I can't believe how good the 990's are (dust an all!). They must be over 20 years old, but every time I put them on I'm blown away.
Congrats! It's the same seller I sent my zishan for the upgrade -despite not being bought it at his shop- He said the upgraded zishan is now on the way so I expect 2 weeks to receive it and post some impressions.
Thanks for the info. Think I will try that OPA2107 route. I assume it is not as "chill" as the IHIFI 812? If it is sort of midway between that and the stock Zishan = that would be interesting I see the Walnut and Zishan seller on ebay I buy from has legit Muses 02, Muses 8820/ 8920 and also 2107's. http://www.ebay.com/sch/m.html?_odkw=&_sac=1&_ssn=shenglongsi&hash=item3f6d07a516%3Ag%3AfM0AAOSwYIxX%7E61O&item=272412157206&_osacat=0&_from=R40&_trksid=p2046732.m570.l1313.TR12.TRC2.A0.H0.Xopamp.TRS0&_nkw=opamp&_sacat=0 whoa. I was NOT expecting that much extra boost power with the Turbo Mode in the DAC setting. Ok let's try this out then, a little bit of a boost I thought....it could blow up headphones and eardrums for sure. Halfway up the volume dial is terribly loud on this inefficient Fostex T50RP mod
There's no way for me to know about a standard version. I got the 15v version right away. I'm sure someone in here would know. There was a post or two back in the thread here briefly comparing the two. I forget where now.
Does anyone know how many mW does the zishan output at 32ohm? I have a pair of Audeze Sine, 20ohm impedance but the need at least 500mW; should I but with the zishan an external amp?
Measures (0dBFS), using DMM: Output impedance: phones out, 0.2Ω (@1KHz), 0.5Ω (@120Hz), 0.9Ω (@60Hz), due to output coupling caps; line out: 450Ω (@1KHz). Max. output (not clipping / "low" distortion): - phones out: high gain, 2.74Vrms (@20Ω), 3.64Vrms (@33Ω), 3.75Vrms (@64Ω, or unloaded); low gain, 0.276Vrms - line out, fixed: high gain, 1.885Vrms; low gain, 0.138Vrms If you need 500mW, at 20Ω (to reach 110dB?), it's 3.16Vrms, so Zishan would be a bit forced. But I don't understand why Audeze says they need such power. At innerfidelity, got these measures for Sine: Volts RMS required to reach 90dB SPL: 0.096 Vrms Impedance @ 1kHz: 24Ω (but they show an impedance peak at 2.5KHz: >40Ω) Power Needed for 90d BSPL 0.38 mW According to this, it has a sensitivity of 94.2dBSPL/mW. You'd need only 0.96Vrms to reach 110dB (quite loud), 1.7Vrms to reach 115dB, 3.04 to reach 120dB (I can't listen to music at such high volume). So Zishan power would be more than enough.
thanks for the detailed answer. For Audeze the optional requirement is 500mw-1w, and the peak Power is 4w. They sound good with the 200mW@32 output of my home DAC but if I use the 1900mW@32 amp that I own It seems to listen to a different pair of headphones, in particular at high volumes and at the low frequencies. I think I'm gonna buy the zishan, I can also pair it in the future with a Cayin c5 amp which is 800mW x 2 @32. Thanks again for your detailed answer
normal zishan allows you to change the LPF (Low Pass Filter) opamp (dual channel). the I/V opamp (dual channel) is soldered, not so easy to change. upgraded zishan allows you to change both opamps, by using dip-8 sockets. stock zishan (well, LPF opamp changed): upgraded zishan (upgrade 5): Cayin C5 measured 6.36Vrms @ 68Ω, no clipping nor high distortion. I'll measure it again with lower loads (33Ω, 16Ω), when I get time. That's 595mW @ 68Ω, more than 1W for Sine's impedance, if it doesn't clip with them at this power. Upgraded Zishan measured 6.11Vrms @ 68Ω, no clipping nor high distortion. I'd measure it again with lower loads. 549mW @ 68Ω. More than 1W for Sine, if it doesn't clip nor distort with such load at this power. Besides, these don't suffer bass roll-off due to coupling caps. But battery drains off very quickly at that power. And upgraded Zishan shows some more noise than stock Zishan, and gets hotter. I'll probably get rid of the upgraded Zishan, because I don't own power hungry cans now.
Just a quick note, received my Zhisan DSD 560 today and the firmware was automatically updated to 0.4 E
seller of zhisan also mentions that minimum 2 to 7 days burn in for new machine. Just plug it into a socket and forget about it.