Component selection for a Klone build.

Started by negan, October 19, 2021, 12:53:13 AM

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negan

Hi Everyone, I am fairly new to guitar pedal building and I am currently working on a Klone build based on a generic schematic PCB.

I have some questions about selecting and sourcing components, that I am hoping would be okay to ask for help here.

1. Resistor type and wattage: Is it okay to substitute Carbon 1/4 watt resistors for Metal Film resistors ? and  is a carbon resistor rated at 1 watt instead of 1/4 watt going to make much of a difference ?

2. Capacitors: the original spec calls for Panasonic PET caps rated at 50V. These are no longer made and are difficult to source, my options are green cap mylar capacitors rated at 100V or MKT style capacitors rated at 63v. Which substitution would be ok/better?

3. I am also stumped by the power input jack, which is noted to accept a positive tip 3.55mm jack. I can't seem to find the correct part for this input jack. Can I just use a panel mounted 3.55mm audio input jack ? Can I convert to a standard 2.1mm centre pin power jack ?

Sorry for the all the questions I am a noob at this. Thanks in advance  :D



fowl

1.  1/4W resistors are fine for this circuit.  Anything higher wattage will work too, but a waste of space and/or money.  Either carbon film or metal film is fine.  Metal film will theoretically have less noise, but I doubt it would be an audible difference.

2.  Any film caps rated for 25V or higher will be fine.

3.  I would definitely recommend a 2.1mm center-pin-negative power jack, as that has become a virtual standard for pedals, and will work with most power supplies.

duck_arse

as fowl always sez, welcome to the forum.

2. get box caps. they are standard spacings and will fall into a printed circuit board. greencaps are noted for no two values having the same leg spacings or body width fatness. you will go mad bending the legs to fit yer bord.
don't make me draw another line.

idy

You do have to look at your PCB: some are very crowded and bigger film caps (like 1uf notoriously) come in a variety of sizes. So don't go for highest voltage, 63v is plenty, and I don't know about lower voltage in box caps. +1 on greenies being awkward.

If we knew what PCB you are using (photo, if the documentation online is poor) we could be sure about sizes.

Electrolytics also come in many sizes, even for the same voltage.

A resistor rated at 1watt may be quite large! We don't use those outside amps... but I guess the Klon uses it as a magic charm to make the pedal more ampy or something... Probably silly.

negan

Thanks for the advice everyone! Sourcing everything from one supplier is proving difficult, I'm trying to get it down to 2 suppliers to save on shipping. This pedal seems to have some hard to come by component values. Ive stuck to carbon film and metal 1/4 watt resistors based on the pcb spacing advice. The electrolytic caps 35v/50v seem okay for spacing as well. The other caps, I'm trying to go with pet film but I might have to go with MKT box types as they are the cheapest and easiest to source. I'll get some photos up when I get the project rolling. Thanks again everyone and good to be on the forum.

This has sparked my interest in getting into breadboard projects in order to test different components prior to transferring to a PCB. That might just be my next project to take on.

negan

Quote from: fowl on October 19, 2021, 02:08:59 AM

3.  I would definitely recommend a 2.1mm center-pin-negative power jack, as that has become a virtual standard for pedals, and will work with most power supplies.

I just found what what 2.1mm neg centre is  ;D

I was thinking of keeping the 1/8" input jack to keep aesthetic originality. I can't seem to find any 1/8" DC input jacks, only audio jacks. Can I use them, maybe something like this ?
(https://www.mouser.com/ProductDetail/Amphenol-Audio/ACJM-MV35-2S?qs=t8%2F5FiDdxGai2lqRGe%2FRiQ==)

Im also wondering how to wire up the jack to ensure the 9V battery is disabled with I plug the DC jack in and vice versa, the battery is enabled when I unplug the DC plug.

Appreciate any advice on this.

Thanks!

anotherjim

#6
There have been 1/8" audio style jacks for power, though I've never met a Klon Centaur myself. The Jen Super Crybaby for example was 1/8" audio. Now if the enclosure is grounded, the + plug tip will hit that first (doesn't make sense to have the sleeve +), so it either needs a PSU isolated from AC ground (only 2 prongs used from the AC outlet) or a socket isolated from the chassis.
I wouldn't hesitate to change to 2.1 DC jack, it doesn't have this headache so long as a common plastic-bodied type is used.

Oh, and how is Lucille?



negan

Thanks Jim! I think I've figured out how to wire my pcb for a neg centre 2.1 dc socket. Changing over will need me to drill the enclosure to accommodate the larger dc socket. The unit is drilled for a 6mm 1/8" socket.

Lucille is toast, been replaced by a crowbar.  ;D