No, it's NOT a filter at all. It a non-linear wave shaper. What I don't get is why are some so passionately *against* sine waves? I must violating some unwritten analog commandment here but can't figure out what it is. After all, most vintage modular VCOs had clean sines - what's wrong with that? All I asked was which VCO generated undistorted sines and got lots of rude replies and insults. My favorite is the very angry guy below who is pushing I get banned from this group! Yikes... --- In Doepfer_a100@yahoogroups.com, Monroe Eskew <monroe.eskew@...> wrote: > > I don't get it... If the upgrade just filters the triangle in a better > way, then an LPF should do the same work. If your real concern is > additive synthesis, then perhaps you should get the digital RS370, or > a computer program. Or perhaps use self-oscillation on a filter that > has good tracking? > > > On Dec 2, 2008, at 4:13 PM, laryn91 wrote: > > > I wouldn't send mine back to Germany either. > > > > But I would buy upgrade boards and wire them in for all my Doepfer > > oscillators (110, 111, > > 145, etc.) > > > > --- In Doepfer_a100@yahoogroups.com, Bakis Sirros > > <synth_freak_2000@> wrote: > > > > > > ok, i could do that poll. > > > Dieter, any more specific details for the poll? > > > > > > btw, in case there was a modified Sine circuit for the A111 > > produced, i would be > > probably not bothered to send my 8 A111's back to doepfer to be > > 'converted' with the new > > sine design... it would be much trouble and time lost, for me... > > > > > > > > > Bakis Sirros - Parallel Worlds / Interconnected / Memory Geist > > > [Doepfer_a100] group owner > > > www. parallel - worlds - music. com > > > www. myspace. com/ parallelworldsmusic > > > www. myspace. com/ interconnectedmusic > > > www. myspace. com/ memorygeist > > > www. DiN. org. uk > > > www. musicamaximamagnetica. com > > > www. shimarecords. co. uk > > > www. rubberrecords. gr > > > Athens - Greece > > > > > > --- On Wed, 12/3/08, york luethje <ybl@> wrote: > > > > > > From: york luethje <ybl@> > > > Subject: Re: [Doepfer_a100] Re: Sine wave discussion - Poll > > suggestion > > > To: Doepfer_a100@yahoogroups.com > > > Date: Wednesday, December 3, 2008, 12:52 AM > > > > > > > > > > > > > > > > > > > > > > > > > > > Couldn't we just have a poll? My suspicion is that the practical > > value of very good > > analogue sine waves will be high for only some. As Dieter posted, an > > earlier discussion > > then fizzled out and didn't result in any product modifications. > > Maybe the discussion has > > shown there there is indeed a lot of (commercially tangible) > > interest in an oscillator with a > > very good sine output. On the other hand, maybe the interest is more > > intellectual and > > doesn't incite people to actually part with their money and buy the > > new design. A poll > > could give us at least an indication. I suggest something like this > > > > > > "Do you want Doepfer to modify the sine-converter in the A-111 to > > produce a purer > > sine wave? The cost increase would be in the 5% - 10% range." > > > > > > York > > > > > > ____________ _________ _________ __ > > > From: Monroe Eskew <monroe.eskew@ gmail.com> > > > To: Doepfer_a100@ yahoogroups. com > > > Sent: Tuesday, December 2, 2008 3:39:52 PM > > > Subject: Re: [Doepfer_a100] Re: Sine wave discussion > > > > > > Couldn't we just use a standard LPF for this? > > > > > > On Dec 2, 2008, at 11:46 AM, James Husted wrote: > > > > > > > The part of this circuit that does the conversion seems pretty > > > > straight ahead and looks simple enough to make as a stan-alone > > module. > > > > If one was needing to make sines and had a triangle VCO already > > (that > > > > made a decent Triangle wave) then a converter module would work > > fine - > > > > a bit esoteric for mass production though. > > > > -James > > > > > > > > PS - sorry to all for starting this thread with my Z3000 post. I > > had > > > > my questions answered a long time ago.. > > > > > > > > On Dec 2, 2008, at 10:38 AM, laryn91 wrote: > > > > > > > > > Sorry, I missed the "will" part :-p > > > > > > > > > > I had this link to the Aries VCO in one of the posts on this > > > > > (endless) thread. This is an > > > > > excellent tri-to-sine converter (I can't hear any additional > > > > > overtones). Better than the more > > > > > common 3080 converter and significantly better than your diode > > > > > converter. Aries claimed > > > > > to produce <1% THD. > > > > > > > > > > http://www.leinerme dia.net/aries/ AriesSchematics/ AR-317s.gif > > > > > > > > > > I'm not sure why you found adding a slightly filtered triangle > > > > > sounding wave useful when > > > > > there's already a triangle wave output. My suggestion is if your > > > > > customers are not > > > > > interested in a clean Sine output, use the panel real estate for > > > > > something more useful. > > > > > > > > > > --- In Doepfer_a100@ yahoogroups. com, <yahoo@> wrote: > > > > > > > > > > > > You find my answers written inline. > > > > > > > > > > > > Best wishes > > > > > > Dieter Doepfer > > > > > > > > > > > > > -----Ursprüngliche Nachricht--- -- > > > > > > > Von: Doepfer_a100@ yahoogroups. com > > > > > > > [mailto:Doepfer_ a100@ yahoogroups. com]Im Auftrag von > > laryn91 > > > > > > > Gesendet: Dienstag, 2. Dezember 2008 17:20 > > > > > > > An: Doepfer_a100@ yahoogroups. com > > > > > > > Betreff: [Doepfer_a100] Re: Sine wave discussion > > > > > > > > > > > > > > > > > > > > > > And we will point out in the module information and user's > > > > > guide of > > > > > > A-110 > > > > > > > > and A-111 that the sine outputs should be called more > > > > precisely > > > > > > "sine-like". > > > > > > > > > > > > > > Dieter, > > > > > > > > > > > > > > It's probably just me, but where do you point that out for > > the > > > > > A-111? > > > > > > > > > > > > I wrote that "we will", not that "we did". That's the future > > tense > > > > > from what > > > > > > I learned in scool - but I'm not a native speaker. > > > > > > > > > > > > > >If you want a perfect sine you need a VCO with a sine core. > > > > > > > > > > > > > > Instead of an impossible "perfect sine", how about just a > > sine > > > > > with no > > > > > > *audible* overtones > > > > > > > (<1% THD) like Arp, Moog, Aries, Polyfusion, EML,etc. used > > to > > > > > make? That > > > > > > would now > > > > > > > make the A-111 useful for additive synthesis and FM. > > > > > > > > > > > > > > All you need to do is copy their simple but superior > > > > > > > triangle-to- sine converter design. ;-) > > > > > > > > > > > > Though I can't believe that they really reach <1% THD (but > > indeed > > > > > I never > > > > > > measured it): do you (or anybody else in the group) know the > > > > > circuitry of > > > > > > these converters. Are they made with diodes, OTAs or the JFET > > > > > circuit (these > > > > > > are the three triangle-to- sine converter principles I > > know). I > > > > > don't have > > > > > > the schematics of these VCOs. > > > > > > > > > > > > We would have offered a VCO with a more perfect sine in the > > past. > > > > > But it > > > > > > took more than 12 years (the A-111 is available since spring > > 1996) > > > > > until > > > > > > someone complained about the poor sine. I'll see what we can > > do. > > > > > Maybe we > > > > > > offer a small tri-to-sine converter board for the A-111-1 > > that can > > > > > be used > > > > > > instead of the simple diode converter. > > > > > > > > > > > > There was a similar discussion about 2 years ago (~ September > > > > > 2006) and Tim > > > > > > Stinchcombe suggested an improved sine wave converter based > > on the > > > > > JFET > > > > > > principle. We have built a prototype of this converter in > > 2006 but > > > > > the > > > > > > discussion fell asleep very soon and it seemed that nobody was > > > > > interested > > > > > > anymore. We could dig this design and offer it as an > > addendum to > > > > > the A-111-1 > > > > > > or equip all new A-111-1 with this board. The additional > > charges > > > > > would be in > > > > > > the 15 Euro range (about 10 electronical parts mounted on a > > small > > > > > board). > > > > > > > > > > > > Best wishes > > > > > > Dieter Doepfer > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > > > > > > > > > [Non-text portions of this message have been removed] > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > > > > [Non-text portions of this message have been removed] >
Message
Re: Sine wave discussion - Poll suggestion
2008-12-03 by laryn91
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