DIY Effects

[ahpook]

[quote name='paul_5' timestamp='1407506375' post='2521305']
Don't forget to bias those 201s properly - they're fussy buggers when it comes to current...
[/quote]

Wildo, thanks.

[KingBollock]

I've done a design for the Muff/Musket pedal, but I need to figure out how to make it the correct size. I made it in Paintshop Pro, and used their guides, but their idea of a millimetre and an actual millimetre are not quite the same... Even resizing by 50% has left it still too big (it'll be going on a 145mm x 125mm box).


(I was just going to call it Dank & Fetid, but got carried away.... The image is a negative of a photograph I took of a sunset.)

I am probably going to have to redo all the text and diagrams when I do resize it, but I have the layers saved, so it won't be too big a pain in the bum, just a bit annoying.

[ahpook]

Looks fantastic tho - I hope you get the layout sorted.

[KingBollock]

Does anyone know what thread, size and pitch, jack sockets and footswitches use? I am thinking of either buying nicer looking nuts, or making my own covers, which would require the relevant taps.

Edit: After trying the taps in my set I have a feeling that, if they are M sized threads, they're m9 and m11, which, of course, I don't have. I can't tell by the crappy little gauge that came with the set.

Edited August 9, 2014 by KingBollock

[KingBollock]

This is probably the wrong place to put this, but as I intend to use it for fault finding in DIY pedals...

I built a Noisy Cricket on veroboard, but it didn't work, all I got was a constant tone and the IC got warm. So I took it apart and put together a Ruby on breadboard. The Ruby worked, but as I haven't built the bench power supply I am planning on building, I have to reach behind me to get at the PSU lead that I use, so, as I couldn't be bothered with all that hard work, this time I used a battery instead. Then, once I knew it was working, I tried it with the PSU, but again all I get is a constant tone. The only thing that changed is the supply, I definitely have the wires the correct way around and the PSU is measuring at just over 9v and the battery just under 9v.

What the blinkin' nora is all that about?

Edit: It turns out that it only does it when the gain is turned up more than about half way/ I tried a regulated PSU and I tried a multi PSU in 9v, 12v and 7.5v, all with the exact same result.

Re-dit: Thought I was going to have to replace my soldering iron today when I saw that I had left it plugged in for the last three days... Still works perfectly and it is over twenty years old. Bless.

Edited August 10, 2014 by KingBollock

[KingBollock]

Just discovered something cool. About three hundred million and twenty three years ago, give or take three hundred million years, while in college, I built a signal injector/tracer. For the vast majority of the time since it has been bouncing about in boxes with half its case missing and cannibalised for parts (switch and battery clip missing). In fact, I was about to nick some other bits off it when I decided to see if it actually still worked, and it does!

It still has the problem that it can't do both at the same time but, as I was planning on building a little amp for tracing anyway, this means I don't have to make a new injector. Which is nice.

[paul_5]

KingBollock, I've just looked on the Alpha website at the specs for their 24mm pots and they're using M8 threads with a 0.75 pitch.

http://www.alphapotentiometers.net/html/24mm_pot_11.html

[KingBollock]

[quote name='paul_5' timestamp='1407655979' post='2522563']
KingBollock, I've just looked on the Alpha website at the specs for their 24mm pots and they're using M8 threads with a 0.75 pitch.

http://www.alphapotentiometers.net/html/24mm_pot_11.html
[/quote]
Thanks dude. Unfortunately, the pots are the only things I don't want to change the nuts on, because they get covered by knobs. But thanks to you I went and had a look at the switchcraft site and found that the jack sockets have a 3/8-32 thread. I will see if there is a diagram for the footswitches, too.

Edit: The thread on the footswitches is M12 - .75. Unfortunately, my M12 tap is 1.75.

Thanks for nudge in the right direction.

Edited August 10, 2014 by KingBollock

[KingBollock]

Has anyone tried any of the circuit simulation apps, like iCircuit? I have been using DIY Layout Creator (which is ace by the way. Free, too, which is always good) and kept thinking how nice it would be if I could virtually test the layouts.
I enjoy using breadboards but sometimes my eyes don't work so well, even my huge magnifying lamp doesn't help, so it can get frustrating when doing complex circuits.

http://icircuitapp.com
https://code.google.com/p/diy-layout-creator/

[DolganoFF]

I am actively using LTSpice for my circuit simulations. The learning curve can be a little steep but once mastered it becomes a great tool (and it is free)!

Edited August 18, 2014 by DolganoFF

[KingBollock]

[quote name='DolganoFF' timestamp='1408367358' post='2529436']
I am actively using LTSpice for my circuit simulations. The learning courve can be a little steep but once mastered it becomes a great tool (and it is free)!
[/quote]
Thank you, that looks ideal.

[DolganoFF]

Yep, it saves a lot of time otherways spent on fiddling with prototypes, and helps to better understand what changes when you adjust this or that component's values.
What I like it the most for, is the frequency responce analysis. One exemple here (sorry, my blog is in French, too lazy to translate everything ) : [url="http://www.dolganoff.com/fr/pedale-de-crossover-variable-schema/"]http://www.dolganoff.com/fr/pedale-de-crossover-variable-schema/[/url]

[ahpook]

[quote name='KingBollock' timestamp='1408369198' post='2529466']
Thank you, that looks ideal.
[/quote]

It does....I think I'm going to give that a go.

Excellent !

[paul_5]

Just replaced the 4148 (Si) diodes in my coloursound bass fuzz with a pair of OA47s (Ge) and it really brings it to life. GRRRRRRR!

[ahpook]

Well, I succumbed to a bit of pedal geek snake oil this afternoon and replaced the OP07 chip in my RAT with a socket and an LM308...and dammit, I'm sure it sounds smoother, especially at lower gain settings - it crackes less as the distortion comes in.

Did I do a before and after recording ? Nope...what a fool - I think I got a bit of flux frenzy when the chip arrived

Edited August 21, 2014 by ahpook

[LukeFRC]

[quote name='KingBollock' timestamp='1405163481' post='2499290']
It turns out that I will have to put in another order with Bitsbox (bloomin' love that place!) after all, but I can't for a couple of weeks, leaving me with far too much thinking time... So I have had an idea for the LED indicator for my double muff box. There is probably a really obvious solution to it but I have started another new medication recently that has left my brain even woolier than usual so I can't think straight. Which is rather frustrating.

There will be a standardish Big Muff on one side and a Musket on the other, each with their own footswitch. What I want to do is use a single RGB LED that will glow green when the Muff is on, red when the Musket is on and blue when both are on together. Anyone got any ideas?

Something like this but with the third LED option.


I am wondering if a relay of some sort might be called for. I have only ever used relays once before and that was many, many years ago.

Edit: Looks like it I is actually as complicated as I was imagining. I have been Googling all day and asking for help has been less than fruitful. I might end up just using the red and blue parts (can't find a blue and red LED with 3 legs) so it is red on one switch, blue on the other, but when both are on it turns purple.
[/quote]

just a thought, when I stuck a Muff clone (russian green one for me) a chorus and a preamp in a box I made a wee board to separate the power supplies from one another. Can't remember what I did but I think it was a cap and a resistor on each outlet to separate them. No idea if it made a difference to not having them but at the time I must have felt I needed them.
[quote name='ahpook' timestamp='1407449557' post='2520791']
I'm mulling this over as my next project - a JFET-based version of the Alembic F-2B preamp.

I've always fancied building a 1U bass preamp - though this would be a good place to start.

Anyone built anything similar ? I did have a version of the 'Flipster' JFET version of an Ampeg Portaflex, but didn't like the EQ that much.
[/quote] Have a look for a very layout of the Caitlinbread SFT.... if you look at the flipster as a version of the Portaflex... the SFT is a version of a SVT with transistors instead of tubes. Really cool bit of kit and a fun build.

[KingBollock]

In the end I went with the red / blue / purple, it works fine and the different colours are nice and obvious. It is actually all boxed up, now, with knobs on, all ten of them, I just need to get around to putting the design on the box.
As well as the '73 Ram's Head Big Muff and the Musket, it has an overall blend circuit, I am not very happy with the blend circuit, though. I am currently putting together a double bypass loop pedal with the intention of making it with one passive and one paralooper loop. If the paralooper works well, though, I may well put two of them in there and replace the blend circuit in the muff with one, too. The dual looper will also have an order switching footswitch. The order switcher on the double muff thing is so useful that I started thinking about replacing the toggle switch with a footswitch, but there isn't room for it, sadly.

Another pedal I have in my head, is another bypass loop with a momentary switch in parallel and a latching switch to bypass the momentary switch. I was looking at a tune I would like to play on the bass as a solo but to be able to add an occasional octave note down, at the start of a bar, would be handy, and I think this pedal will do that if I include an octave pedal in its loop and have the momentary switch only disconnect the input to the loop. That way the octave note down will be able to ring.
I have probably got that all wrong, I've only been thinking about it tonight, I'll probably have to iron out wrinkles in the idea. If anyone can see any obvious flaws and point them out, that'd be very helpful.

I have built a temporary board to put my pedals on. It was while working on the layout for it that the idea for the dual loop with a blend circuit in it came to me. Mostly because the chorus pedal I currently have, until I build a bass specific one (blimey I wish Al Heeley was still here so I could ask him about the one he built earlier in this thread), is a guitar one and it rather saps the bass, so having it on a loop with a blend would really help. At this rate, though, I will have more utility pedals on my board than effect pedals, but they're so easy to build and so bloomin' useful.

[ahpook]

[quote name='LukeFRC' timestamp='1408661541' post='2532407']
Have a look for a very layout of the Caitlinbread SFT.... if you look at the flipster as a version of the Portaflex... the SFT is a version of a SVT with transistors instead of tubes. Really cool bit of kit and a fun build.
[/quote]

I had an SFT for a while, but didn't really like it as an overdrive...but as a straight preamp, maybe.

I've very much gone off the idea of the Alembic due to the limitations of the passive EQ.

[ahpook]

[quote name='KingBollock' timestamp='1408668827' post='2532440']
I have built a temporary board to put my pedals on....
[/quote]

Well, first of all, we need to see this board !

The dual loop pedal sounds really interesting. Which circuit do you use for the paralooper ?

[KingBollock]

[quote name='ahpook' timestamp='1408730754' post='2533073']
Well, first of all, we need to see this board !

The dual loop pedal sounds really interesting. Which circuit do you use for the paralooper ?
[/quote]
It's just made from bare wooden bed slats with a small step for the pedals at the rear. But I will take a photo when I have finished making the leads for it.

The plan was to use this:



Because I have the parts, but I have put it together and I can't get it to work. There are others but they use either 4x TL071 or 2x TL072s, which I don't have. I'll probably have to take the schematic and try to knock it up in DIY Layout Creator.

I seem to be struggling with even the most simple of circuits lately. My poor state of mind is causing me to miss even obvious things. Normally this would be where I would find my "Zen", but I appear to have misplaced it.

Edited August 23, 2014 by KingBollock

[ahpook]

[quote name='KingBollock' timestamp='1408764378' post='2533326']
It's just made from bare wooden bed slats with a small step for the pedals at the rear. But I will take a photo when I have finished making the leads for it.

The plan was to use this:



Because I have the parts, but I have put it together and I can't get it to work. There are others but they use either 4x TL071 or 2x TL072s, which I don't have. I'll probably have to take the schematic and try to knock it up in DIY Layout Creator.

I seem to be struggling with even the most simple of circuits lately. My poor state of mind is causing me to miss even obvious things. Normally this would be where I would find my "Zen", but I appear to have misplaced it.
[/quote]

I've a clutch of TL072s - I may try and dig out a schematic for a paralooper that uses those instead - thanks for the info.

I have runs of good projects and bad ones - my two attempts to design and build a blend box from scratch went totally arwy - I think down to the design rathert than the practical side. Take heart, I'm sure your zen will return.

First tho, my LM386s just arrived, so next on the list is a variant of the Run Off Groove Grace Drive - I'm hoping for something along the lines of a Fuzzrocious 'Ram the Manparts' pedal...

[paul_5]

[quote name='KingBollock' timestamp='1408764378' post='2533326']
It's just made from bare wooden bed slats with a small step for the pedals at the rear. But I will take a photo when I have finished making the leads for it.

The plan was to use this:



Because I have the parts, but I have put it together and I can't get it to work.
[/quote]

I tried one of these and couldn't get it to play ball, I figured it was a build error so I put it to one side for bug fixing later. Might revisit it with a probe now...

[kyboo]

[quote name='DolganoFF' timestamp='1408370438' post='2529492']
Yep, it saves a lot of time otherways spent on fiddling with prototypes, and helps to better understand what changes when you adjust this or that component's values.
What I like it the most for, is the frequency responce analysis. One exemple here (sorry, my blog is in French, too lazy to translate everything ) : [url="http://www.dolganoff.com/fr/pedale-de-crossover-variable-schema/"]http://www.dolganoff...ariable-schema/[/url]
[/quote]

Nice. Just a few comments, if you don't mind

You don't need C3, C4. Voltage sources V1 and V4 are ideal. 'Gain 25k' wiring feels weird. Instead, think of a circuit where a taper goes to the ground. That way the gain can be completely muted. In a real pedal, you need to buffer HIGH, SUM, LOW outputs because any impedance connected to them will change their parameters. Try connecting a resistor there and see what happens.

Edited August 23, 2014 by kyboo

[DolganoFF]

I never mind comments, anybody more than welcome

C3 and C4 aren't needed for simulation, for sure, but will be with real power supply. I include them for consistency with the later production schematics...
The gain pot wiring is correct (but I may reconsider if one day I'll want to be able to mute it) , the gain of inverting amplifiers can be set this way too... by the way, the design is based on state variable filter topology, widely used in synths but not so much in other instruments or preamps: [url="http://en.wikipedia.org/wiki/State_variable_filter"]http://en.wikipedia....variable_filter[/url]
The output buffering will be needed only if the load impedance goes low enough to compete with output impedance of the opamps (which is reasonably low), and in the real world the load shouldn't go below the 10K (typical line input), so should be fine without dedicated buffers[b][color=#ff0000] in theory[/color][/b].
In practice - maybe not, that's what are prototypes for

Edited August 23, 2014 by DolganoFF

[pete.young]

Anyone looking for a 1u enclosure I have a dead Sabine feedback destroyer in a decent quality chassis, collect from Ipswich or pm me and we will work out postage.