Basses for Newbies - Bass #6

Let's get #6 started. . . back to SX's . I've been doing a lot of jazz basses lately, so I figured I'd try something different with a P/J.

This bass was the one that's started this whole basses for newbies ordeal. It's been sitting in the studio making its way onto various projects that come through. I leveled the frets already, but think I need to take another look at the level job and probably cut more fall-off. Hopefully this one will be straight forward and fast. Mainly, this bass makes noise so I will try to shield and re-wire. . . and throw in neck inserts. I was debating the series/parallel switch on a P/J, but I think I'll put that in as well just for kicks and giggles. . . see what "super phat" mode sounds like.

Thinking about trying out a GFS p-bass pickup on the neck position and see if the shielding alleviates the hum issues on the stock bridge position SX pickup because the "SX effect" only seems to happen on the neck pickup. If it still hums, I'll have to look into a split coil bridge pup.

IJ Research F76 Compressor Build

The Universal Audio 1176 FET compressor originally released in 1968 is broadly recognized as one of the all time great audio compressors.  It seems every major studio has a few of these in their outboard racks and the particular way the FET circuit compresses is distinctive and a "familiar" sound due to the widespread use of the 1176 through the years in the industry.

The I.J. Research F76 is a 51X format FET compressor designed around Universal Audio's revision F 1176 with a few very useful added features most notably, the addition of a 2:1 ratio, a side-chain high pass filter, and relay controlled true bypass.  The kit also allows for a myriad of build options.

Igor Kapelevich based in Haifa, Israel can only be described as a prolific designer, and he is the mastermind behind the F76 compressor.  Igor's primary business is building complete turn-key audio devices for various studios worldwide and his custom work is not cheap, but he is very active in the DIY community and makes his partial kits and PCB's available for purchase as a side business so that DIY people have an opportunity to build some fantastic sounding pieces of audio gear at very reasonable prices.  For support and technical questions regarding this project, please refer to the official support thread.  To purchase PCB's and font panel/hardware kits check out the IJ Research webstore.  Complete kits may be available again from time to time depending on Igor's current stock of parts.  In this post, I will try to show a complete build from start to finish.

VP312DI Microphone Preamp Build

One preamp that was very interesting to me from my initial DIY research was the VP312DI kit from Classic Audio Products of Il.  One of the main reasons I wanted to try this kit was the feature set seemed very conducive to live use for bass guitar.  It has some really cool modular features that allow for a wide range of customizations.  In particular, this preamp has easily detachable modules to allow for 4 completely different flavors of DI.  It also has a built-in switch to bypass the DI module and inject the signal directly into the opamp which yields a different sound option that is built-in and always available.  In addition, the opamp is a standard footprint 2520 opamp.  Because this preamp comes in a full 51X Alliance standard configuration, not only are API-type +/- 16V opamps accepted, but a number of +/- 24V opamps can also be used.  The DI section of this kit also has a selector switch for 16V and 24V operation depending on the module being used.

So, in short, there are a mind-boggling array of possible configurations for this preamp kit that can all be changed quickly and without soldering.  For this build, I will explore a few of them.

opamps:  GAR2520, APP2520E (+/- 24V)
DI modules:  FET DI, Picatron passive transformer DI, and the IC chip DI

The current revision of the VP312DI preamp has a new option on the PCB for stepped resistors on the gain knob, so you can now choose between the constant variable Bourns pot (as depicted in this older revision build) and the Grayhill switch with stepped resistors when purchasing this kit.


There is no in-depth step-by-step assembly guide for this build, but a lot of critical build information is consolidated in the official support thread on the http://www.groupdiy.com forum.  All of the critical build documents (schematics, bill of materials, and assembly guide) are also sent via email upon purchase.  In this post, I will attempt to detail every step of the VP312DI kit build.

Basses for Newbies - Bass #5 (part 2)

This is the continuation of the Bass #5 build.

We start out this installment with new electronics being installed.

Basses for Newbies - How to Install Copper Shielding Foil

It seems like there are a lot of folks out there with questions about how to shield the control cavity and pickup routes. I figured I'd take some more in-process photos on this one and see if it's helpful. This may very well not be the best or cleanest way to do this, but it is "one" way that works for me.

Let's start with the hardest part. . . the pickup cavity. I start from the bottom of the route and work my way up, so the first step is to make our bottom piece. I measure a piece of 50mm foil to the length of the pickup with an extra ~1/4" on top and bottom.

Basses for Newbies - Bass #5

So, curiosity killed the cat, and this cat was very curious indeed this weekend.

#5. . . something's a little different about this guy. I ended up picking up 2 "Mexican Standard" jazz basses this weekend locally. I backed out of the deal I previously almost got into from the classifieds here on TB. At any rate, #5 is a 9.56 lb. dark burgundy metallic copy and set me back $235.00 . . . the other one (black) set me back $300. Both is great condition.

Basses for Newbies - The "SX Effect"

After playing the stock SX pickups for a while, we discovered a serious sonic defect.  While these pickups have a unique sound that is punchy with a nice mid-forward growl. . .super fun to play by the way. . . when pushed past a certain threshold during aggressive playing, the pickups distort severely.  For lack of a better term, we started calling this the "SX Effect".  This clipping is very abrupt popping sound as the pickup spikes.  It sounds very similar to digital clipping when an A/D converter is driven too hard.  In the studio, the instrument sometimes really needs to be feathered to stay just under the level where the "SX Effect" rears its ugly head.  Some players would probably never push the pickup to distortion, but if a player is unaware of its existence and finds himself in the middle of a recording session, the engineer may spend hours trying to chase down the clipping because all meters and indeed the input signals would be showing very normal levels.

While I was unhappy it would drive the cost of the instruments up . . . perhaps quite significantly, I deemed the stock SX pickups unsuitable for the mission which is to deliver an instrument capable of going the distance (an entire lifetime) and stay with a student from beginner all the way through professional use.  A few players I know are lucky enough to still have that first instrument, and I wanted to put an instrument into the student's hands that could still be a go-to gigging or studio weapon of choice well into a playing career.  After all, there is always ample use for a nice 4 string jazz or p-bass in the studio.  Sonically and ergonomically, it needs to be able to run with the big boys.

The search for a replacement pickup lead me to a conversation with Carey Nordstrand of Nordstrand Pickups, Inc.  through and introduction from a friend who was developing his electric guitar designs.   Nordstrand is a premium brand, and there was much debate about whether the pedigree and cost of these meticulously spec'd pickups is too high for newbies.  They are after all manufactured in the US on state of the art CNC winding machines with the finest materials and processes.  In my mind, there was only one way to find out and that was to test them and discover with my own fingers and ears if there is some magic left in pickup development that has not been successfully translated to off-shore manufacturing.