E1DA Cosmos APU - Teardown and personal thoughts and measurements

[Rja4000]

You can also build it yourself.

Would you mind sharing details about this ? (Diagram, components) in PM ?

 

[don'ttrustauthority]

What does APU mean?

 

[staticV3]

Analog Processing Unit

 

[IVX]

I forgot to leave the link about Cosmos Scaler proto https://archimago.blogspot.com/2022/11/early-look-e1da-cosmos-scaler-prototype.html

 

[thin bLue]

I forgot to leave the link about Cosmos Scaler proto https://archimago.blogspot.com/2022/11/early-look-e1da-cosmos-scaler-prototype.html

1. Add Switchable gane range selecter(default, 2nd about +50dB and 3rd about +70 dB) would be really sweet.

2. Add 48V power like APU. It would be killing point again!!!!

3.XLR Cable soldered version make more customer purchase the Scaler. XLR is Tradition quite many people refuse non XLR connections.

 

[IVX]

hm, what about the knob gain control, just replace that for your switches?

 

[thin bLue]

hm, what about the knob gain control, just replace that for your switches?

Knob with gain(range) selecter will be smart solutions.
->Wide range with No extremely sensitive knob

Topping's Headphone Amps are great examples!

 

[eeMGee]

I forgot to leave the link about Cosmos Scaler proto https://archimago.blogspot.com/2022/11/early-look-e1da-cosmos-scaler-prototype.html

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.

 

[IVX]

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.

Anyhow you can see that by the knob position, however, the autorange mode is blind.

 

[oal]

I forgot to leave the link about Cosmos Scaler proto https://archimago.blogspot.com/2022/11/early-look-e1da-cosmos-scaler-prototype.html

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.

 

[okok]

doesn't look too practical

 

[pma]

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.