Bias Peak Pro 6 Serial Number
Download >>> https://urlin.us/2t4NVj
Sidebar 3: MeasurementsI examined the Meridian Explorer's electrical performance with Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It.") For some tests, I also used my vintage Audio Precision System One. I used the supplied USB cable and played files with Bias Peak Pro running on my MacBook Pro, using Apple's AudioMIDI utility to make sure that the data output from the USB port had the correct sample rate and bit depth. I performed a complete set of measurements from both the line-level and headphone outputs, but most of what I describe here is the Explorer's performance from its line output; I comment on the headphone output only when it differed.Apple's USB Prober utility identified the Explorer as "Meridian Explorer USB DAC," operating in isochronous asynchronous mode. Although there was no serial number on the product itself, USB Prober identified our sample as having serial no.020005BC. The Explorer operated correctly with data sampled at 44.1, 48, 88.2, 96, 176.4, and 192kHz, with a word length identified as "24 bit Integer."The maximum output level at 1kHz was 2.124V from the line output with my laptop's volume control set to its maximum, but 2.2dB lower from the headphone jack, at 1.745V. While the line output preserved absolute polarity (ie, was non-inverting), the headphone output inverted absolute polarity. The line-level output impedance was a fairly high 466 ohms at low and middle frequencies, dropping slightly to 457 ohms at the top of the audioband, which is why this jack should not be used to drive headphones. The headphone output impedance was a low 5.25 ohms at all audio frequencies, which is appropriate for driving even low-impedance headphones.The Explorer's impulse response with 44.1kHz data (fig.1, taken with a test signal comprising digital black, into which I had inserted one sample at 0dBFS) reveals the reconstruction filter to be a minimum-phase type, with all the ringing occurring after the impulse. The blue trace in fig.2, taken with 44.1kHz-sampled white noise, reveals the filter to be a minimum-phase type with a sharply defined null at 0.55Fs. I originally thought this filter to be an apodizer, of the type pioneered by Meridian, with a null at half the sample rate, but I misread my own graph. It has less stop-band rejection than a conventional filter at higher frequencies: the red trace in fig.2, which is the wideband spectrum of a full-scale, 44.1kHz-sampled tone at 19.1kHz, shows that the 25kHz aliasing product is suppressed by only 55dB or so. The third harmonic of the 19.1kHz tone, at 57.3kHz, is the highest in level at –69dB (0.03%).Fig.1 Meridian Explorer, impulse response (one sample at 0dBFS, 44.1kHz sampling, 4ms time window).Fig.2 Meridian Explorer, wideband spectrum of white noise at –4dBFS (left channel blue, right cyan) and 19.1kHz tone at 0dBFS (left magenta, right red), with data sampled at 44.1kHz (20dB/vertical div.).Fig.3 shows the conventional plot of frequency response, taken with data sampled at 44.1kHz (green and gray traces), 96kHz (cyan, magenta), and 192kHz (blue, red). The ultrasonic responses with the two higher sample rates are very similar, the 96kHz response dropping sharply above 47kHz, the 192kHz response smoothly rolling off to reach –3dB at 70kHz. The CD response (green, gray) is a little different, in that the rolloff at 20kHz is not as pronounced as at the higher sample rates, and the channel levels are better matched. Channel separation (not shown) was good rather than great, at 71dB at 1kHz from the line output, 59dB from the headphone output.Fig.3 Meridian Explorer, frequency response at –12dBFS into 100k ohms with data sampled at: 44.1kHz (left channel green, right gray), 96kHz (left cyan, right magenta), 192kHz (left blue, right red) (0.5dB/vertical div.).Consistent with Stereophile's tests of digital products going back a quarter century, my primary test of resolution is to sweep a 1/3-octave bandpass filter from 20kHz to 20Hz while the DAC reproduces a dithered 1kHz tone at –90dBFS with both 16- and 24-bit data. The result is shown in fig.4: with both 16-bit data (top pair of traces) and 24-bit data (middle pair of traces), the spectrum peaks at exactly –90dBFS, implying low linearity error. (This was confirmed with a separate test, not shown.) The 16-bit noise floor in this graph is actually the spectrum of the dither used to encode the data. With 24-bit data, the noise floor drops by up to 15dB, suggesting resolution approaching 19 bits, which is excellent considering that the Explorer is powered by the host computer's USB bus, and readily enough to allow the Meridian to resolve a 24-bit tone at –120dBFS (bottom traces). Modern FFT analysis (fig.5) confirms the excellent resolution.Fig.4 Meridian Explorer, 1/3-octave spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with 16-bit data (top) and 24-bit data (middle), and at –120dBFS with 24-bit data (bottom) (right channel dashed).Fig.5 Meridian Explorer, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (10dB/vertical div.).With its low noise and excellent resolution, the Explorer had no problem reproducing an undithered 16-bit tone at exactly –90.31dBFS (fig.6), with a symmetrical waveform clearly describing the data's three DC voltage levels, and with a hint of the reconstruction filter's asymmetric ringing on the leading edges. With 24-bit undithered data (fig.7), the Meridian output a clean sinewave despite the very low signal level.Fig.6 Meridian Explorer, waveform of undithered 1kHz sinewave at –90.31dBFS, 16-bit data (left channel blue, right red).Fig.7 Meridian Explorer, waveform of undithered 1kHz sinewave at –90.31dBFS, 24-bit data (left channel blue, right red).The Explorer offered very low levels of distortion from its line output (fig.8), with the highest-level harmonic into the high 100k ohm load the subjectively innocuous second harmonic, at a very low –96dB (0.0015%). This graph indicates that the left channel (blue trace) had slightly higher levels of higher-order harmonics, though not to any significant extent. The Explorer's headphone output, tested into a lower load of 300 ohms (fig.9), both had higher levels of distortion—the second harmonic is still the highest, at –80dB right (red trace, 0.01%) and –86dB left (blue, 0.005%)—and a regular, if low-level, series of higher-order harmonics visible. Tested for high-frequency intermodulation (fig.10 shows the line output spectrum; the headphone output was similar, if somewhat worse), the Explorer shows only mild rejection of the imaging products at 24.1 and 25.1kHz, though actual intermodulation products are low in level. Again, the left channel is slightly worse than the right.Fig.8 Meridian Explorer, line output, spectrum of 50Hz sinewave, DC–1kHz, at 0dBFS into 100k ohms (left channel blue, right red; linear frequency scale).Fig.9 Meridian Explorer, headphone output, spectrum of 50Hz sinewave, DC–1kHz, at 0dBFS into 300 ohms (left channel blue, right red; linear frequency scale).Fig.10 Meridian Explorer, line output, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 0dBFS into 100k ohms (left channel blue, right red) (linear frequency scale).With a USB connection operating in asynchronous mode, a DAC should be immune to the effects of interface-related word-clock jitter. Tested with a 16-bit version of the Miller-Dunn J-Test signal, the Explorer hardly affected the levels of the odd-order harmonics of the low-frequency, LSB-level squarewave (fig.11), though some low-frequency, random spectral spreading of the spike that represents the high-level 11.025kHz tone can be seen. With 24-bit J-Test data (fig.12), the harmonics and sidebands have disappeared as expected, but the spectral spreading is still evident.Fig.11 Meridian Explorer, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 16-bit data via USB from MacBook Pro (left channel cyan, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.Fig.12 Meridian Explorer, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 24-bit data via USB from MacBook Pro (left channel cyan, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.Even without considering that it has to operate on the 5V supply available from the USB bus, Meridian's Explorer offers generally superb measured performance.—John Atkinson COMPANY INFOMeridian Audio Ltd.US distributor: Meridian America Inc.110 Greene Street, Suite 407New York, NY 10012(646) 666-0140www.meridian-audio.comARTICLE CONTENTSPage 1 Specifications Associated Equipment Measurements Log in or register to post comments COMMENTS usb cable Submitted by jaywillin on August 30, 2013 - 2:18pm i believe there are several companies that make aftermarket usb cables, with all the necessary connector types at either end of the cable, and at differing degrees of quality, when i had the explorer, i used an audioquest forest usb cable.
As an additional method to rule out potential unrelated biases on the serial dependence effect, we explored the effect of future trials on the current response (Fornaciai & Park, 2020; Maus et al., 2013). That is, we compared the current trial response error to the difference in shape between the current and following trial (n-forward). Since observers have not seen the future trial shape, their current response in a given trial should not be in any ways related to the shape that will be presented to them next.
Spatial tuning of serial dependence. A refers to Experiment 1, whereas B refers to Experiment 2. Each red dot refers to a different relative angular distance between current lesion and lesion in the 1-back trial, super-subject bootstrapped mean. For example, a bin distance 0° indicates that current and previous simulated tumor presented at the same location (30° of angular distance, for example). Error bars are bootstrapped 95% confidence intervals. Dashed line indicates half-amplitude zero (no bias) 2b1af7f3a8
https://sway.office.com/9fucmNBg5TzjXxwn
https://sway.office.com/KqMNw94LejYTA84q
https://sway.office.com/0DUYkieYpWRU4ZsH
https://sway.office.com/avqeeUha4HxZa3vL
https://sway.office.com/eJBpeVKsoCZXCuQ3
https://sway.office.com/Sh4kFK7dBQJ5Pbsc
https://sway.office.com/sYqp3cZxF9DrWl8H
https://sway.office.com/EnA7r3hrO83HrvmC
https://sway.office.com/oCJClV7YwMfUs24r
https://sway.office.com/jCwcB36cDdis7QRb
https://sway.office.com/6KRPDtuH9WcAR2Nl
https://sway.office.com/bPfamB7m49V3vb12
https://sway.office.com/k5fDErSOy64Kl0rE
https://sway.office.com/QwacN9mS5pjWF6Y4
https://sway.office.com/3G11vMxVnSDgpZCd
https://sway.office.com/l7ozIvLZYBKDtCln
https://sway.office.com/DT6DfDMJmCkh5dSU
https://sway.office.com/fb908mXgOsZTJ0sJ
https://sway.office.com/DrIXRDROh7uqEP4R
https://sway.office.com/P2J7grWOLjPPU6lg
https://sway.office.com/o12iAk6n3eshcOb2
https://sway.office.com/khWy4v02WiedNaOP
https://sway.office.com/nvCjF3iNx60YTEaL
https://sway.office.com/rLG5F5CAp69pLbM1
https://sway.office.com/90FkOP1LkGOgBtAd
https://sway.office.com/yOO1BrXoThfTD8wg
https://sway.office.com/VBMlstha0aK3oFif
https://sway.office.com/DCLVpbBEPhOnQGgj
https://sway.office.com/vkCWxnMa3dQkceud
https://sway.office.com/LX3hb9WtssSFYhz6
https://sway.office.com/QEwfGY895GbNIyy1
https://sway.office.com/SFRQLxIh7Nl8FeeT
https://sway.office.com/JHp6FnXsxVM4L1CP
https://sway.office.com/GReFLyCiPaKXRORF
https://sway.office.com/1VZmQjbdXeukDd3Q
https://sway.office.com/po1ZvLTEmvnyszUK
https://sway.office.com/H0PcoMBrJZYwpKMF
https://sway.office.com/jP25jAbqqGb6D41n
https://sway.office.com/VvEmlQU3r3T1rDEW
https://sway.office.com/n4zGdb4w3Cqt0HNX
https://sway.office.com/D9aQfiosCCiXT7Un
https://sway.office.com/DYkuvQF6X2qR0dzh
https://sway.office.com/xFD4GAXkDRHgDrJe
https://sway.office.com/eaxkVuD0HDnSgbR9
https://sway.office.com/JFBXzyT7kgrvXcA6
https://sway.office.com/PffWswrUBcMzynZX
https://sway.office.com/GShh0IztCqXoYd07
https://sway.office.com/xJB1YNeNRLVC3fqv
https://sway.office.com/FBzan1bW4sTdCeNi
https://sway.office.com/XKhOFWmXUzf2GtZK
https://sway.office.com/aCfjvn9qTmdVpMOs
https://sway.office.com/r4A8QpmniGRXYpUD
https://sway.office.com/ezrSZsm6sZgovcAm
https://sway.office.com/SVj4zsK80EE5WBKr
https://sway.office.com/1q7MUCiYZkbo8JwJ
https://sway.office.com/RJtceqtEbKJPkGEg
https://sway.office.com/423TgsekOj7dz3Ql
https://sway.office.com/OtsKjnu5HxJRNGkM
https://sway.office.com/3iMDO830IouFKmB6
https://sway.office.com/FM25bXIIuajsgS4o
https://sway.office.com/xQoOfjAbUvyDICLQ
https://sway.office.com/CNOpks50DkHnkITh
https://sway.office.com/zvaVUiNHyRgHMCFY
https://sway.office.com/rSxHAtGsdhXbFHf5
https://sway.office.com/wVZcwHAMjQI59kB2
https://sway.office.com/L4nNOnRV7HjLqo8s
https://sway.office.com/7c7Hwd3ThwNJjDMi
https://sway.office.com/sG1jLrIeSt1jbrOi
https://sway.office.com/IMToy5cgXdXZg1KS
https://sway.office.com/klYrOCEfpI6HxHGW
https://sway.office.com/TGB88XyUCCSDrvNe
https://sway.office.com/5Izi9kB4RzhZR6AV
https://sway.office.com/6b5ycte7V2d7qJQJ
https://sway.office.com/x84mYnwO5ypWBiE7
https://sway.office.com/Aj1CiGxhISjPM7Mz
https://sway.office.com/HEtAH5yj0EH73wYa
https://sway.office.com/bXJ7MynpTdGaUmUT
https://sway.office.com/xoH3kjfA6pYz2XtO
https://sway.office.com/E4ZGxU4N7t4IUpSW
https://sway.office.com/7ux1w0oulpZrIAAg
https://sway.office.com/J79pOYC7bjNHW7ye
https://sway.office.com/TkXenQHfrSAJ6t3j
https://sway.office.com/bDZo0mREDaXpenjF
https://sway.office.com/T5GQuYI7RI1YjHL0
https://sway.office.com/yzMpRiPKHqJV1i07
https://sway.office.com/xt6LcMQl7wQ4zCsr
https://sway.office.com/PrtLCUDzNSvAUpQK
https://sway.office.com/HhoxeHAtePhxCiVV
https://sway.office.com/3IWwGFY9dqa3J8Mo
https://sway.office.com/LbxsQjGdiZJ3hhJW
https://sway.office.com/jobhrfiuSTFGryY6
https://sway.office.com/rKa3M1TR0YovQJ26
https://sway.office.com/bhBoL7osVyJbvO7g
https://sway.office.com/xNdKddM4AqAryDUO
https://sway.office.com/CrdJcjG8ZaYWNEV2
https://sway.office.com/SbzqicRRBCxoiYit
https://sway.office.com/cVsj6p7wEZEqoGBM
https://sway.office.com/IiX8Hur7yIycBpp3
https://sway.office.com/ydHdlng5bziLURmC
https://sway.office.com/O5vUhaSBKdwOya6r
https://sway.office.com/YmZ7aUVUZg6Ul0g4
https://sway.office.com/pjDUMziKOXpS3dPg
https://sway.office.com/ZJENaJDNWdVF31zr
https://sway.office.com/aC8gFzdb84z6PXCX
https://sway.office.com/SiV0oVR5C0cPabyM
https://sway.office.com/CUqbp3uByThFMxAm
https://sway.office.com/D7ssMWX0ZzkmzHeD
https://sway.office.com/lWXCuVDuNfRELYYr
https://sway.office.com/BQWHms7l7sjNLr0E
https://sway.office.com/7XBHP6NRiLj7ajxV
https://sway.office.com/VUGcPy6epl0fqiVb
https://sway.office.com/lCNDhRDvO62UxqLT
https://sway.office.com/TBsJldCAYhp2g4fT
https://sway.office.com/BFd3VNrQVqIjMfRQ
https://sway.office.com/Nzod9V3jGpqAytcB
https://sway.office.com/eUjsxFu7eHR6QkSG
https://sway.office.com/wVH5p1J13BExTBL9
https://sway.office.com/ejzh88OQbGle3wou
https://sway.office.com/NaM5kCmcqK22yQBl
https://sway.office.com/jASYo6nJhBxtBkeA
https://sway.office.com/XDpORqyv18FaOPPX
https://sway.office.com/7DXUmvZoD0dlTTYg
https://sway.office.com/3XE8Ct2RfHhvBecV
https://sway.office.com/c6rrELKxWRGtXBBU