Nice review, but I did not find the way how Scaler indicate gain used - in manual and autoranger mode. There are 16 gains and for dBu/dBV/V scale you should know what gain is used.
Nice review. If you sell the Scaler, I will definitely buy it! Having said that, it would have been nice if the APU's 1kHz/10kHz notch switch were 1kHz/No-notch switch. I do not use 10kHz notch, however, the No-notch option will be useful for various measurements such as J-Test, multi-tone signal, etc. The APU can be used as an input buffer for the ADC. My primary issue with Cosmos ADC is low impedance, gain control is only secondly.
Exactly. The race for lowest noise pushed the designers to offer low input impedance ADCs and preamps (Topping …). However, it is not practical at all. Cosmos ADC would need a high impedance, low noise input buffer (FET). This would be a real challenge for the designer. Anyone can use the low impedance BJT opamp. A good anti-alias input filter would be good as well.My primary issue with Cosmos ADC is low impedance, gain control is only secondly.
This is 100% normal.With 34dB gain setting, I am getting 14V out of the APU preamp output.
Obviously this is too high for Cosmos ADC (10V max input)
What are my options for gain matching? Prefer not to use digital volume control of the DAC because I lose a lot of SINAD dB's this method.
How is everyone tackling this issue ?
Noted thanks.This is 100% normal.
60/34dB Gain are supposed to work with either -60dBFS or -34dBFS signals, in intend to measure SNR/DR (not SINAD). That way, you bypass the Noise from the ADC itself.
A Look at ADC Noise Limits and Distortion - Or "How much difference does the Cosmos APU make?" And a look at 2-channel Room EQ Wizard measurements!A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.archimago.blogspot.com