Post-Lockdown pedal building

english_bob

stickyfiddle said:

english_bob said:

^^^ This is exactly why I wouldn't do anything that complicated on vero. You're only ever one mistake away from ballsing the whole thing up.
Not saying nobody should do it, just that I wouldn't trust myself with the level of focus  attention to detail it requires.

Same here. There is a point with Vero above very basic stuff that the build becomes stressful rather than enjoyable for me...

Yep. I think the most complicated thing I've built on Vero was a Skreddy Screwdriver Deluxe (in a 1590BB enclosure because measuring and drilling for five knobs on anything smaller would have been a recipe for disaster). That's about my limit.

It's actually the enclosure drilling that I hate the most- decent enclosures are by far the most expensive individual part of most builds (unless you're into NOS germanium transistors or something) and it's very easy to make mistakes that you can't un-make.

roberty

Kalimna said:

Most of the bigger Vero boards Ive done have been OK, with the exception of phasers (which seem to have a personality of their own and a fickle approach to working or not), a Klon, and a WayHuge Purple Platypus (not a big board, but perhaps very dependent on component choice - an odd sounding pedal).
If everything is done in a logical fashion, and double checked, then they *should* work if a correct layout is followed. However, i wonder how much inter-track capacitance affects the circuits? Or poor quality components (semiconductors here)? Obviously misplaced components and solder bridges incresse in likelihood the more solder joints there are.

Id suggest a Naga Viper as a simple Vero circuit that soundz good.

Adam

I went super lazy and ordered a Maestro PS-1 phaser board with most of the components pre-soldered as SMD from PCB Mania. The spiel about matched FETs on Fuzz Dog's page put me off trying any phasers, it sounds fickle. But maybe I am the one who is fickle

roberty

This guy https://pcbguitarmania.com/product/master-phaser-smd/

Keefy

stickyfiddle said:

english_bob said:

^^^ This is exactly why I wouldn't do anything that complicated on vero. You're only ever one mistake away from ballsing the whole thing up.
Not saying nobody should do it, just that I wouldn't trust myself with the level of focus  attention to detail it requires.

Same here. There is a point with Vero above very basic stuff that the build becomes stressful rather than enjoyable for me...

Without a PCB I don't have the option. I have thought about getting two Fuzzdog 'Echo Blue' (Deep Blue Delay clone) PCBs and/or kits and just building the tape speed and modulation circuits on Vero (latter already done and working), but that would bring its own complications.

On the plus side, the Vero layout incorporates trim pots for the tape speed ramp-up and -down, and LEDs that act as crude limiters to stop the PT2399s distorting too much.

The 'focus and attention to detail' thing is what makes these builds so engrossing. Vero builds can be pretty hard to troubleshoot, but so satisfying when you get them all working. Building a pedal kit is more fulfilling than just buying a pedal, making the board from scratch even more so, incorporating your own tweaks better still.

Anyway I've ordered a pack of Vero and it should be here this week.

english_bob

roberty said:

I went super lazy and ordered a Maestro PS-1 phaser board with most of the components pre-soldered as SMD from PCB Mania. The spiel about matched FETs on Fuzz Dog's page put me off trying any phasers, it sounds fickle. But maybe I am the one who is fickle

Not all phasers need matched FETs. I built a Jed's Peds EQD Grand Orbiter clone a while back. All ICs, not a single discrete transistor in the house, and sounds brilliant. They have a Mu-Tron phaser kit too- it's a big kit, and looks complicated, but no FETs.
I wouldn't want to be matching transistors myself either, but that doesn't have to stop you building phasers...

Cookiemonster

Keefy said:

Well that's annoying! I had assumed that the right-hand diagram was a view from the track side of the board, but I've just realised it's not. Consequently all my cuts are in the wrong place. That's a couple of hours' work and a nice piece of Vero board down the drain - grrr! Fortunately I hadn't started fitting any components yet.

At least you noticed before building. You can flip the image

Cookiemonster

I’ve done loads on vero but mostly smaller circuits. I just like that I can google a layout and with parts I have already I can quickly make something and it almost feels free. 

I think the Rat I built on Vero is the best one I’ve done 

roberty

english_bob said:

It's actually the enclosure drilling that I hate the most- decent enclosures are by far the most expensive individual part of most builds (unless you're into NOS germanium transistors or something) and it's very easy to make mistakes that you can't un-make.

Me too. You can fill holes with a metal epoxy but you can't drill over those areas again. Drilling templates improve the experience but I've accepted that my own hand drilling will always be a bit wonky (boutique!)

Kalimna

Re: phasers, the first one I built, a Ross Phaser, took 3 attempts to get it working. Now, that might be down to dodgy IC's from eBay, but with a circuit that complex, it's likely the builds themselves were at fault. I have done a Grand Orbiter on vero that works (http://dirtboxlayouts.blogspot.com/2020/06/blog-post.html) but again, there's plenty to go wrong, and as mentioned above it can be much harder to troubleshoot errors beyond the simple component placement and soldering.
I havent tweaked any circuits yet, but there are a few I have in mind, mostly simpler Lovepedal copies/evolutions of the Electra OD circuit.

As yet, I havent tried a kit, or SMD components - although if I do anything else with J201's, I might have to.

Adam

Keefy

Kalimna said:

...
 However, i wonder how much inter-track capacitance affects the circuits? Or poor quality components (semiconductors here)?

 ...

The formula capacitance for a parallel-plate capacitor is C = εA/d where ε is permittivity of the dielectric material, A is the parallel plate area, and d is the distance between the two conductive plates.

Let's consider a 5cm run of parallel copper strips. We are considering the capacitor formed by their two thin edges.

The thickness of the strip is maybe 0.1mm, so area of an edge is A = 0.05m x 0.0001m = 5x10^-6m^2 (sorry I can't get superscripts to work).

I measured the gap d at 0.5mm i.e. 5x10^-4m.

The relative permittivity of air is as close to 1 as to make no difference so we use the free space figure 8.854x10^-12Fm^-1.

So the capacitance is
C = 8.854x10^-12Fm^-1 x 5x10^-6m^2 / 5x10^-4m
   = 4.427x10^-13F
   = 0.44pF.

I'd call that negligible!

The quality of the chips is an issue though - PT2399s are well know to vary in quality so I bought a pack of 4 to start with and will use the best 2.

Kalimna

Keefy said:

Kalimna said:

...
 However, i wonder how much inter-track capacitance affects the circuits? Or poor quality components (semiconductors here)?

 ...

The formula capacitance for a parallel-plate capacitor is C = εA/d where ε is permittivity of the dielectric material, A is the parallel plate area, and d is the distance between the two conductive plates.

Let's consider a 5cm run of parallel copper strips. We are considering the capacitor formed by their two thin edges.

The thickness of the strip is maybe 0.1mm, so area of an edge is A = 0.05m x 0.0001m = 5x10^-6m^2 (sorry I can't get superscripts to work).

I measured the gap d at 0.5mm i.e. 5x10^-4m.

The relative permittivity of air is as close to 1 as to make no difference so we use the free space figure 8.854x10^-12Fm^-1.

So the capacitance is
C = 8.854x10^-12Fm^-1 x 5x10^-6m^2 / 5x10^-4m
   = 4.427x10^-13F
   = 0.44pF.

I'd call that negligible!

The quality of the chips is an issue though - PT2399s are well know to vary in quality so I bought a pack of 4 to start with and will use the best 2.

Ok. Perhaps I overestimated!

Keefy

Kalimna said:

Keefy said:

Kalimna said:

...
 However, i wonder how much inter-track capacitance affects the circuits? Or poor quality components (semiconductors here)?

 ...

The formula capacitance for a parallel-plate capacitor is C = εA/d where ε is permittivity of the dielectric material, A is the parallel plate area, and d is the distance between the two conductive plates.

Let's consider a 5cm run of parallel copper strips. We are considering the capacitor formed by their two thin edges.

The thickness of the strip is maybe 0.1mm, so area of an edge is A = 0.05m x 0.0001m = 5x10^-6m^2 (sorry I can't get superscripts to work).

I measured the gap d at 0.5mm i.e. 5x10^-4m.

The relative permittivity of air is as close to 1 as to make no difference so we use the free space figure 8.854x10^-12Fm^-1.

So the capacitance is
C = 8.854x10^-12Fm^-1 x 5x10^-6m^2 / 5x10^-4m
   = 4.427x10^-13F
   = 0.44pF.

I'd call that negligible!

The quality of the chips is an issue though - PT2399s are well know to vary in quality so I bought a pack of 4 to start with and will use the best 2.

Ok. Perhaps I overestimated!

‘Stray capacitance’ is one of those ideas that gets bandied around guitar forums. Yes it’s a thing, but usually a much tinier thing than people imagine.

Kalimna

thank you - im always happy to be educated. it just occurred to me that in an effect as particular about circuit 'setup' as a phaser, that even small 'errors' of capacitance may be important.

Cookiemonster

roberty said:

english_bob said:

It's actually the enclosure drilling that I hate the most- decent enclosures are by far the most expensive individual part of most builds (unless you're into NOS germanium transistors or something) and it's very easy to make mistakes that you can't un-make.

Me too. You can fill holes with a metal epoxy but you can't drill over those areas again. Drilling templates improve the experience but I've accepted that my own hand drilling will always be a bit wonky (boutique!)

Where did you get the metal epoxy I have one I would like to try that on. 

roberty

Cookiemonster said:

roberty said:

english_bob said:

It's actually the enclosure drilling that I hate the most- decent enclosures are by far the most expensive individual part of most builds (unless you're into NOS germanium transistors or something) and it's very easy to make mistakes that you can't un-make.

Me too. You can fill holes with a metal epoxy but you can't drill over those areas again. Drilling templates improve the experience but I've accepted that my own hand drilling will always be a bit wonky (boutique!)

Where did you get the metal epoxy I have one I would like to try that on. 

This one here mate https://smile.amazon.co.uk/gp/product/B00361819W

You can't redrill over the same area but it fixes like a champ

Keefy

roberty said:

Cookiemonster said:

roberty said:

english_bob said:

It's actually the enclosure drilling that I hate the most- decent enclosures are by far the most expensive individual part of most builds (unless you're into NOS germanium transistors or something) and it's very easy to make mistakes that you can't un-make.

Me too. You can fill holes with a metal epoxy but you can't drill over those areas again. Drilling templates improve the experience but I've accepted that my own hand drilling will always be a bit wonky (boutique!)

Where did you get the metal epoxy I have one I would like to try that on. 

This one here mate https://smile.amazon.co.uk/gp/product/B00361819W

You can't redrill over the same area but it fixes like a champ

I’ve filled ‘unintended’ holes in cast aluminium enclosures using car body filler.

TJT1979

Just made two Fuzzdog phasers… 90 script and basic 45. Easy to put together…. everything pre-matched.  Once I figured out how the multi-turn trimmers work the biasing was pretty simple too. 

Keefy

My pack of strip boards arrived yesterday so I cut a new board, marked and made the 72 breaks (in the right places!) and fitted the 26 wire links. It helped a lot that the new board is marked in 5x5 blocks. I have followed the link colour coding from the layout i.e. red = 9V, yellow = 5V, green = earth. So I'm now at a stage equivalent to having a blank PCB!

Keefy

3 IC sockets and 33 resistors now soldered in place. There is one more resistor on the layout, labelled CLR. I am 99% sure this is for the on/off indicator LED so I won't fit that until I have decided what kind of LED I am using, and how bright I want it to be!

I don't think this board is ever going to look super tidy but then that's not the point of the build...

Kalimna

CLR = Current Limiting Resistor, for the LED as you knew. I normally use a 2.2k