Rockin the Mockman!

Way back in September 2021 I built a RunOffGroove Mockman. The circuit is based off the distortion found in the Rockman amp line, from Tom Scholz Research and Development Inc. Once it was built it sounded amazing, but I still wasn't completely happy with the circuit. Firstly it was way too loud, of course it could be turned down but it felt odd that the volume was on five or six and my ears were bleeding. Second, there was no way to control the gain, which really isn't the point of the circuit, but still it would be a nice option to have. Finally there was no tonal adjustment at all, leaving you to shape everything else around the Mockman. Again, the circuit sounded great as it was, but I felt it could be improved.

The circuit sat in my done, but no clue what to do with box, and from time to time I would ponder what its future would be. Eventually I decided to search around to see if anyone had added a gain control to the circuit, and to my surprise there seemed to be only one person, besides myself, who wanted to do so. A person by the name of Elijah-Baley said they adjusted a resistor value, replaced a jumper with a potentiometer and created a working gain control. I decided to try this out and see how well it would go. As suggested by Elijah I replaced the furthest left 1Meg resistor with a 22k-47k resistor, I split the middle (kind of) and used a 33k. Then I replaced the jumper that is left of that with a 1Meg potentiometer, I used a C1Meg on mine. And to their credit, it works! It doesn't clean up the pedal entirely, but if you need a clean signal just turn the pedal off. As far as the gain control goes, it does work.

Stock layout from
http://tagboardeffects.blogspot.com

Gain Mod
(Wired for Reverse Log)

Now that I had a working gain control I felt I'll take it one step further (in for a penny!) and try to get more tonal adjustment out of it. A well known mystery of the ROG Mockman is the bass switch, which really only seems to serve as some kind of placebo. I mean, if you flip a switch you expect something to happen, so your brain does something to fulfil that request, but in reality whether the switch does anything is still up for debate. Still being new to building and modifying circuits I looked for the easiest way to add tonal control, and the answer came in the form of a BMP tone stack. The BMP tone stack is named such as it is the tone stack used within Big Muff Pi pedals to give some form of tonal control.

Stock BMP Tone Stack

The BMP tone stack is super simple, highly customizable and doesn't require very many components at all. I downloaded the tone stack calculator and fiddled with the components until I found what I thought would be a pleasing tone stack. In the end I used two 22k resistors for R1 and R2, and upped C1 to a 47nf capacitor. This gave me a bit of a scoop but also allowed me to adjust for single coils and humbuckers. Now I'm not saying this is the definitive tone stack for this circuit, it's just what worked best to my ears. Many of you familiar with BMP tone stacks will also notice I used the passive version, which helped cut down the extra volume from the Mockman perfectly! You know what else adding the tone stack did? It made the bass switch noticeable. Before there honestly seemed to be no change whatsoever, but now there is a noticeable bit of bass/bass cut, depending on which position the switch is in.

Now that my Mockman has a working gain control, tone control and, while still loud, it no longer makes my ears bleed, this circuit is much more versatile and useable than I felt it was stock. These mods might not be for everyone, and that's fine, but I figured that someone else out there might enjoy tinkering with theirs, and these are a few good mods to start with. Both mods are highly adjustable, super simple and add much more versatility to the circuit. I give all the credit of the gain control to Elijah-Baley (if there was a way to link to them I would) and the BMP tone stack to Beavis Audio. I hope this starts someone on their own journey in modifying not just the Mockman, but other circuits as well, the same way it did for me. Please use these mods, adjust these mods and perfect these mods, and report back as to how you adjusted them to your own tastes. My chosen values might not be the best, and I'm very interested in seeing what someone else comes up with.

Kalamazoo Model 1 Restoration

I tend to collect projects, whether it be my Washburn A20, my Kalamazoo Model 1 or one of the myriad of other projects I have long since forgotten I even have. Lately, however, I've felt a deep, inner push to get things together and finish many of these projects. As I have owned my Kalamazoo Model 1 for almost 7 years I decided it was finally time to finally, and hopefully, let this little bird sing again.

The first process was to change out the power cable. Originally I chopped the end off a PC power cable so that I had a three prong cable, but that proved to be more of a mess than was necessary. After some thinking I decided to try using what is referred to as a "Micky Mouse" style three prong cable, because the end looks a bit like Mickey Mouse, because it would work perfectly in the original strain relief. Sadly progress was halted when I found only the ground is color coded, unlike the PC power cable. After some multimeter continuity checking I sent hot where it needed, neutral where it needed and soldered the ground right back down where I knew ground was suppose to go.

Next was rebuilding the filter capacitor. After I originally tested the amp a few years back, with the PC power cable, I noticed a loud and slowly rising hum. After going to Google I found many old tube amps suffer from this problem due to the filter capacitor. This time around I was confident enough to chop out the old filter capacitor and test it with my component tester. What was suppose to be 20/10/10 microfarad turned into many various nanofarads, one of them was reading 1600nf. Without a doubt this old capacitor was dead and gone.

In my haste to get this amp done I used what I thought would work. 47/33/33 axial capacitors that were all rated for 450 volts, yeah that should work. I arranged them in a triangle, electrical taped them together, hooped the positive leads, connected all the common leads together and placed them in rubber O rings to keep them off the chassis. After all was said and done I soldered the three positive leads to their terminals and I had to create a brand new common ground point for them as the original wire wouldn't reach where the rebuilt capacitor had to go. Afterwards I zip tied everything down and made sure it was snug and secure, but still not touching the chassis.

Before it was zip tied down. Don't worry.

I have to admit I am fairly proud of how everything came together. Now came the dreaded test. Did I do well? Did I mess up? At first I was slightly disappointed, but once I remembered that you have to wait for tubes to warm up before sounds comes through I was actually quite elated when the sound of my guitar came through without even a hint of hum. I had done it! I had fixed this old amp and given her voice back.

I'm going to finish up here by saying that I'm not a professional solderer, nor are the parts I've used top shelf. Since I've owned this amp for almost 7 years I just wanted this thing to work. I am fully aware I may need to change parts for higher quality parts and do better at soldering later down the road, and I will. For now it's just the desire to finally get this thing back together that dictated how things were done. In the end it all worked out and that, to me, is what matters most right now.

I would like to thank Terry from D-Lab Eletronics and Miles from RRU.com. While any mistakes and poor choices are solely my own, these two have a lot of great information on how to repair Kalamazoo guitar amps and both of their resources helped me greatly in the restoration of my amp.

Guitar Micro Amp and Comparative Overview.

It was Friday, I was in the outlet store when I saw the knobs peaking out from under a large white mass. I moved over quickly to see what it was when I noticed it was a miniature guitar amp. Excited by my find I tossed it in the bag and kept on about my hunting.

After the first round I made the purchase and went outside to do some research. With very little information about these amps I went to Google Images and saw that this little amp had a twin speaker cabinet that it should sit atop. Normally if there is a part to a set of something or any given item is missing a piece, at the outlet store, its more than likely nowhere to be found, but luck was on my side!

Mere minutes before the bin I found the amp in was about to be pushed back to make way for fresh new "junk", I walk up and quickly found the speaker cabinet. The day carried on in a good way, as I found quite a few more things, but the excitement of finding this micro stack never left my mind. Sadly it would have to wait until I got it back home to give it a good and thorough testing.

Once I got it home I plugged it in and wasn't too surprised about the sound, shitty. Its a neat little discussion piece, but its not really all that fuctional, due in LARGE part to the cheap, flabby speakers they tossed into this thing. Original MSRP was $129.99 and probably sold at around $75 to $100 (?), if that were the case whoever bought one of these were seriously ripped off.

Fast forward to today, while doing research on other mini amps, when I came across the Orange Crush Micro. Orange is world renown for making high end (expensive as fuck) amps. Although I've never played one, let alone owned one, I do have to say I at least love all the orange!

But wait a second, that Orange Crush Micro looks suspiciously like the Lyon Amp3. Although they're not an exact copy I have to say the backs look very similar, the built-in tuner is the exact same and the battery door placement is quite similar as well; could these have came from the same factory? The Orange Crush Micro says "Made in PRC", obviously People's Republic of China, and the Lyon Amp3 simply says Made in China, this is getting interesting!

This gives me hope that the internal components are the exact same and with a few tweaks, and possibly a speaker upgrade, I could have a really sweet micro amp stack. Then again maybe I'm just jumping the gun here, the Orange Crush Micro and Lyon could be completely different inside, other than the obviously different face layout. Regardless they sure as hell don't hold the same prestige, or even sound close to one another.

The Lyon Amp3 isn't terrible, but I absolutely can not stand the synthesized farting that this speaker produces under mid-gain settings. This little amp may be able to produce pretty good tones, but until I can find a better alternative for the speakers its all farts from here. I did manage to get a pretty chimey clean out of it, but that was all guitar volume control.