Prostheta

Congrats on NGD! Great to help keep these vintage birds flying.

I forgot to pick up (no joke intended) on this part of your opening post Ian. The high DCR doesn't tell us much without knowing the wire AWG or number of turns in the coils. They do seem a bit hot, however given that the 80s were when experimentation and crazyness went full-on in the new aftermarket world, it's difficult to say. I've seen all sorts of weird values for coils that are intended for active circuits from ridiculously-low ('86 Aria Pro II Integra and SB-Int, only a few k and super hifi) to rare fault conditions in pickups with DCRs in the regions of MOhms that are still able to drive the ultra-high impedance (TOhms) of a preamp without issue. Coincidentally, the pickups in SB-1000s and others that use the MB style have a tendency to fail by going high resistance. Normally pickups drop in DCR through corrosion shorting or just go dead. These pickups were wound for passive end use, so that doesn't add anything useful to the mystery....especially when they are both reading oddly-high DCRs. Perhaps the explanation is that the previous owner who modded it was under the impression that high DCR means more tone?

It's best PMing me as I can do a way better price than I have to do on eBay. Their fees and requirement for fully tracked shipping ends up costing clients more than they should have to spend. That and eBay seem to be leaving sellers out in the cold more and more these days, or sellers having to turn the screws on buyers to turn a penny. Neither are cool in my book. Kill noise on all guitars or just kill guitars? 😉 Well, yes and no. The preamps work by floating the pickups around a virtual earth with a +9v/-9v supply rail, pretty much like a DI box, but in this case an active DI box I guess. The varitone filter is an active part of that circuit. The impedance is silly-low, so when combined with lower value pots (10k-25k) you get a robust signal that doesn't get rolled off by cable capacitance and all those negatives. Noise still occurs on some level, but only the stuff that you can't get rid of in any instance. Things like Floyd Roses or Telecasters. Those are pretty tenacious and require a 10kV active circuit to the noggin to remove. I just fabbed the new batch today and am taking a break in testing before encapsulating them. The messy bit. Get 'em whilst they're a few degrees above room temp!

Apologies for not picking up your post! For some reason I don't get notifications from BC. I'll be finishing up the next batch of preamps Tue-Wed this week.

Morning all, and thanks Mike. A new batch will be fabbed within about a month or so. Sourcing has been a mild nightmare due to the usual political and viral suspects, so I've decided to invest a bit more heavily and do a "doomsday prepper" level of stocking up. Congratulations on the NK-900! You don't see that many kicking around, and especially not ones needing the preamp! I think it's likely that a lot of owners with faults simply gutted them to passive, same as a lots of SB-1000 owners/acquirers. In principle the circuits are almost identical with the difference being the varitone values. It might be worth documenting those for future reference since APII never let their production schematic out from what I know. The replacement pickups work fine in this type of circuit, as will any pickup really. I've built both guitars and basses around the BB preamp and they're inky-quiet, even my custom single-coil 5-string '51 P-bass. Do you want me to keep you updated here? I'm leaning away from eBay right now, since I'm forced to use tracked mail (expensive) and their fees are astronomical amongst many other things. I'd rather try to keep costs lower instead of having to pass them onto customers, which is far more critical given the increase in well, everything these days.

Wow, just wow. This is one looker, and that it also delivers tones makes it something else. Floored....great work @Cosmicrain! I have to mention that Veijo concocted a 5-string version of the MB-1E solely for my experimental 34" 5-string SB-1000/R150. Solid meaty tone to kick your doors in before you even pair it with the preamp! Veijo is also making MB-J repros, which would be a really cool idea to combine with the BB preamp, especially since that never existed in the original Aria Pro II lineup. I'd imagine that some work changing values in the filter would be a rabbithole and a half given the palette a Jazz type bass begins with.... The bottom line is, I copied. Mike made it his own and then some.

Wow, that was pretty quick turnaround given the strangeness that seems to be enveloping the world these days! Despatched on Sunday, arrives on a Friday? Whatever is the world coming to?

I've discussed this briefly with Veijo, because I am also having a large quantity of back orders to fulfil. It seems that quarantine, lockdown or layoffs have given people a lot of time and an excuse to restore their instruments. Since we're both in Finland and see a lot of each other's customers, we see this happen pretty similarly. As much as it sounds biased, I would advise emailing Veijo and asking about lead times. It's worth the wait, especially since Aaron doesn't actually put any effort into reproducing the internal characteristics of the pickups; unless this has changed, he simply puts in "a couple of standard coils" to a mould and makes the whole thing out of epoxy. Veijo vacuum-forms the cases. I'm sure Aaron's pickups are good - don't get me wrong here - however I don't think I could vouch for their accuracy as a like-for-like retrofit. Ultimately, if payment method is a bugbear then sure, go with what works. My PayPal account is still technically a UK one even though I've lived here ten years now. You're right about the gifting money bit though, @RichardH; buyer protection is worth the money if the seller isn't reputable or known to the wider community.

It's funny how much you can learn from seeing photos of instruments in restoration. One thing of note is how Matsumoku processed the neck blank on the control side between the pickups before the wings (and their stringers) went on. It looks like they went in with a router or even a table saw to the side of the neck blank whilst still a five-piece laminate, built the whole thing up and then "revealed" the channel between both pickup routes later in the game. It's a valid technique, and I did something similar to this with a Firebird build. The control cavity looks like it possesses some of Aria Pro II's "afterthought" processing work, which seems to be pretty common. The 70s SB-1000 was the master template which was then modified for the 80s SB-1000 and further for the SB-R150. Even though the cavity machining is better than the SB-1000, it still looks like they went in and did some manual machining anyway. Is that the pickup access wire emerging over the control cavity lip?! Man, that was so close to being a total Friday job. One false move and the world would be one SB-R150 short, perhaps one stressed worker less. Either or. Have you also noticed that most SB bass neck laminations have mismatched Maple, usually with one having figure and the other not? Looks like your R150 has some Birdseye in one!

Glad you got this restored fine! I feel like I missed out on the action 😕 From the outside, that's absolutely spot on. I've got a lot of love for the SB-R150, my white whale! So much so, I got around to making my own hybrid SB-1000/R150 build. Single pickup like the 1000, with the R150 appointments but with the cats eye inlays. Also, there's something distinctly different on one side.... I'm glad that I didn't go for two pickups....those toggles make the circuit another level of complex on top of how they are anyway! She'd look quite comfortable amongst your existing bijou clutchette!

Certainly! The SB-1000 and other SBs of the era had a very singular tonality which made them very recognisable. Being able to alter the format of the instrument and see what type of uniqueness comes out of the other side is a real joy. For my own part, I'm not sure how me taking the format over to five strings will work out including the necessary alteration to the pickup. Having a slightly shorter scale on yours will be super fun to play, especially when you pare back that boat anchor aspect of the SB's physical form!

Hi @Bass Culture! I was just brought into the loop on this build, but better late than never eh? I'm sorting out the required parts for this build with Mike as I write this. The fundamental circuit topology behind the SB-1000 is a real winner, and I used it to silence a single coil pickup in my 5-string '51 P-Bass build a few years back; that one is straight volume/varitone and a real player. Once you can get past the caveats of two batteries and a switched jack socket, they really put a lot of horsepower behind a bass with the option of completely pulling the filter out of circuit and running as a dead transparent, dead quiet pre. You're right about the varitones. I produced a few based on a piggy-backed SMD board which was compact and sounded great, however the switch itself left a lot to be desired, and producing them is such a pig. I don't believe that the original Alps switch used by Aria Pro II is in production any more or even available as NOS. The closest equivalent that I have found is by NSF and costs just shy of fifty quid. It is however, a really nice switch and very easy to work around. I can't quite describe how nice it is without ending up on a register of some sort, because that's the world we're living in now. 😄 It's perhaps difficult to justify the cost of that one part once one factors in the components and labour! Mike sounds like he has some great ideas, and judging by his past work, you're in good hands. This should be an instrument that'll want to be just played. I'm definitely behind the notion that Veijo (Rautia) produces the closest retrofit pickup to the originals. There's perhaps a touch more top end, however that isn't an easy comparison when A/Bing it with a pickup that has 40yrs on the clock. In a blind test, I'd think most would struggle and I would likely get it wrong also. Pull that tone back a notch and I'm certain 50% would. I'm following this build for certain. Cheers!

Thanks for the heads up, Norris. Poly is a catalysed finish, that is, it cures by chemical process rather than the simple solvent evaporation which nitro does. Spraying nitro over nitro for example means the solvent will reflow the existing nitro slightly so they become one finish. Poly doesn't do this, so any nitro sprayed over it will have poor adhesion. Perhaps in some respects this is what you want, however it might be so weak that it sloughs off in sheets or big chips rather than the relic-y wear look. Not what you're looking for. The nitro will need some kind of suitable surface to bond with, such as one that has been scuffed with sandpaper. A mechanically-keyed bond like this should be sufficient for a good nitro over poly finish. Norris mentioned shellac to me in passing, which is an option, however I'd think that simpler is always better. Shellac is fantastic if you're trying to keep the top layers in place over a potentially incompatible base, maybe not so much for something that you want to relic. Hope that helps.

Sure. I'm in.

The originals were potted in epoxy, or at least the MB-1, MB-1E, MB-II and (I think) the MB-III were. The MB-IV was unpotted which meant you could install more poles and potentially rewind.