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New Product Announcement: Low Impedance Bus Board
MUFF WIGGLER Forum Index -> Eurorack Modules Goto page Previous  1, 2, 3 ... , 19, 20, 21  Next [all]
Author New Product Announcement: Low Impedance Bus Board
Leverkusen
As fas as I understood it, both PSU's/distro boards should share the same 0V which should also be connected to ground. The case/panels should also be grounded to mains, but not directly to 0V as in the Doepfer pic.

I am curious how this question evolves!
GenusModu
Todai,

That seems like a really large case, maybe 4 rows high and 126 hp wide? Are you planning to add more bus boards in the future?

For LIBB system installations make sure you review the LIBB System Wiring Guide: http://www.genusmodu.com/files/LIBB/LIBB-wiring-guide-1_00.pdf.

For the safety ground the Doepfer PSU3 does show the recommended practice of grounding directly to the metal chassis, then carrying the ground to the PSU or bus board. If you have a wood cabinet this practice makes less sense. You can try to ground to your system's aluminum mounting rails but panels with anodized or painted panels will tend to defeat the intended purpose of grounding for prevention of electrical shock.

Every LIBB wiring should use both ground connections wherever possible, to improve the system immunity to common impedance coupling. The PSU3s have multiple ground connections, so use as many as needed.

There should be a ground connection between the two bus boards. This helps reduce patching noise between the two PSU3 sections due to differential in the ground voltages. However, do not ever connect the voltage outputs together between multiple power supplies.

John Loffink
Genus Modu
Todai
Hey John,

Thanks for the answer! Sure enough I grew impatient with all my modules on the floor and went ahead...

It's 10U 138hp. 3157 mA +12V | 1585 mA -12V | 0 mA 5V Two PSU3, one on one to the LIBBs.

I came to the same conclusion about Dieters wiring recommendation - it's for the metal cases. After wiring I checked with my multimeter. All good except a deviation of 0,1V on +12.
There's ground on all the jacks and the cut sides of the modules - but not on the anodized surfaces of the face plates so yes - anodized aluminum is a bad conductor.

The only reason I could think of for (trying to) ground the rails is the danger of an electric shock. Which could only happen if the mains touch them. Which, the way I wired everything, would involve some sort of...traffic accident. In which case...ehm, you get the picture... Mr. Green

The only thing I did not do is connecting ground in between the bus boards. Because it's not in the printed manual (version 1.01). If you say it's critical...matter of removing 4 modules. Since these bus boards are so SLEEK!
Seriously - a JOY to install them and to connect the modules. All components tugged away. Screw terminal housings sit flush against the bottom - no danger of braking anything when tightening the terminal screws. And SHROUDED connectors! No more fingernail torture when swapping modules! thumbs up
GenusModu
Todai,

The LIBB System Wiring Guide guides for a single power supply system so your scenario was not fully covered.

There will be a difference in patch cord induced noise when the grounds are not directly coupled between bus systems. It is no different than if you are patching between two cases with independent power supplies and no direct ground connection. Since you are already wired up I suggest you try it and test for noise.

A typical test would be to patch generators and processors between the two power busses, and then patch a series of mixers with no inputs across them as well. Measure at the final output in the mixer chain for noise with a good 24 bit DAW interface and FFT. This process is subject to variability based on the modules used and how they are patched.

While the electrical theory shows that a low impedance ground across all devices is the best, I have never seen empirical data that quantifies the amount of induced noise. Based upon some limited testing that I have done, I expect the patch induced noise level to be much lower than the common impedance coupled noise that is improved by LIBB.

John Loffink
Genus Modu
Todai
Some final (?) words....there is SILENCE

Incredible. My standards of 'acceptable noise floor' have just changed considerably. When before I could crank the output (with no signal) to about 12 o'clock before I heard all the flavours of my Quantum Rainbow I can now go all the way close to max without hearing anything.


Which brings up the next challenge - that crackle on my speakers every time my fridge switches on / off.

But that's just another can o'worms which we shouldn't open. Or should we? Mr. Green
Todai
Now...since neither Furman / Nortek nor the German distributor could answer my questions I simply ordered the Furman ac6- 210 AE. 14 days no questions asked return policy by Thomann.

So let's try without the power conditioner, first.

Picture me, sitting at my desk. Volume knob WIDE open, same for the door of the ubiquitous noisy fridge, waiting for the beast to kick into gear and emit that dreaded noise.

Fridge starts compressor.

Nothing.

Fridge stops compressor.

Nothing.

hmmm.....

Correct me in case I'm missing something ; but those LIBBs seem to be able to filter that noise?!

seriously, i just don't get it
GenusModu
Todai,

LIBB is neither designed nor tested for reduction of motor induced noise. I won't make any claims there without some methodology to back them up.

My own studio/lab is on a separate circuit from compressors or motors, and I run audio equipment through Tripplite surge protectors with isolated filter banks, so I do not experience noise problems as you have seen. I also do not have the equipment to induce noise spikes on the AC lines.

The Furman conditioners provide additional goodness beyond the noisy fridge issues.

John Loffink
Genus Modu
Leverkusen
I am about to build a new case for my system and wonder if my plans regarding power upgrade with LIBB's makes any sense.

Currently I have two small cases (both 208 HP), one with a Make Noise switched PSU, one with a linear Doepfer PSU2.

I plan to build a studio case now (680 HP, 64 modules +400 mA, -2000mA) powered by the PSU2 and a bigger linear Bel PSU I have here. Of course I will need more bus boards now and want to try the LIBB's. The goal to have them in a linear power system would be to prevent inter module influences. Though my plan is to also reuse the two Doepfer bus boards.

Now my question is if this makes any sense or if different bus boards in one system would rather introduce more problems as they probably are different in impedance?

One thought I had was to at least use one type of bus board with one PSU. Of course both PSU's would share a common 0V.
Rex Coil 7
Beautiful and interesting hybrid design by Member *sduck which employs bus boards with tin plated copper bus bars and linear power supplies.

The wonder that is ~modular synths~ ... so flexible in it's overall design that it allows for combining various pieces of tech in such ways as to satisfy the needs and wants of many folks.


sduck wrote:
So instead of having my euro stuff spread out over 2 mantis cases and a variety of other things, now I have this thing -



I literally just finished it a few minutes ago, so no modules in it yet.

A close up of the power section -



And to give it some mojo, even though these will never be seen -



Oh, and it has some extra bonus bling just for fun (the power for this is well outside of the case) - rgb leds, complete with a remote control -

GenusModu
Rex Coil 7 wrote:
Beautiful and interesting hybrid design by Member *sduck which employs bus boards with tin plated copper bus bars and linear power supplies.

The wonder that is ~modular synths~ ... so flexible in it's overall design that it allows for combining various pieces of tech in such ways as to satisfy the needs and wants of many folks.


sduck wrote:
So instead of having my euro stuff spread out over 2 mantis cases and a variety of other things, now I have this thing -



I literally just finished it a few minutes ago, so no modules in it yet.

A close up of the power section -



And to give it some mojo, even though these will never be seen -



Oh, and it has some extra bonus bling just for fun (the power for this is well outside of the case) - rgb leds, complete with a remote control -



That is what I’d call a “Buchla Slope” cabinet like the one Subotnick used. I love it!

John Loffink
Genus Modu
GenusModu
Leverkusen wrote:
I am about to build a new case for my system and wonder if my plans regarding power upgrade with LIBB's makes any sense.

Currently I have two small cases (both 208 HP), one with a Make Noise switched PSU, one with a linear Doepfer PSU2.

I plan to build a studio case now (680 HP, 64 modules +400 mA, -2000mA) powered by the PSU2 and a bigger linear Bel PSU I have here. Of course I will need more bus boards now and want to try the LIBB's. The goal to have them in a linear power system would be to prevent inter module influences. Though my plan is to also reuse the two Doepfer bus boards.

Now my question is if this makes any sense or if different bus boards in one system would rather introduce more problems as they probably are different in impedance?

One thought I had was to at least use one type of bus board with one PSU. Of course both PSU's would share a common 0V.


Hi Leverkusen,

Some clarification here, inter module noise is not improved by linear power supplies. That is a function of the power distribution, primarily wires and bus boards.

Linear PSUs are known for lower generated noise and ripple levels, normally under 5mVpp, whereas common switching PSUs including most euro PSUs will have 50-150 mVpp of noise, much of that in high and ultra audio frequencies.

If you must reuse the Doepfer bus boards, keep them with the Doepfer PSU2 and put as many noise maker modules on those bus boards: sequencers, modules with blinking LEDs, LFOs, VCOs, anything that generates voltages rather than processing it.

Then for the Bel PSU and LIBBs put your audio processing modules: DSP, VCFs, Mixers, VCAs, Ring Modulators, Waveshapers, preamps and so forth.

I would avoid mixing the bus boards in the same system. If the Doepfer bus boards are still too noisy you can replace them further down the road.

John Loffink
Genus Modu
Leverkusen
GenusModu wrote:
Leverkusen wrote:
I am about to build a new case for my system and wonder if my plans regarding power upgrade with LIBB's makes any sense.

Currently I have two small cases (both 208 HP), one with a Make Noise switched PSU, one with a linear Doepfer PSU2.

I plan to build a studio case now (680 HP, 64 modules +400 mA, -2000mA) powered by the PSU2 and a bigger linear Bel PSU I have here. Of course I will need more bus boards now and want to try the LIBB's. The goal to have them in a linear power system would be to prevent inter module influences. Though my plan is to also reuse the two Doepfer bus boards.

Now my question is if this makes any sense or if different bus boards in one system would rather introduce more problems as they probably are different in impedance?

One thought I had was to at least use one type of bus board with one PSU. Of course both PSU's would share a common 0V.


Hi Leverkusen,

Some clarification here, inter module noise is not improved by linear power supplies. That is a function of the power distribution, primarily wires and bus boards.

Linear PSUs are known for lower generated noise and ripple levels, normally under 5mVpp, whereas common switching PSUs including most euro PSUs will have 50-150 mVpp of noise, much of that in high and ultra audio frequencies.

If you must reuse the Doepfer bus boards, keep them with the Doepfer PSU2 and put as many noise maker modules on those bus boards: sequencers, modules with blinking LEDs, LFOs, VCOs, anything that generates voltages rather than processing it.

Then for the Bel PSU and LIBBs put your audio processing modules: DSP, VCFs, Mixers, VCAs, Ring Modulators, Waveshapers, preamps and so forth.

I would avoid mixing the bus boards in the same system. If the Doepfer bus boards are still too noisy you can replace them further down the road.

John Loffink
Genus Modu


Hi John,

Thank you for answering my request - much appreciated!

I might have worded my situation unclear though; I don't expect a linear PSU to reduce inter module noise. I explicitly want to try out the LIBB to achieve this, even if they have been designed mainly to reduce switching ripple noise.

I use linear PSU's because I had issues with switched ones and some modules again and again.

Would you explain why you recommend to put the probably noisier modules on the less protecting bus boards. I am happy to learn something and also hope to make a better decision what to place where.

Thank you for the support,

Sven
Mungo
Leverkusen wrote:
GenusModu wrote:
Leverkusen wrote:
I am about to build a new case for my system and wonder if my plans regarding power upgrade with LIBB's makes any sense.

Currently I have two small cases (both 208 HP), one with a Make Noise switched PSU, one with a linear Doepfer PSU2.

I plan to build a studio case now (680 HP, 64 modules +400 mA, -2000mA) powered by the PSU2 and a bigger linear Bel PSU I have here. Of course I will need more bus boards now and want to try the LIBB's. The goal to have them in a linear power system would be to prevent inter module influences. Though my plan is to also reuse the two Doepfer bus boards.

Now my question is if this makes any sense or if different bus boards in one system would rather introduce more problems as they probably are different in impedance?

One thought I had was to at least use one type of bus board with one PSU. Of course both PSU's would share a common 0V.


Hi Leverkusen,

Some clarification here, inter module noise is not improved by linear power supplies. That is a function of the power distribution, primarily wires and bus boards.

Linear PSUs are known for lower generated noise and ripple levels, normally under 5mVpp, whereas common switching PSUs including most euro PSUs will have 50-150 mVpp of noise, much of that in high and ultra audio frequencies.

If you must reuse the Doepfer bus boards, keep them with the Doepfer PSU2 and put as many noise maker modules on those bus boards: sequencers, modules with blinking LEDs, LFOs, VCOs, anything that generates voltages rather than processing it.

Then for the Bel PSU and LIBBs put your audio processing modules: DSP, VCFs, Mixers, VCAs, Ring Modulators, Waveshapers, preamps and so forth.

I would avoid mixing the bus boards in the same system. If the Doepfer bus boards are still too noisy you can replace them further down the road.

John Loffink
Genus Modu


Hi John,

Thank you for answering my request - much appreciated!

I might have worded my situation unclear though; I don't expect a linear PSU to reduce inter module noise. I explicitly want to try out the LIBB to achieve this, even if they have been designed mainly to reduce switching ripple noise.

I use linear PSU's because I had issues with switched ones and some modules again and again.

Would you explain why you recommend to put the probably noisier modules on the less protecting bus boards. I am happy to learn something and also hope to make a better decision what to place where.

Thank you for the support,

Sven

Hello,
be careful with this advice. It seems that the Genumodu marketing is moving back to saying things that are untrue to try and make their product sound like it is solution and nothing else matters. Power supplies are the majority of the effect to power supply impedance (half of the crosstalk problem) in the audible range.

I have measured their claims and know they are untrue:

The purple line is what happens when you connect a poor power supply to a heavy plane bus board like the LIBB, it makes some good improvement from the original orange performance but cannot magically fix a poor power supply. Just changing to a good power supply (even keeping "normal" bus boards) is almost always better than a bad supply and perfect boards.

We all agree that distribution cabling is usually the weak link in cases, when people add the LIBB boards they improve the distribution cabling too but think (and are told) the improvement was from the LIBB boards. All the people reporting huge improvements by installing their LIBBs also changed either the distribution cabling, and/or the power supply. You can get enough improvement in most cases by just improving the wiring, especially with the Doepfer PSU/bus board combination.
GenusModu
Leverkusen wrote:

Hi John,

Thank you for answering my request - much appreciated!

I might have worded my situation unclear though; I don't expect a linear PSU to reduce inter module noise. I explicitly want to try out the LIBB to achieve this, even if they have been designed mainly to reduce switching ripple noise.

I use linear PSU's because I had issues with switched ones and some modules again and again.

Would you explain why you recommend to put the probably noisier modules on the less protecting bus boards. I am happy to learn something and also hope to make a better decision what to place where.

Thank you for the support,

Sven


Sven,

LIBB was not designed to mainly reduce switching noise. First and foremost the goal was to reduce audio frequency coupled noise through use of heavy copper ground and power planes. Once I had that, I realized that I could effectively build a distributed capacitance scheme that had ultra low resistance from any power connector on the board, and filter into the MegaHertz range with MLCC caps placed throughout the board.

The concept of segmenting noisier modules on their own power segments can be compared to the use of Auditory Masking in MP3 compression. For instance, if your VCO puts out 10 Volt peak to peak sine waves, you will never hear a few millivolts of noise riding on top of the sine wave. It is effectively masked by the higher volume signal. Now consider a few millivolts of noise on a VCA output. At max envelope output, you will not hear the noise either. Only when the envelope and VCA approach or reach zero will the low level noise cut through the masking, higher level signals. So now, when you want silence, you will hear the noise. That is what most folks with noise issues are trying to avoid.

Now the noise can also ride on top of sequencer note control voltages or other CVs. In general the noise impact on VCO tuning will be less noticeable. If not, well then you definitely need an improved power solution such as LIBB everywhere.

I am always happy to provide feedback and support.

John Loffink
Genus Modu
GenusModu
Mungo wrote:
GenusModu wrote:


Hi Leverkusen,

Some clarification here, inter module noise is not improved by linear power supplies. That is a function of the power distribution, primarily wires and bus boards.

Linear PSUs are known for lower generated noise and ripple levels, normally under 5mVpp, whereas common switching PSUs including most euro PSUs will have 50-150 mVpp of noise, much of that in high and ultra audio frequencies.

If you must reuse the Doepfer bus boards, keep them with the Doepfer PSU2 and put as many noise maker modules on those bus boards: sequencers, modules with blinking LEDs, LFOs, VCOs, anything that generates voltages rather than processing it.

Then for the Bel PSU and LIBBs put your audio processing modules: DSP, VCFs, Mixers, VCAs, Ring Modulators, Waveshapers, preamps and so forth.

I would avoid mixing the bus boards in the same system. If the Doepfer bus boards are still too noisy you can replace them further down the road.

John Loffink
Genus Modu


Hello,
be careful with this advice. It seems that the Genumodu marketing is moving back to saying things that are untrue to try and make their product sound like it is solution and nothing else matters. Power supplies are the majority of the effect to power supply impedance (half of the crosstalk problem) in the audible range.

I have measured their claims and know they are untrue:

The purple line is what happens when you connect a poor power supply to a heavy plane bus board like the LIBB, it makes some good improvement from the original orange performance but cannot magically fix a poor power supply. Just changing to a good power supply (even keeping "normal" bus boards) is almost always better than a bad supply and perfect boards.

We all agree that distribution cabling is usually the weak link in cases, when people add the LIBB boards they improve the distribution cabling too but think (and are told) the improvement was from the LIBB boards. All the people reporting huge improvements by installing their LIBBs also changed either the distribution cabling, and/or the power supply. You can get enough improvement in most cases by just improving the wiring, especially with the Doepfer PSU/bus board combination.


John/Mungo,

The quote you highlighted "intermodule noise is not improved by linear power supplies" was directed in comparison to switched power supplies, which seemed implied by the original poster, though this turned out to be incorrect. The second part of the highlight, "That is a function of the power distribution, primarily wires and bus boards" implies that the remaining distribution in the power supply is also a factor. So in that sense we partially agree and I feel you are reading way too much into the description.

Power supply impedance is not a parameter that can be controlled or determined by the user. I cannot recall every seeing an output impedance spec for a power supply. The information is not available to the consumer. So no one cannot compare Linear Power Supply A to Linear Power Supply B without $2K+ active probes, differential amplifiers or $8K+ VNAs and measuring the impedance, as you have done, or doing a fuller noise comparison.

Can you identify the "good" linear power supply (blue and green lines) and "bad" linear PSU (orange and purple lines) used for your tests? That would be useful to know. Are you saying these are power supplies from the Genus Modu recommended list?

The assumption that most customers swap out power supplies and distribution and achieve their results from them is incorrect. The massive system posted by Neil Parfitt used the same Acopian power supplies and similar bus bars between his old solution and the new one with LIBBs. Neil experienced great results, as he posted here. Others are using their current power supplies and only swapping out wires and bus boards. You are correct that some improvement is from the wiring, that is why LIBB provides 2-4 locations for 12 AWG wire. Many passive bus boards can only support 16-18 AWG distribution wire, limiting their effectiveness.

John Loffink
Genus Modu
Rex Coil 7
Todai wrote:
Interesting. Again, I know little about it - but keeping resistance as low as possible seems to be the goal?

I've crimped one ribbon cable so far. Didn't look like any bigger gauge would fit. Are these different connectors than the ones we're used to?

Edit: by the looks they obviously are. I'll see if I can source those.

Recommended AWG? Surely not 12? woah
Those types of header connectors will accept up to 20ga wire ... HOWEVER ... the wire needs to be Teflon insulated fiberglass reinforced 19 strand 20ga. Fiberglass reinforced Teflon insulation is thinner than PVC or vinyl insulation (yet still plenty insulative). 19 strand wire makes for a smaller overall outer diameter since the strands can be bundled tighter with less air gaps between the strands. Military aircraft use fiberglass reinforced Teflon insulated 19 strand wire ... why? ... because when you're talking about trunk lines that may have up to 40 or 50 individual wires, making the wires themselves with the smallest overall OD makes the trunk line smaller. When you're trying to engineer an airframe with limited space available for things like multi-wire trunk lines, every cubic inch matters.

The smaller outer diameter of Teflon insulated 19 strand wire allows you to use 20ga wire when making your own module power cables. The smaller diameter will fit inside of the holes of the plastic headers. 19 strand 20ga wire is the absolute outer edge of what will fit inside of the pins. So using that type of wire allows you to use the largest possible gauge, while still fitting the insulation inside of the plastic multi-pin connector and fitting the strands inside of the pins themselves.

One thing you need to know about fiberglass reinforced Teflon insulation, it can be pretty difficult to strip cleanly unless you have a wire stripper that is SHARP. You may need to modify the wire stripper slightly to produce clean strips as well. Most wire strippers have a "stop" that prevents the jaws of the strippers from closing too far. I've found that filing off small amounts of steel from the "stops" allowed me to tailor the strippers to work excellently with 20ga fiberglass reinforced Tefzel (aka "Teflon") insulated 19 strand Milspec aircraft grade wire.

I use that type of wire all over my project synth. It can be purchased from aircraft supply houses. I usually pay about $9.00 per 100ft roll of 20 ga fiberglass reinforced Tefzel insulated 19 strand Milspec aircraft grade wire. Comes out to $0.09 cents per foot, and comes in about ten different colors.









Mungo
GenusModu wrote:
John/Mungo,

The quote you highlighted "intermodule noise is not improved by linear power supplies" was directed in comparison to switched power supplies, which seemed implied by the original poster, though this turned out to be incorrect. The second part of the highlight, "That is a function of the power distribution, primarily wires and bus boards" implies that the remaining distribution in the power supply is also a factor. So in that sense we partially agree and I feel you are reading way too much into the description.

......

The assumption that most customers swap out power supplies and distribution and achieve their results from them is incorrect. The massive system posted by Neil Parfitt used the same Acopian power supplies and similar bus bars between his old solution and the new one with LIBBs. Neil experienced great results, as he posted here. Others are using their current power supplies and only swapping out wires and bus boards. You are correct that some improvement is from the wiring, that is why LIBB provides 2-4 locations for 12 AWG wire. Many passive bus boards can only support 16-18 AWG distribution wire, limiting their effectiveness.

John Loffink
Genus Modu

Leverkusen asked specifically about the Doepfer bus boards which have open spade connectors, easily capable of connecting to AWG 10 or 12 cable for distribution. Those bus board are well matched to normal sized systems with typical distribution impedance.

You made a clearly falsifiable claim that the power supply would not affect module crosstalk, while you promote power supply impedance so heavily it is disingenuous to ignore the power supplies contribution to this or completely misrepresent it. The power supply is one of the limiting factors in crosstalk by power rail impedance, along with distribution impedance from the wiring and bus boards. With your excellent bus boards and thicker wiring the power supply becomes the dominant factor in the audible range.

To see a difference across the audible range when changing over to lower impedance bus board such as the LIBB there would need to be already a very low impedance distribution system and power supply. The LIBB can't hide problems there. All your capacitance is only significant above the audio range 10kHz and up. This sort of message while accurate is misleading:
GenusModu wrote:
First and foremost the goal was to reduce audio frequency coupled noise through use of heavy copper ground and power planes. Once I had that, I realized that I could effectively build a distributed capacitance scheme that had ultra low resistance from any power connector on the board, and filter into the MegaHertz range with MLCC caps placed throughout the board.

You sure can filter into the Megahertz range, but its yet to be explained how that is important when you are not greatly affecting the audible range below 10kHz/5kHz/wherever you want to put the cutoff. Once the distribution impedance is reduced the power supply is the dominant factor across the audible range.


GenusModu wrote:
Power supply impedance is not a parameter that can be controlled or determined by the user. I cannot recall every seeing an output impedance spec for a power supply. The information is not available to the consumer. So no one cannot compare Linear Power Supply A to Linear Power Supply B without $2K+ active probes, differential amplifiers or $8K+ VNAs and measuring the impedance, as you have done, or doing a fuller noise comparison.

Can you identify the "good" linear power supply (blue and green lines) and "bad" linear PSU (orange and purple lines) used for your tests? That would be useful to know. Are you saying these are power supplies from the Genus Modu recommended list?

There are very few power supplies that specify their output impedance, I have a few on hand for lab use (one with a full frequency range typical specification, more common with limits at a few specific frequencies) but they are not really appropriate or cost effective for a modular rack. If you want to stand behind your simulated impedance results then you'll need to point to the power supplies that can produce that sort of performance, and if there aren't any with the specifications measure it yourself.

I sell a eurorack power supply and recommend the use of LIBB units to expand it, while it has a typical measured impedance thats not a guaranteed specification and only informative. I have suggested to you cost effective ways to measure these parameters or create a standardised test that users could compare.

Trying to make simple binary separations between linear and switching supplies is fundamentally marketing at work. You can find linear supplies with poor output impedance control and noise, and switching supplies with excellent output impedance and noise. If you just pick random supplies without testing them then the situation is likely to be reversed, but clinging to linear supplies as inherently superior is simply false.

What explains much of the improvements in noise floor is not power rail impedance but reduced 0V fluctuations through reduced 0V distribution impedance. Again the distribution wiring is the majority of the contribution and a well planned 0V block/rail along with some thicker 0V wires is usually the place to start, making more of a difference than the choice of bus board.

There are power supplies and bus boards with such low impedances that the wiring will always dominate the result. You've spent a lot of time and effort to end up with a product in that category, engineered right to the edge of practical performance and limited in the audible range by everything around it. Sell it on the actual value, not all the misleading marketing puff you continue to push out.
Mungo
GenusModu wrote:
The concept of segmenting noisier modules on their own power segments can be compared to the use of Auditory Masking in MP3 compression. For instance, if your VCO puts out 10 Volt peak to peak sine waves, you will never hear a few millivolts of noise riding on top of the sine wave. It is effectively masked by the higher volume signal. Now consider a few millivolts of noise on a VCA output. At max envelope output, you will not hear the noise either. Only when the envelope and VCA approach or reach zero will the low level noise cut through the masking, higher level signals. So now, when you want silence, you will hear the noise. That is what most folks with noise issues are trying to avoid.

Segmenting a power system reduces crosstalk immensely, its not hiding the noise behind loud signals but taking the noise out absolutely. Your story doesn't seem to connect to segmenting power distribution or supplies at all.

If there is a noisy module which is disturbing the power rails or 0V, and that is audible in other modules sharing common paths, taking either of the modules onto a separate path will remove the noise. There are some common paths that are more difficult to separate than others but its not impossible.

Its popular to try and fix noise problems with ever lower impedance and bigger wires, bus boards, and power supplies. But there are other ways to solve it, which can be used in combination. Trying to make binary one vs the other comparisons is not helpful when people can use both and end up with a better result.
Rex Coil 7
Mungo wrote:
... It seems that the Genumodu marketing is moving back to saying things that are untrue to try and make their product sound like it is solution and nothing else matters. Power supplies are the majority of the effect to power supply impedance (half of the crosstalk problem) in the audible range.
From the Genus Modu power supply recommendation page:

LINK = http://www.genusmodu.com/products/libb-psus.html

GenusModu wrote:
While LIBB can significantly reduce switching power supply noise, the end solution will still be noiser than an average linear power supply.


Perhaps wording that statement slightly differently ... "While use of the LIBB (which allows for the use of large PSU-to-Busboard wiring which in turn will optimize the entire PSU to Module power distribution chain) can significantly reduce switching power supply noise, the end solution will still be noiser [sic] than an average linear power supply".

Member *Mungo, you're really beating this guy up in public. I (for one) would respect you a lot more if you took your sharpest criticisms to private messaging. You're also insulting the intelligence of LIBB buyers, automatically assuming that they cannot discern use of heavier distribution wire along with the LIBB as combined reasons for increased performance.

Lastly, since you've set precedence here, I guess if it's ok to call Member *Genus Modu a liar, then it's also ok to call you a bloated ego maniacal attention seeking narcissist.

Respect is earned, not bestowed. Behavior is a choice. Tact; discover it.

thumbs up
Leverkusen
I really appreciate the insights and the different standpoints shown by members @GenusModu and @Mungo in response to my question and about power distribution in general. That's very helpful for me and my decision process.

Also I appreciate the willingness to openly discuss ones product in public. That's showing a great spirit.

I don't see any use though in breezing in and insulting someone. I am very happy that this thread has become more civic and would prefer if it stays like that and we can stay on topic instead of unnecessarily getting personal.

Chugging Beers
Mungo
Leverkusen wrote:
I really appreciate the insights and the different standpoints shown by members @GenusModu and @Mungo in response to my question and about power distribution in general. That's very helpful for me and my decision process.
Not a problem, if you are getting heavy wire to connect the LIBB boards to the power supply it is a good opportunity to improve the wiring on the Doepfer boards at the same time.

Your still unanswered question is a good one:
Leverkusen wrote:
Now my question is if this makes any sense or if different bus boards in one system would rather introduce more problems as they probably are different in impedance?
Having a mixture of bus boards won't introduce new problems. If you started with all Doepfer boards and swapped out some improved boards such as LIBBs one at a time, it would only improve with each one.

Leverkusen wrote:
Would you explain why you recommend to put the probably noisier modules on the less protecting bus boards. I am happy to learn something and also hope to make a better decision what to place where.
The higher impedance bus boards introduce more crosstalk between modules, so the general thinking is to put the most sensitive modules in the lowest impedance place, and then put modules which will introduce noise somewhere else with as few common paths as possible.

It strongly depends how everything is wired together, using a bus type connection going from one board to the next, or using a star type connection all coming from a single point (creating more isolation). The result also changes if you are trying to reduce noise at a single module instead of across all modules.

On a bus type connection you get lowest noise overall when the noise creating modules are closest to the power supply (at the lower impedance position!) this sort of non intuitive result is very confusing and the opposite of what most people would think is the correct answer. The module with the lowest noise is closest to the power supply so the logical answer is to put the most noise critical module there, but that will increase the noise in all the other modules!

There was a great thread looking at the detail of where the wiring connects in the DIY forum:
https://www.muffwiggler.com/forum/viewtopic.php?t=211316&highlight=
That sets up a case with each board having its own path back to a star 0V point and star power paths for improved crosstalk reduction. With a star arrangement noise creating modules mostly affect the modules on the same bus board, so you can group all the noise sensitive modules on their own bus board to keep them quiet. With a mixture of different bus board impedances (and/or different distribution impedances from different wire lengths) you have the same choice to reduce noise overall (noise producers connected to lowest impedances), or prioritise reducing noise on some specific modules (sensitive modules at lowest impedance).

As always, the answer is complicated and changes depending on your specific priorities and choices.
Joe.
Rex Coil 7 wrote:
Member *Mungo, you're really beating this guy up in public. I (for one) would respect you a lot more if you took your sharpest criticisms to private messaging. You're also insulting the intelligence of LIBB buyers, automatically assuming that they cannot discern use of heavier distribution wire along with the LIBB as combined reasons for increased performance.

Lastly, since you've set precedence here, I guess if it's ok to call Member *Genus Modu a liar, then it's also ok to call you a bloated ego maniacal attention seeking narcissist.


I've already pointed out the extreme hyperbole in the marketing earlier in this thread, the legal implications it would have if LIBB were to be sold in Australia without modifying their claims. The claims were modified, because they were not the truth, and there continues to be claims made here without supporting evidence.

Your recent political posting, along with this clear bullying/intimidation of qualified people positing their valid criticisms, means you're rapidly reaching a point you won't be coming back from.

Something to consider before your next post mate.
meatbeatz
paults wrote:
The LIBB is specifically designed to filter noise from switching power supplies like the PSU3.

GenusModu wrote:
LIBB was not designed to mainly reduce switching noise.

Pokeout
GenusModu
Joe. wrote:
Rex Coil 7 wrote:
Member *Mungo, you're really beating this guy up in public. I (for one) would respect you a lot more if you took your sharpest criticisms to private messaging. You're also insulting the intelligence of LIBB buyers, automatically assuming that they cannot discern use of heavier distribution wire along with the LIBB as combined reasons for increased performance.

Lastly, since you've set precedence here, I guess if it's ok to call Member *Genus Modu a liar, then it's also ok to call you a bloated ego maniacal attention seeking narcissist.


I've already pointed out the extreme hyperbole in the marketing earlier in this thread, the legal implications it would have if LIBB were to be sold in Australia without modifying their claims. The claims were modified, because they were not the truth, and there continues to be claims made here without supporting evidence.

Your recent political posting, along with this clear bullying/intimidation of qualified people positing their valid criticisms, means you're rapidly reaching a point you won't be coming back from.

Something to consider before your next post mate.


Here is the single change to the LIBB web page in terms of marketing, and my response to that from Apr. 9 2018:

Genus Modu wrote:
The Genus Modu web site states "Quietest Eurorack passive bus board you can buy." I thought the "passive" part was obvious, but recently added the qualifier to be technically correct.


John Loffink
Genus Modu
GenusModu
meatbeatz wrote:
paults wrote:
The LIBB is specifically designed to filter noise from switching power supplies like the PSU3.

GenusModu wrote:
LIBB was not designed to mainly reduce switching noise.

Pokeout


meatbeatz,

I believe you are addressing semantics, between two different people on top of that. The two aspects are not mutually exclusive. LIBB can do both. I started with the low resistance board and bulk caps on the first LIBB prototype. The MLCC caps to address switching noise, both from switching PSUs and switching regulators on modules, were added in the second revision, after consulting with Lars Larsen on a good range to support for video synthesis.

I did want to be clear for the recent poster that LIBB is effective for users of linear PSUs, not just switchers.

John Loffink
Genus Modu
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