The test was performed with OP20 and OP21 all set to high output and at 75 ohm. I agree it gives a more dynamic sound. This setting was my favorite one for some time, but recently I switched to 50 ohm and low. The sound is more refined and smoother. It is personal preference and system dependent.Hi, thanks for this interesting comparison. Do you still remember whether the two Cybershaft units had their 10 MHz output level set to "high" or "low"? Because I found that this setting changes the sound quite a bit, the "high" setting sounding even more "airy" and "detailed", three-dimensional, while the "low" setting sounding a little more "grounded". Just in case you had the OP21 and OP20 accidentally set to different settings without noticing or paying attention, this could potentially explain the sonic differences you described. Any idea?
Remark: My observation is based on a test I did with the Cybershaft OP21E clocking an Antelope Audio OCX-HD word clock. While the Antelope device seems to be able to handle the Cybershaft's "high" output level setting, I read that most other word clocks with a 10 MHz input would only be able to sync to the standard "low" 10 MHz level. My personal sonic preference, however, is that unique "high" level setting. Compared to the standard "low" setting (which most other 10 MHz atomic clocks produce without the option to change it), I would describe the "high" gain 10 MHz sound as more airy, precise, detailed, focused, three-dimensional, almost like being "detached" from the speakers.
The improvement from OP20 to OP21 is more than just high and low setting.