MEASURES
-
Rails: +/- 24VDC under load
-
DC offset at speaker teminals: +/- 2mV
-
BIAS: 1.3A (0.61V on R13/R14)
-
Voltage gain: 10 (20dB)
-
THD+N (at 1 Watt into 8 Ohms at 1kHz): 0.08%
-
THD (at 1 Watt into 8 Ohms at 1kHz): 0.04%
MEASURES
-
Rails: +/- 24VDC under load
-
DC offset at speaker teminals: +/- 2mV
-
BIAS: 1.3A (0.61V on R13/R14)
-
Voltage gain: 10 (20dB)
-
THD+N (at 1 Watt into 8 Ohms at 1kHz): 0.08%
-
THD (at 1 Watt into 8 Ohms at 1kHz): 0.04%
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NOTES
-
R7 changed to 52.3k to remove excess negative DC offset at the output of the amp
-
R4 changed to 8.2 Ohms and 220uF bipolar capacitor added to remove DC offset at Edcor input (pin 1)
-
Boards, Edcor transformers and MOSFETs from TeaBag
-
Harris IRFP9240 MOSFETs
-
Matched Toshiba JFETs from FET Audio
-
Dual mono implementation
-
2 x 250VA transformers from Toroidy - 230V primary, 2x18V secondary
-
8 x 22000uF KEMET PEH200 in power supply
-
Deluxe 4U chassis from Hi-Fi 2000
RESOURCES
-
Manual: First Watt M2
-
diyAudio: Official M2 schematic, M2 Clone boards with 120mm UMS spacing
-
Other: Edcor
Last update: 10.03.2019.
NOTES
-
R7 changed to 52.3k to remove excess negative DC offset at the output of the amp
-
R4 changed to 8.2 Ohms and 220uF bipolar capacitor added to remove DC offset at Edcor input (pin 1)
-
Boards, Edcor transformers and MOSFETs from TeaBag
-
Harris IRFP9240 MOSFETs
-
Matched Toshiba JFETs from FET Audio
-
Dual mono implementation
-
2 x 250VA transformers from Toroidy - 230V primary, 2x18V secondary
-
8 x 22000uF KEMET PEH200 in power supply
-
Deluxe 4U chassis from Hi-Fi 2000
RESOURCES
-
Manual: First Watt M2
-
diyAudio: Official M2 schematic, M2 Clone boards with 120mm UMS spacing
-
Other: Edcor
Last update: 10.03.2019.
NOS AD1865 DAC
​Non-oversampling, resistor ladder architecture (R-2R) digital to analogue converter based on AD1865 chip. Supports up to 24 bit 192kHz. Main components and features:
-
Cirrus Logic CS8416 192kHz Digital Audio Receiver
-
Analog Devices AD1865 N-K dual 18-bit DAC
-
Amanero USB adapter
-
No digital filtering
-
Passive I/V converter using high quality transformers from Sowter
-
Power supply with shunt regulators
-
Separate mains transformers for digital board and I/V
Please refresh the page if you see "This video is unavailable" above.
DISCRETE I/V CONVERTER
LINKS
-
Audio Note Kits: ANK Audio Kits, Audio Note UK
-
Audiodesignguide: DAC End, DAC End 2, DAC End 24
-
diyAudio forum: AD1865 the best DAC, Zen I/V Converter, Zen -> Cen -> Sen, evolution of a minimalistic IV Converter
-
Various: Modifying CD player DACs, Grounding of Mixed Signal PCBs, Audio Note DAC 4.1 DIY and mods, DAC Kit 2.1 Build
-
Useful: RC filter, RMS voltage calculator
SCHEMATICS
-
IV Power Supply: Floating pre-regulator, 18V floating regulator
Last update: 11.06.2023.