Original Four Banger – Schematic & Layout

18 02 2011

I haven’t posted in awhile. I’ve been unbelievably busy with all sorts of stuff. To make up for it, here is the schematic and a layout for the original version of the Four Banger.  The connections for the controls aren’t labeled on the board, but if you use the schematic as a guide, it should be easy enough to figure all the connections out.

Even though the schematic shows an AC128 for the germanium transistor in the Rangemaster section, this circuit can accommodate a wide variety of PNP germanium transistors easily with the (proper) Emitter trimmer to set the bias however you see fit.

Please don’t flood me with how-to questions. I honestly don’t have time to answer them all, and there is more than enough help available to you on the various DIY forums.

New Site Soon

17 09 2010

Greetings Everyone,
I haven’t posted in awhile… I’ve been exceedingly busy and distracted these last few months. Three moves in less than a year is enough to really jumble your senses! Most importantly, after much thought, I’ve decided to finally commit myself to building effects and custom electronics full-time and treat it as a real business.

Sometime during the next few weeks, I will be updating my commercial site, www.soulsonicfx.com. After much thought, I’ve decided to do the entire site using WordPress. I’ve been very pleased with the results I’ve gotten using this WordPress blog, so I’d like to stick with something that I’ve grown very comfortable with. I also enjoy the challenge of seeing what I can do with it.

If you’ve tried to access the site in the past 24 hours, you’ve probably noticed it’s down. My host says they’re performing file maintenance, so it should be back up soon. This has affected the email accounts as well, so if you’ve had trouble getting in touch with me, please use my secondary email address: solgrind (at) lavabit.com

I have some exciting new things in the works like, a cool new tube overdrive, an Echorec-inspired delay, and an innovative fully-modular mixing system!


Four Banger mk2 – FINALLY!!!

3 12 2009

First, I must apologize for not posting for such a long time. I’ve been exceedingly busy with a number of things, so I’ve neglected this site. But, I have certainly not neglected building wonderful new effects!

I first built the Four Banger during July 2008. Since then, it has gotten alot of attention. I am very pleased that people have found it to be a useful and good-sounding tool; but the original design was quickly thrown together as a one-off build, and despite the fact that it sounded great, I found it to be deficient in several ways from a technical point of view. So, I decided to stop taking orders for it and went back to the drawing board to re-design the entire thing from scratch and try to improve it in every way possible.

Here is a photo of the first build:
Four Banger mk2

The hardest decision was deciding what kind of enclosure to put it in. After much consideration, I decided upon the standard “125B” enclosure style. The reasons are because it is a fairly compact size – but can still easily fit a battery (unlike the previous Four Banger Mini), it is readily available, and it is reasonably priced. I also put much thought into how I would paint it. Enamel paint or powdercoat are the usual choices, but I decided to go with a hand-painted acrylic finish over a matte enamel primer with a lacquer top coat. I like acrylic because of the wide color pallet available, the brightness of the colors, and the fast drying time. The lacquer top coat protects the finish very well from everyday wear and gives a nice gloss.

Here, we can see inside:
Four Banger mk2 guts

I’ve taken several new approaches in this design. First thing you may notice is that the jacks are mounted directly to the circuit board. This greatly reduces the amount of material and time required to wire the circuit. I have chosen this style of jack because they have proven to be very reliable when used this way and they are of very good quality. The next thing that catches your eye is the bypass switch. I have chosen to move away from the standard “Taiwan Blue” 3PDT footswitch as I, and many other builders, have used. Instead, the Four Banger mk2 uses a miniature 4PDT pushbutton switch with an external actuator to activate it and protect it from damage. I have chosen this switch because it is higher quality, is more suited for guitar-level signals, and has a much lighter feel without the loud “KA-CHUNK!” sound and no need to stomp on it to turn the effect on and off. Despite the lighter feel, it can easily withstand heavy stomping without any danger of accidental damage; the amount of force required to damage it would easily do equal damage to a standard large footswitch. And because it is mounted on its own board, it can easily be replaced if necessary. The Boost Select switches are now small pushbutton switches instead of toggles. I chose them because they make installation easier and there is less chance of damage if they are accidentally stepped upon.

Now, to discuss the re-designed circuit: Let’s begin with the Rangemaster (R). I have painstakingly designed a new modern silicon-based treble boost circuit that gets as closely as possible to the sound of the original germanium version of the Rangemaster. I built an original spec circuit with a vintage black glass OC44 to use as my reference, and I believe I have captured that sound. The main reason for dropping the germanium circuit in favor of a modern version is because of consistency. It is simply too difficult to find a large enough supply of great sounding germaniums and be able to offer the unit for a reasonable price. Additionally, I relished the challenge of a new design… as always ;). Moving on, the MOSFET (M) boost is my “No Crackle” re-interpretation of a certain popular boost. After coming up with the initial No-Crackle design, I haven’t seen much reason to change it, though I may tweak it a bit before final release, to try and reduce the noise a little bit. The Opamp (O) boost is another new design. Though the original Opamp boost was nice, I personally found it to be a tad boring and I wanted something with more versatility. Now, the Opamp’s gain can be dialed from a transparent buffer all the way up to a great hot overdrive. I’m very pleased with how that one turned out, and I’m going to be offering a deluxe standalone version that will compete against such heavy hitters as the Klon Centaur. Finally the JFET (J) boost has been re-worked as an SRPP style circuit instead of the previous Mu-Amp stye. The SRPP has lower noise, lower output impedance, and greater drive capability. It is a small change, but surely a worthwhile one.

I will be passing around a demo unit to some known pedal guys to get some first-hand feedback and reviews. I plan to begin officially shipping these at the beginning of January 2010. The projected price will be $200USD. This price will included worldwide shipping cost. I am also working on a deal to get these and other SoulSonicFX products distributed in Australia so it will be easier for my Australian customers to obtain them. Also, the soulsonicfx.com website will soon be updated with more information about this and other products I will be selling.

I have now officially opened a pre-order list for the Four Banger mk2. This will allow me to more accurately judge the demand and plan production accordingly. If you would like to be on the pre-order list, please send an inquiry to preorder@soulsonicfx.com.
If you have previously contacted me about the Four Banger, PLEASE send a note to the above pre-order address. This will allow me to organize all the requests and keep track of everyone. Thanks to all of you for your patience, I know some of you have been waiting to hear about the new Four Banger for quite some time.


Freestompboxes Temporarily Down

4 07 2009

My favorite forum, Freestompboxes.org, is currently down due to hosting and server migration issues. If you are a member, please be patient, and hopefully Johan will have everything squared away soon.

Here is the quote from his blog:

What happened, in short, is the following: we registered with a new hosting company 3ix.com, everything seemed to be fine and the people very helpful. Until this afternoon CET they just pulled the plug without any prior notice.

There was no explanation given and no illegal material pointed out by the provider, but as a matter of fact, the terms of service mention that in case of abuse they are allowed to take measures without any justification.

The Honey Bee Challenge – Folk Driver DIY Overdrive

19 04 2009

Hi everyone, as some of you may already know, Björn Juhl sent me a Honey Bee pedal to play with. The idea was to listen to the sound and see if it can inspire a nice DIY project. Well, after spending some time with it, I’ve come up with something that sounds good and will certainly remind people familiar with the sound of the Honey Bee.

My goal was to keep the design as simple as possible, but still try to fit in some tricks. This uses both positive and negative feedback to get its sound. R8 is something I learned from the big old red RCA book – it’s positive feedback to boost the gain of the first stage; it was suggested as an alternative to using cathode bypass capacitor in a tube stage, well, it works just as well with a transistor. The combination of R9+C4 is negative feedback to reduce the high frequency gain and give the signature smooth sound. It also promotes stability in the circuit. I settled on the clipping diode combination after trying several different kinds, and the 1N4001+1N4148 combo had the best sound for this thing and reminded me most of the HB.

The Timbre control adjusts both the low-frequencies and the amount of drive. At the 12 o’clock position is the minimum drive amount. At one extreme it’s max gain with lows emphasized, and the other is max gain with the lows cut. It’s sort of like having the HB’s Gain and Nature controls on one knob.

Here is the schematic: Folk Driver
I have a PCB design done up with ExpressPCB so people could order some if they want, and the board is a single-sided design so it is easy to make yourself. I will post the file up after I verify it (probably tomorrow…).
Stay tuned for the full build project.