No they don't! You vary the stimulus amplitude on digital generator instead of attenuating the amplitude using builtin volume control.The IMD measurements show those steps. A THD+N curve would be similar.
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No they don't! You vary the stimulus amplitude on digital generator instead of attenuating the amplitude using builtin volume control.The IMD measurements show those steps. A THD+N curve would be similar.
Thanks. I have seen that but I wasn't sure if you used 100k/200k for all tests. You know you would be surprised what one may find in some cases. Passive preamp I have mentioned previously is not the only example. About a year ago I had to deal with AUX input port in my wife's BMW. The input impedance at 100 and 1000 Hz was around 1.1kOhm and at 10kHz it was at 180 Ohm! The Android device I have installed had 1kOhm series resistor in the output. To make matters worth Aux port in BMW has 2 caps in parallel with the signal... You can imagine what frequency response looked like. Similarly it had no bass response as someone created the RC filter with incorrect selection of nominal values. Though it was relatively easy fix... This is a mass produced device.If you look at the the bottom of the dashboard, you see the test conditions such as what you ask:
View attachment 23552
For unbalanced, it is 100 K ohm. For balanced it is naturally double that per above.
This is for DAC testing. The dashboard for headphone amps does use 600 ohm.
I don't think it makes much sense to test a DAC output at 300 or 600 ohm. I know stereophile does that but I don't see a common case where the target device has such a low input impedance.
IMD is that way. And any THD graph I run will be the same.No they don't! You vary the stimulus amplitude on digital generator instead of attenuating the amplitude using builtin volume control.
I sent an email to Gustard, which also mentioned this question.I am not sure. Their marking material just says it goes from 0 to 90 and is digital in nature.
It shows up in the jitter test. If you look there, you see a spike at 8 Khz.Hi @amirm
In which of your typical measurements would you expect to best see any USB 8kHz PHY microframe packet noise?
I will test them together when it arrives. For now, USB is the universal input as far as I am concerned and there, Empirical doesn't offer anything.Is it fair to assume the Gustard X26 is an example of a proven, very well designed modern DAC that would gain no benefit from something like an Empirical Audio device?
I will test them together when it arrives. For now, USB is the universal input as far as I am concerned and there, Empirical doesn't offer anything.
I think Amir was getting the whole mesh and dynamo stack though.Not sure the Synchro Mesh is the right product to compare to the USB. The result will surely be interesting but the Off Ramp is the USB product with much more sophistication including S/PDIF by BNC and balanced connections. Also I2S by HDMI and RJ45, although the HDMI pinout is not compatible with the Gustard (according to Shenzhenaudio). An optioned Off Ramp has Hynes regulators on important circuits. The Synchro Mesh maybe none until it's powered by the Dynamo. The Off Ramp is bit perfect, the Synchro Mesh not. I expect Steve asked you to test the Synchro Mesh because it's his most popular product and he's getting ready to introduce a new Off Ramp making a test of the OR5 nearly a waste of everybody's time.
I will test them together when it arrives. For now, USB is the universal input as far as I am concerned and there, Empirical doesn't offer anything.
Not sure the Synchro Mesh is the right product to compare to the USB. The result will surely be interesting but the Off Ramp is the USB product with much more sophistication including S/PDIF by BNC and balanced connections. Also I2S by HDMI and RJ45, although the HDMI pinout is not compatible with the Gustard (according to Shenzhenaudio). An optioned Off Ramp has Hynes regulators on important circuits. The Synchro Mesh maybe none until it's powered by the Dynamo. The Off Ramp is bit perfect, the Synchro Mesh not. I expect Steve asked you to test the Synchro Mesh because it's his most popular product and he's getting ready to introduce a new Off Ramp making a test of the OR5 nearly a waste of everybody's time.
I think Amir was getting the whole mesh and dynamo stack though.