[sdiy] Prebuilt bipolar 15v supply?

Fri Oct 12 16:03:12 CEST 2007

Hi Sam,

If I were in your shoes, I would probably build a small linear power supply 
and feed it with a 12 or 15VAC wall wart.  You'd just need a small board 
with a few regulators, diodes, caps.... pretty simple.

Bipolar wall warts are a bit harder to find, and they are generally pretty 
expensive.

Doesn't Paia sell a linear power supply kit?  I can't remember (and don't 
really have the time to search at the moment.)  I thought they had one that 
attached to their "power wing" or something

Dave

----- Original Message ----- 
From: "Sam Ecoff" <secoff at execpc.com>
To: "Kevin" <kevingeo at gmail.com>
Cc: "Synth DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Friday, October 12, 2007 9:23 AM
Subject: Re: [sdiy] Prebuilt bipolar 15v supply?

> hi Kevin,
>
> Thanks for the info. I probably should have been a bit more  forthcoming 
> with my plans, because I think you would have answered  differently. 
> Anyhow, here's a bit more in-depth explanation of what  I'm planning to 
> do....
>
> Ray Wilson has kindly granted me permission to build and sell some of  his 
> modules commercially. I'm going to be offering them in Frac  format in 
> which case the power supply isn't a problem because that's  up to the 
> user. However, I realized that I could reach a wider  audience if I also 
> offered an optional wooden case for the sequencer  where the wide (9 
> space!!) frac module could slide in and become the  front panel. The only 
> little hang up I'm faced with is providing a  power supply. As I said in 
> my original post, this is not something  I'm comfortable building myself 
> (at least not at the moment). So, I  was hoping to find a pre-built 
> supply, preferably a wall-wart sort of  affair, because if the user has 
> the option to open the case to put in  or remove the sequencer for 
> racking/unracking, I don't want high  voltages floating around in there 
> where some one could get hurt. Thus  the appeal of a wall wart. The other 
> really appealing thing is that  the wall wart is pre built and all I would 
> have to do is just buy  them from Mouser, and I can get more of them as 
> time goes on (hence  my lack of interest in power supplies from Ebay). 
> So... knowing the  complete circumstances behind my question, what would 
> anyone on the  list recommend? Perhaps a wall wart with an voltage 
> regulation system  inside the case that would be completely low-voltage?
>
> Regarding my blacet supplies, yes they are expensive, but the reason  I 
> went with them is that I had originally thought I'd need only 3 (ha  ha) 
> and that would power all the modules I'd ever have or want.  (Funny how 
> that works, isn't it?) So, they've just accumulated over  time. I'm very 
> pleased with them, however, and wouldn't consider  selling them. Plus, 
> given that my modular is bolted to the wall,  whatever solution I go with 
> has to be accessed strictly from the  front of the unit, so implementing a 
> system where I have a wiring  harness would be difficult at best. It's 
> just one of those things  where at the present time, I know I could 
> actually make money by  selling off the Blacet supplies and buying one 
> huge supply, but it's  just not worth the time I'd have to spend to make 
> it happen. Plus, I  don't have any real worries about dirty power as the 
> studio has a  $50,000 power conditioning unit in the basement which 
> (supposedly)  keeps everything really clean electrically. I've never had 
> an issue  with a ground loop.
>
> Thanks guys...
>
> Sam E.
>
>
>
> On Oct 12, 2007, at 2:46 AM, Kevin wrote:
>
>> I should probably mention that if you are uncomfortable getting
>> something like that used, Allied Electronics is their distributor.
>> They cost quite a bit more new, but not so much compared to what you
>> should be able to sell your 6 blacet power supplies for.
>>
>> https://www.alliedelec.com/default.asp
>>
>> On 10/12/07, Kevin <kevingeo at gmail.com> wrote:
>>> Hi,
>>>
>>> You probably don't want a wall wart.  You want a regulated linear
>>> supply where the output voltage is trimmable.  A lot of wall warts
>>> like this will have voltages that fluctuate a lot.  It wouldn't be
>>> unusual for 15v to really mean 17 or 19v.
>>>
>>> The specs say that supply regulates to +/-5%, which would be from
>>> 14.25 to 15.75 volts.  If you use this power supply to power an
>>> oscillator I suspect it will cause the pitch to drift.  If it goes
>>> over 16 or 17 volts you may be into the range of possibly damaging
>>> components on modules, so be careful.
>>>
>>> You might be interested in one of these two power supplies:
>>>
>>> http://cgi.ebay.com/ws/eBayISAPI.dll? 
>>> ViewItem&rd=1&item=7596518741&ssPageName=STRK:MEWA:IT
>>>
>>> http://cgi.ebay.com/ws/eBayISAPI.dll? 
>>> ViewItem&rd=1&item=7602669028&ssPageName=STRK:MEWA:IT
>>>
>>> I have the 5 amp version and am using it to power a bunch of Doepfer
>>> modules.  It will output +/-15v or +/-12v.  I bought it from that  same
>>> ebay seller.
>>>
>>> You do have to wire an electrical plug to it, but that isn't
>>> exceedingly difficult.  If you are uncomfortable doing that part
>>> yourself you could probably find someone to do it for you.  The only
>>> other thing you have to do is calibrate the output voltage with the
>>> trimmers, which requires a voltmeter.
>>>
>>> This is basically the same power supply used by Cynthia/Cyndustries,
>>> people use it for MOTM systems, and also the plan B space case uses a
>>> similar supply from the same company.
>>>
>>> I have a link somewhere with someone showing how they wired their  MOTM
>>> system with this type of power supply if it would help you.
>>>
>>> Thanks,
>>> Kevin
>>>
>>> On 10/11/07, Sam Ecoff <secoff at execpc.com> wrote:
>>>> Hi All...
>>>>
>>>> Can anyone recommend a cost effective prebuilt power supply? I am
>>>> aware of the Blacet PS 500 (great supply, already own 6 of them).  I'm
>>>> planning to build Ray Wilson's 16 step sequencer (http://
>>>> www.musicfromouterspace.com/analogsynth/SEQ16_2006/SEQ16_2006.php)
>>>> and put it in a separate case.  Hence, another PS500 would really be
>>>> overkill. I did a bit of searching, and came across this supply...
>>>>
>>>> http://tinyurl.com/yt67t9
>>>>
>>>> Seems like it would do everything I want it to do, but this is
>>>> uncharted territory for me, so maybe there's something I'm  missing...
>>>> The only problem I see with it is that it terminates in a five pin
>>>> DIN plug, which means that at some point some student or an  intern is
>>>> going to say "Oh... I found the other end of that MIDI cable!" and
>>>> plug it into a MIDI jack on whichever piece of gear would cause the
>>>> greatest catastrophe at the moment...
>>>>
>>>> I know that I could save a lot of money by building my own supply,
>>>> but this is not something I'm currently comfortable doing. I don't
>>>> feel that it is safely within my skill set, which means that it's
>>>> probably best that I don't attempt it. ;-) I'm also aware that there
>>>> are some prebuilt supplies that I could put in the enclosure, but to
>>>> keep the unit as small as possible, I'd like to go with an external
>>>> supply.
>>>>
>>>> Thanks in advance...
>>>>
>>>> Sam E.
>>>> _______________________________
>>>> Sam Ecoff
>>>> Tanner/Monagle
>>>> 1120 N. Market St.
>>>> Milwaukee, WI 53202
>>>> (414) 727-8190
>>>> www.samecoff.com
>>>
>>
>
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