DCO just means the tuning of the analog oscillators are digitally controlled. This was a big selling point when it came out (no more pitch drifts, manual tuning, waiting to warm up etc) but these days the more unstable (but improved) VCO synths are often the most desirable, even though they are considerably more costly to build.
1 Like
Yeah, a DCO is an analog oscillator.
It’s synced to the frequency of a digital counter. The counter works as a frequency divider, counting the pulses from a master clock and outputs a square wave when a predetermined value is reached.
The square wave, is used to output a reset pulse which discharges a capacitor in the oscillator. This way, the oscillator frequency is the same as the counter frequency.
On a VCO, the control voltage directly controls the frequency of the oscillator.
You can apply modulation directly to the control voltage to do fm and pm.
Afaik that’s how it works…there might be other ways to implement the control part, but…
Certainly, both are analog
3 Likes
Like I think the guy said earlier, the DCO’s are easily uniform, with VCO’s you have to use a voltmeter and test each component for the voice/VCO and literally go through multiple’s of the same part, sifting out the one’s that have the same response, because even though you have parts that are the same part, they don’t behave perfectly the same every time like a digital chip and the manufacturer’s have a basic kind of leeway in what variances are acceptable enough to consider them a good part over a bad one. Plus general room temperature, humidity, all factor in to how those parts will perform, like how you have a warm up period for old analog synths before they perform to the expected standard. So it takes more to give you uniformity in the voices, which takes more time than just slapping a ‘Digital’ Control chip in there which automatically gives you the same uniformity over the voltage which has more variables and results in that kind of imperfect ‘classic’ analog tone, with the minor variations in the parts behaving slightly differently.
So just to make each synth they’re say, testing a pile of the same part, like a resistor or transistor and then grouping out of that pile a small number from that, that match in response to the voltmeter to give you the closest possible uniformity in performance. Which as you can guess takes more time, and more money to buy all those duplicates in parts that will be sifted through for each synth.
There is probably more to it but that is what I have learned basically over the years, and so then your also paying someone the labor hours to do this, and as you can see, up goes the price… like the OB-6, it’s quite a hefty price tag, at least for me, but the quality and performance are made at that premium level to the standard Tom has and yeah I’m sure it’s a little of the whole legendary status of the OB’s too, but you are getting a poly OB from Tom and Dave that set the specs for it themselves.
1 Like
Because what sounds “good” and “bad” to people is subjective.
Why worry about any of it if you have gotten to know and really enjoy what you have?
1 Like
This is exactly why there is a cost difference as you stated.
On the REV2 you have custom DSI IC’s that are full synth voices. Those chips have the majority of the external components built into the chip to tune all of the components (VCA’s Transistor pairs etc…). After setup costs, the wafer manufacturing of those chips is very inexpensive.
On OB6 etc you have separate VCA chips that are used with precision external components like 0.1% precision resistors which are expensive to make.
This means there are a lot more expensive components to make each individual part of the synth circuit (VCO,s, Filters, VCA’s, etc). This also means that each voice will sound slightly different because the external components will never be perfect.
On a chip, precision and consistency is better due to the manufacturing process. In theory this is better and definitely cheaper on a large scale. But I think those imperfections are what some people like about the OB6 etc…
REV2 is probably a more perfect synth (due to the voice chips), but we all know that imperfection is sometimes preferred and can subjectively sound better.
The ones with separate voice cards is probably a design feature. Due to the fact that the voice cards vary they probably match sets of voice cards based on some tests. If these were on the main board, components would have to be desoldered and matched. Much more work than swapping a card.
Things like the REV2 can be on one board because the chips are so precise that there is no voice matching required.
4 Likes
I’m not worried, I’m curious.
2 Likes
Fortunately for my wallet, I’m not too fussed about Analog vs digital. I gravitate towards harsher, grittier sounds, and if I want a nice thick pad, my summit (with its reverb) gets me where I’m happy.
I remember when the sub 37 came out people complained about its slightly overdriven character. That’s what I like about it. Each to their own.
Most of the mythos behind Analog gear comes from tracks treated with a load of outboard processing anyway, IMO.
1 Like
Cool! Apologies for the more cynical take on that, then.
Been explained more accurately elsewhere surely, but certainly the greater complexity of design and more specific, less generically available components, smaller scale of industry, larger designs and more manual labor would cause the simpler, small package designs to be cheaper to mass produce.