Pete Cornish - Mystery Pedal [gooped][x-ray'd]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
FlyingWild
Information
Posts: 30
Joined: 28 Oct 2018, 21:01
Has thanked: 9 times
Been thanked: 7 times

Post by FlyingWild »

Looks very interesting, could one of the pots be a 'Blend' pot?
aionios wrote:...And yes, there is an opto-isolator :)
I hope it's not one of the hard to find or rather expensive ones?

User avatar
aion
Solder Soldier
Information
Posts: 230
Joined: 22 Mar 2012, 00:12
Location: Des Moines, IA
Has thanked: 9 times
Been thanked: 472 times
Contact:

Post by aion »

FlyingWild wrote:Looks very interesting, could one of the pots be a 'Blend' pot?
aionios wrote:...And yes, there is an opto-isolator :)
I hope it's not one of the hard to find or rather expensive ones?
NSL-32, fortunately one of the easier and cheaper ones!

User avatar
Chugs
Resistor Ronker
Information
Posts: 277
Joined: 16 May 2009, 09:47
Has thanked: 63 times
Been thanked: 47 times

Post by Chugs »

OC-1?

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

aionios wrote:
johnk wrote:nothing yet?
I don't mean to tease, the layout's just extremely tight and it's been kicking me in the pants the past month or so. I finally was able to hunker down and finish it though. An appetizer...

[ Image ]

Now shooting for the end of November for this, assuming prototyping goes well.
Design this in too small a foot print and using design choices more appropriate for digital circuits does not help you achieve all that you can ring out of the schematic design intent. You of course make fet it to work to some level, but not the best you could achieve tone wise. with what you have here.

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

without dyslexic typing...

Designing this in too small a foot print and using design choices more appropriate for digital circuits does not help you achieve all that you can ring out of the schematic design intent. You can of course can get the layout to work to some level, but not the best you could achieve tone wise. with what you have here.

User avatar
aion
Solder Soldier
Information
Posts: 230
Joined: 22 Mar 2012, 00:12
Location: Des Moines, IA
Has thanked: 9 times
Been thanked: 472 times
Contact:

Post by aion »

mookyj wrote:Designing this in too small a foot print and using design choices more appropriate for digital circuits does not help you achieve all that you can ring out of the schematic design intent. You can of course can get the layout to work to some level, but not the best you could achieve tone wise. with what you have here.
Respectfully...

1) You are missing some crucial information about the "schematic design intent", namely the schematic itself. You don't even have a view of the traces on the underside of the board. So this is a broad and unfounded criticism. It comes off as a pre-packaged posture rather than a conclusion you arrived at based on studying this particular PCB layout.

2) Looking at your post history, I see seven posts, not counting the duplicate. Four of them are talking about your own skills and expertise. Two of them are broadly critical without being constructive in any applicable way. (You were critical of Cornish's original G-2 layout as well and claimed you could do it better than Pete.) Only one of your posts was contributing to a discussion with any specificity, and even that one came from a place of criticism.

3) In the field of DIY guitar effects, we're all hobbyists who spend most of our time immersed in technology from 40-60 years ago. There's a saying, "close enough for rock and roll", that has long been a sort of unofficial slogan for what we do - but it has some grounding in truth as well. This is all low-voltage, low-kilohertz stuff, and it mostly gets distorted later in the chain anyway. It's not going to benefit from gigahertz or megahertz design considerations. At least not in a tangible way, which I'd define as the average guitarist being able to distinguish in a blind test between two circuits with identical schematics but different PCB layouts. That's really what it all comes down to anyway. It's not medical equipment.

The day I become convinced that a meander trace on the PCB is going to help me squeeze out more tone is the day I should probably move on to something else other than nine-volt guitar pedals, because everywhere I look I'm going to see nothing but deficiency and nothing will ever be good enough.

There is always room for improvement in our craft, and we can always learn from those who have more experience, including those who work outside the field. Your experience is extensive, and it'd honestly be fascinating to get a window into a single day at work for you, because nearly everything on your resume is foreign to me.

But, if you are just going to drop in with vague criticisms and no specific suggestions for improvement, you can perhaps understand that we may not be inclined to want to hear it. You'd do well to study the post history of mictester (Chris) on this forum and R.G. Keen on DIYSB and learn from the way they communicate. Those two people are rocket scientists compared to the rest of us, with experience comparable to your own. But they're patient and constructive, and because of that, their contributions have pulled thousands of others forward by leaps and bounds.

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

In your poor response, it is clear I hit a nerve. It is valid criticism without regard to nostalgia, or tech of 40 years ago, in which I was fully immersed. since 1975, rather than stay stuck in it, I evolved with it. Deflecting with personal attacks or assumptions is just poor form, even for you.... For you to assume that I would apply requirements of state of the art medical equipment is rather ignorant. What I do apply is best practices for music gear, and that is without the awful noise floors, and uninspiring tone that some are willing to put up with.

I do not need to see the traces underneath as I can with a general knowledge of circuitry be very close as to what is not connected on the top layer.Very familiar with the base design. You don't have anything on the cutting edge, just another take on the original concept, which is perfectly fine. I did not go thru your design and rip it to shreds, but if you are suggesting it could not be greatly improved, you are drinking your own kool aid. Again, with just a few observations I posted you could take that input and improve it. If you are butt hurt over it, then your feelings are more important than your desire to improve. As one who worked their way up thru more than a few engineering departments before I launched my own, I would have had a short path to the door with a perspective similar to yours.

It is not an elite observation that swiss cheesing a PCB with that density of parts leaves something to be desired. Narrow traces with narrow spaced ground pours is appropriate for so many other designs except audio, effect pedals. The fad of stuffing too much in a small hammond box is a flawed design choice pushed by marketing hype. Making something small because you can or because is cool is fine if you are willing to forgo performance. SMD is not the end all be all as improperly done is something small that also falls short. So rather then seeing valid criticism of a design approach you take the time to make it personal, but didn't bother to see how many people I have personally mentored in other groups and they are making better layouts and having less "odd issues with their builds. Calling out poor design choices is not the same as saying someone is less skilled or stupid. it is a inflated ego or confidence issue to assume that is what is said. You spent the time to fit all that in that form factor, clearly did neat work, and yet you are offended that I point out that you sold yourself short on your efforts. I see that by way of example you mislead others with assumptions that you have mentioned.

You make mention of the Cornish design, it is not a leap for any competent PCB layout person with an audio background to vastly improve it . You and many other engineers fall for the same misguided notion that it's low frequency and all this pcb techniques stuff do not apply. Not remotely true and it is measurable as pedals and amps all operate in very noisy environments from the grid, and from personal devices that emit all over the spectrum. EMI, ingress mitigation, integration of offsets on RC circuits all contribute to degraded performance, Back in the 70's and 80's the same pedals that everyone is orgasming over I got rid of as they performed poorly, unreliable, and noisy as hell. Had I kept them, would have made a handsome profit. Noise gates came of age for a reason.

Good enough for rock and roll is a rather defeatist and lazy perspective when for the same efforts, and a bit more diligence in applications could be making better sounding and less noisy pedals. Not having it the way you want to hear it is a bit entitlement posturing as I can recall in my youth I would have given my eye teeth to have access to information as there is now, and to be guided by any engineer willing to share their best practices and tricks of the trade. This is a sharing of information and ideas group, not a group hug therapy session.

User avatar
FlyingWild
Information
Posts: 30
Joined: 28 Oct 2018, 21:01
Has thanked: 9 times
Been thanked: 7 times

Post by FlyingWild »

Dear Mookyj,

I'm interested in PCB layout, and I'm sure my attempts would be deservedly looked down upon by yourself, so would you be open to passing on some of your knowledge? I could post a schematic and the top and bottom PCB layout for say a Big Muff (Eagle PCB file) and you could educate me and maybe others on why you'd do it differently. My design is to fit a Hammond 1590BB which I would consider a fair size for this pedal, many do it in a much smaller enclosure.

I should add, that I etch my own boards at home and started all this a year ago, almost to the day, it is not a commercial venture in any respect, so your advice would purely be helping me make better PCB layouts for my own enjoyment. Home fabrication does also mean I'm limited to two layers and have to insert vias to move from one layer to another or use the leg of a resistor.

If agreeable to you I'll start a new thread, if not that's fine.

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

"Deservedly look down on?" before commenting further, I'll say this- it is of little benefit to critique for any reason other than to see it improved. Looked down on would be personalizing it for reasons I would find less than honorable.

That said, and from further reading your post, I went down nearly the same path back many decades ago doing acid etched boards, and score and peel as I could not afford commercial fab'd pcb's and at the time unaware of tape and mylar which I did later out of high school. If you are willing to work up a two layer stack, then we have more resources to improve implementation of your schematic intent. Let me know what tools (eagle?) you are thinking of using to create your design, and any special features you are hoping to add. Let me know how much background electronic knowledge you have as I would rather not oversimplify it or take it the other way without at least giving you some things to look up as source material to learn from. You can send to me directly or post here for others and we can start there.


FlyingWild wrote:Dear Mookyj,

I'm interested in PCB layout, and I'm sure my attempts would be deservedly looked down upon by yourself, so would you be open to passing on some of your knowledge? I could post a schematic and the top and bottom PCB layout for say a Big Muff (Eagle PCB file) and you could educate me and maybe others on why you'd do it differently. My design is to fit a Hammond 1590BB which I would consider a fair size for this pedal, many do it in a much smaller enclosure.

I should add, that I etch my own boards at home and started all this a year ago, almost to the day, it is not a commercial venture in any respect, so your advice would purely be helping me make better PCB layouts for my own enjoyment. Home fabrication does also mean I'm limited to two layers and have to insert vias to move from one layer to another or use the leg of a resistor.

If agreeable to you I'll start a new thread, if not that's fine.

User avatar
FlyingWild
Information
Posts: 30
Joined: 28 Oct 2018, 21:01
Has thanked: 9 times
Been thanked: 7 times

Post by FlyingWild »

I apologise for my poor choice of words.

My Dad got into electronics, many years ago, and I well remember as a kid him using sheets of mylar, reels of thin black tape, and pads on letraset, he would trace off a diagram he'd made on graph paper. It is through him that I have access to a UV box and we made some new etch tanks out of acrylic sheet a couple of months ago after discovering his old original etch tank had really seen better days!

I've started a new thread here: https://www.freestompboxes.org/viewtopic.php?f=1&t=30214

And would be grateful for any thoughts you might have on what I have produced and any tips and advice on how it could be improved.

User avatar
Seiche
Old Solderhand
Information
Posts: 2526
Joined: 01 Nov 2010, 00:16
Location: Germany
Has thanked: 231 times
Been thanked: 189 times

Post by Seiche »

This is getting derailed. I just wanted to see the schematic :cry:

User avatar
palelight
Information
Posts: 24
Joined: 03 Nov 2016, 22:13
Has thanked: 4 times

Post by palelight »

Seiche wrote:This is getting derailed. I just wanted to see the schematic :cry:
It wouldn't be a Cornish thread unless it got wildly derailed by arguments about construction, layout, part choice, and Pete's methodologies, [smilie=a_whyme.gif]

Hopefully with some patience, we'll get to see/build what's under the hood of this guy.

User avatar
andy-h-h
Breadboard Brother
Information
Posts: 112
Joined: 22 Jul 2017, 03:54
Location: Brisbane, Australia
Has thanked: 23 times
Been thanked: 42 times
Contact:

Post by andy-h-h »

Seiche wrote:This is getting derailed. I just wanted to see the schematic :cry:
Yep - bring on the schematic. [smilie=a_biggrin.gif] [smilie=a_biggrin.gif] this is all too serious for my liking.

Poor old Pete Cornish - I hope he never swings by here to read the trash talk he cops. But then why would he? He's probably too busy building and selling pedals to people - something most of us would probably love to making a living from if we could.

User avatar
turbofeedus
Breadboard Brother
Information
Posts: 88
Joined: 17 Feb 2012, 04:08
Has thanked: 41 times
Been thanked: 100 times

Post by turbofeedus »

mookyj wrote:In your poor response, it is clear I hit a nerve. It is valid criticism without regard to nostalgia, or tech of 40 years ago, in which I was fully immersed. since 1975, rather than stay stuck in it, I evolved with it. Deflecting with personal attacks or assumptions is just poor form, even for you.... For you to assume that I would apply requirements of state of the art medical equipment is rather ignorant. What I do apply is best practices for music gear, and that is without the awful noise floors, and uninspiring tone that some are willing to put up with.

I do not need to see the traces...

How you interpreted anything Kevin said as a "personal attack" eludes me. They said you didn't have the full picture (literally and figuratively), that you haven't been particularly or meaningfully active on this board, and that you might misunderstand what the fuck we're all doing here. I didn't detect any "nerve-striking" until your post.
mookyj wrote:You don't have anything on the cutting edge, just another take on the original concept, which is perfectly fine.
It's not just fine, it's pretty much all we're looking for. Who cares about a perfectly optimized PCB layout in a guitar pedal? It's sat between a couple pieces of wood with copper wound magnets, and a dusty 60 year old amp using vacuum tubes. Get a grip.

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

mookyj wrote:You don't have anything on the cutting edge, just another take on the original concept, which is perfectly fine.
It's not just fine, it's pretty much all we're looking for. Who cares about a perfectly optimized PCB layout in a guitar pedal? It's sat between a couple pieces of wood with copper wound magnets, and a dusty 60 year old amp using vacuum tubes. Get a grip.[/quote]


Last I checked, folks in here want to make better pedals as they learn their craft, general electronics. Rather big of you to assume that "all we're looking for" when so many are chasing better sound, lower noise, and a build better than their last one. Gleeful bliss of ignorance? Not sure the peanut gallery would agree. Seems to me you are championing the "good enough, don't need to improve" mantra. Maybe a participation trophy would placate your trouble with my comments.

You have a problem in advocating optimizing PCB's that could be easily improve pedals that fetch a handsome price to own or build? Maybe you ought to get a grip in that it takes the same effort to build a well designed pedal as a poorly designed one. Sad that you aim low in one's efforts... Willful ignorance is not the answer.

User avatar
Ben N
Cap Cooler
Information
Posts: 506
Joined: 12 Dec 2008, 03:34
my favorite amplifier: Ampeg J12D Jet
Location: Israel
Has thanked: 192 times
Been thanked: 53 times

Post by Ben N »

I can't speak to the fine points of pcb design, but I can tell you that a pedal based on one of Kevin's pcbs (Andromeda, old layout) is now a mainstay on my board, and that I had the pedal on which it is based, the Nobels ODR-1, and sold it because it was too noisy, but the Aion version sounds great with far less noise and, of course, a superior bypass. Obviously that doesn't say anything about the quality of the layout of this particular Cornish mystery pedal, but it at least suggests that Kevin isn't just tossing these things off, but is putting in the work to make sure they behave as they should. So, until shown otherwise, he gets the benefit of the doubt for me. (BTW, his customer service is also excellent.)

User avatar
turbofeedus
Breadboard Brother
Information
Posts: 88
Joined: 17 Feb 2012, 04:08
Has thanked: 41 times
Been thanked: 100 times

Post by turbofeedus »

mookyj wrote: Last I checked, folks in here want to make better pedals as they learn their craft, general electronics. Rather big of you to assume that "all we're looking for" when so many are chasing better sound, lower noise, and a build better than their last one. Gleeful bliss of ignorance? Not sure the peanut gallery would agree. Seems to me you are championing the "good enough, don't need to improve" mantra. Maybe a participation trophy would placate your trouble with my comments.

You have a problem in advocating optimizing PCB's that could be easily improve pedals that fetch a handsome price to own or build? Maybe you ought to get a grip in that it takes the same effort to build a well designed pedal as a poorly designed one. Sad that you aim low in one's efforts... Willful ignorance is not the answer.

How much more time and energy (and money) do you think Aion should dump into a single PCB? Do you recognize there definitely an upper limit to what people will spend on a single project, and maybe Kevin is trying to strike a balance between "good enough for rock and roll" design and affordability, so it's approachable and usable?

It's not that I'm against making improvements, but you must recognize there's a huge difference between your profession and making guitar pedal PCBs in terms of supply/demand. Maybe they could spend another ten hours on the PCB, get it up to NASA spec, and sell it for $100 to be bought by nobody. Or they can strike that balance I stated, keep the board reasonably priced, and let the masses play ball. I'm pretty confident saying most people on this forum will take the latter option every time.

User avatar
mookyj
Information
Posts: 20
Joined: 17 Jul 2018, 02:13
Completed builds: Mu-Tron Digital Delay-memory, level display
Moog Taurus II, full midi conversion
Furman Preamp, revoiced, Level display
SPX 90, converted to II memory
Custom designs for OEM
Accutronics brick reverb
FV-1 Prototype
Location: Cortland, NY
Has thanked: 10 times
Been thanked: 7 times
Contact:

Post by mookyj »

turbofeedus wrote:
mookyj wrote: How much more time and energy (and money) do you think Aion should dump into a single PCB? Do you recognize there definitely an upper limit to what people will spend on a single project, and maybe Kevin is trying to strike a balance between "good enough for rock and roll" design and affordability, so it's approachable and usable?

It's not that I'm against making improvements, but you must recognize there's a huge difference between your profession and making guitar pedal PCBs in terms of supply/demand. Maybe they could spend another ten hours on the PCB, get it up to NASA spec, and sell it for $100 to be bought by nobody. Or they can strike that balance I stated, keep the board reasonably priced, and let the masses play ball. I'm pretty confident saying most people on this forum will take the latter option every time.

This is the problem with assumptions... NASA spec? nobody is doing class III for pedals. Hardly... Sorry but another 10 hours? Maybe if I was drunk... The balance you speak of is in your head, doesn't exist.

Custom boutique pedals go for $100-$400 dollars, at what point is it a "professional product" A weekend hobbyist is just as capable of making a great PCB as any career layout engineer as long as they are willing to learn. Your remark on professional vs "just making pedals" is rather lame. There is nothing to stop them from creating a great layout as any full-time professional would.

"keep the board reasonably priced" you do realize that board pricing is based on real estate, number of drill holes, and layers? Bad design, good design doesn't change the price. So what point are you making? If I or anyone else were to offer something like the board in question why would it cost any more? As it is he is making a handsome profit on it. That is what the market supports. In small quantities, you are under $2 a board with ENIG finish and 2ox copper. It doesn't take long to recoup your hours in bringing to market.

All things being equal, tools, mechanicals, schematic it takes no additional time to have an improved a layout, you just assume that I spend man-days tweaking the last electron out of 30-50 part pedal or whatever I have my teeth into, There is no extra effort to be had, better design choices yes, spend more time on placement than routing, yes, it ends up a wash as a good placement makes it appear strikingly simple. What takes time is trying to fit 14 pounds in a 10-pound bag, or trying to route a placement less streamlined than it could be. Start with a well-drawn schematic that has clear signal flow and you are more than halfway there. There are plenty of well-drawn schematics in this forum. Start out with practical pedal configuration choices, and size it in an enclosure that allows you to place and route cleanly rather than stuffing it in. There is no real valid reason for not bringing out the best of your design intent. It would be a start by not assuming so many things with PCB's that are taken out of context or akin to wive's tales.

User avatar
Seiche
Old Solderhand
Information
Posts: 2526
Joined: 01 Nov 2010, 00:16
Location: Germany
Has thanked: 231 times
Been thanked: 189 times

Post by Seiche »

Can you point out areas in the posted layout that are problematic and could be improved or are you just trying to get this thread moved into the catfight thread? Because this discussion is highly off topic (at best it's valid/or not criticism of kevin's pcb layout which is still off topic).

Maybe you could contribute your expertise in an efficient way by some kind of "pcb layout best practice" thread that doesn't get lost in the mix like your comments surely are right now.

I'm sure this would be highly appreciated by most.

User avatar
andy-h-h
Breadboard Brother
Information
Posts: 112
Joined: 22 Jul 2017, 03:54
Location: Brisbane, Australia
Has thanked: 23 times
Been thanked: 42 times
Contact:

Post by andy-h-h »

Anyone familiar with Monty Python’s argument clinic??? :wink: Seems appropriate

Post Reply