Cosmos Scaler
Specifications:
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Device purpose: ultra-low THD+N variable gain buffer for Cosmos ADC
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Status: production
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Materials: Sandblasted/black anodized aluminum/laser mark/OPA1612+OPA1656 composite
Viking resistors, Murata, Samsung C0G caps, Taiwanese connectors/relays
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Dimensions: PCBA 90x50x29mm
104x61x39mm
Weight: PCBA 40g
160g
Power: USB-C +5V rail, <500mA idle current
Input: 2 channels balanced 200/100kOhm bal/unbal
3.5mm jack up to 20/10Vrms bal/unbal
If only the left input is plugged, the signal is routed to the right
channel as well, to implement MONO mode for Cosmos ADC.
Cosmos APU's short cables are suitable for Scaler as well.
Output: 2 channels balanced 20/10ohm bal/unbal
3.5mm jack up to 20/10Vrms bal/unbal
Cosmos APU's short cables are suitable for Scaler as well.
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Variable gain table: in db 0, 7, 10.7, 13.38, 15.788, 17.38, 18.673, 19.844,
21.08, 21.98, 22.764, 23.513, 24.336, 24.965, 25.527, 26.078
16 positions controllable by the knob, in the "Auto" position Scaler
works like a ultrafast autoranger(100mS) with the left channel target 4.5Vrms.
The right channel output voltage is ignored. 20Hz-20kHz is the valid
frequency range for autoranger.
Indication: front panel per each channel 1.7Vrms<Blue LEDs<4.5Vrms
4.5Vrms<Green LEDs<10Vrms
Red LEDs>10Vrms
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Frequency response: .2Hz-570kHz @ 26db gain +.5/-3db, .2Hz-7..11MHz @ 0db gain 10MHz area
depends on a cable(Scaler's output is stable up to 7m of mic cable) capacitance
Residual noise: 250nVrms(A) @ 26db gain typical.
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Distortions: the only indirect measurement method is available at such a low level
due to a huge loop gain OPA1612+OPA1656 composite
(170db@1kHz/130db@10kHz)
Something like 100x times less than Cosmos ADC or H3 -175db@1kHz at 0db
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Crosstalk: L->R -133db, R->L -158db@1kHz unused input is shorted @0db gain
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