Kurzweil DMTi

The DMTI is a digital format converter fairly universal, with generation / clock resynchronization.

It can handle 4 inputs and 4 digital outputs stereo formats, and can route each other very freely through the selectors on the front. These I / O formats:
- KDS (Kurzweil specific): 1 input and 1 output
- AES / EBU: 2 inputs and 4 outputs
- S / PDIF Optical 1 input and 1 output, coupled with the first entry and the first output AES / EBU
- ADAT or TDIF with one of two optional cards

It can serve as master clock generator (word clock) and sample rate converter. It thus has an input and an output word clock (in NLC).

Each selector on the front is a digital bus output, and allows you to select which input bus is connected. The stereo pairs of output formats are all connected together. For example, the Stereo 2 out on both the AES / EBU 2, Bus 3-4 of the optional ADAT or TDIF (denoted MDM) and the stereo bus output KDS B (to cascade two DMTI, or out to an effects processor or a Kurzweil K2600).

Notes specific to K2500/K2600:
- KDS entry vehicle is also in the other direction on a stereo bus output (connected to the first switch) to the digital input card of a sampling K2500/K2600 if it is equipped
- For use with a DMTI K2500, it must be equipped with the optional KDFX; for use with a K2600, it must be equipped with the optional DIO-26
- The K2600 only (not K2500), we can use the output of the KDS DMTI to inject information about the 4 internal stereo bus it

A fifth selector selects the clock source to use as reference for all outputs. All input signals are then resynchronized on the clock (with possible conversion of sampling frequency), which is extremely convenient.

To clarify things a bit, here is a concrete example of use in my studio. FYI, I own a Yamaha 02R console with ADAT and TDIF cards, one of KDFX K2500X provided and thus the KDS interface, and a few other instruments in digital output (S760, E6400 and ASR-10).

ADAT output and the output clock (word clock) of the DMTI are connected to corresponding inputs of the 02R.
The K2500 is connected to the cable DMTI KDS (which is nothing other than a VGA cable for PC) bus carrying the four digital stereo.
The output of ADAT E6400 (which is equipped with the optional one) is plugged into the ADAT input of DMTI, and S / PDIF outputs S760 and the ASR-10 on the AES / EBU inputs of DMTI.

With this system, can be connected on 8 of the 02R channels allocated to any of the card ADAT digital inputs of DMTI example is the 4 bus K2500 if you want to simultaneously record four of his instruments without any mixing, the same goes for the E6400, a mix of all instruments connected (eg, a bus K2500, E6400 2 bus, the S760 and the ASR-10) ...
The huge advantage is that as DMTI resynchronizes everything and can generate its own clock (which is also much cleaner than the internal clock of 02R), there are no clocks to worry about of a particular instrument, and no more "clicks". In addition, by connecting the word clock of the corresponding input of the soundcard (I have a MOTU 2408 Mk2), a digital channel is perfectly synchronized.

It is therefore the ideal system to work with a digital mixer or sound card equipped with digital inputs. If my 02R was equipped with AES / EBU and ADAT not (I bought it used), I could use the AES / EBU outputs of DMTI.

These features are therefore a very interesting, almost unique in the market (the proposed rates in hand) and not necessarily restricted to owners K2500/K2600. Just a small defect that can be annoying for certain configurations: it works only up to 48 kHz. In addition, Kurzweil is unclear, even contradictory, on the maximum resolution of DMTI used with K2500. The manual says it works DMTI up to 26 bits from the K2500 (which works by default for 20-bit digital output), but the KDFX says the resolution does not exceed 16 bits. Where is the truth? I simply do not know, I left the K2500 20-bit mode and everything works ...

OVERALL OPINION

This small device (brand new very expensive at the time, but much more affordable in hand) has revolutionized the way I work, since it allowed me to completely homogenize my digital home studio, keeping up to signals in the digital conversions without parasites, and managing digital clocks with great efficiency (often a nightmare for owners of such studio).
Highly recommended to all owners of digital consoles, not least for his word clock generator often more stable than the internal clocks of the consoles, while remaining much cheaper than a dedicated generator certainly more effective, but rather reserved for the wealthy studios because of its price. And if you have a more K2500/K2600 is happiness, especially since the D / A converters of the K2500 is not what is the best in my opinion ...