Neutron Mutron GGG layouts?

[steelerkid]

I've come across two different layouts for the Neutron envelope from GGG.  One is directly from GGG site which leads to Geofex, I believe,  and the other is on the Geofex site under the PCB layouts tab and titled   "A Neutron Wiring Diagram for the Schematic-Impaired"


http://www.geofex.com/
http://www.geofex.com/PCB_layouts/Layouts/neutronpub.pdf


I looked at the part placement and the traces and they look different from one another.  One is dated 1998-2001 and the other is dated 1998-2002.  Anyone know if either of these layouts is for the current board GGG is selling or if there is another diagram to use?   Hoping to build one soon but I rely on these layouts and dont want to end up with a board my simple mind cannot follow.   BTW, I asked GGG via email and they said to follow their link... which makes sense... but that leads to the older layout from what I can determine.   Just wanted to see if anyone succesfully built one recently with the current board and what layout you used.  Thanks.

[R.G.]

Do you find any differences in the two?

[steelerkid]

I see a few differences.  The actual board drawings look different.  The power supply wirings are different. One has the cap/resistor between the rotary and the footswitch,  the other says to put it between footswitch and jack... not sure if any of that matters but it does appear different to me.

[R.G.]

I see a few differences.  The actual board drawings look different.  The power supply wirings are different. One has the cap/resistor between the rotary and the footswitch,  the other says to put it between footswitch and jack... not sure if any of that matters but it does appear different to me.

My question was to pick out the exact differences so I could run them down, since I drew up both versions. It may be they look different but are electrically equivalent. It's been a long time since I did those, so a guide to differences you found would help me run down what is OK, what is not, and what makes differences.

To answer your underlying question, people have built and had working units from both versions.

[steelerkid]

Oh ok.  I posted two links that shows the differences but as you said they are probably equivalent.  I have them printed on paper so I' ll check on them later and make a list. Thanks.

[R.G.]

That would be a great help in running them down.

[steelerkid]

Ok, there are 2 layouts that I'm referring to.  One is from a link on GGG and the other is from Geofex's layout for schematically impaired.  After putting them together and starting to make a list I am discovering that most of the differences I'm seeing are only in the actual layout and not necessarily in the circuit. 

Here are some confusing (to me anyway) issues I've found.

From GGG link:
1. layout says to put C14 and R 18 between the footswitch and the output jack.  On the layout R18 is 560R but on the parts list R18 is 180K.... R21 is 560.
ON the GEOFEX "Impaired version"  C14 and a 560ohm resistor are between the footswitch and the rotary switch...  Therefore, I suspect the 560ohm resistor is the one to use since both layouts state that... but does the cap/resistor combo go between footswitch and rotary    or   between footswitch and output jack?  Or does it even matter? 

2. on the Geofex "impaired version", on the layout it shows a "Lorlin CK2396"  switch with 4 lugs in the middle.   I ordered from the GGG link and ended up with a 3PST rotary switch with 3 lugs in the middle.  I assume I just wire it based off the "impaired" layout and ignore the lug that corrsponding lugs that are not there??  (The GGG version just has a bunch of dots as connection points and doesnt actually show the switches and which lugs to use... I'm sure there is a way to decode it but I have NO electrical experience therefore I rely on the layouts with the pictures)

3.  while wer're at it , Im not sure what the arrows mean that are stationed within the rotary switch on the Impaired version.   Are they connections ?  For example do I connect the inner lugs to their corresponding  outter lugs or leave them be?

4.  and lastly, on the Impaired version,  the output jack appears to be a stereo jack.  I imagine that is not necessary.... or is it?


Here are the links again:

For the "impaired" version:

http://www.geofex.com/   then go to "PCB layouts for download"   and then " A Neutron Wiring Diagram for the Schematic-Impaired"



for the GGG link it is this addy:

http://www.geofex.com/PCB_layouts/Layouts/neutronpub.pdf




I appreciate your time and direction.   

[R.G.]

From GGG link:
1. layout says to put C14 and R 18 between the footswitch and the output jack.  On the layout R18 is 560R but on the parts list R18 is 180K.... R21 is 560.
ON the GEOFEX "Impaired version"  C14 and a 560ohm resistor are between the footswitch and the rotary switch...  Therefore, I suspect the 560ohm resistor is the one to use since both layouts state that... but does the cap/resistor combo go between footswitch and rotary    or   between footswitch and output jack?  Or does it even matter? 

In both versions, there is a cap + resistor between the bypass switch and rotary switch. This is there to do two things. The cap breaks any residual DC from leaking out the output jack and causing switching pops. The 560 ohm protects the circuit against an accidentally shorted output cable.

Resistor numbers sometimes have to change between versions. All that matters is you get the right value in the right holes. This leads to possible bugs in parts lists. You are correct that the resistor between switch and output jack is 560, and the one on the PCB is 180K, no matter what they are called.

You have stumbled onto a difference in bypassing. The real Mutron did not have true bypass. People these days frequently jump up and down and hold their breaths until they get true bypass. One version of the wiring is how you do it for the original (R and C connect between footswitch and jack) and true bypass (R and C connect between rotary and footswitch). It matters only for subtle reasons of minor DC offsets on the circuit which may or may not be a problem.

2. on the Geofex "impaired version", on the layout it shows a "Lorlin CK2396"  switch with 4 lugs in the middle.   I ordered from the GGG link and ended up with a 3PST rotary switch with 3 lugs in the middle.  I assume I just wire it based off the "impaired" layout and ignore the lug that corrsponding lugs that are not there??

Yes, that will work. The 4P3T switch in the "impaired version" has three separate SP3T sections that happen to be connected together mechanically so they all move at the same time. Since the Mutron only has three valid settings for this switch, I picked out a rotary switch that will only switch to three positions. There exist 3P4T switches that have only three poles, but will turn to four different positions. These are less confusing to wire, because you don't have to ignore the unused pins, but more confusing to actually use because there is a fourth position that isn't needed or wanted. Some 3P4T switches let you move a limiter washer to limit them to only turn to three positions. But some people find that even more confusing than an extra position that doesn't do the right thing.

Take your switch and turn it from end to end, counting positions, and find out if there are four positions it will stop in or only three. If there are four, you probably ought to take it apart and fix it so it will only go to three places. If there are three positions it will stop in, you're fine; wire it like the "impaired" version, ignoring one center pin and three outer-circle pins on the "impaired version" and ignoring every fourth pin on the outer circle of pins on the actual switch you have.

(The GGG version just has a bunch of dots as connection points and doesnt actually show the switches and which lugs to use... I'm sure there is a way to decode it but I have NO electrical experience therefore I rely on the layouts with the pictures)

You are in what we refer to as a learning experience. Before you get done with this you're going to know more about switches than you did.

3.  while wer're at it , Im not sure what the arrows mean that are stationed within the rotary switch on the Impaired version.   Are they connections ?  For example do I connect the inner lugs to their corresponding  outter lugs or leave them be?

... like this  . The arrows are a schematic representation of what the internal contacts are doing. Imagine that the arrows are metal bars hidden inside the switch. You don't wire them, they're already there. What the arrows mean is that in one position of the shaft, there is an internal metal contact between A and pin 1, B and 4, C and 7, and D and 10. When you rotate the shaft one position, the internal metal arrow moves from where it was so it contacts betwen A and 2, B and 5, C and 8, and D and 11. The next shaft rotation makes the arrows connect between A and 3, B and 6, C and 9 and D and 12. Each "set" of A and 1,2,3, B and 4, 5, 6, etc. are electrically separate inside the switch.

Notice that section D and 10/11/12 are not used on that diagram; no wires go to them. But they still exist and are switching, even if not used. That's what the diagram shows.

So you wire to the noted pins, and ignore the arrows.

4.  and lastly, on the Impaired version,  the output jack appears to be a stereo jack.  I imagine that is not necessary.... or is it?

You're right, it's not necessary for electrical reasons. I like stereo jacks because the extra unused contact causes more friction on the mono plug and makes it a bit harder to pull out of the jack. Also, I can order all one kind of jacks, not some of one and some of another.

I appreciate your time and direction. 

You're welcome. Ask more where I've muddied it up more than cleared it up.

[steelerkid]

I really appreciate you taking the time to list all of this information.  I guess I can just pick either layout and roll with it and be ok.  I'll continue to refer to this as I put it together.  I really appreciate everything.  You have been a HUGE help to me and you have put together some outstanding layouts and pedals and I am having a blast putting these things together and I am now getting some OUTSTANDING sounds and effects out of my rig.   I sincerely appreciate all of it. 

[R.G.]

You're very welcome. Enjoy it and learn as you go. Ask back here when you run into problems.