oneQ Specifications
Input impedances: |
Mic: 1.2kohm; Line: 20kohm |
Pre-amp overall
gain: |
10dB to 60dB (variable) |
Common mode
rejection: |
70dB |
Equivalent
input noise: |
-128.5dBu (unweighted) |
Distortion:
|
0.001% (below Compressor threshold) |
Frequency response: |
15Hz to 70kHz (-3dB) |
Maximum input
before clipping: |
Mic: +21dBu; Line:
+45dBu |
Headroom before
clipping: |
+21dBu |
Compressor
threshold: |
∞dBu to -20dBu (variable) |
Compressor
ratio: |
1:1 to 10:1 (variable) |
Compressor
attack time: |
1 msec to 100 msec
(adaptive) |
Compressor
release time: |
0.1 sec to 3 sec (adaptive) |
Nominal output
levels: |
+4dBu/-10dBv |
Output impedance: |
100ohm |
Output Level
switch: |
12dB attenuation |
Noise Floor: |
-85dBu (typical, with ~40dB mic gain) |
VU Meter: |
Analogue movement |
Power supply: |
115V / 230V ac mains, 50/60Hz |
Power consumption: |
30W |
Mechanical: |
482W x 88H x 220D (overall) |
Weight: |
3 kilos |
High Pass Filter: |
12dB per octave cut below 80Hz |
EQ Boost & Cut: |
+/-15dB (zero phase-shift bell response) |
LF Frequency : |
80Hz/120Hz switchable |
LMF Frequency : |
200Hz to 2kHz variable |
HMF Frequency : |
1kHz to 6kHz variable |
HF Frequency : |
7kHz/14kHz (selectable) |
EQ “Q” |
0.9 (1.6 octaves |
Digital Output Specifications
Sampling: |
24 Bit |
Resolution: |
24-bit delta sigma using Wolfson WM8738 ADC |
Sampling Rate: |
44.1kHz, 48kHz, 88.2kHz or 96kHz
selectable |
Output Formats: |
AES3 compliant (balanced), S/PDIF
electrical |
| Oversampling: |
This is [sample frequency divided by twice the bandwidth]. So for a 20kHz bandwidth sampled at 96kHz, oversampling = 2.4x.
However the term oversampling is sometimes confused with [clock frequency divided by sample rate]. In the DB-1 that would be 256x at 96kHz |
| Noise Floor: |
typically 92dB A-weighted (referenced to 0dBFS = +18dBu). So for a +4dBu signal, the SNR is 78dB |
| Distortion: |
typically 0.01% @ 0dBu (20Hz - 20kHz) at 96kHz sample rate
typically 0.02% @ 0dBu (20Hz - 20kHz) at 48kHz sample rate
typically 0.02% @ -1dBFS (20Hz - 20kHz) at all sample rates |
External Word
Clock input: |
75ohm, 1.25V - TTL level, 44.1kHz
to 96kHz (auto synchronising) |
Crosstalk: |
typically -67dB (20Hz - 20kHz) |
Digital
Interface
The Joemeek Digital Audio Interface provides high quality
digital audio outputs plus the ability to synchronize to
an external word clock. The digital audio outputs are compatible
with most digital recorders, as well as Digital Audio Workstations
and mixers. S/PDIF format is available from the RCA phono connectors, while the transformer coupled
XLR connector provides an AES3 compatible output.
The Joemeek
Digital Interface has highly stable onboard master clocks
for low-jitter, hi-fi results. Internal sample rates of 44.1kHz,
48kHz, 88.2kHz or 96kHz are selected by means of rear panel
switches. 44.1kHz is the standard used for audio CD's, while
48kHz and 96kHz are widely used in recording studios. In
general, the higher the sample rate, the better the audio
fidelity, but the more disk space is required for the recording.
For example, recording at 96kHz requires twice as much storage
as 48kHz. Consult the manual of your recorder or DAW as to
what sample rates it will accommodate.
Alternatively the oneQ may be set
to the frequency of an external master word clock, generated,
for example, by the studio's recorder or DAW. When connected
to the BNC socket provided, a suitable external word
clock will be detected automatically and will override
the twinQ's internal word clock.
The front panel LED labelled
'EXT CLK' illuminates when the oneQ is successfully locked
to an external word clock. To avoid distortion, care should
be taken not to overdrive the input to the Digital Interface.
The red LED next to the Output Gain control is labeled "PEAK
FSD" which stands for "Full
Scale Digital". Occasional flashes are OK but if it is on
all the time, turn something down!
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