My beginnings, and some tips from an intermediate DIYer.
Just ordered the res/eq "Panel + PCB" from Modular Addict (USA). They also have the pots, jacks, and euro (10pin to 16pin) power cable (I already have knobs).
Just placed a Mouser order using this B.O.M. as a reference... https://www.mouser.com/ProjectManager/P ... dca4c4a741
....but I won't know if everything is correct until I populate the board(s).
Mouser does not carry all the polystyrene caps, but those can be found on ebay.
I still get confused when reading cap values, so I always use a "value conversion chart" printed off the net, for reference. Here's one: http://oshgarage.com/capacitor-conversion-chart/
Tips when searching ebay for caps:
Because some cap values can be expressed 3 or more different ways (but are really the same value) ....you should preform different searches for each expression..... if you want to find all the listings on ebay.
For example: 2n2 = 2.2n = 2200pf = 0.0022uf ....all mean the same value. Ebay sellers decide which expression to use, so if you only search "2n2", you'll miss the listings titled, "2200pf", and so-on.
One trick to converting the expressions without a chart, is this:
...Move the decimal point three places.
If it's 0.22 UF, move the decimal 3 places to the right = 220 NF.
Move it again 3 places right = 220000 PF.
Works in reverse too..... 5600pf = 56nf = .056uf.
Larger voltage ratings usually mean bigger caps. Anything rated 25v and above, will work fine.
I always order extras, for matching (if desired), and for future projects.
Here's a good conversation on polystyrenes:
Polystyrene Caps for Filters
I don't have the board yet so I hope my alternative choices for resistors will not be too long (length). According to the above B.O.M. recommendations, a resistor length of 6.8mm will work. (I ordered some that are 7.2mm L......we'll see)
I will be matching the caps and resistors to better than 1%, for the individual filter circuits.
I am not claiming that this will alter or improve the sound in any way, but it may make me feel better and satisfy my OCD.
Because these EQ filters are already variable (the pots), matched resistors might be pointless. EDIT, NOT TRUE. THESE ARE FIXED FILTERS WITH GAIN. Perhaps the more important spec for my resistor choice was temperature coefficient, where I went for a low value here (25ppm or less). This should help any small drift in the EQ filters as the board heats-up -- and I want a setting to stay where it is, over time. Again, this is minutia.....and such resistor accuracy/tempco is really for building "fixed" filters, so not here.
My knowledge of filter equations is weak, but basically it's the relationship of resistor and cap ratios, called an R-C filter.... ...that target a desired frequency. http://www.muzique.com/schem/filter.htm
Resistor matching tip for 2 or more resistors.....You generally don't need to buy .01% expensive parts ($2 ea +). You just need a half-way decent DVM, and find pairs/sets that match among a pile of cheap 1% resistors ( @50ppm tempco).... $0. 14 ea.
I believe many (most ?) popular resistors are sorted at the factory for accuracy, before labeling (called: binning). 5%, 2%, 1%, 0.1%....separated into different bins.
Here's a question though...
The build docs claim the 2604 "has a nice clipping behavior".
Does "nice" mean as in 'soft-clipping', or as in 'gritty and lovely-nasty' like some people desire ?