Advice for stripboard layouts

Started by Ell, September 26, 2022, 08:32:21 PM

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Ell

I have tried to make my first layout from a schematic. It's messy as hell, and I've probably made mistakes, the main one being that the input is in the middle of the board, this happened because I worked backwards... I will probably not even attempt to build this, but would like to know if there are any guidelines I should be following, or any better ways of converting schematics to stripboard?

I've sort of combined the two schematics below to get something workable.




There is another schematic available in this pdf https://aionfx.com/app/files/docs/heliodor_documentation.pdf

Ell

I've decided to practice on simpler circuits and improve my skills at making layouts before retrying the OD3. I've studied a few of Torchy's layouts, there is often a clear direction that the signal is travelling in. I think I can work in a better order to the randomness that was this attempt.

Ell

I threw together a quick layout of an MXR Distortion + mod that Brian Wampler suggested in a Premier Guitar article here: https://www.premierguitar.com/gear/mxr-distortion-plus-mods

Any feedback would be appreciated. There are a couple of things I'm not sure about. The schematic didn't say to use Electrolytic capacitors, is it okay that I used these? And, does the orientation matter?
Also, for the power supply section I followed a different schematic here: https://www.electrosmash.com/images/tech/mxr-distortion-plus/mxr_distortion_schematic_parts.png
Am I right in thinking that there are 2x 1M resistors in the power section to act as a voltage divider to provide 4.5V, AND then another 1M resistor to supply pin 3 of the 741? To be completely honest, I have next to no true knowledge of electronics or physics, I've just been messing around with guitar parts for a long time.


antonis

#3
Quote from: Ell on September 27, 2022, 04:14:11 AM
The schematic didn't say to use Electrolytic capacitors, is it okay that I used these? And, does the orientation matter?

You can easily find commercially availiable 1μF non-polarized caps, for AC implementation (signal axis)..
Orientation (polarity) DOES matter only for voltage difference higher than 1V, say (but it should be better to ignore it..) so YES (it does matter)..!!
Cap positive leg (+) should be connected to the node of higher voltage compared to the voltage of the other node..

Quote from: Ell on September 27, 2022, 04:14:11 AM
Am I right in thinking that there are 2x 1M resistors in the power section to act as a voltage divider to provide 4.5V, AND then another 1M resistor to supply pin 3 of the 741?
Quite right..
(and quite wrong)

2X1M(*) resistors indeed act as a voltage divider but the 3rd 1M resistor just "pass" that voltage to 741 non-inverting input (pin 3)..
(it's called bias configuration)
For inverting configuration (input through R3 gain pot), 1M resistor shouldn't be necessary..
(pin 3  could be directly connected to 2X1M joint..)
The above mentioned resistor acts as an "isolator" (due to its high value) between signal and +4.5V, which is considered AC ground (due to 1μF cap..)

(*) As long as bias resistor value is large enough (1M hereto), voltage divider resistors values should be much lower for reasons beyond present discussion.. :icon_wink:
(in brief: noise, voltage divider loading, bias offset, etc)

P.S.
I think you've mixed up 1nF & 10nF input caps..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

idy

Good idea to start smaller. That first circuit, I just glazed over. Distortion + is about right for experiments.

I like to make the boards bigger than the ones you see on the layout sites: As long as it fits in the box, I see no reason to make them smaller. This gives room to make a more logical layout. I sort of follow the schematic especially for simpler things like Dist+ or boosters, i.e. the layout looks like a schematic. This makes trouble shooting easy.

I usually make the top and bottom rows ground (always lots of connections) and the second from the top power. And a few rows down I make the mid voltage for biasing things.

I also like to make the off-board wires come off one side, but with all those switches and pots (like the modded Dist+) not likely. I try to make them logical. Adds rows but I don't care.

I don't mind making extra cuts so I can run Rs and Cs on a single row, this helps with the schematic-like approach.

The Guitar FX layout page has a good intro from a guy who has done hundreds (thousands?)
https://tagboardeffects.blogspot.com/2012/09/vero-layout-guide.html


duck_arse

re. your smaller board - the 1M in the divider to ground doesn't reach ground, you seem to have put a cut there. you need to learn that parts can go east-west as well as north-south. you can utilise much otherwise empty space on boards just by turning the parts and cutting a track.

also - don't be stretching resistors across the whole height [?] of the board. fit them across 5 holes, 6 if you must, then link them where they need to go. long and unrestrained leads are a recipe for shorts. same with caps.

re. your big board - start with a blank board a third that size, and make the parts fit the space. and your first layout will never be the final layout, there will always be other ways the parts will fit.
" I will say no more "

Ell

Thank you for all the feedback, I really appreciate all the time that you've all spent helping me with this! I have read everything once, including the  vero-layout-guide website, I still have a lot to learn, so I will probably continue trying to process everything you've all said. Also, well done for noticing my mistake duck_arse, I will correct this before testing the Wampler/MXR layout.

In terms of the OD-3 layout, I am tempted to do the layout as two smaller boards that are then connected, like a daughter board kind of thing. Is this wise? Or, am I just adding even more complexity? My idea is based on, getting each half working independently, and then just combining them.

andy-h-h

#7
Separate boards is not ideal.  I get your thought process, but then you have to make a bunch of compromises elsewhere.  Maybe just build it in segments on one board and test as you go.

Personally like making layouts that in some way resemble the schematic, or follow a clear signal path (where possible).   I also find building my own layouts is easier as I know exactly what I'm looking at when I'm building.   Less mistakes are made. 

Apart from things like not having an input run directly next to an output, there aren't any hard and fast rules.  Just try and be logical, and have realistic amount of space on the board for the components that you have access to.


Oh and check, check and check again before picking up the soldering iron.   :icon_biggrin:   

Edit:  I see you are running the volume pot the other way around?  Normally pin 1 goes to ground.  Pin 2 goes to the switch and pin 3 is the output from the board.   

ElectricDruid

Quote from: andy-h-h on September 28, 2022, 02:54:39 AM
Maybe just build it in segments on one board and test as you go.
+1 this!! It's *much* easier to debug the next bit you do if you know that the bits up to that point are working. If you build the whole thing, you have to debug the whole thing. That's much more complicated.

Some circuits make this building-and-testing-in-stages much easier than others, but most are amenable to it to some extent.

Ell

#9
So here is a working layout of the Distortion + with Wampler mods.
The only problem is that the tone control does nothing. I saw a post SOMEWHERE where Mark Hammer and other people offered alternative schematics for working tone controls, but I can't find the page anywhere?! Could anyone please point me in the right direction, or suggest a good alternative? I am using a 100k pot like it suggests in the article (it also suggests 1M in the same article, but I can't get 1M). I also used a 500k pot for my distortion control, but it seems to be working fine.  EDIT: Found it, it's called Stupidly Wonderful Tone Control https://hammer.ampage.org/files/SWTC.gif

Also, I'm very tempted to do a diode selector control for the soft-clipping diodes as well. Is this worth doing? I'm really enjoying the diode switch, and think it could be fun to have ABSOLUTE CONTROL over this aspect of the sound hahaha.



matopotato

I saw a YT clip by Wampler about how a circuit works and can be designed. https://m.youtube.com/watch?v=F-WHBgIowmU I then added various diodes for soft clipping and put 2 rotary switches to select between them.
No diodes (boost), 1+1, 2+2 (Both diodes from some old TV set from the 70's), 2+2 Ge and 1+... Ge with the second switch doing ...+1, ...+2 until ...+6.
Got a bit overloaded, but fun and works.



I then did a similar thing based on Distortion + and suggestions from Jack Orman's http://www.muzique.com/ so based on hard clipping this time. There were two sections covering saturation control http://www.muzique.com/lab/sat.htm, http://www.muzique.com/lab/sat2.htm and one about Warp control(?)/Asymmetrical clipping http://www.muzique.com/lab/warp.htm. I breadboarded the Dist + and experimented with the suggestions on those pages.
Ended up with a rotary solution again to swap between various diode pairs. And a switch in the middle to move between saturation variations or Cross-over/Warp thingy...

Again a bit overworked, but it was fun. I arranged the diodes from warm to fuzziest.


And the LEDs light up on Jack when distortion is "high enough"






"Should have breadboarded it first"

Ell

Quote from: matopotato on October 06, 2022, 06:37:58 PM
I saw a YT clip by Wampler about how a circuit works and can be designed... And the LEDs light up on Jack when distortion is "high enough"



That's all insane! I love it hahaha

amptramp

Just a reminder that this thread:

https://www.diystompboxes.com/smfforum/index.php?topic=44838.0

has a layout creator that will help document what you decide to do.