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Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

LDR Pre MkII - LDR volume control and I/O switching
LDR Pre MkII - LDR volume control and I/O switching
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Old 2nd September 2019, 03:43 PM   #251
fab is offline fab  Canada
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LDR Pre MkII - LDR volume control and I/O switching
Niss_man
Have you read this article about LDR thd profile ?
Tortuga Audio LDR3 Volume Control: Measurements & Review

Fab
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Old 27th September 2019, 10:05 AM   #252
zdr is online now zdr  Belgium
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I uploaded new firmware for graphic oled, corrected some issues with press and hold commands on remote.
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Old 7th October 2019, 05:57 PM   #253
maal is offline maal  Poland
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I found some time and installed the preamplifier in the chassis.
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Old 9th October 2019, 03:30 AM   #254
ppap64 is offline ppap64  Canada
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Hi. In the power supply BOM C3,4,5 are listed as 100nF caps, but the mouser link is a 220nF cap...which one is correct ?
Thank you.
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Old 9th October 2019, 06:13 AM   #255
zdr is online now zdr  Belgium
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Either will work fine.
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Old 21st November 2019, 09:15 PM   #256
zdr is online now zdr  Belgium
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I made another firmware which incorporates second encoder for direct input switching, and button used for on/off function for power amp, very useful for amps.
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Old 21st November 2019, 09:21 PM   #257
zdr is online now zdr  Belgium
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Allows you to build something like this

Adjustments.jpg
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Old 30th November 2019, 05:21 PM   #258
zdr is online now zdr  Belgium
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I did some cumulative THD measurements, with sine passing through this chain: USB DAC>LDR Pre (volume at 36)>RMI-FC100 > PC internal sound card. At 1KHz, THD+N is around 0.05%. Not sure what I am doing wrong.
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Old 1st December 2019, 08:39 AM   #259
zdr is online now zdr  Belgium
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Test with 300mV Vrms input signal. Signal path: USB DAC>LDR Pre MkII>RMI-FC100>Scarlet 2i2.
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Old 1st December 2019, 08:42 AM   #260
zdr is online now zdr  Belgium
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Same setup, volume at 40.
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