makepeace
Hi guys.
I've recently received a hand-wound dog-ear P90 from Jess Loureiro Pickups in Spain that I bought for my Harmony H1215 acoustic archtop. Now comes the part where I have to drill holes/take chunks out of my guitar. I would just like to know if anyone has any recommendations regarding where i should physically put the pickup. I have about 21cm to work with between the fretboard and the bridge. The resistance of the pickup is about 7.8k and it has alnico IV magnets. I'll be using 500k tone and vol pots and either a 0.047uf/0.022uf mallory cap, depending on which I prefer once I've tested them.
I'm not really sure what type of tone I want out of it, but if someone could tell me how the position close to/further away from the bridge would affect the tone, I would be grateful ?.
Cool.
MikeM
Well closer to the neck is warmer basically, can get muddy if it's too hot. Close to the bridge and it gets nasal and thin.
What's the guitar being used for? I'd suggest aiming for below the 24th fret node.
makepeace
the guitar will play mainly blues i think, possibly a bit of jazz.
tonerider
Will the guitar have only one pickup?
7.8K with Alnico IV is a fairly low output pickup.
"Traditional" values for P-90s are 500k pots with .022uF capacitors. (If my memory serves me right Gibson used 300K pots on some of their P90 guitars in the 60's)
What I've done before is to extend the pickup's two main output wires (hot and ground) and solder these directly to a jack plug. Plug the jack into an amp and the pickup will be 100% active. Touch the pole pieces with the tip of a screwdriver and you should hear a thudding sound coming through the amp's speakers.
Then gently position the pickup under the guitar's strings (an arch-top normally allows one to do this) and play single notes or strum gently. Then slide the pickup around until you find a sweet spot that will give you a happy medium to work with in terms of tone. Once you've found a good spot tape the pickup into place with masking tape and leave it there for the night. Go back the next day and try it out with fresh ears. If it still sounds best there then that's the spot. Otherwise, note down the position and start again until you're happy!
makepeace
yea it will have only one pickup. i've also read about the 300k pots gibson used to use. i've tried to locate them and its worked out to be more of a mission than its worth to me. i've read that you can put a resistor on the 1 and 3 lugs of a volume pot to tweak its functional resistance. don't know how you could do that with the tone pot. might do that, but i think the 500ks will work out fine. i've read about the tone caps that the bigger the cap, the darker the tone, which is why i've ordered a 22 and a 47 to see which sounds the best.
ok so if its a lowish output, i could get away with putting it relatively close to the fretboard without things getting muddy?
i also thought about wiring it up and testing out different positions but unfortunately there's just no space. at the moment the strings are about 1.75 cm from the body, and the pickup is a lot thicker than that ☹
AlanRatcliffe
7.8K is IMO a perfect value for a low wind neck P90. Retains clarity and pick attack, while still being fat enough for Jazz.
Don't worry about 300K pots - everyone finds them too dark and swaps them out for 500K anyway (at least on the tone). The RS Guitarworks 250K Super pot actually measures at least 280K. By all means experiment - my last P90 guitar I ended up with 500K on the volume and a 280K on the tone with (IIRC) a 33pF cap (0.0033 uF) - very unusual, but very cool.
makepeace
so one could even go as low as 33pF caps! wow. i shall have to get some more to fiddle around with. whats the sort of range i should look at for tone caps?
AlanRatcliffe
You can try 10pF up to about 0.1uF.
I don't often even have tone controls fitted, but when I do, I like smaller values because they can be relatively subtle in small doses, just shaving off some of the brittleness, but leaving most of the guitar's tone and volume intact. Certain values do interesting stuff with the midrange on specific pickups when the tone is backed off all the way and you can end up with some pretty unique tones for drive.
If you really want to get fancy, you can fiddle with multiple caps (and even multiple fixed/variable resistors) on a rotary switch - something like Gibson's Varitone or the ToneStyler tone control. Fun, fun, fun... ?
