PLAN B analog blog

The big issues with switchers is the ripple and frequency which they 
oscillate (they are named as they are because the current actually 
turns on and off many times second).  If they're switching rate is in 
the audio band, you're f'd.  We are looking into ones that ocsillate 
in the 60K range so we're fine. The ripple out of the gate on 
switchers is huge, over 100 mv, ten times the amount of a linear 
supply.  But this can be filtered and regulated.  Botton line, to 
compensate for their rather huge energy defecit (thank you, Emron), 
legislation is in the works in California that will make it illegal 
to product machinery which operates on linear supplies with the 
exception of emergency medical equipment. SO unless we start making a 
defibulator module we will have problems in the future anyway.

- P




--- In PLAN_B_analog_blog@yahoogroups.com, Chris Muir <cbm@...> wrote:
>
> 
> While I may have described the Salamander (SMS) power supply system 
as  
> overkill, it was only so in the cost / weight department. In the  
> stability department it is really terrific. I have never used a 
more  
> stable analog synth. The combination of system wide coarse 
regulation,  
> local +/- 15V regulation, and system wide clean & dirty ground 
really  
> made for a clean power supply. As I think I mentioned before, once 
a  
> module was tuned, it could be swapped into another system, and 
retain  
> its tuning, because of the local regulation.
> 
> That said, I love the way the supply works in my 200e. The fact 
that  
> the switchers are hidden under the buss board of the middle boat, 
and  
> that the switchers use the aluminum case as a heat sink is really  
> clever. It makes the system really light, too. I love that the 
200e  
> takes DC input, also. I have visions of playing the 200e in a 
field  
> somewhere with a solar panel.
> 
> I have no experience in running all-analog VCOs on this power 
supply,  
> but I bet it would work fine. Buchla is meticulous about this 
stuff. I  
> may find out when Cyndustries ships their ZOe.
> 
> The historic, perceived, problems with using switchers for analog  
> systems fall into two main areas: radiated RF and ground noise. 
The  
> ground noise issue, if it even exists with modern switchers, could 
be  
> taken care of with an appropriate bypass cap / power distribution  
> scheme. If the RF radiation thing was a problem with modern 
switchers,  
> it would show up in the 200e, I think (and it doesn't.) The spacing 
is  
> really tight between the switching supplies and the modules in the  
> middle boat.
> 
> –C
> 
> On Apr 22, 2008, at 9:36 AM, (i think you can figure that out) 
wrote:
> > The cases which are under development now include a rack system 
and
> > two desktop chassis, one single and one double width. I suppose 
they
> > could be used on the road but it would require an outer shell.
> > Possibly when these are released we will address mobile solutions.
> >
> > Presently we are working on the power system. There is a lot of
> > banter about the ills of using switching power supplies for 
powering
> > synthesizers, and while all of the instances which come up in 
these
> > discussions are just, none of them make the case that it's bad
> > technology, just that is can be troublesome wen not handled 
correctly.
> > What I'm saying is I'm not convinced by any means. I would really
> > like to use switching supplies. They're much more efficient, they
> > save the user and the planet energy, they're lighter and they take
> > much less space. This is where we are with the cases.
> >
> > Even though Buchla's e is largely digital, there is a lot of 
audio  
> > circuitry and he is running this system on a switcher. If Don is  
> > willing to take this risk so am I.
> >
> > Chris Muir...you have inside experience with Salamander, do you 
have  
> > any feelings on this?
> >
> > - P
> >
> > --- In PLAN_B_analog_blog@yahoogroups.com, "Igor Medeiros"
> > <igormpc@> wrote:
> > >
> > > this topic really makes me want to hear more about the new 
cases...
> > > 3 types, just big university systems ?
> > > or any small enough to travel with / play live ?
> > >
> > > or some motivity news?
> > >
> > 
http://launch.ph.groups.yahoo.com/group/PLAN_B_analog_blog/photos/view
/abc9?b=7
> > >
> > > :)
> > >
> > >
> > > On Tue, Apr 22, 2008 at 2:12 AM, mritenburg <mritenburg@> wrote:
> > >
> > > > I'm looking at it right now and I see: Mini Milton + ELF LFO 
+ ELF
> > > > ADSR + Heisenberg + 3x VCO + Dual LPG + Headphone Pre = a 
good  
> > chunk
> > > > of the features of the 208. You would need to add reverb, 
balanced
> > > > modulation, mic pre, inverter, patch saving, and (of course) 
a  
> > touch
> > > > controller. From the looks of the new modules, it looks 
possible  
> > to
> > > > have a uniquely Plan-b instrument with more feature than an  
> > easel in
> > > > a similar portable package.
> > > >
> > > > Matt
> > > >
> > > > --- In
> > PLAN_B_analog_blog@yahoogroups.com<PLAN_B_analog_blog 
> > %40yahoogroups.com>,
> > > > amnesia <amni56@> wrote:
> > > > >
> > > > > Now if you can make a Music Easel you would clean 
up...sooooo  
> > much
> > > > > demand for something like this :-)
> > > > >
> >
> 
> Chris Muir
> cbm@...	
> http://www.xfade.com
>