For Violectric V800 I would like to contribute for once.
There is a great uncertainty about how it sounds for now.
Well, we have done everything that he does not sound.
Sound is a very subjective matter, the one like something that does not like the other.
Basically, we go with the design of our equipment before so that we measure first and then listen.
Only when improving the FFT spectrum can no longer are we satisfied.
And to include a "UPL" from Rohde & Schwarz and two "D-Scope III" by Prism Sound available.
There are 4 analog and 2 digital storage of Texas Instruments.
Significant differences in sound, there should be not in "good" actually DACs, marginal already.
Why is that?
If we augehen them arriving a perfect digital signal
then convert all "premium device" at a high level with the same chips.
Namely PCM1792 and AD1955 and derivatives and derivatives.
Somewhat lower quality found CS4398 or PCM1793.
Theoretically, there is still the top about it ESS9012/9018.
We have just the test and unfortunately he does not behave really better than PCM1792 ...
The transducer, it can not be the.
The analog output is the key.
Here is filtered, buffered, amplified.
And here all manufacturers work a little differently.
If this is found in the thread that you need when no line-V800 driver to operate further away boxes, it is because that has the V800 really about professional outputs.
The matches will be driven over the radio in sometimes even 300 meters cable.
This requires a very low impedance outputs that are at the V800 level adjustable and remain low. A feature which some devices in the market obviously missing.
All modern converters have power outputs, so they must necessarily use the inverting inputs of an operational amplifier. Bandwidth is not required, on the contrary, because here also still the same, the low pass is that filters out any high frequency noise of the converter.
At this point we do not have the same tension drying on the signal because of the D / A converter is only one voltage (3.3V or 5V), the analog output electronics but with + / 15 - 18 V.
A conventional D / A converter chip has an output voltage of up incidentally +8 dB = 2.5 volts.
After the filtering stage at Violectric is the level matching - unfortunately in the unit because the circuit is so sensitive that they do not like long lines.
Here Ausgangsspanungen of +24, 18, +15, +12, +6 dBu are set for the digital full scale. The above values are for the balanced output.
Because of the unbalanced output has its own independent drivers, here are always at 9 dB lower level. Next is active in the level adjustment stage the dc offset of the transducer eliminated - without Elko!
It follows the balanced output signal in the same way as we do it 100,000 times for radio, television and studios - with low resistance and excellent value for THD, frequency response, dynamics, common-mode rejection.
As mentioned above, there are [url] before [/ url] the balancer a branch for the active single-ended output.
These are plenty of operational amplifiers in the signal path. Nevertheless, we achieve a dynamic range of 120 dB and THD (THD) of -112 dB.
The digital receiver before the transducer is also a sample-rate converter.
Here you will - if required - takes the resampling / upsampling.
The USB receiver has the little peculiarity that he is from the connected computer has power. Recovered from the USB signal PCM signal is passed through an isolation transformer on the remaining circuit. This computer and D / A converters are safely isolated and excluded the possibility of hum.
The sample rate converter extract the digital audio data, and recombine it with its own clock.
This measure jitter in the input signal is eliminated almost completely.
This works konstuktionsbedingt all input signals. USB signals can thus also the technically less demanding "asynchronous mode" can be omitted.
A sample rate converter way, is a highly complex matter. The first integrated solutions were introduced in the mid '90iger.
Since there was a very rapid Development has come to a standstill for several years because the physical maximum is reached in practice.
SRC has a modern and distortion and dynamic range beyond 140 dB, making it superior to any computer solution. Especially with odd changes!
There are different modes selectable V800:
- OFF = SRC off
- X 1 = SRC activated, input and output clock rates are equal
- X 2 = SRC switched input to sim output clock rate ratio of 1:2
Since this is not for values above 110 kHz, this mode does not then be selected
and the unit will automatically because firstly a lower mode.
- X 4 = SRC switched input to sim output clock rate ratio of 1:4
Since this is not for values above 55 kHz does this fashion can not be selected
and the unit will automatically because firstly a lower mode.
- = Best it all incoming sample rates converted to approximately 94 kHz.
The conversion of the love the most!
Many people are not aware that each D / A converter halved above 110 kHz be oversampling.
So about 3 dB THD and dynamics will be lost - and bring the vague prospect of a tonal event from 45 to 90 kHz for playback ...
The overall volume of the V800 is controlled in the digital domain in 256 steps of 0.5 dB.
Of course, bits cut off and that's not so bad, bad how much alleged.
Some do it differently, namely analog with digital control, with so-called DCA's - Digital Controlled Attenuator. The Lake People at the end of the last millennium used in 7.1 controller VOL CON-F38, so we know from the technical and sonic .... Idiosyncrasies.
Besides the fact that a digital potentiometer not noisy, does not scratch, does not know any synchronization problems and no crosstalk problems, it is also dynamic the better solution!
If we assume that the output level of the anaolge V800 is set correctly on the following equipment for this purpose a few small bills:
First
A 16-bit CD signal is extrapolated in the V800 to 24 bits.
Now you can cut 8 bits = 48 dB = factor of 200 before the original quality of the CD is ever attacked.
... and at such low volumes, no one can make a Ausage about the quality of the program or want!
or 2
Who ever recorded himself, the white, which can be for a single-track to realize a dynamic about 60-70 dB only in exceptional cases. The rest is noise in the truest sense.
This maximum displayable dynamic limits but also the maximum realizable distortion attenuation.
One more is in itself the sum of noise - also a digital mixer - contrary.
Of course you can still come through good mix this or that bit of it.
More than 90 dB dynamic range with the corresponding distortion attenuation can be realized but never and are not really useful - we are talking about ratios of 30,000:1!
A digital system with 144 dB dynamic always has about 50 dB more headroom.
or 3
The maximum achievable system dynamics of a stereo system at 130 dB.
An amplifier, the volume control goes beyond the 9 rare clock position limitert in the system dynamics by 20-30 dB.
So there is much less choice than if you were to regulate digital.
Greeting
Fried
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