basses for newbies (SX batch build thread) Part 2

Discussion in 'Hardware, Setup & Repair [BG]' started by chunger, Nov 15, 2010.

  1. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    The amp thing is a side-project that started out because I was getting frustrated in testing some of the available options. Then, as I dug deeper and got more and more into it, I started getting excited about the possibilities. I'm just following through at this point. I only update on this subject when I reach my major milestones, so I'll spend the time on this one post to describe my plan (ambitious and likely not to materialize).

    I will probably not be able to DIY a complex electronic device with primary focus on low cost better than a major manufacturer doing it at scale. So, if looking for a cheap, functional amp. . . right now I can't find better than Markbass Little Mark II/III and f100/f500.

    If you are looking for a robust no-holds-barred studio caliber bass signal chain that can also be conveniently gigged, this is what I'm looking to do. . . and at that caliber, there is plenty of room to price compete and savings to be had from DIY. . . just take a look around at the retail options.

    Phase 1 for me is simply to develop a package for currently available analog modules in the API 500 series and GroupDIY 51x standards as well as package an OEM switch mode digital power amp to go with it. Need an EQ? Find one or buy one, there are tons of GREAT options.. . ie. API 312 pre --> Neve 1084 EQ --> 1176 compressor --> power amp module or big amp.

    Phase 2 will be to develop a bass-specific module that contains all the basics. DI, preamp, shelving high/low, and possibly semi-parametric EQ or simpler with switchable set frequencies. This would bring the system cost down especially if I make DIY kit available. This would not have to be a cost-no-object type design. It could simply be a good one with decent components spec'd correctly.

    Phase 3 would be to go the way of amp 2.0 and move to digital signal processing.

    Why go through with it? Phase 1 requires a minimum of actual development work. It is just packaging existing, proven components into an ergonomic form. I also simply need preamps for the studio so if I am not able to package these for ergonomic road use, I can still use them in studio. A robust signal chain like what's possible in this setup can be used not just for bass guitar, but for whatever you want. Also, on a more ethical slant, I see bass amps as going the way of disposable electronics which is kindof sad. Things get really cheap which is great, but they also are either not built as robustly as could be or, there are high wear parts on compact, high power amps, and in the end, people continuously cycle through amps and/or throw them away (when there's only one part broken). I traded my Alembic F-1X preamp for a Markbass f1 that I currently use which was a good move, but I was a bit sad to see the F-1X go because I knew that was a "forever" kind of pre that would last me my entire life. My feeling right now is that great quality preamps and EQ's have been around for a long time and with exceptions, have not been changing too drastically. We see lots of slight variations on the same general circuits a lot. Power amps, on the other hand have taken a drastic turn as of late and seem to wear out (particularly small ones). I hope people will be able to build up a robust system and tweak it to their own tastes. . . then, the front end is pretty much set, and as technology improves or you wear out an amplifier, you replace just the part that you need to and keep using the old preamp and EQ modules which are much less prone to failure I think if built with care from quality parts. Also, if the entire system is tweakable, if someone doesn't like the sound they are getting, they can alter the parts of the system they don't like until they do like it instead of throwing the whole thing out and starting over.

    Well, anyways, I probably wrote too much, but there it is. We'll see if I make it to phase 1. . . and it'll be nice to do some testing on this. I may be completely underwhelmed with my resuilts, but I'm having fun along the way.
  2. Happy 1000th, Chunger.
  3. FWIW, I'm totally into a tweakable DIY amp kit.
  4. Awesome Chunger I just read the whole trhead and have learned a lot trought your pics and explains, :D

  5. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Update on production batch. . . it seems the situations have changed a bit. Small orders are bogging down the factory too much, and tooling up to do the chambered bodies does not make things any easier.

    My 1st order will have to scale up from 40 units to 200 units which is a big jump given the scale of my operation. Fortunately, this also has a positive effect on the pricing and allows for more immediate shipping to a closer port (direct to Northern California instead of shipping with a batch to Southern California warehouse).

    Samples (chambered) in time for NAMM are also questionable due to time required to tool up for producing the chambered bodies.

    I've been in amp development land for the last few weeks and will probably remain there for a while, but will start up another SX build hopefully tonight. The client is an upright bass player making who is adding bass guitar to his setup. A professional grade instrument will be required. The blonde Jazz bass w/ black binding will be #18.
  6. Nice, waiting for development
  7. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Back to the regular scheduled programming for a while. . . this one is for Eric. He's starting in on lessons with Jasaman. . . not a novice player, but transitioning from upright. He was going to buy a new Stingray, but Jasaman had a talk with him about how he feels running one of mine would serve better in the long run. After trying out #3 and concurring with jasaman's opinion, Eric contacted me about options. Since I'm plum out of finished jazz basses right now, I grabbed what I felt to be the best jazz bass I had remaining in inventory and started in. This one will run stock NJ4SE's without the push/pull push/pull push/pull options. In conversations with Jasaman, he has not yet used the parallel mode yet live on #3. I'm sure there will be situations where they will come into play in the future, but in my conversations with Eric, if 90% of the time, the pickups run in their optimized series mode, he didn't want to escalate the price for the more complex wiring harness. It will still have the global push/pull pot as usual.

    We won't know how this one stacks up until it is finished, but I have a pretty good track record of first impressions. . . maybe because I have an active imagination, but I did call #11 and #4 as ones with "great potential" before they were built :D


    Here it is. . . pretty. I have no idea how people play with all that stuff on there, but off it comes the metal covers.. . . I won't be putting them back on.


    The strings, neck, bridge, and pickups are pretty well aligned on this bass :eek: excellent!


    I was starting to wonder whether this one was truly "custom handmade" but sure enough, the good folks at the SX factory do not disappoint. . . this has got to be the awesomest example of factory assembly talent thus far!


    Enlarging the holes for threaded inserts. . . avoiding that REALLY crooked one for a while. . . I ended up drilling a crooked hole in my little wood jig to try and match the wonky angle as best I could.


    The holes came out pretty ok.


    From looking at the setup as the bass came to me, I figured this one needed a shim.


    And, the neck is set. . . that crooked screw was a trip, but I think mechanically, this should work just fine.


    After verifying neck alignment and tightening down the neck screws to final torque, the body is stripped. . .


    And, I realize the neck pickup holes are drilled all wonky, so I decided to plug them and make new holes when I install the new pickups.


    Next, I enlarge the 3 control pot holes on the cover plate to 3/8"


    . . . and test to see if the large diameter pots fit without needing to route the body for clearance. Most SX's need to be routed some to fit the big pots. This one, luckily, does not. So I'm on the fast track.


    Copper shielding foil is installed and tack soldered. After electronics go in, this bass should be ready for PLEK, and then after PLEK, it'll be ready to deliver. . . But, for today:

  8. nice job as always. That neck screw was really crooked, I guess they don't have drill presses in their factories over there?
  9. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Pickups have been on my mind lately again. I had a chance to test #18 before I stripped it with the stock SX pickups. . . just to double check and see if I'm on the right track in terms of pickup development. I thought I'd write down some thoughts before they get too distant.

    The bass sounded good with the stock pickups. . . this is a good bass, and there is reason I had to go searching far and wide to find a replacement for those stock pups. I then plugged in #9 with the prototype A single coil that I've been spending a bit of time with lately. . . the prototype pickup just about destroyed the stock SX pickup on all levels. In terms of overal tonality and vibe, it is very close to the stock pickup with a good amount of midrange growl, but the custom Nordy is way more transparent, I'd say has a hint more upper mid snarl to it, carries a fuller bass response, and a ton more highs. . . that can be attenuated back with some tone knob. Push the SX pickup, and it falls apart (SX effect). . . push the Nordy, and it snarls and gets "dirty" on you. Lots of highs, but very harmonic and not harsh.

    Stew over at Nordstrand informs me that the next iteration pickups will be shipping tomorrow or the day after. I've only tweaked the specs slighting from this prototype. Simulated handwind instead of the straight wind, a slightly shorter magnet, and I've ordered an iteration with .350" coil depth as opposed to the .310" depth of prototype A. . . and then, a 5 string set incoming as well. The prototype is so close that the tweaks made are pretty minor. I am pretty confident the new pickups will be nailed and I will have a standard setup to build out my remaining few SX jazz basses and move forward on the "modified" series new spec instruments.

    Back to #18. . . I've been sitting on this little idea for a while now and thought I'd give it a go on #18.

    These are the Molex quick disconnects recommended here a while ago. I bought a small stash of them. Here's the female end bare.


    And installed on harness with shrink wrap:


    and the male end:



    And, everything ready to install:


    As with anything new, it took longer the 1st time. I wondered to myself whether all the hassle of crimping and fiddling with these tiny connectors will be worth it not to mention the addition of another potential point of failure in the harness, but this does allow for pickups and wiring harness to be changed out more readily. From a sale perspective, it might open the door to offer complete harnesses. . . I don't know. There was only one way to find out though and that was to just give it a go. If I do end up with a few really nice pickup iterations I could see wanting to change pickups on certain instruments after initial testing which this would facilitate. . . and then again, it might be faster just to do it the old fashioned way and solder to the pots. 3 connectors fit OK through the drill hole from the pickup route to the control cavity, but it was tight. . . 5 connectors on the 4 wire series/parallel setup would be no-go for sure.
  10. JebDude


    Sep 22, 2010
    Try putting one pair of the connectors in the tunnel first, then the next pair behind them. That way only two at a time have to fit in. I've used this staggering to fit plugs through holes I drilled too small. Just my 2 ¢.

  11. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Well, looks like I'm going to lift my self-imposed embargo on Rondo Music now. Kurt seems to be making a strong effort to stock old-profile replacement necks, so I feel the situation is good enough.

    I had a p-bass that I was hoping to put a jazz neck on, but the neck pocket gaps were too unsightly for me. . . a brief look back at the Rondo Music website revealed all neck profiles in old-type headstock are available. I had a few email conversations with Kurt about stocking necks as a possible solution, and he seems to have responded to the requests.

    Still, the wheels are already in motion for my production batch that will hopefully not have the chronic Q/C issues of the SX line due to better materials and assembly tooling/procedures.

    But, very welcome developments over at Rondo Music :cool:
  12. JebDude


    Sep 22, 2010
    Mr. CHunger, sir. I've a question on your cavity shielding that I don't remember seeing elsewhere in this thread. I've seen on some other forums mention of using aluminum foil. Other than the obvious factors; ease of soldering for grounding, dissimilar metals, adhesive backing. Are there any other factors in your choice of the copper foil?

    Thanks for your time.

  13. Poor Places

    Poor Places

    Dec 9, 2010
    Hey Guys,

    First post on here, but I felt the need to post a review here. I picked up #7 from Chunger a few weeks ago and have been playing and trying to get a real feel for what this bass is all about. We were up in the bay area a little while back and I had a chance to play pretty much every bass that was out at his house. I do need to qualify this with a note that I am by trade a guitarist and not a true bassist. On the drive up to their house I was wavering between the SX and a Lakland bass seeing that I had just sold some preamps and had a little extra money. After catching up, I went upstairs and plugged in #7. Instantly, I was elated with what I was hearing. It had the Nordie Modified P's in it and it just had a perfect hollow growl to it while still keeping some smoothness on both ends. The neck was great (I play a 60 Les Paul special so I love fat necks), clean, fast and had perfect intonation. I sat for a good time more playing his personal P (which is epic), then a few jazzes and eventually a fretless. We had to leave Sat afternoon due to my being book on Sunday. After we got back to L.A. I brought the bass to my gig the next day where my brother in law (who has his degree in bass) picked it up and didn't set it down all night. His Music Man just sat there. After it was done, he first asked where he could get one, then followed it up with the fact that he hates almost every pbass but loved this one. He's taken it with him on his past few gigs as well. I have used to track a lot of demos and cant get over how easy to play this thing is. Anyways, I wanted to say that Chunger does great work and if you can get your hands on one of these, do it. If you want to modify your own, this thread is a great resource. I also want to add that the bass is dead quiet... I mean, no noise.

    As a side note, Chunger's preamps look amazing as well. He is a great example of starting somewhere and just working and reading until you have it down.
  14. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    I had this little problem lately of not having any more basses to sell, and a fair amount of demand, so I had to get off my butt and 1-800 get some done. I set a PLEK date, and figured I'd just try to prep as many as I could do. PLEK was today (Friday), and Thursday, I went for it after a 1/2 day of work at the office, but called it quits at 4:30am. But, got a good deal done, so I'm happy. I'm running out of components I was certain I bought plenty of :eek:

    I first had to pack everything up take this for the Christmas card. . .


    Then, on to the usual shenanigans like plugging loose necks I purchased previously. . .


    I also purchased a new production replacement neck from Rondo Music thinking I was going to use it on one of the previously fretless p-basses.



    Because when I tried using a jazz bass neck on it, the gap was really ugly. . . uglier than I am willing to live with anyways.


    So, I started prepping the new neck. . . tuner bushings get pressed in.


    And then, I secured the neck to the table so I could position the tuners.


    I ended up aligning pretty much by eyeball. . . not the most precise way, but "one" way.




    Voila!. . . well, I've seen better and I've seen worse.


    Neck is ready to install.. . but, the bass that I was planning to put it in had a REALLY tight neck pocket. . . so tight as a matter of fact that a jazz bass neck fit pretty ok in it. After thinking about it for a while, I decided to just run the jazz neck instead of sand/fit the neck pocket to the new neck. I wasn't planning on buying any more SX's, and felt I had a better shot of selling off an unmolested neck as opposed to a take-off jazz neck that has previous holes plugged.

    I think this bass handles pretty good . . . #19 then. . .


    Drilling new holes in the neck. . .


    And, inserts installed. I decided not to run a shim on this one.


    And, all strung up with new 45, 65, 85, 105 DR lo-riders and ready for PLEK.


    Next, I decided to finally break out the "other" MIM that I have had laying around.

    Viva #20!



    And, what the heck. . . the last of the new old-headstock SX's. . . #21



    And, that's when I called it quits. . . 5 basses going to PLEK.

    #9 (the pass-around bass) I got this bass playing pretty darn ok, but I know there's something the matter in the ~8-11 fret area that I can't accurately level out, and I'm getting to the point where I don't want to take off more metal.

    #18 for Eric

    #19 the jazz-necked p-bass

    #20 the Mexican Standard

    #21 . . nice to work on a new, blue instrument. Feels like the beginning. I'm pretty sure this one is going to be standard grade, and Jasaman has requested more standard grade instruments as of late. I may build it out with stock SX pups to keep cost down.
  15. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Back to Music Go Round in Citrus Heights for PLEK. . .


    If in the Bay Area and in need of PLEK, there is one machine in San Francisco, but I don't think it's a PLEK Station. I recommend the trip out to Sac. Mike has long-term experience in machining and that background helps him maintain and operate the PLEK optimally.

    At any rate, I always learn something significant when going to PLEK because the machine can measure things across the entire fretboard that are not easy to detect with conventional straight edges. There was talk of getting me up to speed as a PLEK operator which would simplify things for all parties and allow me to directly bring in work and fill in the machine down-time. But, that's the future, and #19 is now :D



    and, the result. . . green line is theoretical optimum, red line is final measurement in after cut in this graph.

    #20 goes in. . .




    #21 goes in


    . . . and, this is where it all went to hell. . . there were a couple of issues with the neck on 21. . . one of the main ones is a low 12th fret particularly on the E string. You can see on the graph that I am not able to achieve fall-off, and this situation would buzz. It certainly wouldn't be able to run low action. If I were to set the heights for optimal, there would not be enough fret at the end of the board to cut. (the red line is above the green line after the 12th fret).


    So, I ended up pulling the bass out of the machine and loading in another one and yank out the 12th fret and replace it.

  16. BananaKing

    BananaKing Supporting Member

    May 15, 2008
    Vancouver, B.C.
    I love watching this thread. I'm learning a lot just from the pics alone!
  17. Agreed.

    #19 lookin sexy. Curious as to how that one will turn out.
  18. chunger


    Jan 10, 2006
    Albany, CA
    Chunger basses by Studio 939
    Next up was #9. . . this is the pass-around bass that I'd been wrestling with on the fret leveling for a few passes. I know there's more playability potential on this particular bass but for whatever reason, I have not been able to figure out the issue. . . well, actually, I knew pretty much where the problem was, but didn't think I could accurately resolve it with the tooling I had, so I just threw it on PLEK. Here's where my hand leveling efforts landed on this bass.


    Notice fret 11-7 there's a slight hump. . . or, you might be able to say there is a slight dip from fret 2-5. Fall away is generous (the way I like it). I had the truss rod adjusted to run pretty much flat on this bass which the PLEK confirmed is optimal. There was untapped potential though, and I need this "pass-around" demo bass to run perfect. The proposed cut on this guy is very optimal. The radius will be compound from 333mm at the 1st fret to 433mm at the 20th fret with excellent fall-off after the 12th fret, and I had PLEK cut a TUSQ nut for me just for kicks and giggles so I could see the machine cut.


    And, #9 comes out of the machine ready to rock.

    OK. . . back to my "problem child" bass for this round #21. . . after changing out the 12th fret, things are shaping up. I still don't have an optimal fall-away, but this is as low as the machine will cut. PLEK made an outright error on the 13th fret on this instrument. You can see how high it is in the chart, and the fret rocker revealed the issue after I detected bad buzzing. Since I had already cut the 20th fret to the lowest it could go, I could not run the bass through the PLEK process again. The best solution was to use the fret rocker and hand cut the 13th fret down to the proper height with my crowning file slowly.


    As you can see, there is not the usual generous fall-away I like to have on this bass, so I imagine it will not be able to run as low as some of the others. All in all, I think this one is the most problematic SX I've seen so far. . . well, #7 was pretty problematic as well and required a fret replacement. Sure, you can buy a new neck now from Rondo for $40 which is probably cheaper than the repair (if not doing it yourself), but I do not believe in throwing away serviceable necks, so I chose to fix it. I don't have a picture a PLEK scan (no cut) confirmed the 13th fret was pulled into reasonable alignment after filing. Buzzing resolved. Keep in mind, this bass can still run at .085" so it's not shabby at all in terms of playability. Light years better than most.

    Last, but not least, #18 goes into the fridge.


    and comes out nicely:


    That's all for now. . . I have a few basses now to button up. I have 3 more SX basses to build and then I'm out. 2 jazz basses and a nice p-bass. Plus an extra p-bass neck that I have to figure out what to do with. Hopefully this will keep the masses at bay until I can get a few spec basses in.

    On a side note, a few high profile players have now touched chungerized basses (#4 and #3) and the feedback has been excellent. Jasaman reports back that #3 now is performing beyond expectations, and under heavy long-term use, it is holding up very well and has stabilized. I think when originally built, the instrument was still very raw and needed to settle in. It should start to sweeten up as it's played out more now. All of this is reassuring because the high profile players really do have access to whatever they want in terms of instruments, and verifies that I am indeed still building what is practically speaking a product with very few compromises.

    onward! :bassist::bassist:
  19. dude, you rock.
  20. selowitch


    Aug 6, 2005
    Rockville MD
    Obsessive. In a great way.