Recently I have been offered the opportunity to buy an Audio Precision analyser. Without too much contemplation I jumped on it.
Since it has arrived it quickly became an indispensable tool on my bench. Initially I was scared it might become a novel toy.
My initial experience with Audio Precision was at Bop Studios a couple of years back. The AP1000 was a machine of my dreams.
Here are its specifications off the website.
Additional Features:
Analog Signal Outputs
Low Distortion Sine Wave
Frequency Range: 10 Hz to 120 kHz
Frequency Accuracy: ?0.5 %
Amplitude Range: (20 Hz to 30 kHz)
Balanced: <0.25 mV to 26.25 Vrms [?70 dBu to +30.6 dBu]
Unbalanced: <0.25 mV to 13.12 Vrms [?70 dBu to +24.6 dBu]
Amplitude Accuracy: ?0.2 dB [?2.3 %] at 1 kHz
Amplitude Resolution: 0.01 dB
Flatness (1 kHz ref) 10 Hz?20 kHz: ?0.05 dB
Residual THD+N 25 Hz?20 kHz: ≤(0.0025% + 3 μV), 80 kHz BW [?92 dB]
Square Wave
Frequency Range: 20 Hz?30 kHz
Amplitude Range
Balanced: 0.71 mVpp to 34.73 Vpp
Unbalanced: 0.71 mVpp to 17.36 Vpp
Amplitude Accuracy: ?0.3 dB [?3.5 %] at 400 Hz
Rise/fall time: Typically 2.5?3.0 μs
Output Characteristics
Source Impedances: Balanced: 40 Ω (?2 Ω), 150 Ω (?2 Ω), or 600 Ω (?6 Ω); Unbalanced: 40 Ω (?2 Ω)
Output Current Limit: 75 mA peak
Max Output Power
Balanced: +30.0 dBm into 600 Ω (Rs = 40 Ω)
Unbalanced: +23.9 dBm into 600 Ω (Rs = 40 Ω)
Output Related Crosstalk (10 Hz?20 kHz): ≤?110 dB or 10 μV, whichever is greater
Analog Analyzer
Analog Input Characteristics
Input Ranges: 80 mV to 250 V in 10 dB steps
Maximum Rated Input: 350 Vpk, 140 Vrms (dc to 20 kHz); overload protected
Input Impedance: Balanced (each side): Nominally 100 kΩ // 150?200 pF; Unbalanced: Nominally 100 kΩ // 150?200 pF
Terminations Selectable 600 Ω ?1 %
CMRR 80 mV?2.5 V range: ≥70 dB, 50 Hz?20 kHz
Input Related Crosstalk 10 Hz?20 kHz: ≤?120 dB or 1 μV, whichever is greater
Wideband Amplitude/Noise Function
Measurement Range: <1 μVrms to 140 Vrms [?118 dBu to +45 dBu]
Accuracy (1 kHz): ?0.2 dB [?2.37 %] unweighted
Flatness (1 kHz ref): ?0.05 dB (20 Hz?20 kHz)
Bandwidth Limiting Filters: LF ?3 dB: <10 Hz; 400 Hz ?5 % (3-pole); HF ?3 dB: 22 kHz; 30 kHz; 80 kHz (3-pole), or 300 kHz
Weighting Filters: ANSI-IEC ?A?; CCIR-QPK; CCIR-ARM; CCIR-RMS
Optional Filters: Up to 2 (Aux 1 and Aux 2)
Detection: RMS (=60 ms); AVG; QPK (CCIR Rec 468)
Residual Noise
22 Hz?22 kHz BW: ≤1.5 μV [?114 dBu]
A-weighted: ≤1.0 μV [?118 dBu]
CCIR-QPK: ≤5.0 μV [?104 dBu]
Frequency Meter Related (both channels)
Measurement Range: 10 Hz?200 kHz
Accuracy: ?0.01 % [?100 PPM]
Resolution: 5 digits
Phase Measurement Related
Measurement Ranges: ?180, +90/?270, or ?90/+270 deg
Accuracy 20 Hz?20 kHz: ?2.0 deg
Resolution: 0.1 deg
Level Meter Related (both channels)
Measurement Range: 10 mV to 140 V for specified accuracy and flatness, useable to <100 μV [?38 dBu to + 45 dBu]
Accuracy (1 kHz): ?0.1 dB + 100 μV
Flatness (1 kHz ref): (Vin >10 mV) ?0.05 dB (20 Hz?20 kHz)
Bandpass Amplitude Function
Tuning Range (f?): 20 Hz to 120 kHz
Bandpass Response: Q=5 (2-pole)
Accuracy (at fo): ?0.3 dB, 20 Hz?120 kHz
THD+N / SINAD Function
Fundamental Range: 10 Hz to 100 kHz, THD+N mode
Measurement Range: .001 %?100 %
SINAD Range: 400 Hz?1 kHz
Accuracy: ?1 dB, 20 Hz?120 kHz harmonics
Measurement Bandwidth: LF ?3 dB: <10 or 400 Hz; HF ?3 dB: 22k, 30k, 80k, or 300 kHz
Residual THD+N 25 Hz?20 kHz: ≤(0.0025% + 3.0 μV), 80 kHz BW [?92 dB]
Crosstalk Function
Frequency Range: 10 Hz to 120 kHz
Measurement Range: ?140 dB to 0 dB
Accuracy: ?0.5 dB
Wow & Flutter Function
Test Signal Compatibility: 2.80 kHz?3.35 kHz
Accuracy (4 Hz): ? (5 % of reading + 0.002 %)
Detection Modes: IEC/DIN; NAB; JIS
Residual W+F: ≤0.005% Weighted; ≤0.01% Unweighted
Digital Signal Generator
Digital Output Characteristics
Output Formats: AES/EBU (per AES3-1992); SPDIFEIAJ; Optical
Sample Rates: 28.8 kHz?99.9999 kHz
Sample Rate Accuracy: ?0.002% [?20 PPM] lockable to external reference
Word Length: 16 to 24 bits (even values)
Sine Wave
Frequency Range: 10 Hz to 47 % of sample rate (22.56 kHz at 48 ks/s)
Frequency Resolution: Sample Rate DIVIDED BY (typically 0.006 Hz at 48 ks/sec)
Flatness: ?0.001 dB
Residual Distortion: ?0.00001 % [?140 dB]
Square Wave
Frequency Range: 10 Hz to 1/6 sample rate
Frequencies available: f s ? 4096 to f s ? 6, in even integer divisors
Random Generator Waveform
Waveform Compatible with Audio Precision BITTEST
Dither (all waveforms)
Probability Distribution: Triangular or rectangular; independent for each channel
Spectral Distribution: Flat (white) or Shaped (+6 dB/oct, triangular only)
Amplitude: Automatically tracks word length or off
AES/EBU Interface Generation
Interface Signal
Amplitude Range: Balanced (XLR): 0?5.11 Vpp, into 110 Ω in 5 mV steps; Unbalanced (BNC): 0?1.62 Vpp, into 75 Ω in 1.6 mV steps
Channel Status Bits: English language decoded, Professional/Consumer
Validity Flag: Selectable, set or cleared
AES/EBU Impairments
Induced Jitter: Sine wave
Jitter Freq Range: 10 Hz to 38.8 kHz
Jitter Amplitude: 0?1.28 UI (pk), in steps of 0.005 UI or better 1.3?12.75 UI, in steps of 0.05 UI or better
Residual Jitter (total generator/analyzer) peak calibrated
RMS response: ≤0.005 UI (700 Hz?30 kHz BW)
Peak response: ≤0.015 UI (700 Hz?30 kHz BW)
Spurious Jitter Products
Jitter & Ref Delay Off: /=0.0005 UI
Jitter On: /=?30 dB below jitter signal
Reference Input Characteristics
Input Formats: AES/EBU (per AES3-1992)
Input Sample Rates: 28.8 kHz?99.9999 kHz
Lock Range: ?0.0025% [?25 PPM]
Digital Analyzer
Digital Input Characteristics
Input Formats: AES/EBU (per AES3-1992); SPDIFEIAJ; Optical
Sample Rates: 28.8 kHz?99.9999 kHz
Word Length: 16 to 24 bits
Embedded Audio Measurements
Wideband Level/Amplitude
Range: 0 dBFS to ?140 dBFS
Frequency Range: <10 Hz?22.0 kHz at 48 ks/sec
Accuracy: ?0.01 dB, ≥?90 dBFS
Flatness: ?0.01 dB, 15 Hz?22 kHz
High pass Filters: 22 Hz, 400 Hz, 2-pole Butterworth
Low pass Filters: 15 kHz, 20 kHz 6-pole elliptic lowpass
Weighting Filters: ANSI-IEC ?A? weighting; CCIR QPK; CCIR RMS
Residual Noise: ?140 dBFS unweighted; ?142 dBFS A-weighted
Narrow Band Amplitude
Frequency Range: 0.04% to 40% of sample rate (10 Hz?19.2 kHz at 48.0 ks/sec)
Filter Shape: 10-pole, Q=19 (BW = 5.3% of f?)
THD+N Measurements
Fundamental Range: 0.02% to 45% of sample rate (10 Hz?22.0 kHz at 48.0 ks/sec
Residual THD+N: ≤?138 dBFS
High pass Filters: 22 Hz, 400 Hz 2-pole Butterworth
Low pass Filters: 15 kHz, 20 kHz 6-pole elliptic lowpass
Weighting Filters: ANSI-IEC ?A? weighting; CCIR QPK; CCIR RMS
Frequency Measurements
Range: 5 Hz to 47% of sample rate
Phase Measurement Related
Measurement Ranges: ?180, +90/?270, or ?90/+270 deg
Accuracy: ?2.0 deg (20 Hz?20 kHz)
Resolution: 0.1 deg
BITTEST Measurement
Measurement: Compatible with random mode of Audio Precision BITTEST
Digital Interface Measurements
AES/EBU Impairments, Real Time Displays
Input Sample Rate ?0.002% [?20 PPM] internal ref, ?0.0001% [*1 PPM] external ref
Output to Input or Reference Input to Input Delay: Measures status propagation from the AES/EBU output to the input. Range is 0?192 (frames), resolution ?60 ns.
AES/EBU Input Voltage
Balanced: 400 mV to 10.24 Vpp, ? (10% + 50 mV)
Unbalanced: 100 mV to 2.56 Vpp, ? (10% + 30 mV)
Jitter Amplitude (500 Hz): (peak-peak sine wave calibrated) 0?10 UI
Jitter Flatness: ?1.5 dB, 100 Hz?22 kHz (50 Hz HP selection, RMS detection, 48 kHz sample rate)
Residual Jitter, peak calibrated: (analyzer only) (700 Hz?30 kHz BW)≤0.01 UI RMS; ≤0.03 UI Peak
Spurious Jitter Products: ≤0.002 UI (1.2 kHz) or 0 dB below jitter signal
Channel Status Bits: English language decoded (Professional/Consumer)
Validity Flag: Displayed for selected channel
Parity; Signal Confidence; Receiver Lock; Coding Error: Displayed for total signal (both channels combined)
Auxiliary Signals
Generator Analog Sync Output; Digital Sync Output; Analyzer Input Monitor; Analyzer Reading
Audio Monitor
Power Output: Typically 1 watt
General/Environmental
Power Requirements: 100/120/230/240 Vac (?10%/+6%), 50?60 Hz, 50 VA max
Temperature Range: 0? C to +40? C Operating; ?20? C to +60? C Storage
Humidity: 90% RH to at least +40? C (noncondensing)
EMC: Complies with 89/336/EEC, CISPR 22 (class B), and FCC 15 subpart J (class B)
The Portable One Plus measures amplitude, signal-to-noise, distortion (THD+N) , SINAD, IMD (option), frequency, wow & flutter, input impedance plus AC mains check. Portable One Plus Access includes comprehensive analog generation and measurement, with two outputs and two inputs. Easy-to-set-up sweep capability produces graphs of frequency response, distortion vs. frequency and even amplitude sweeps. Non-volatile storage of up to 30 tests allows easy one-button recall of your favorite test setup. Connect Portable One to a compatible printer and produce reports incorporating high-resolution graphs.
Here are some pictures that can do a great deal of talking:
Following some shots of equipment being tested
Gainclone amplifier with Pass crossover unit on-board - confirming its x-over point
Audio Research LS5 line amplifier distortion measurement
Yamaha C2a phono stage curve confirmed
Since it has arrived it quickly became an indispensable tool on my bench. Initially I was scared it might become a novel toy.
My initial experience with Audio Precision was at Bop Studios a couple of years back. The AP1000 was a machine of my dreams.
Here are its specifications off the website.
Additional Features:
Analog Signal Outputs
Low Distortion Sine Wave
Frequency Range: 10 Hz to 120 kHz
Frequency Accuracy: ?0.5 %
Amplitude Range: (20 Hz to 30 kHz)
Balanced: <0.25 mV to 26.25 Vrms [?70 dBu to +30.6 dBu]
Unbalanced: <0.25 mV to 13.12 Vrms [?70 dBu to +24.6 dBu]
Amplitude Accuracy: ?0.2 dB [?2.3 %] at 1 kHz
Amplitude Resolution: 0.01 dB
Flatness (1 kHz ref) 10 Hz?20 kHz: ?0.05 dB
Residual THD+N 25 Hz?20 kHz: ≤(0.0025% + 3 μV), 80 kHz BW [?92 dB]
Square Wave
Frequency Range: 20 Hz?30 kHz
Amplitude Range
Balanced: 0.71 mVpp to 34.73 Vpp
Unbalanced: 0.71 mVpp to 17.36 Vpp
Amplitude Accuracy: ?0.3 dB [?3.5 %] at 400 Hz
Rise/fall time: Typically 2.5?3.0 μs
Output Characteristics
Source Impedances: Balanced: 40 Ω (?2 Ω), 150 Ω (?2 Ω), or 600 Ω (?6 Ω); Unbalanced: 40 Ω (?2 Ω)
Output Current Limit: 75 mA peak
Max Output Power
Balanced: +30.0 dBm into 600 Ω (Rs = 40 Ω)
Unbalanced: +23.9 dBm into 600 Ω (Rs = 40 Ω)
Output Related Crosstalk (10 Hz?20 kHz): ≤?110 dB or 10 μV, whichever is greater
Analog Analyzer
Analog Input Characteristics
Input Ranges: 80 mV to 250 V in 10 dB steps
Maximum Rated Input: 350 Vpk, 140 Vrms (dc to 20 kHz); overload protected
Input Impedance: Balanced (each side): Nominally 100 kΩ // 150?200 pF; Unbalanced: Nominally 100 kΩ // 150?200 pF
Terminations Selectable 600 Ω ?1 %
CMRR 80 mV?2.5 V range: ≥70 dB, 50 Hz?20 kHz
Input Related Crosstalk 10 Hz?20 kHz: ≤?120 dB or 1 μV, whichever is greater
Wideband Amplitude/Noise Function
Measurement Range: <1 μVrms to 140 Vrms [?118 dBu to +45 dBu]
Accuracy (1 kHz): ?0.2 dB [?2.37 %] unweighted
Flatness (1 kHz ref): ?0.05 dB (20 Hz?20 kHz)
Bandwidth Limiting Filters: LF ?3 dB: <10 Hz; 400 Hz ?5 % (3-pole); HF ?3 dB: 22 kHz; 30 kHz; 80 kHz (3-pole), or 300 kHz
Weighting Filters: ANSI-IEC ?A?; CCIR-QPK; CCIR-ARM; CCIR-RMS
Optional Filters: Up to 2 (Aux 1 and Aux 2)
Detection: RMS (=60 ms); AVG; QPK (CCIR Rec 468)
Residual Noise
22 Hz?22 kHz BW: ≤1.5 μV [?114 dBu]
A-weighted: ≤1.0 μV [?118 dBu]
CCIR-QPK: ≤5.0 μV [?104 dBu]
Frequency Meter Related (both channels)
Measurement Range: 10 Hz?200 kHz
Accuracy: ?0.01 % [?100 PPM]
Resolution: 5 digits
Phase Measurement Related
Measurement Ranges: ?180, +90/?270, or ?90/+270 deg
Accuracy 20 Hz?20 kHz: ?2.0 deg
Resolution: 0.1 deg
Level Meter Related (both channels)
Measurement Range: 10 mV to 140 V for specified accuracy and flatness, useable to <100 μV [?38 dBu to + 45 dBu]
Accuracy (1 kHz): ?0.1 dB + 100 μV
Flatness (1 kHz ref): (Vin >10 mV) ?0.05 dB (20 Hz?20 kHz)
Bandpass Amplitude Function
Tuning Range (f?): 20 Hz to 120 kHz
Bandpass Response: Q=5 (2-pole)
Accuracy (at fo): ?0.3 dB, 20 Hz?120 kHz
THD+N / SINAD Function
Fundamental Range: 10 Hz to 100 kHz, THD+N mode
Measurement Range: .001 %?100 %
SINAD Range: 400 Hz?1 kHz
Accuracy: ?1 dB, 20 Hz?120 kHz harmonics
Measurement Bandwidth: LF ?3 dB: <10 or 400 Hz; HF ?3 dB: 22k, 30k, 80k, or 300 kHz
Residual THD+N 25 Hz?20 kHz: ≤(0.0025% + 3.0 μV), 80 kHz BW [?92 dB]
Crosstalk Function
Frequency Range: 10 Hz to 120 kHz
Measurement Range: ?140 dB to 0 dB
Accuracy: ?0.5 dB
Wow & Flutter Function
Test Signal Compatibility: 2.80 kHz?3.35 kHz
Accuracy (4 Hz): ? (5 % of reading + 0.002 %)
Detection Modes: IEC/DIN; NAB; JIS
Residual W+F: ≤0.005% Weighted; ≤0.01% Unweighted
Digital Signal Generator
Digital Output Characteristics
Output Formats: AES/EBU (per AES3-1992); SPDIFEIAJ; Optical
Sample Rates: 28.8 kHz?99.9999 kHz
Sample Rate Accuracy: ?0.002% [?20 PPM] lockable to external reference
Word Length: 16 to 24 bits (even values)
Sine Wave
Frequency Range: 10 Hz to 47 % of sample rate (22.56 kHz at 48 ks/s)
Frequency Resolution: Sample Rate DIVIDED BY (typically 0.006 Hz at 48 ks/sec)
Flatness: ?0.001 dB
Residual Distortion: ?0.00001 % [?140 dB]
Square Wave
Frequency Range: 10 Hz to 1/6 sample rate
Frequencies available: f s ? 4096 to f s ? 6, in even integer divisors
Random Generator Waveform
Waveform Compatible with Audio Precision BITTEST
Dither (all waveforms)
Probability Distribution: Triangular or rectangular; independent for each channel
Spectral Distribution: Flat (white) or Shaped (+6 dB/oct, triangular only)
Amplitude: Automatically tracks word length or off
AES/EBU Interface Generation
Interface Signal
Amplitude Range: Balanced (XLR): 0?5.11 Vpp, into 110 Ω in 5 mV steps; Unbalanced (BNC): 0?1.62 Vpp, into 75 Ω in 1.6 mV steps
Channel Status Bits: English language decoded, Professional/Consumer
Validity Flag: Selectable, set or cleared
AES/EBU Impairments
Induced Jitter: Sine wave
Jitter Freq Range: 10 Hz to 38.8 kHz
Jitter Amplitude: 0?1.28 UI (pk), in steps of 0.005 UI or better 1.3?12.75 UI, in steps of 0.05 UI or better
Residual Jitter (total generator/analyzer) peak calibrated
RMS response: ≤0.005 UI (700 Hz?30 kHz BW)
Peak response: ≤0.015 UI (700 Hz?30 kHz BW)
Spurious Jitter Products
Jitter & Ref Delay Off: /=0.0005 UI
Jitter On: /=?30 dB below jitter signal
Reference Input Characteristics
Input Formats: AES/EBU (per AES3-1992)
Input Sample Rates: 28.8 kHz?99.9999 kHz
Lock Range: ?0.0025% [?25 PPM]
Digital Analyzer
Digital Input Characteristics
Input Formats: AES/EBU (per AES3-1992); SPDIFEIAJ; Optical
Sample Rates: 28.8 kHz?99.9999 kHz
Word Length: 16 to 24 bits
Embedded Audio Measurements
Wideband Level/Amplitude
Range: 0 dBFS to ?140 dBFS
Frequency Range: <10 Hz?22.0 kHz at 48 ks/sec
Accuracy: ?0.01 dB, ≥?90 dBFS
Flatness: ?0.01 dB, 15 Hz?22 kHz
High pass Filters: 22 Hz, 400 Hz, 2-pole Butterworth
Low pass Filters: 15 kHz, 20 kHz 6-pole elliptic lowpass
Weighting Filters: ANSI-IEC ?A? weighting; CCIR QPK; CCIR RMS
Residual Noise: ?140 dBFS unweighted; ?142 dBFS A-weighted
Narrow Band Amplitude
Frequency Range: 0.04% to 40% of sample rate (10 Hz?19.2 kHz at 48.0 ks/sec)
Filter Shape: 10-pole, Q=19 (BW = 5.3% of f?)
THD+N Measurements
Fundamental Range: 0.02% to 45% of sample rate (10 Hz?22.0 kHz at 48.0 ks/sec
Residual THD+N: ≤?138 dBFS
High pass Filters: 22 Hz, 400 Hz 2-pole Butterworth
Low pass Filters: 15 kHz, 20 kHz 6-pole elliptic lowpass
Weighting Filters: ANSI-IEC ?A? weighting; CCIR QPK; CCIR RMS
Frequency Measurements
Range: 5 Hz to 47% of sample rate
Phase Measurement Related
Measurement Ranges: ?180, +90/?270, or ?90/+270 deg
Accuracy: ?2.0 deg (20 Hz?20 kHz)
Resolution: 0.1 deg
BITTEST Measurement
Measurement: Compatible with random mode of Audio Precision BITTEST
Digital Interface Measurements
AES/EBU Impairments, Real Time Displays
Input Sample Rate ?0.002% [?20 PPM] internal ref, ?0.0001% [*1 PPM] external ref
Output to Input or Reference Input to Input Delay: Measures status propagation from the AES/EBU output to the input. Range is 0?192 (frames), resolution ?60 ns.
AES/EBU Input Voltage
Balanced: 400 mV to 10.24 Vpp, ? (10% + 50 mV)
Unbalanced: 100 mV to 2.56 Vpp, ? (10% + 30 mV)
Jitter Amplitude (500 Hz): (peak-peak sine wave calibrated) 0?10 UI
Jitter Flatness: ?1.5 dB, 100 Hz?22 kHz (50 Hz HP selection, RMS detection, 48 kHz sample rate)
Residual Jitter, peak calibrated: (analyzer only) (700 Hz?30 kHz BW)≤0.01 UI RMS; ≤0.03 UI Peak
Spurious Jitter Products: ≤0.002 UI (1.2 kHz) or 0 dB below jitter signal
Channel Status Bits: English language decoded (Professional/Consumer)
Validity Flag: Displayed for selected channel
Parity; Signal Confidence; Receiver Lock; Coding Error: Displayed for total signal (both channels combined)
Auxiliary Signals
Generator Analog Sync Output; Digital Sync Output; Analyzer Input Monitor; Analyzer Reading
Audio Monitor
Power Output: Typically 1 watt
General/Environmental
Power Requirements: 100/120/230/240 Vac (?10%/+6%), 50?60 Hz, 50 VA max
Temperature Range: 0? C to +40? C Operating; ?20? C to +60? C Storage
Humidity: 90% RH to at least +40? C (noncondensing)
EMC: Complies with 89/336/EEC, CISPR 22 (class B), and FCC 15 subpart J (class B)
The Portable One Plus measures amplitude, signal-to-noise, distortion (THD+N) , SINAD, IMD (option), frequency, wow & flutter, input impedance plus AC mains check. Portable One Plus Access includes comprehensive analog generation and measurement, with two outputs and two inputs. Easy-to-set-up sweep capability produces graphs of frequency response, distortion vs. frequency and even amplitude sweeps. Non-volatile storage of up to 30 tests allows easy one-button recall of your favorite test setup. Connect Portable One to a compatible printer and produce reports incorporating high-resolution graphs.
Here are some pictures that can do a great deal of talking:
Following some shots of equipment being tested
Gainclone amplifier with Pass crossover unit on-board - confirming its x-over point
Audio Research LS5 line amplifier distortion measurement
Yamaha C2a phono stage curve confirmed
