October 20, 201114 yr What is the default bias for the he60? I wonder if the different bias from the 5 pin stax jack will effect the measurements.
October 20, 201114 yr There's already enough blatant bias out there! (OK, it's a random pharmaceutical product, but wouldn't Biggie still look good in one of these caps?)
October 20, 201114 yr I want one as well... What is the default bias for the he60? I wonder if the different bias from the 5 pin stax jack will effect the measurements. It will. The stock bias is 540V with a 10M ballast resistor. Anything else that that will alter the measurements in unforeseen ways.
October 23, 201114 yr Hi Guys. I had a little chat with Alex, and I'm going to send his gear back to him on Nov 4th. That gives us two more weeks to mmeasure Stax cans. If anyone has some they'd like measured, it's now or not for a good while. Lemme know!
October 23, 201114 yr Author Anyone got a pair of HE90 or HE60 to send in? I'd love to see how they stand up to the stats Tyll's already measured.
October 23, 201114 yr Larry gave me his HE-60 at RMAF to measure. Anyone have an HE-90 they're interested in sending in?
October 24, 201114 yr Cool. Your set has the o rings replaced right? Yes. I sent them to Sennheiser summer of 2009 for new drivers, o-rings, ear pads, and headband pad. I bought them from Kees with the Stax plug already done, and a 6" pigtail to let me use the HEV-70 if I wanted. I slso had to replace the PSU at the same time with Sennheiser. They did all the refurb work for about $550 + shipping (incl PSU). [edit iPad auto correct] Edited October 24, 201114 yr by HeadphoneAddict
October 24, 201114 yr Why is there a need to fix the polarity of the HE60 drivers Spritzer? Whats the best way of doing this? ...and the polarity of the drivers fixed? Edited October 24, 201114 yr by complin
October 24, 201114 yr Because the drivers are wired out of absolute phase compared to the Stax sets. The HEV70 might be inverting which is why they did this. Best way to fix it is either install the Stax plug properly or use a an adapter that is wired correctly. One thing that should be noted about these phones (HE60 and HE90) is that there is potential to damage the drivers while under testing. The HE90 clearly states in its specs that max input voltage is 1000V P-P which the BHSE will easily reach when fed a high enough input voltage. Now under normal usage this wouldn't be a problem but testing does expose the limits. What is the output voltage of the test gear Tyll?
October 24, 201114 yr Well, the system always regulates to a level equal to 90dB at the ear with the exception of the 100dB THD test where it's 100dB. So I don't know the exact voltage. I don't expect those levels should be a problem though. What do you think?
October 24, 201114 yr I never found any real problem with the absolute phase of the HE-60s. Now if one driver vwas wired out-of-phase with the other, that would have been a problem.
October 24, 201114 yr Well, the system always regulates to a level equal to 90dB at the ear with the exception of the 100dB THD test where it's 100dB. So I don't know the exact voltage. I don't expect those levels should be a problem though. What do you think? If there is a feedback loop which adjusts the input voltage then it should be fine. The sensitivity of these sets is above 100dB for 100VRMS so they will be pushing 115+dB at their breaking point, well out of range. I never found any real problem with the absolute phase of the HE-60s. Now if one driver vwas wired out-of-phase with the other, that would have been a problem. Some people are more sensitive to this then others but while measuring this will be easily evident. I'm more worried about how the bias and ballast resistors will alter the sound even though the change in bias is relatively tiny.
October 24, 201114 yr Some people are more sensitive to this then others but while measuring this will be easily evident. I'm more worried about how the bias and ballast resistors will alter the sound even though the change in bias is relatively tiny. Agreed on both counts.
October 25, 201114 yr If you think the 404LE would be a worthy donor, Tyll. I think it's stock. Purchased here from Birgir, but his FS thread apparently didn't survive the new forum software.
October 25, 201114 yr If you think the 404LE would be a worthy donor, Tyll. I think it's stock. Purchased here from Birgir, but his FS thread apparently didn't survive the new forum software. It's not an issue of whether it is worthy or not, but simply if it is electrostatic. I would even send grandma over to get measured if she was electrostatic. Alas, she is in Nicaragua... oh, and she's also not electrostatic.
October 25, 201114 yr It's not an issue of whether it is worthy or not, but simply if it is electrostatic. I would even send grandma over to get measured if she was electrostatic. Alas, she is in Nicaragua... oh, and she's also not electrostatic.
October 25, 201114 yr I think I already measured a 404LE didn't I? Just checked, yup. No problem measureing a second pair though, if you get it in quickly. PM if interested.
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