Max Normal Posted December 30, 2010 Share Posted December 30, 2010 I know that this is perhaps a daft design, you can tell me it is, but I'm doing it for fun and experimentation as much as anything, so i'll probably try and avoid any reasonable but boring suggestions like VVVT circuits or switched pickups for as long as possible. Here's what I'm building, I have a nice natural swamp ash P-bass body with standard single pickup routing I'm going to rout for 2 more pickups, a WD Jazz bass neck with a rosewood fretboard, a Dimarzio Model One mudbucker (to fit a Gibson EB3) for the neck position, a Seymour Duncan quarterpounder P-bass pickup for the normal P-bass position, and a Dimarzio Ultra-J pickup for the bridge (Thanks Santa!). I chose the pickups based on advice from some of the guys on here a few months back, and I have checked that they all have very similar resistance (as advised), so should not have a huge imbalance in output. I want to wire each pickup to have it's own volume control like a Jazz, but also to have it's own tone control in a stacked knob configuration. This way I use the sound characteristics and string position of each pickup to develop the tone (i.e. a dark powerful bottom end from the Model One, with a glassy cut-through from the Ultra-J, and then mix in middle and P-bass growl with the Quarterpounder) Looking at other forums, I have discovered that the '62 Jazz has individual volume/tone for each of it's 2 pickups, so there is a circuit diagram that is easily developed for 3 pickups. Problems are, most forums suggest that people forget this setup and go for VVT (or VVVT in my case) as when the volume pots are set to equal values, either of the tone controls becomes a master tone - i.e. tones effect each other - you have no true control over the tone of each individual pickup. Tone control interference can be uncoupled by adding a resistor (200-300k) on the output of each individual volume/tone circuit, but this cuts the overall output of the bass by ~50% leading to an underpowered instrument (particularly in light of the high gain pickups involved), which is presumably going to also cause a terrible signal/noise ratio if there is any hum. Questions are: *If the tone controls effect each other in this kind of setup, did it work ok for the '62 Jazz, and if so, why, and how was it to use? *Is this setup too complicated to have series/parallel switching? I don't want my P-bass pickup to sound thin like a Jazz. *Is it best to wire the whole thing in parallel or series? *Why can't I just make 3 standard P-bass volume/tone circuits (one for each pickup), and then wire them all straight to the jack so everything is in parallel (and I keep pickup power and grunt). will tone controls still interfere with each other? This is probaby the daftest question of all, but my electronics is quite basic: *why can't I put a diode in line with the output of each pickups volume/tone circuit to prevent the tone controls from interfering with each other, instead of a power-sapping resistor, and wire each vol/tone circuit separately to the jack as described above? Any help greatly appreciated, thanks guys! Quote Link to comment Share on other sites More sharing options...
Ou7shined Posted December 30, 2010 Share Posted December 30, 2010 Sounds like a fantastic approach Max. Why not go and build it (roughly and outside the bass if needs be) and report back. Quote Link to comment Share on other sites More sharing options...
Max Normal Posted December 30, 2010 Author Share Posted December 30, 2010 Ok, I'll go for the 3 parallel P-bass style vol/tone circuits with a diode inline then. If anyone knows something I don't (and that'll be most of you!) let me know in the meantime, as it might me some time and effort! Can't really build it outside the bass though as I don't have any way of measuring tone except with my a vibrating string and my ears! Quote Link to comment Share on other sites More sharing options...
Max Normal Posted December 30, 2010 Author Share Posted December 30, 2010 By the way, sorry that our sigs look like before and after photo's. I am actually a cat lover. Quote Link to comment Share on other sites More sharing options...
Ou7shined Posted December 30, 2010 Share Posted December 30, 2010 [quote name='Max Normal' post='1072920' date='Dec 30 2010, 05:30 PM']... Can't really build it outside the bass though as I don't have any way of measuring tone except with my a vibrating string and my ears![/quote] Yeah I just kind of meant wire it up without attaching to a control plate or drilling holes through from the rear until you've ironed out the bugs. [quote]By the way, sorry that our sigs look like before and after photo's. I am actually a cat lover.[/quote] What the hell is it btw, clingfilm? Quote Link to comment Share on other sites More sharing options...
Max Normal Posted December 30, 2010 Author Share Posted December 30, 2010 Yes, From the Australian black comedy "Bad Boy Bubby". Clingwrapped his cat and then his drunk/sleeping parents having never left his flat until the age of 30. Then goes on to join a rock band as a ranting lead vocalist dressed as a priest. Possibly the best film ever, very anti-religious and punk to the movie industry. Highly recommend it. Quote Link to comment Share on other sites More sharing options...
Max Normal Posted January 2, 2011 Author Share Posted January 2, 2011 (edited) Just thought, presumably the output from the pickups will be alternating as the strings pass in and out of the magnetic field of their pole pieces, meaning that I can't use a diode in the circuit. Is this right? Edited January 2, 2011 by Max Normal Quote Link to comment Share on other sites More sharing options...
obbm Posted January 2, 2011 Share Posted January 2, 2011 [quote name='Max Normal' post='1075378' date='Jan 2 2011, 03:27 PM']Just thought, presumably the output from the pickups will be alternating as the strings pass in and out of the magnetic field of their pole pieces, meaning that I can't use a diode in the circuit. Is this right?[/quote] In the words of Captain Mannering "I wondered when you would spot that". Yes pick-up output (audio) is AC so your diodes will provide nice half-wave rectification. Fuzzy. Quote Link to comment Share on other sites More sharing options...
Max Normal Posted January 8, 2011 Author Share Posted January 8, 2011 [quote name='obbm' post='1075390' date='Jan 2 2011, 03:40 PM']In the words of Captain Mannering "I wondered when you would spot that". Yes pick-up output (audio) is AC so your diodes will provide nice half-wave rectification. Fuzzy. [/quote] Thanks obbm! Saved me some soldering and head scratching. Next time a "Now listen here men!" would be appreciated rather than a "Stupid boy!". I'm here loking for advice from you chaps, don't want my fumblings with a soldering iron to become an amusing sideshow for electronics geeks. Any thoughts on decoupling the tone circuits? I'll reitterate: I want to wire three pickups in parallel, each a P-bass style Volume and tone circuit on a stacked pot, each connected directly to the output jack (or a master volume pot). The pickups will not be switched, volume and control will be operated in a similar way to a '62 Jazz bass, although the wiring is parallel, not series and there will be 3 pickups instead of two. I really don't want to use resistors on the output of each vol/tone circuit to uncouple the tone controls, as this will seriously attenuate the signal. If anyone else can spot any major daftness in my plan, I'd really appreciate the advice before I go ahead an try and do it, which I surely will soon. Quote Link to comment Share on other sites More sharing options...
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