Mojo Parts Suggestions Please, Specifically Pots

[Highsmith]

Hello from rainy San Francisco!

A couple questions:

What are your favorite ‘mojo’ parts brands & models?
What are your favorite mojo pots, and where are they available?

The build calls for a 100k and 50k log. I have sourced a 100k ALPS Blue Velvet for a reasonable price.  Can I put a resistor on the 100k to make it a 50k without ill effects in the sweep?

I’m not really interested in anyone’s ill opinion of mojo parts in general, because 30 builds in, I have decided to build my first mojo parts/fancy guts pedal for fun.

I am going to do a Harmonic Percolator.

I have obtained tropical fish, silver mica, and tantalum caps.  Also, Switchcraft jacks, and ½ watt resistors.  The NOS transistors are en route. I even got an 8mm LED for this thing...

[IvIark]

I love mojo builds, there's something very pleasing to me building something which looks great.  Yes you can build things cheaper and which sound just as good with cheaper components, but who cares?  Sometimes you don't need any other reason for doing something other than the fact that you're pleasing yourself.  And it doesn't cost a lot of money to build something for yourself even with mojo parts, especially if you shop around.

Check out the Russian paper in oil (K40/K42) and/or PETP (K73) caps you can find on eBay.  Some are huge so you have to watch the dimensions but they look great in builds and everything I've built with them sounded fantastic.  Russian silver mica can also be bought cheaply off eBay and are definitely worth a try.  Carbon comp resistors are easy to find, lots of NOS on eBay or you can buy newly manufactured ones like Arcol from some big electronic sellers (RS sell them in the UK).  Or maybe consider some mojo carbon or metal film resistors like Shinkoh, Kiwame, Holco or Takman.  Yes they are expensive if you're buying in bulk but if you're buying a few resistors for a specific build then you could get them all for just a few dollars.

I've used Alps and Bourn pots a few times and have got some Alps stocked up which I found at a good price on eBay.

Mojo build aren't for everyone, but you don't have to buy into audiophile fantasies about gold plated power cables to build and enjoy them.  This is DIY and you should do what makes you enthusiastic about building, not what anyone else thinks you should do.  Just make sure they're appropriately sized or sort out a new layout to accommodate the bits you buy to keep everything neat and tidy and give you maximum mojo points!

Don't forget to posts the pics when you've finished

[Neil mcNasty]

Greetings from rainy west coast of Norway!

I have to say that Tropical Fish and Oil in Paper caps are one of the few things that actually has a certain Mojo to it that you actually can notice.
I specially love the tone you get from using Tropical Fish caps.
It is of course not a drastic difference, but enough to notice.
Oil in Paper caps seems to have a little less high end to them (or a fuller low-mid sound) and they take up a lot of space. But hell... They look really cool, and sound great in my tube builds.
Silver Mica are sometimes a great substitute for Disc caps, and has a slightly softer sound to it as far as I can tell. But in a Harmonic Percolator I would stick with the disc caps where it is specified, as this seems to give it some of it's nasty character.
Tantilums I stay far away from, unless they are absolutely required to get the circuit to work, as they have an extremely high fault rate.

Many people regard Carbon Comp resistors as Mojo, but I shy away from them as they seem to be more noisy than modern Metal Film resistors, and Metal Film are also much more consistent in values compared to the 20% error rate that you find with old Carbon Comp.
With resistors I always stay modern, but many people use Carbon Comp in the Audio-Path, and claim that it has a certain Mojo to it.

Germanium Transistors is where the real Mojo happens!
But it can take a lot of time to find the one that sounds perfect.
Specially if you have a leaky batch that has to be measured and tested.
But it's worth the time!
I simply love the sound of Germanium!

Yes you can add a 100K resistor in parallel with the pot (between lug 1 & 3) to create a 50K, but the taper/sweep will be slightly altered towards a S-Shaped curve when applied to a B-Tapered pot (if I remember correctly).
I have never been disappointed with the sweep when I have done this myself...

For pots I tend stick to standard Alpha pots, for of the same reason I use film resistors.
The lower the fault rating, the better!
I have never noticed any difference in sound between different pot types when building pedals.
But logic tells me that it can have some effect, specially on simple and passive circuits.
A friend of mine replaced the pots on his Gibson 330, and had to put the originals back, because it totally changed the tone of his guitar.
This is not a big surprise, since the original pots had an error rate of about 20%, which can be quite drastic when we are talking 500K and 1M pots, connected to a coil/pickup/passive circuit.
I have not tried them myself, but I hear that ALPS are a great choice.

Switchcraft Jacks are a no-brainer. Nothing beats them!