The Expressionist, a review

[BJ]

Rob wrote:

> 
> Inside there's a 68k of some sort controlling the whole machine. 

Which one , a 68302,68332,68HC12 etc ???



> choice for such a box. It's got power for days for this job and isn't
> likely to ever be bogged down by the requests of the user.  Many boxes made
> these days put the cheepest processor in the box that they can get away
> with and that is fine for 80% of the uses of the box.  The manufacture
> saves money and the box is cheeper.  But then when you push those boxes you
> get timing errors.  Timing errors are the bane of beat oriented musician.
> With the 68k the Expressionist wont have this problem.

Thats not all of the truth, it depends on what the box have to do,
LFO's,HZ/volt etc
and it depends on how well written the code is.
 
> The mother board is layed out with separate power supplies for the
> processor and the analogue circuits.  This is important because it keeps
> processor noise from effecting your CVs.  Again this costs more and most
> manufactures wont include this on their machines. 

Ouch!! costly!!
But there is up to the PCB designer to do a good power layout if
mixed technology are used, usally a +/-1 mV of power noise 
are not causing any problems ! :)

> What effect does this
> have on using the box?  Well you don't have to worry about sending a
> command to the box that will cause a voice that you are holding to go out
> of tune.

> The D/A convertor on the Expressionist is 16 bit. 

Wich one??

> This allows for smooth
> control of your voltages from -3 to +10 volts, more then 32,000 steps. I
> don't know what the other midi to CV boxes are using (I'm sure you can find
> out though), but this seems to be yet another place where the Expressionist
> has done the job right.

Many boxes uses 8 bitters infact,and then you have to use multiturn
pots to set the scaling of the CV. many boxes uses 12bitters (as mine
does).
Most 12 bitters uses software scaling of the CV's, depending on the
range
the DAC has to work at, 0 to + 8volt as a example. 
And as you say some uses 16 bitters. 

For any modular or regular synths using 1/v oct 12 bit is more then
enough
for any unit using HZ/v then 12 bits will do up to a sertain voltage
range.
If software scaling is still to be used. 16 bits is of course the best
solution
but then you have to do a very good powersupply (ground path) for not to
lose 
any bits in the converter due to noise.
  
> The code for this machine is all in an FPGA, meaning that you can down
> load, from Encore's website (http://www.encoreelectronics.com),

In a FPGA?????
That is strange , are you sure on this , perhaps you ment "Flash" or
EEPROM!!

> The whole user interface has been given a lot of thought. For instance the
> buttons have great debounce code. This means that they don't double trigger
> when you press them. After many years of use this becomes even more
> important as the switches start to fail, and yes all switches wear out.

Hmm, any synth and for that matter Midi to CV converters who uses 
momentary buttoms has debounch code applied in the software in some
form so that i dont think this is a reference for "qualiy factor" to
use.
And how can you know that the debounce code is great?? Have you
dissasemble the code???
 
> The buttons also repeat as you hold them and will speed up if you hold them
> for a moment.  Very nice indeed, but there's more too.  Hold one button and
> tap another will take you to the end of the allowable values.  Very trick.
> There's more here too, but you get the idea. Somebody though about using
> this box.

Nice function implemented!
 
> Pitch bend only goes 1 octave.  This seems a bit arbitrary to me. 

Most converters use this range ,due to the fact that most manufacturers
only decode the 7 bits of the pitch bend midi code.

> the great things about a CV synth is that there is no real difference from
> a voltage received from a pitch bend or a new note.  So you can have some
> really wild pitch bending going on. This would require some boundry code,
> but it's something that could be implemented.
 
> The wall wart, I hate, but Encore is a one person shop.  Every thing is
> done by one guy.  The hardware, software, testing, shipping - every thing!
> So taking the wall wart rout saved him lots of FCC and UL hassle.

Keep on the good work!!
 
>Would I buy one? Yeah I already did. Encore is known for making quality
>products.  The Expressionist does them proud. If you are serious about what
>you are doing and want some serious control over your CV machines then this
>is the box.

Thanks for the review!
I to think Encores CV converter is among the best, sad its "wery"
expensive here!

BJ