Prostheta Posted July 6, 2016 Report Share Posted July 6, 2016 This is definitely a bit left of centre for our usual fare. People that know me a little beyond ProjectGuitar.com will be aware that I've been a big Aria Pro II (and Japanese instruments in general) for many years. To the point that I have fallen into being a go-to guy for the SB-1000 in terms of electronics and the stuff that makes it what it is. So anyway, I get an email reference that a guy is looking to restoring the electronics on his 1981 SB-1000. That's what I do. He drops round, we have coffee and have a nice afternoon discussing the job and all manner of other things. His bass needs a bit of physical restoration work, but is fundamentally in original condition. Not bad for a 35yr-old bass! Come up to the lab and let's see what's on the slab: By this point, I'd taken off the strings, nut and spent time degunking the fingerboard.... I know that you'll love this even though it doesn't have magnets, @curtisa. The cover is a neat and perfect Rosewood inlay.... The frets are fairly worn in the lower region as you'd expect. I'm thinking that it could possibly do with a refret, however we'll see how the remaining wire levels out once the rod is relaxed and the neck acclimated. Either the existing gunk was more resistant to my charms than your average common-or-garden gunk, or that's residue from a glued refret. I've also noticed a couple of light cracks in the Ebony..... Now this is where the problems really lie. The SB-1000 (both 70s and 80s variants) had odd electronics and pickups of a very specific size. Unfortunately, when something goes in those, most owners tended to rip the lot out and replace it with something like an EMG or Bartolini. Fundamentally, that alters the tonal character that SB-1000s are known for, so that's heartbreaking for me. In this instance, the pickup was an EMG-P4 with what looks like an old EMG BTC system. Nothing of the original electronics remained. Well, at least the modification didn't involve truly invasive surgery like I've seen on some. A couple of shims to block up the gaps at either end and a bit in the floor to raise it up. I'd already pulled off the foam rubber.... Careful work with a hammer/chisel, inspection lenses and tweezers removed all evidence of the offending infills. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 Most importantly there, the original threaded inserts for the pickup still remain. The pickup is fitted using M4x35mm machine screws instead of crappy wood screws. Another reason why I love the upper end of old Aria Pro II stuff. They didn't cut corners and produced fine instruments. Weird choices sometimes (we'll get to that) but fundamentally sound. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 This is where the fun is (don't you agree, @Norris?). Normally this is populated with (left, clockwise) a DPDT switched jack socket, an active 6-position rotary varitone, active/passive circuit switch, always-on LED monitor, plus dual value volume and tone controls. The cavity at the far right housed the differential preamp (another speciality part which only I make) plus 2x PP3 batteries. Pretty hefty circuit all in all. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 The missing MB-1E pickup is being replaced by a reproduction part made by Veijo Rautia, coincidentally also here in Finland: http://www.rautiaguitars.net/aria-pro-ii.html It always seems that either Veijo or myself get all of the resto queries. Unsurprising since these are unique and loved basses. The pickup itself is a hot dual ceramic humbucker encased in a plastic case and encapsulated in epoxy. When they fail, they fail. Two original pickups, both non-functional. I dissected these many years ago now so this is old stuff. One was configured differently, for a different Aria Pro II bass....these also made their way into Westones of the same era IIRC, although packaged differently.... Underneath the plastic case (this is not easy). Note the copper tab and what I think is conductive paint from the inside of the plastic case? (@curtisa: thoughts on this?) Two "king big" ceramic bar mags. Both cracked which is why this pickup was non-functional, or at least....probably having happened from whatever hit it (check the case above): Gutspill: Essentially, kind of a "double J" humbucker, however the poles are evenly spaced. The bobbins interlock beautifully. Each pole was cut to an exact length to create a radius. 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 Pickup schematic I drew long ago: Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 So this is what a populated 80s SB-1000 should look like: The thing in the electrical tape is original, surprisingly. It consisted of a thrown-together PCB designed to blink the LED. Not monitor the battery condition or indicate anything other than that the batteries were not dead. I think we can improve on that. Now there's the beast of a varitone. Sounds great, but it's like a Fabergé egg to construct. Note the values on the pots. These aren't simply concentric pots or dual gang, they're dual value dual gang. The SB-1000 circuit is build on two completely parallel circuits; one active (20k gangs, preamp, varitone) and one passive (500k gangs only) bypassed or switched in with the 4PDT (only three poles used) switch. Ergh. So yeah, they're not simple circuits to work with. Proper ratnesting. For this bass, I'll be going for a scheme which is more or less like you see above, however in the longer term I am producing a PCB-based solution with quick connectors that I can supply to people refitting SB-1000s directly. The bass on the healing bench was lucky because it lives 1-1/2hrs from here. Other people aren't so lucky. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 Other considerations for this are things like the LED flasher circuit. Over time, the supply buffering (mistyped, "buggering" which is actually apt) capacitors in the preamp which smooth out any fluctuations become leaky. As the LED circuit bangs the supply rails with big current spikes, those end up pushed onto the audio as clicks. Nice. I think that a nice "breathing" LED will be better than that. Perhaps even one that switches red/green using the spare pole on the switch.... Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted July 6, 2016 Report Share Posted July 6, 2016 I love the look of Arias. @Norris has a scrumptious one.... But I had no idea that the electrics could be this unique! Fascinating read so far Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 ....about dual value pots.... They don't exist on the open market. This means that I either need to hybridise a load of dual gang 500k and 20k pots (usual method) or have them custom made with a MOQ of 1000. Good job I had 5 sets custom-made as a favour then. Beyond this very limited stock, I'm going to move to the hybridised pots mounted on PCBs with quick connectors. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 6, 2016 Author Report Share Posted July 6, 2016 These are literally a nightmare, Andy. The number of hours that get sunk into them.... Quote Link to comment Share on other sites More sharing options...
curtisa Posted July 6, 2016 Report Share Posted July 6, 2016 7 hours ago, Prostheta said: Underneath the plastic case (this is not easy). Note the copper tab and what I think is conductive paint from the inside of the plastic case? (@curtisa: thoughts on this?) Probably shielding. Easy way to tell (if you still have the pickup) would be to ohm it to the ground connection on the pickup cable. 5 hours ago, Prostheta said: They don't exist on the open market. This means that I either need to hybridise a load of dual gang 500k and 20k pots (usual method) or have them custom made with a MOQ of 1000. Omeg used to do MOQs of 100 pieces, don't know if they still do. Looks like you can request mixed value wafers on their dual gang product selector too. Quote Link to comment Share on other sites More sharing options...
SIMpleONe89 Posted July 6, 2016 Report Share Posted July 6, 2016 That is some intense wiring! And that bass looks great for 35 years old! Quote Link to comment Share on other sites More sharing options...
Norris Posted July 7, 2016 Report Share Posted July 7, 2016 (edited) Nice job and great to see another one getting some TLC! I'm not sure if mine is a very early bass or something, but my pickups are fitted with wood screws - not the threaded inserts. But yes, it's a complete rats nest of wiring, and the varitone switch is a work of art. Edit: (June 2022) I just happened upon this old post and hated seeing the PhotoBucket "photo not found" image, so I guess these couple of photos lingering on my phone may have originally been here... Edited June 3, 2022 by Norris Replaced broken PhotoBucket photos Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 7, 2016 Author Report Share Posted July 7, 2016 Yes - the 70s "batwings" like your own had a number of differences. Bridge placement, varitone function, internal pickup configuration. Easier to work on than these 80s SB-1000s with their crazy component choices! Quote Link to comment Share on other sites More sharing options...
Prostheta Posted July 7, 2016 Author Report Share Posted July 7, 2016 12 hours ago, curtisa said: Omeg used to do MOQs of 100 pieces, don't know if they still do. Looks like you can request mixed value wafers on their dual gang product selector too. I can't spring for that number of parts. It's simply way too expensive for the low number of clients that ask me about these basses. That and there'd need to be a LIN and a LOG model for tone and volume respectively. Omeg doesn't stack up even if I could afford to buy 200 pots! Quote Link to comment Share on other sites More sharing options...
Chrise Posted January 15, 2017 Report Share Posted January 15, 2017 Hi, can anyone help please. I have just bought a 1979 SB1000 that has not been played for years and the volume control has seized. From previous comments it does not appear to be a standard pot. Can any recommend where I can buy a replacement? Quote Link to comment Share on other sites More sharing options...
Prostheta Posted January 15, 2017 Author Report Share Posted January 15, 2017 A 1979 SB-1000 should be single-gang 20k pots. They're relatively easy to source. You might have to settle for 22k or 25k depending on where you look though. Not sure of specific UK suppliers, however you have Banzai over in Germany: https://www.banzaimusic.com/Alpha-24mm-Full-Shaft-Standard/ https://www.banzaimusic.com/Alpha-16mm-split-shaft-20k-lin.html The problem is the splining; the original Aria knobs are unlikely to fit the splining of common pots. This may mean a modification to the knob or replacing it. Quote Link to comment Share on other sites More sharing options...
Chrise Posted January 15, 2017 Report Share Posted January 15, 2017 Thank you very much for your rapid reply Quote Link to comment Share on other sites More sharing options...
Prostheta Posted January 15, 2017 Author Report Share Posted January 15, 2017 You're welcome. Fire me any questions you might have and I'll do what I can. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted January 31, 2017 Author Report Share Posted January 31, 2017 I can't believe that I didn't finish this thread! I took a load of photos of the bass's new electronics; the switch and varitone all had custom daughterboards for the interconnects. I'm kicking myself now....I think I might have lost a lot when I transitioned from the old desktop machine to this new computer. Sorry....I'll see what I can find.... Quote Link to comment Share on other sites More sharing options...
Carteken Posted May 14, 2020 Report Share Posted May 14, 2020 Have you been forced to replace the electronics in an SB and if so, what recommendations do you have? Quote Link to comment Share on other sites More sharing options...
Norris Posted May 15, 2020 Report Share Posted May 15, 2020 You might want to tag @Prostheta to get a response on an old thread I had to replace the pickup in mine. Prostheta put me onto Rautia Guitars, who makes the closest reproduction available. Prostheta also makes replacement pre-amps for the SB-1000 (available on Ebay) I heard an old ('95!) recording of me playing mine last week. I really must gig it again now that it's fixed - it sounded great Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted May 15, 2020 Report Share Posted May 15, 2020 How nice to hear that you've found Veijo Rautia. Without him I would never have built a guitar in my life! Quote Link to comment Share on other sites More sharing options...
Johnas Posted June 3, 2020 Report Share Posted June 3, 2020 I was wondering if You help with issues I have with one of my 2 sb1000’s , I’ve got one from 1980 (batwing headstock and have no problems with it although it has a replacement pickup from Kent Armstrong uk about 15 years ago, my other from 1984 has all original circuitry and although plays and sounds fine when I am not playing and say mute the strings with my left hand and turn from side to side I get a creaking sound coming out of amp . I think it must be a circuitry issue ps battery’s are fine, any advice appreciated ,even does it in passive mode , it maybe is the sound of the strap rubbing on the guitar body and the sound being picked up by the pick upThanks Tony Newcastle England Quote Link to comment Share on other sites More sharing options...
Prostheta Posted September 4, 2020 Author Report Share Posted September 4, 2020 Hey Tony. Sorry, I didn't see this post. Not sure why I didn't get a notification, but there you go. I think you might have emailed me about this problem? I recall having a conversation about creaking coming from the amp when moving the instrument, but I can't remember if we solved it or not. Quote Link to comment Share on other sites More sharing options...
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