PLAN B analog blog

This explains why Billy Idol's White Wedding showed up in the audio in
one of my videos.  Not a huge deal for me since it was inaudible once
the patch was started.



On Fri, Jan 9, 2009 at 8:00 AM, (i think you can figure that out)
<peter@buzzclick-music.com> wrote:
> There's a lot of words on this problem on this and other lists.
>
> It's ain't the M15's fault, partially an attribute of the
> Frequenstiener's open loop transistor-based final amplifier stage and
> largely due to the fact that Doepfer, Analogue Solutions and Analogue
> Systems daisychain the ground connections on their busboards. Big no no.
>
> In fact you'd be able to hear LFOs out of the Frequen. if there was
> one if those powered in the same rack. It could be Doepfer's, A.
> Sys's, A. Sol's or mine. Put a Harvestman microp based module in the
> same rack and your filter frequency will wiggle as if slightly
> controlled by a squarewave LFO. Sounds like I'm bagging these guys,
> I'm not - they're my friends. I'm making a comment about the
> potential risks of daisychaining ground connections - those part of
> the power distribution system AND those used on the circuits
> themselves, in audio applications. You'll find on most Plan B
> modules the grounds go on their own trace directly to the power
> connector. These are the types of safeguards you must put in play to
> keep things a quiet as possible. BUt this type of safegaurd goes out
> the window on a power buss that ties it's grounds n a row instead of
> individual feeds directly back to the PSU return.
>
> One thing you can do to kill the potential from the M15 contributing to this
> keeping the square wave pot adjusted to the far left far right when it's not
> being used, thus holding the square in it's DC range and not generating a
> signal.
>
> While we're at it, an even more interesting attribute of the Steiner circuit
> is if metal can 2N2222 transistors were used, putting your finger on one or
> more of them while the unit is under power, depending on your location
> you'll receive AM and Ham radio transmissions through the speakers. Your
> location does not govern if it happens or not, your location onlydetermines
> how busy the airwaves are, increasing the likelihood there's a station at
> the filter's frequency band. basically there's an antenna in play. I've
> pulled this anomaly from Cynthia, Ken Stone's and Elby's Stiener filters -
> it's not them, it's the circuit.
>
> But in particular I need to stress this isn't Mike's issue. I was there when
> he put this together, I got the Synthasystem schematic from Nyle for him.
> Mike did an excellent job of reconstructing the original design and I
> commend him for that. Not Mike's fault, it's the circuit but as a filter it
> sounds marvelous, so (in a nice way), deal with it!
>
> Also remember that the original Steiner system was line level. Euro
> is four times hotter. With that, the potentisal of this occurring is four
> times as great. Such is the way things are in the 21th century when people
> are pulling circuits from the old days and integrating them into
> environments they weren't intended to be exposed to. Know though that I'm as
> guilty as the rest of them with the M13.
>
> To chill this down a bit, try increasing the 10mf electrolytic caps
> which filter the power inputs of the Frequenstiener. Then increase
> any bypass caps used in the circuit. I'd be careful though - a cap is
> littered with caps, some as bypass, and some part of the filtering
> circuit. Basically the .01's should be increased to .1 but do a
> listen test after each to make sre the particular cap isn't part of
> the filter structure. Sorry, I can't publish the Stiener circuit, this
> comes form a request of Nyle's. The Synthacon schematic is all over
> the place, this one is very similar but has more diodes in the ladder.
> Yu know what 90% of white noise circuits are based on? Diodes or
> transistors configured as diodes...it's a tough thing keeping them
> hushed form picking up any sort of noise floatng around the power buss.
>
> Also try putting the filter in a rack without any alternating current
> sources or modules whih have microps, especially Harvestman. This
> improves things a lot. As a last resort, consider the purchase of the
> Plan B cases when they are released Q1 2009. All of our ground
> terminations, from every terminal on the busboard lead directly to the
> ground source on the PSU - no daisychaining!
>
> - P
>
> --- In PLAN_B_analog_blog@yahoogroups.com, "theglyph2000"
>
> <theglyph.aaron@...> wrote:
>>
>> My model 15 can be heard through my FrequenSteiner through the power
>> rails. Not a big deal but just curious.
>>
>> The 15 and the AFG are working f@#$ing great for me! Peter and Mike
>> are doing it right!!!
>>
>> Cheers,
>> theglyph
>>
>
>