Laowei

Returning Member
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    318
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About Laowei

Profile Information

  • Gender
    Male
  • Location
    Vancouver, WA USA

Converted

  • Headphones
    Stax SR-009, SR-L700, SR-007mk2, SR-207, SR-003mk2
  • Headphone Amps
    KGST, KGSSHV Carbon -in process
  • Sources
    Mac mini > Airport Express> microRendu > Schiit Yggdrasil
  • Other Audio Gear
    DIY PP 6V6 amplifier. ALTEC Model 19 speakers. ALTEC 809C Bolero speakers modified with vintage Great Heil AMT

Recent Profile Visitors

1,387 profile views
  1. If you can stomach Jude, this is worth a viewng:
  2. Congrats!
  3. FYI, Gary Pimm's pages have been deleted for some time. Here is a link to the archived pages on The Wayback Machine. Unfortunately. the CCS measurement page did not make it. The other links work OK. http://web.archive.org/web/20151117131328/http://pimmlabs.com/ I had a few screen shots of Gary's CCS impedance measurements saved:
  4. Thanks Soren.
  5. Any opinions on the advantages of revisiting using BJTs as current sources (as in the original KGBH), as opposed to the latest FET cascode design? Is there an increase in performance. or just another way to skin the cat with currently available parts?
  6. Visiting Osaka, and it seems they take thier audio very seriously here. Running a Blue Hawaii is not simply a choice, but a Lifestyle!
  7. I have not used this in your particular case, but Goof Off Professional Strength Remover has never let me down on other nasty adhesive removal jobs. In the US, Home Depot carries it. Don't know if it is available in France/EU http://m.homedepot.com/p/Goof-Off-16-oz-Professional-Strength-Remover-FG654/100671841
  8. Are you planning to just carry the main STAX product line, or will you also be including accessories and service/repairs too?
  9. I'm pretty sure that riveting was done there simply to reduce assembly cost. The rivet is so damned small, it loses the mechanical integrity of the rivet bond when heated soldering the bias wire to it. Not enough to fully break contact and cause an obvious failure on manufacture. Could possibly cause intermittent problems after time and handling as folks have written about on the forums. All anecdotal on my part.
  10. Replaced the cable in my SR-009 yesterday. They are playing great now. When soldering the wires to the stator and diaphragm tabs, I came across some details that I thought should be passed on. Desoldering all the wires and removing the old cable was not a problem. See the "Ants in My Stax" thread for 009 disassembly. Remove all the plastic parts mounting the cable to the ear pod, don't try to desolder the wires/cable with these in place -no room. On reassembly, first note orientation of the cable for each ear pod, The arrow on one side of the molded strain relief is to be assembled on the inside only (ear side) and will help ensure signal polarity between L&R channels. Soldering the +/- signal wires to the stator tabs was straightforward. Where it got interesting was when I went to solder the pro bias wires to the diaphragm tabs. The diaphragm solder tabs on my SR-009 are a small additional part that had been riveted to the actual diaphagm. The right side rivet was well attached and the wire/tab easily soldered. But the left side rivet was loose and the tab rotated wildly when I touched it with my solder tip. Took some doing, but got it soldered. Then to double check when done, I measured the continuity of each wire from solder tab to cable pin. All measured 0.01 ohm, except the left bias wire. That measured ~25 ohms and varied wildly as the tab was minimally rotated. I then attempted to solder the bias wire to the diaphragm directly, but did not want to heat too much and possible melt it. Also, the material did not take to solder (probably aluminum?) and so the reason for the riveted solder tab. I finally resorted to adding a blob of solder (with the bias wire) on the tab, and rotating until the tab wedged tight under the diaphragm. That ended up also measuring 0.01 ohm and was stable with the cable assembled. Powering up the headphones, I noticed that both L and R channels started playing at nearly the same time. Previously, the L channel took several seconds longer to start playing, and usually had a sllght and wandering imbalance with the R channel for the first 1/2 hour or so. I took that as amp warm up (KGST), as things settled in nicely after that time. Now, the central image is rock stable from the start up, and the soundstage is balanced and huge. Got me thinking that loose rivets may be a cause of imbalance in some SR-009s, and takes longer to fully charge? My 009s are around 3 years old. I did not take photos while I was working on them, but attached detailed photos from the "Ants in My Stax" thread from 2012. In those earlier headphones, Stax is seen to have used a screw and nut to assemble the solder tab to the central diaphragm. Later versions like mine were "cost reduced" to rivet that connection. When that changed over in production, I do not know. I could image the intermittent coming and going of stereo balance problems written about, may be due to a loose rivet and random cable handling. That might be something others with SR-009 channel imbalance issues may want to check out. Earside view (note arrow), circa 2012: Opposite view, circa 2012:
  11. HS can be the Head Case dumpster diver.
  12. We'll have to wait to find out.
  13. Finally received my replacement SR-009 cable from STAX Japan and their shipper A&M Enterprises. All looks good and will be soldering it in a few days. Talking via email with Douglas Ip of STAX, he mentioned that as of Jan 1, 2017 Yama Enterprises is no longer their STAX distributor/dealer here. Douglas is working now to establish a company and warehouse out of Dallas/Fort Worth Texas. Great news.
  14. I got a pair of SR-009 earpads from STAX USA for $350 several years ago.