6v & 90v DC Power supply
in [Design]
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From: Spehro Pefhany on 28 Dec 2005 20:28 On Thu, 29 Dec 2005 01:06:02 GMT, the renowned Rich Grise <richgrise(a)example.net> wrote: >On Wed, 28 Dec 2005 22:03:48 +0000, Joerg wrote: > >> Hello Rich, >>> >>> It seems like, no matter how closely you try to mimic the waveform of a >>> real instrument,... >> >> >> I have a feeling that this is exactly the problem. Engineers try to >> mimic the output waveform instead of looking how the real instrument is >> built. If they did that, they'd try to emulate all the individual parts >> and pieces. >> >> Regards, Joerg >> >> http://www.analogconsultants.com > >Yabbut, how many gyrators and phase shifters and stuff does it take to >model, for example, a bowed string? ;-) > >Thanks! >Rich Whatever it is, if it has to come out of speakers it isn't going to sound quite right. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: Joerg on 28 Dec 2005 21:13 Hello Spehro, > > Whatever it is, if it has to come out of speakers it isn't going to > sound quite right. > In case of a Hammond organ it might since it has a speaker. Of course, it's a tube amp but that is a whole other matter which alone could make this thread balloon. It'll take a lot of gyrators and filters but considering that one can buy a 400MHz DSP for less than a crate of beer these days it should be feasible. In case of our piano the DSP still couldn't win. The piano doesn't need power. Not even light since it has its own candles. Regards, Joerg http://www.analogconsultants.com
From: nothermark on 28 Dec 2005 21:24 On Tue, 27 Dec 2005 18:59:56 GMT, Joerg <notthisjoergsch(a)removethispacbell.net> wrote: >Hello Jim, > >> Do it the way the original radio did it -- dynamotor. You can still find >> them in the back room at a lot of military surplus electronics junk stores. >> > >But then be prepared for some major restoration. The bearings of a lot >of these are nearly shot, mostly from sitting in an attic for decades. >It's like old pond pumps. They run fine for a few weeks and then the >racket increases, some weird noises appear, things get hot and they >seize up. > >I restored an old Hammond organ. These generate the tones in a similar >manner. A motor (plus a start motor) and over a hundred pickup coils on >the long secondary shaft. 20 hours of hard work got it going again but >we have accepted the fact that some of the bearings are pretty much over >the hill. So it needs 2-3 starts to coax it to run without that mild >screeching in the background. Getting spare parts from a company that >went out of business 30 years ago just isn't going to happen. > >Regards, Joerg > >http://www.analogconsultants.com what kind of bearings? - ball bearings are like tubes - thay have numbers and substitutes. Bronze bearings are routinely made by machinists. Babbit is hardest as it is poured in place but you might be better off replacing them with something else like bronze. Bearing technology is not all that complicated if you poke into the right group of folks.
From: Spehro Pefhany on 28 Dec 2005 21:37 On Thu, 29 Dec 2005 02:13:05 GMT, the renowned Joerg <notthisjoergsch(a)removethispacbell.net> wrote: >Hello Spehro, >> >> Whatever it is, if it has to come out of speakers it isn't going to >> sound quite right. >> > >In case of a Hammond organ it might since it has a speaker. Of course, >it's a tube amp but that is a whole other matter which alone could make >this thread balloon. Don't some of them have rotating speakers? > >It'll take a lot of gyrators and filters but considering that one can >buy a 400MHz DSP for less than a crate of beer these days it should be >feasible. In case of our piano the DSP still couldn't win. The piano >doesn't need power. Not even light since it has its own candles. > >Regards, Joerg > >http://www.analogconsultants.com Sure, but can you flip a switch and be playing the flute or er-hu? Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: Michael A. Terrell on 29 Dec 2005 00:11
Spehro Pefhany wrote: > > Don't some of them have rotating speakers? That is a "Leslie" speaker. I have to service the one at my church. The bearings are shot. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |