.  Just in time for Christmas too!!


I'm wondering if we use a headphone with a very clean waterfall such as HD800 or LCD3, if it would be possible to see the sound floor differences of various amps.
 
 
Dec 4, 2011 at 10:19 PM Post #535 of 937


Quote:
I'm wondering if we use a headphone with a very clean waterfall such as HD800 or LCD3, if it would be possible to see the sound floor differences of various amps.
 


Well, we've discussed this idea before.  You know where I stand.  We actually need to try for methodological reasons IMO.
 
 
Dec 9, 2011 at 2:47 PM Post #536 of 937

LCD2 revision 2

Definitely sound less shelved than LCD3, even with the TP mod. I moved the "floor" way down to -40db. My other measurements typically had the floor at -30db or on occasion -36db. The ringing is there, but it's lower in magnitude than on the r1. At 8-9kHz, the resonance nodes are a little higher in frequency compared to the the r1 which are were in the 6.5-7.5kHz area. Overall very clean except for the resonance modes, but we can put tubes in the chain to take the edge off. The modes aren't terrible sharp-bladed (those sound the worst) anyhow.
 
 
 
Dec 9, 2011 at 5:23 PM Post #539 of 937
Marv, btw, it's modes not nodes. You are using the word more and more lately and it's getting hard to read for me :wink:
 

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