Pro-2 vs. Tom Oberheim SEM

[DavidDever]

Apologies if this thread seems fairly opinionated, without any audio samples to back these claims up.

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination, mostly in an attempt to offload patches that I would normally use the SEM for, to the Pro-2 for ease of recall, etc. It's hardly scratching the surface, mind you, of what the combination can do, with or without CV patching into the SEM from the Pro-2–that said, I think I've got a handle on some comparisons between the two voices:

• The Tom Oberheim SEM filter response seems to vary with oscillator pitch, even when keyboard tracking is turned off, making it quite complicated to match the filter response between it and the Pro-2's SEM implementation (which does not seem to vary when keyboard tracking is turned off). Of course, the same also applies once keyboard tracking is turned on–and as the SEM filter does not self-oscillate, it becomes quite difficult to guess where the variance occurs; I believe that I had to add some additional negative tracking to approximate the response at the Pro-2.
• The SEM ramp/sawtooth wave contains more fundamental than the Pro-2 sawtooth, so it is necessary to add an additional sine wave underneath to match the timbre. The girth, drive or air controls do not change this.
• Once you have a reasonable approximation, the Pro-2's girth ( 64 ), air ( 32 ) and drive ( 8 ) controls can be used to mimic the even-harmonic distortion that occurs when the Tom Oberheim SEM filter resonance is in the uppermost position.
• The two units together, panned slightly within the stereo field, give you a pretty good idea as to what a Two-Voice (Pro or otherwise) might sound like. And it's awesome.

So my shallow recommendation is that the Pro-2 + SEM combo is absolutely killer–but you might have guessed that anyway. 

Also - it is most definitely possible to approximate the sound of a monophonic SEM voice on the Pro-2, provided that you spend a little bit of time to add some chaos to your final patch.

I'm gonna guess that the OB-6 variant of the SEM design likely has compensated for many of these irregularities in response, some of which would be quite beneficial, others which might very well be somewhat annoying if you were trying to match the response across multiple SEM units (or SEM filter-equipped voices).

[Shaw]

Apologies if this thread seems fairly opinionated, without any audio samples to back these claims up.

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination, mostly in an attempt to offload patches that I would normally use the SEM for, to the Pro-2 for ease of recall, etc. It's hardly scratching the surface, mind you, of what the combination can do, with or without CV patching into the SEM from the Pro-2–that said, I think I've got a handle on some comparisons between the two voices:

• The Tom Oberheim SEM filter response seems to vary with oscillator pitch, even when keyboard tracking is turned off, making it quite complicated to match the filter response between it and the Pro-2's SEM implementation (which does not seem to vary when keyboard tracking is turned off). Of course, the same also applies once keyboard tracking is turned on–and as the SEM filter does not self-oscillate, it becomes quite difficult to guess where the variance occurs; I believe that I had to add some additional negative tracking to approximate the response at the Pro-2.
• The SEM ramp/sawtooth wave contains more fundamental than the Pro-2 sawtooth, so it is necessary to add an additional sine wave underneath to match the timbre. The girth, drive or air controls do not change this.
• Once you have a reasonable approximation, the Pro-2's girth ( 64 ), air ( 32 ) and drive ( 8 ) controls can be used to mimic the even-harmonic distortion that occurs when the Tom Oberheim SEM filter resonance is in the uppermost position.
• The two units together, panned slightly within the stereo field, give you a pretty good idea as to what a Two-Voice (Pro or otherwise) might sound like. And it's awesome.

So my shallow recommendation is that the Pro-2 + SEM combo is absolutely killer–but you might have guessed that anyway. 

Also - it is most definitely possible to approximate the sound of a monophonic SEM voice on the Pro-2, provided that you spend a little bit of time to add some chaos to your final patch.

I'm gonna guess that the OB-6 variant of the SEM design likely has compensated for many of these irregularities in response, some of which would be quite beneficial, others which might very well be somewhat annoying if you were trying to match the response across multiple SEM units (or SEM filter-equipped voices).

Found this post when trying to do a little research on one of my “hair-brained” ideas.  My thought was to get a two SEMs (one SEM-Pro MIDI & Patch Panel, and one SEM Patch Panel), control them with my Pro2, and voila, I’d have something approaching an Oberheim Two Voice Pro, though perhaps more flexible in a way (considering all of the the Pro2’s CV routing possibilities)


Thoughts?  Would it be better to have two of the MIDI SEMs instead of one MIDI SEM and one with just the patch panel? 

[DavidDever]

Apologies if this thread seems fairly opinionated, without any audio samples to back these claims up.

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination, mostly in an attempt to offload patches that I would normally use the SEM for, to the Pro-2 for ease of recall, etc. It's hardly scratching the surface, mind you, of what the combination can do, with or without CV patching into the SEM from the Pro-2–that said, I think I've got a handle on some comparisons between the two voices:

• The Tom Oberheim SEM filter response seems to vary with oscillator pitch, even when keyboard tracking is turned off, making it quite complicated to match the filter response between it and the Pro-2's SEM implementation (which does not seem to vary when keyboard tracking is turned off). Of course, the same also applies once keyboard tracking is turned on–and as the SEM filter does not self-oscillate, it becomes quite difficult to guess where the variance occurs; I believe that I had to add some additional negative tracking to approximate the response at the Pro-2.
• The SEM ramp/sawtooth wave contains more fundamental than the Pro-2 sawtooth, so it is necessary to add an additional sine wave underneath to match the timbre. The girth, drive or air controls do not change this.
• Once you have a reasonable approximation, the Pro-2's girth ( 64 ), air ( 32 ) and drive ( 8 ) controls can be used to mimic the even-harmonic distortion that occurs when the Tom Oberheim SEM filter resonance is in the uppermost position.
• The two units together, panned slightly within the stereo field, give you a pretty good idea as to what a Two-Voice (Pro or otherwise) might sound like. And it's awesome.

So my shallow recommendation is that the Pro-2 + SEM combo is absolutely killer–but you might have guessed that anyway. 

Also - it is most definitely possible to approximate the sound of a monophonic SEM voice on the Pro-2, provided that you spend a little bit of time to add some chaos to your final patch.

I'm gonna guess that the OB-6 variant of the SEM design likely has compensated for many of these irregularities in response, some of which would be quite beneficial, others which might very well be somewhat annoying if you were trying to match the response across multiple SEM units (or SEM filter-equipped voices).

Found this post when trying to do a little research on one of my “hair-brained” ideas.  My thought was to get a two SEMs (one SEM-Pro MIDI & Patch Panel, and one SEM Patch Panel), control them with my Pro2, and voila, I’d have something approaching an Oberheim Two Voice Pro, though perhaps more flexible in a way (considering all of the the Pro2’s CV routing possibilities)


Thoughts?  Would it be better to have two of the MIDI SEMs instead of one MIDI SEM and one with just the patch panel?

Funny, I'm considering something similar, though I'm not sure as to whether it makes more sense to attempt to control them via CV/gate (no dependency on internal microprocessor) or MIDI at this point; I'm concerned that the firmware on the MIDIed units might itself be dicey / unsupported in the future.

[Shaw]

Funny, I'm considering something similar, though I'm not sure as to whether it makes more sense to attempt to control them via CV/gate (no dependency on internal microprocessor) or MIDI at this point; I'm concerned that the firmware on the MIDIed units might itself be dicey / unsupported in the future.

Understood.  Recent stories of Tom’s health issues and the fact that he seems to be a one man organization are both cause for concern.

So, I did so more internet reading and research and listening.  I decided to get 2 Analogue Solutions Telemarks.  Along with the Pro2, that setup will be as capable and and flexible as I should ever need from a monosynth. I’ve already snagged the 2 Telemarks from Reverb.  They will be delivered early next week! 

[Sacred Synthesis]

Keep in mind that the Telemarks have no glide/portamento.  Last year I was on the verge of buying two myself, until I became aware of this strange omission.  The Analogue Solutions instruments sound fabulous.  But glide is such a fundamental element that it's hard to imagine not having it.

[Shaw]

Keep in mind that the Telemarks have no glide/portamento.  Last year I was on the verge of buying two myself, until I became aware of this strange omission.  The Analogue Solutions instruments sound fabulous.  But glide is such a fundamental element that it's hard to imagine not having it.

Right, and there’s no way to approximate the sound using the Pro2 CV outs, is there?  I suppose one could you and envelope to modulate the pitch amount, but no really the same thing.

[DavidDever]

Keep in mind that the Telemarks have no glide/portamento.  Last year I was on the verge of buying two myself, until I became aware of this strange omission.  The Analogue Solutions instruments sound fabulous.  But glide is such a fundamental element that it's hard to imagine not having it.

Right, and there’s no way to approximate the sound using the Pro2 CV outs, is there?  I suppose one could you and envelope to modulate the pitch amount, but no really the same thing.

You'd need an external lag processor (in Eurorack, likely)....

[Shaw]

Keep in mind that the Telemarks have no glide/portamento.  Last year I was on the verge of buying two myself, until I became aware of this strange omission.  The Analogue Solutions instruments sound fabulous.  But glide is such a fundamental element that it's hard to imagine not having it.

Right, and there’s no way to approximate the sound using the Pro2 CV outs, is there?  I suppose one could you and envelope to modulate the pitch amount, but no really the same thing.

You'd need an external lag processor (in Eurorack, likely)....

Yeah... if it bothers me that much, I’d sell the Telemarks and get SEMs or Boomstars.

[Sacred Synthesis]

The Analog Solutions Leipzig has glide, but its square wave is actually a pulse - rather nasal sounding, rather than the classic hollow.

[Shaw]

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination...

You wouldn't happened to have recorded that dynamic duo would you?

Cheers!

[DavidDever]

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination...

You wouldn't happened to have recorded that dynamic duo would you?

Cheers!

I ought to–but with a newborn in the house, I'll be getting to it at _some_ point

[Shaw]

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination...

You wouldn't happened to have recorded that dynamic duo would you?

Cheers!

I ought to–but with a newborn in the house, I'll be getting to it at _some_ point

Ah... you've got way more important things going on... Congratulations!

[Sacred Synthesis]

So–I've finally had a chance to tinker around with my DSI Pro-2 + Tom Oberheim MIDI-to-CV SEM combination...

You wouldn't happened to have recorded that dynamic duo would you?

Cheers!

I ought to–but with a newborn in the house, I'll be getting to it at _some_ point

Ah... you've got way more important things going on... Congratulations!

I second that, David.  Congratulations on the little new maestro.  Have you sampled his/her cry yet?