Older Stuff

Seven Knob Muff

Well the Four Knob Rat (FKR) wasn't enough. I'm working on the Seven Knob Muff (SNM, actually it is going to be something like 25 knobs, but that's not the point.) 10 of the knobs are going to control parameters for the 10-step sequencer. Here's a quick vid of the prototype sequencer on the breadboard. It is firing of 5 of 10 LEDs for a test...

 

Powering Your Pedals

A new article about pedal powering with batteries, AC-DC adaptors, measuring current draw, multi-power units and all that good stuff.

All About Caps

Added a new article about capacitors.

Test Drive of the New Board

Some video wankage of the Board Pimpin creation in action.

 

Board Pimpin

Time to replace that tired old carpet board with some real pedalboards.

Dallas Rangemaster

You know it's a crying shame to admit this, but with all the pedal tinkering over the last year, I've never actually built one of the most amazing circuits of all time: the Dallas Rangemaster (check out RG Keen's seminal analysis of this pedal). Born in a time when British guitarists were looking for ways to lighten up their dark amps, the Rangemaster was a brilliantly simple circuit with some interesting twists. I procured some vintage Mullard OC44 transistors from SmallBear and set to work. The result is something that should be in every pedal junkie's arsenal.


The Board


The Box

12 Volt Tube Amp

The conventional wisdom regarding tube amps is that low voltages designs generally suck. And that is correct. But I refuse to accept the knowledge and experience of a whole generation of engineers :) I found an interesting design for a12K5 power amp running at 12 volts from a Japanese site and decided to breadboard it. The first step was to build a test rig that would hold the tubes and allow the connection of an output transformer. (Previous tube breadboarding projects have been wiring nightmares, so I decided to invest an evening in building  the test rig first).

The result is interesting, but not great. It puts out about 300 ma of power and will drive a speaker, but really requires a boost pedal in front of it. Even then, it sounds good, not great. I'm going to do more tweaking on this over the coming months and work on refining the sound.

Big Bag O' Updates

Trotsky--More than just a communist

Finally got time to finish up S/N 001 of the Trotsky drive. I am still as enthralled with the simplicity and tone of this design as I was a month ago when I had it finalized on the breadboard. The first one is going off to Mr. Nitefly who provided most excellent and discerning feedback and critique on the design.

Junior Hits The Bench

It's been over a year since I built a Guytronix Ardmore. Great amp that has earned a permanent place in the wall o' doom. I've had the guts for a Gilmore Jr. sitting in a box for way to long now so I got out the stuff tonight. Rich at Guytronix went out of his way to get me set up with all the parts so it's time to start. I have a few interesting additions planned for this amp.

Most Promising Amp of the Year

Gary at Backline Engineering is putting the finishing touches on his revolutionary ZenTone amplifier. I don't often talk about products here at Beavis Audio unless they are really worth of some attention. And friends, this is worthy of attention.

This is a 7 watt all-tube Class A amplifier with a twist. All control parameters are handled in the digital domain, so you can save and recall "patches". But only the switching and knobs are digital--everything else remains 100% tube goodness. It can accept a wide array of tubes without re-biasing and allows on-the-fly switching between 3 different preamp gain structures, and switching between pentode and triode mode. And with a full MIDI implementation and 64 preset slots, you end up with what is essentially a 64-channel tube amp. This one's on the Beavis list of gear to track down and get in the basement ASAP. If you are interested, give Gary at Backline a holler and tell him Beavis sent you.

 

Trotsky Drive Getting Closer

This is a very light gain pedal, great for adding brightness and bit of grit to any amp. A single transistor in a classic configuration, and I'm liking it a lot. I have the details almost completed, in the meantime, here is the Rev 1.02 Build It Yourself PDF.

Knobapallooza

Here's a nice selection of knobs available from various places

Noisy Cricket Redux

I stopped building Noisy Crickets because it was about 50% point-to-point and as such, too much work. I have designed a new board where all three pots, the two switches, and the LED are all on the PCB. Noisy Crickets are coming back! I also have a cool enclosure surprise for them to unveil next week. Mike, my new Vice President in Charge of General Mayhem is helping me build them.

I found the perfect enclosures from a Illinois manufacturer called BOX Enclosures. Check them out--very cool products. Here are some photos of the process so far:


The Parts - Small as possible PCB, Alpha snap-in pots,
and board-mounted switches.


The Assembled PCB


The Sweet Boxes


The Mark II Prototype

In other Noisy Cricket news, many readers have pointed out that the Noisy Cricket schematic doesn't match the Build Your Own Noisy Cricket instructions. Sure enough, the schematic had errors. I've fixed and updated it--check out the page.

Hey Dude, Nice Rack

Since I have a week off from building fkrs (waitin' on the boxes wouldn't ya know??) I've started on the prototype racker thing.

From Russia with Love

Scored me a few boxes of prime Soviet NOS transistors off ebay. (Thanks to meanderthal for the pointer). I'm trying these out in various circuits. So far my favorite is the Trotsky Overdrive--a medium overdrive based on the Electra design from way back. This one is good enough for a bit more work. Schematic and layout on the way. Update: finished this one today and I am very happy with the sound. Schematic here.

One Year of Beavis

February 20 marks the 1 year anniversary of Beavis Audio Research. What a wild ride it has been so far. The best part for me is all the emails from my fellow pedal dorks--the questions, ideas, complaints and kudos make it all worthwhile. Thanks! In commemoration, I'm working on redesigning the site. I'm especially proud of the new motto up top. Here's to you, and the next twenty years of insanity.

The Old 'n the New

Alesis Bitrman bit-crusher meets Roland Space Echo and 1968 Vibrolux amp. I've been groovin' on this combo all night. Clips soon, if I remember.

 

Mouser Gets Sent to the Back of the Bus

For quite a while I've been getting the huge paper loaf that is the Mouser Catalog. It is great because it has thousands and thousands of parts. But it is hard to find things, and there are only black and white line drawings of parts. Recently I ordered some parts from Allied Electronics thanks to a link from Devi at Effector 13. They also mailed me a catalog. Talk about about parts pron. It is sweet--clearly laid out with color pix of all the parts goodness. Sorry Mouser, your black and white phonebook parts nudie shots are now second fiddle to the full-color Allied book.

The FKR Mark II

Working on the front panel layout for the FKR. The next batch will be the mark II model. The only difference on the outside is the addition of a switch to turn lube off and switch in the stock rat resistor value. Here's an early shot of one of the front layout ideas:

I have been getting a lot of email about the FKR waiting list. The plan is to re-open it once I get caught up. So if you aren't on the list, check back towards the end of February. In the meantime, I working this weekend on my new FKR PCB designs. First prototype should be built today.


FKR MK II proto boards

Danger Muff - The Modular BMP

Been working on some ideas for the Danger Muff. I started out with a standard BMP circuit inside a 1590BB size box. I was able to fit in diode clipper switches, a feedback pot, and a gate pot. But the sequencer, oscillator and light-controlled Theremin circuits that I had as part of the overall Danger Muff design wouldn't fit. So I used a couple of additional enclosures to end up with a plug-in modular thing. The additional circuits add some great potential but it is somewhat unstable right now--needs so more tweaking.

Here's a tip if you want to hack a BMP: get the General Guitar Gadgets kit. Great value and a superb springboard to creating some wicked fuzz devices.

Junk Fuzz (Time to use up some old parts)

I've been playing around with one-transistor designs, boosts, fuzzes etc. This one was a lot of fun. It is a one transistor fuzz built completely from random junk that I had laying around on the bench. Not true-bypass, in fact there is no bypass at all. Turn it off and it doesn't even pass the signal. Also, it is held together with solder and super glue and will most likely fall apart if you look at it wrong. Finally, it also has an antenna to actually *increase* radio frequency interference. Reducing RFI is something those silly engineers are always striving for, so I decide to increase it. Finally, continuing on the contrary design path, the input is on the left, the reverse of every other pedal.


Rack-Mounted Effects

I'm tired of bending over and fiddling with my pedals. Why the hell are they on the floor? Who thought that up? Time to design a modular rack architecture for pedals.

Misc Stuff from the Lab

Arghh! More injuries. Smashed three of my right hand finger tips in the garage door. Now the right hand is outta commission for a while. This is ridiculous--I think I am in serious karma-deficit mode. I'm going to learn to hold the soldering iron with my teeth tonight. Got some more big muff pi clone/lab work done on Sunday. Between the gate and atari knobs, and germanium diodes, the thing will get octaves on its own! Very excited. Also, 7 FKRs will be ready for ship this week. Sending out emails today. And to all the cool people who keep sending me emails--thanks! It is words of encouragement and pedal questions and ideas that make the whole Beavis experience a joy every day.

Another Bag of Steaming Updates

It has been a while since any updates, so here is a mega catch-up list of news:

  •  FKR News: The FKR batch two is really almost done. Will only have eight units in batch two, but folks on the list will get emails for purchase next weekend (Saturday January 22nd). Like the first batch, I'll post a page with pix of the specific models so you can choose your box. I've almost finished my new rev 2 PCB which should make them easier to build so I can turn them around faster. The list is now up around 100 people, so I'll probably have a bit of a backlog.
     
  •  Danger Muff News: I gave one of the early Danger Muff design prototypes to a friend and have received some good feedback. The emitter resistor mods are useless except on the last transistor. The Atari and gate mods work nicely. I've almost got the design working for the sequencer and am looking at a couple of possible changes. First, I was thinking of having a switch to go between the stock classic BMP tone control and a 6-band EQ. Another possibility is the addition of a fuzz face circuit that is stompable independent of the BMP, and possibly a single transistor booster up front. Not sure about the octave part yet. If you have any preferences or ideas, let me know!
     
  •  Effector13: Devi Ever, the creative lunatic behind the Effector13 pedal brand put together a point-to-point one-transistor fuzz and made a very fun and interesting enclosure for it. Check it out.

  •  BuildYourOwnClone: Keith over at BYOC has shared some information about potential future kits: an Ocatvia, a 120-second looper, and an analog delay. All sound very exciting, so ping the byoc forums every once in a while for news.
     
  •  Tube Cricket: Still no real movement on this. I built the first PCB, wired it all up and no joy. A bit of debugging remains on that one.
     
  • Flesh Wound Theatre: Sliced my arm open with a razor blade while working on project. Only three stitches, but it was only an inch away from a major artery. I was lucky. But luck runs out eventually. Just a friendly beavis reminder--think safety!

  • Rack Rat: I scored an interesting double-rat in a rack off ebay over the holiday break. Very interesting--I think this would be an awesome box to add all the FKR mods to. Here are some pixs of the stock unit: (click the image for larger versions)

Tube Cricket, Part Deux

Working on the Tube Cricket Prototype a bit more. Don't have the right pot values this weekend to fire it up, so maybe next week!

FKR VID n' Stuff

Fatbackribs did a video of his FKR. I'm honored. Check it out.

Got the first ten four knob rats done and ready to ship. Waiting for parts on the other ten.

Random Stuff

A fellow in my neck of the woods (Virginia) runs an outfit called Spencer Amps. He posted some information about a new boost pedal he designed. This thing puts out a *huge* signal which is only good if you have a tube amp. Very interesting idea, check it out.

It has been a while since I've done the blog thing--been busy building FKRs. The first five were relegated to the "prototype" bin as I worked out the finish and internal layout. I now have the entire thing memorized so I can knock out one per evening. Hopefully this weekend will yield some productive build time also. I know a lot of folks are waiting for these, and I'm gonna get 'em done before xmas. Woohoo! Here's some pix:

I've also been doing some more design work on the Danger Muff. I've worked out most of the muff stuff, and have started on the sequencer. The DM will either be very cool, or a complete waste of time.

Space Charge Toobz?

Space-charge tubes were designed for car radios back in the day. Since cars have a 12v electrical system, space-charge tubes were designed to run at 12 volts instead of the usual high-voltage. I've been playing around with a design for an all-tube (zero solid-state) overdrive circuit. The idea is to use space charge tubes in a chain, each one gently increasing the signal and passing it on to the next tube. Currently it doesn't sound great, but there is probably a lot of potential here. Update: Arghh, found out that "Tubester" is already used for a pedal. I'll have to think up something new. Ideas are welcome :)

Pedal Hard with a Vengeance

Spent a good part of this weekend working on the Four Knob Rat. Had to quite a bit of re-engineering since the prototype. I think I have it down now and can go into factory mode and start churning them out. The custom 440+ envelope filter I made for James in Nebraska arrived at his doorstep and he called to say he loves it! I was a bit worried about the 440+: it is what I think an envelope filter should sound like, but I have a strange ear. Fortunately, it all worked out in the end.

Analog Delays

I've been searching for the "right" analog delay for a while. I picked up a used Ibanez AD-9 reissue and it has a very nice mellow sound. Problem is the delay isn't long enough at ~300msec max. I found a used Diamond Memory Lane, and it has great tone, a built in LFO and tap-tempo. We'll have to see how it sounds after the honeymoon's over.

Beavis Box in a Day

Tired and frustrated with painting and labeling boxes? Me too. If it takes more than a day, I figure it ain't worth doing. To that end, I've worked to develop an enclosure painting/labeling technique that is easy, relatively foolproof, and can be done in one day or less, including drying time. Take a look at the Beavis Box in a Day.

 

For U.S. folks, remember that tomorrow, Tuesday 6 November is election day. Go out and vote. It is time to shit-can what is the most corrupt, vile and onerous congress in this history of our country. Send them packing folks, I'm counting on you.

There are many fascinating people I have come across during this guitar audio DIY adventure. I've shared emails and conversations with lots of folks and learned a lot along the way. It seems like a good idea to start widening that community. To that end, I'm starting up a series of interviews with people with the same interests. As I find time, I'll try and contact folks and see if they are interested. It's called "Ten Minutes With...". The first installment is up today, a conversation with my good friend Mark from Officially Licensed Circuits. Give it a read. And if there is someone in the DIY or commercial guitar audio world you would like me to harass into an interview, send me an email.

Andy Warhol was right. My five minutes of fame: the fuzzLab on MusicThing. Gotta make sure this doesn't go to my head.

Basement of the Month Club: Someday, my basement will look like this.

October 2006

If a Tree Falls in the Forest Dept: I don't think anybody reads this spew of drivel I manage to cobble together every couple of days. Prove me wrong. Tel me a story. Send me an email.

What happens when you take a big muff pi, add a thick gooey wad of switchable mods (atari/siamese dream/creamy dreamer/etc), trail it with a graphic equalizer and a secret "hidden octave" circuit? Why, you get the Danger Muff of course. If possible, this one may also have an 8-step sequencer to control the fuzz in a sample and hold fashion. From the bench, this thing easily tops the fuzzLab in terms of versatility and slap-in-the-face sonic rudeness. My accountant advises me that for the price of one of my kidneys, I may actually be able to bring this to production. More details forthcoming.

What a drag it is getting old. Been sick for a week now. One of the many benefits of living in the hellish bunghole known as the Greater Wash DC ass-sprawl is that we get a daily influx of fascinating and interesting new strains of sickness arriving daily at our airports from overseas. Just to be clear, I'm not an isolationist. I grew up overseas and I've had a long and varied list of exotic (mostly tropical) diseases. My pinnacle years were in Nigeria where I enjoyed ringworm, tinea, amoebic dysentery,  malaria, and for a moment, I came close to schistosomiasis.  But I was young then. Remember when you were young? You shone like the sun. I used to heal like Jesus. Now I'm older and when the latest strain of birdflu/sars/madpig disease arrive at my doorstep through those fantastic little vectors I call my children, it' fever time. I like to whine and complain when I'm sick, so there you go. In the meantime, FKR parts continue to be delivered to the Beavis loading dock--today I received this gigantic anti-static tube o' MOSFETS from Mouser.  I swear to god it was over 2 feet long. Also got the enclosures also from Pedal Parts Plus and they are gorgeous. Can't wait to get started on these.

I ordered a metric buttload of parts yesterday for the FKR project, enough to build 10-12 units. All the folks who have emailed me or asked on forums are on the list. The list is longer than the number I can afford to make in the first run, but usually there are drop-outs on these lists. Plan is to keep the price under 200 bucks and be ready to ship in about 30 days. Thanks for all the support from the FKR Phan Club.

 Another great resource on the web for beginner/intermediate folks (like me). Here are the PDFs of the Radio Shack experimenter's thingy. You don't need to buy the thingy. Just download the manuals. Why? Because it was done by Forrest Mims III. He is legendary. He is cool. And he writes and draws everything by hand. Beyond the cool descriptions of how to build basic circuits, you can learn a lot from this PDF. Volume 1 is linear/analog stuff. Volume 2 is digital. Plus, it is an engineering work of art.

The Best Free Electronics Primer on the web. I've been digging this site for the last few weeks.

DIYStompboxes.com: You will never find a more wretched hive of scum and villainy. Ok, actually that’s not true. What you will find is the best place on the web for hardcore (and lightcore) pedal hacking and innovation. A few months ago it was decided that a monthly contest would be a cool thing. Each month a theme would be announced and various folks would think up something ingenious along the lines of the theme. No prizes, no trunks full of Rice-a-Roni, no hookers 'n blow, just the adulation of the pedal building community.

The first month required the use a CMOS device. To my mind, all the entries were incredible, some were downright crazy, but all were ingenious and novel:

Here’s the thread where the builder’s introduce their idea and some have sound clips as well. This month's competition is shaping up to be pretty incredible also. Folks, you will not find a more amazing collection of smart and crazy pedal hackers anywhere else in the world.

I posted a preliminary clip of the FKR. It's set to MOSFET clipping with no overdrive. Strat->FKR->Boss Delay->Marshall JCM800 on clean. Apologies for the wankish playing, but I'm really getting excited about this box. WMA Version  MP3 Version:)

Picked up the latest copy of Make magazine last night. Neat stuff, but what really caught my eye was the last page. A guy name Tyler Rourke built a reproduction of the original tube amplifier that was built for Albert Einstien. That's right the really smart patent clerk from Austria who did all that relativity stuff. On one hand, there is a fascinating story behind the amplifier. On the other hand, the Tyler's build is a work of art, and I mean that in literal sense--it should be in a museum. Take a look.

Tyler Rourke, Bellingham WA, with working replica of hi-fi amplifier designed and built by Jack Rosenberg (engineer on John von Neumann's Electronic Computer Project) as a gift from the Institute for Advanced Study to Albert Einstein on his 70th birthday in 1949. Sounds as good as it looks! 

I while ago Keith over at BYOC posted a very cool diagram for building a killer Fuzz Face clone without a PCB. Basically point to point. I though this was a very cool idea and added my own version of it with a few mods. After thinking about the whole point to point idea for pedals, I decided to try a Way Huge Red Llama clone using the same technique. I drew up the diagram and posted it. Finally have the build verified after another intrepid soul on the BYOC board got my layout to work. Take a look at the wiring diagram.

Got the Studio Twin Cricket wired up finally. I left the bottom of the enclosure and left the PCB hanging out. I double and triple checked this one since it a proper tube amp with the associated life-threatening high voltage bits. Fired it up and it sounds great! Very clean all the way up to max volume with some nice compression. So I plug a booster in front of it and start wailing away. After about 5 minutes, it starts to slowly lose volume. Then the tubes go dark. Then the smoke. Then a healthy spew of flame on the PCB. Holy crap! After unplugging it, letting the fire go out and draining the caps I found the problem. I had mounted a small heat sink on one of the resistors because it is supposed to get really hot. My mount job was apparently shoddy, so the heat sink came loose and shorted out heaters. A quick fix and it was back in action. This circuit has turned out to be a very interesting pedal-friendly amp. Since it has a pretty flat response, it will not overdrive on its own. So I can use all sorts of dirt-box combinations in front of it. The problem is that it gets *very* hot. Between the power resistor section and the tubes, I don't think my approach of mounting it in a smallish Hammond enclosure is going to be very safe. Back to the drawing board on the enclosure, but the amp itself is very cool.

BuildYourOwnClone has just released some new kits: a Wah, a 250 clone and a Rat clone. Check em' out. I drew up a diagram of some of my favorite Rat mods as applied to the BYOC Mighty Mouse to come up with the Mightier Mouse.

Universal Audio has unveiled their new remote-controlled preamp. I'm not even sure what all the knobbage is for, but it just plain looks hot. Sometimes the constraints of building stompboxes (i.e. has to be stomp-able, and fit in the smallest possible pedalboard space, etc) is a drag.

In a recent thread on  a fellow asked about building a fuzz pedal using tubes instead of transistors or op-amps. The general gist of the responses were that it really isn't feasible and could be a high-voltage hazard. How about a series of cascaded starved-plate 12AX7's? Hmmm, sounds like a challenge to me.

Last year I was looking for a replacement bridge for a Grestch DuoJet. I found a seller on eBay who had exactly what I was looking for. Ordered the parts, got them quick and cheap, and they worked great. Fast-forward to today. I was reminded on a guitar forum of this seller and some awesome low-cost solutions and products. Very cool. GuitarFetish.com has lot's of what you need :) They are also developing a line of small effects you can mount directly in your guitar's control cavity. Highly recommended for pickups, parts and other stuff. http://store.guitarfetish.com/

Always on the hunt for cheap or unusual parts, I was looking for analog panel meters and alternative enclosures the other day. Some really good finds:

Got a coat of fire-engine red paint on the Studio Twin Cricket enclosure. Another coat tomorrow and I should be ready to finish it up. I had purchased a Jensen Mod series 6” speaker to have a small “cab” on my workbench to test my amp designs. Mounted it in a small wooden box that I had refinished a year or so ago. Sounds great, but argghhhh—it’s 4 ohms. Doh. Workable, but not optimal.

Mid-Scoop Tone Control! Mark Hammer on DIYStompboxes.com  pointed out that the Shin-Ei FY-2 fuzzbox that has a decent mid-scoop. I’m thinking this snippet should be easy to add to any dirtbox, perhaps even the FKR…

I heard somewhere that the Fulltone OCD was a clone of a Rat and uses MOSFETS for clippers. Then I heard it somewhere else. So then I started to say the same thing. Should have known better. Beavis was *wrong*. The OCD isn’t a clone of the Rat. It is actually a variation of the now-defunct Voodoo Labs Overdrive. Lot’s of folks consider the VLO to be a great overdrive pedal. I found a good vero layout for it, so I think I’ll give it a stab.

Talked to OLCircuits.com today and we are looking good for an actual kit for the Tube Cricket! I’m thrilled that Mark wanted to do this (he was a great help on the tube preamp part). More details to come soon. I’m liking this model: 1)  develop something interesting. 2) have a kit available for DIY folks. 3) have schematics on my site for hard-core DIY folks and 4) build some for people who aren’t into DIY. Details forthcoming...

I was thinking the other day about how to create modulation effects using electro-mechanical means. In other words, instead of pure electronics, why not experiment with mechanical methods? The result of this thinking so far is the Beavis Doppler. I really should find time to build this thing. I also came across this Rotary Woofer, looks very intriguing.

You know what sucks? When you find an online store that has some decent parts at good prices. Then you order some stuff from them. Then the owner of said store goes on the internet and starts talking trash. Resulting shitstorm means I’ll never order from there again.

I took a trip to Oregon last week with the family for a wedding. Quick 3-day trip but I had time to check out one of the local small guitar bodegas in Bend. Their pedal selection consisted of a stack of new FABs and that was about it. But behind some boxes was a Marshall Shredmaster in like new condition. It was priced at 70 bucks. So I had to buy it. Very awesome pedal with a “countour” knob that does a *huge* mid-scoop. Built like a tank. The Shredmaster was discontinued a while ago so they fetch around $200 on eBay. Score! The best part is that I was talking with Mark at OLCircuits.com and told him about it. He mentioned that he was working a Shredmaster kit and that all of the available schematics on the internet are wrong in one way or another. So I shipped it off to OLCircuits and now we have a 100% authentic reproduction available in kit form at a fraction of the cost. Exciting stuff.

Recharging My Karma, Episode 209: I like to take a weekly visit to my favorite local small guitar and dig around in the used pedals case to see what’s new. Yesterday I came across some type of old Japanese fuzz. No label but it was definitely a vintage piece. They were asking $90. I played it and it sounded really good, lots of fuzzy grunt. I popped the case only to find that it was a very desirable Shin-Ei FY2. I asked bodega-man to do a quick ebay search and sure enough, these things go on eBay for around $300. Aforementioned bodega-man says he’ll honor the price of $90 because that’s what it was listed as. Another dilemma—what to do? I passed on it and told him to mark it up to the correct price and put it back in the case. Sucker, or karma points awardee? You be the judge.

Still enthralled with small wattage amps. After the Noisy Cricket and Ruby builds, I’ve been working on the Tube Cricket. After weeks of misery, it is finally up and running. Why a tube? Well, with the Noisy Cricket I essentially had LM386 ½ watt amp with a transistor buffer and a tone control of my own design. It sounds nice, but the tone control sucks about 6db of signal off the front-end. This is typical of passive tone controls and results in the LM386 not being driven hard enough to get good distortion, more like simple overdrive. The Eclipse Valve has a very nice pre-amp that uses a single 12AU7 to yield about 20db of gain. A natural match for the Tube Cricket. The preamp stage design resulted in two gain controls. Gain 1 controls how much of the boosted signal goes into the front of the LM386. Gain 2 controls the internal gain on the 386. This allows for quite a bit of versatility. I also came up with a new tone control design that imparts a bit more control. Finally, I found that I can also run a 12AT7 instead of a 12AU7. The circuit has two trimmer to set the bias levels for the tube, so its easy to swap tubes and be up and running. Now I just have to figure out how I want to build it….

September 2006

I’ve bought a few parts from Antique Electronic Supply (http://www.tubesandmore.com) and was browsing through their catalog the other day and came across this:

An all-tube monoblock amplifier that uses 11MS8 tubes to put out about 8 watts. It is designed as an audio amplifier that accepts line-in signals (they also have a stereo kit). For 90 bucks it seemed like a fun project. Hello paypal. After it arrived I dumped all the parts out for a look. Nice big heavy transformers, and professional dual-sided silkscreened PCB and a bunch of other stuff. For some reason though, the enclosure is a pine board. I think their idea is that you’ll build it on a pine board and then put it in some type of enclosure so you don’t shock the living piss out of yourself. I had the board populated in about 10 minutes and then went to work on the enclosure. It is a big Hammond diecast box. Drilled holes for all the parts, and test-mounted everything.

Can’t wait to hear what it sounds like—hopefully it has a completely flat response—that’s what I’m looking for: an amp to test pedals that doesn’t add any coloration.

Working on the Four Knob Rat (FKR).

This is coming along very nicely. I’ve updated the schematic on my FKR page with the latest version. My prototype is complete and it has turned out to be a very versatile distortion box. This thing has all sorts of clipping variations, but the most interesting part is the feedback loop in the Rat circuit. It has two R/C pairs to ground in the feedback loop. The Ruetz mod turns one of the fixed resistors into a pot. This is probably the coolest feature of the FKR. Hope to have the engineering done on this one soon so I can build a few.

 

Harry J's OD SHOOT OUT

Harry J ran a comparison of the following overdrive pedals:

  • MJM Blues devil
  • Love Pedal White Dragon
  • Tech 21 Sans Amp (Original model)
  • Hermida Zen Drive (original model)
  • Proco Rat (80's unmodded)
  • Paul Cochrane Tim Pedal
  • Fulltone OCD (newest version)
  • ToadWorks John Bull
  • Ibanez TS-9 w/ Analogman classic mod as well as the SUPERB Vaughn dual tri-mode mod
  • Xotic AC Booster
  • Keeley modded Boss BD-2 (Blues Driver)

Complete with commentary and clips. Hats off to you Harry, thanks for the effort!

Read more

    

Stand Up PVC Bass

beatcatcher builds a stand up bass out of PVC and various parts. Ingenious, wonderful, and a full PDF build guide also.

" In my opinion the only thing that is absolutely critical in this design is the fingerboard and string length of the bass. This is what gives it some upright bass characteristics. Everything else could be modified to the builder's liking. If you try something different and it works, let me know. This PVC EUB uses nylon strings from traditionmusic.com, but one was built with a length of square steel tubing attached inside the main pipe which should make it strong enough for steel strings, but this has yet to be tested. I suppose gut would work, but why have strings that are more expensive than the bass?!?

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Electron Band Structure In Germanium, My Ass

Quote: "Abstract: The exponential dependence of resistivity on temperature in germanium is found to be a great big lie. My careful theoretical modeling and painstaking experimentation reveal 1) that my equipment is crap, as are all the available texts on the subject and 2) that this whole exercise was a complete waste of my time. "

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BYOC Delay in a Wah Pedal

dotdotdot posted his latest creation on the HCDIY forum. It's a BYOC delay kit mounted in a salvaged wah pedal. The wah pot controls the amount of delay mix. Very nice pedal hackery and a clean looking build to boot. dotdotdot is also the force behind MonkeyFX, a great UK-based pedal foundary.

Wah Delay Pedal Thread

MonkeyFX

    

Forrest M Mims III Mini-Notebooks

Back in the 1980's Forrest M Mims, one of the great DIY writers and circuit explorers created a set of Mini-Notebooks that were sold through Radio Shack. I remember paging through the 555 Mini-Notebook as a teenager. The beauty of these works was that they were all hand-written with hand-drawn circuits. Just too cool. Forrest sells these volumes from his site for a mere pittance. Well worth the investment.

Forrest Mims

    

Need a tube head with 18 tubes? How about 200 watts?

Before Fred Nachbaur succumbed to cancer, he was the tube genius. He's the they guy who designed the great Real McTube tube-based pedal overdrive among other cool things. He may be gone, but his legacy is still with us. Part of that legacy is Dogzilla--the coolest amp head I've ever seen. Specs:

  • # Power output: Over 200 watts RMS (original spec 300W Class B modified to 200W AB2, Apr. '02)
  • Power consumption: Est. 800W max.
  • Footprint: 17" x 14" (43.2 cm x 35.6 cm)
    # Weight: ca. 70 lb. (32 kg) # Chassis height: 9.5" (24 cm)

More at: Introducing Dogzilla

    

Love for the Shaka Tube

Here's Chuck's Shaka Tube build. Very nice and you have to love the orange. Lots of other Shaka Tube info:

Paul Marossy's The Shaka Tube In A Hammond 1590BB Enclosure and Shaka Tube Clipping Characteristics and The Shaka Tube Chronicles

Aron Nelson's Original Schematic

    

Gotta Love Those Europeans

When it comes to cool and inventive modding ideas (i.e. synth stuff) these guys are the doob smoking bohemian mofos. Quote: "Monome Modular  Synthesizer. My modular is a System, that uses modules from different sources. But most of the modules I've planned to build so far are FormantPro based.

Cabinett: The cabinet is made out of old furniture (my old bed and a shelf *G*)

Frontpanels: The frontpanels are hand drilled 19" blindpanels...I absolutely CAN'T RECOMMEND this method!!! The panels are made of steel and are very hard. So it's a real pain in the a** to drill them. For myself, I decided to order my further panels from Schaeffer Apparatebau If you just let them drill the holes, and make the panel printing yourself, it's quite affordable.
http://www.monome.de/

    

Build your own SMD soldering rig

More and more circuits are being built today in big automated megafactories where robots suck tape-mounted discrete Surface Mount Device (SMD) components out of giant rolls and blast them on to boards by the thousands. You could use a typical soldering iron to muck about with SMD but I wouldn't recommend it. Will over at Engadget provides a great step-by-step tutorial on building your own SMD soldering rig using cheap and commonly available parts. As an added bonus--it does a great job on heat-shrink tubing.

Homebrew SMD DIY

    

Modding a $100 Tube Amp

When Epiphone launched its ~$100 Class A tube amp late last year, it was quite a hit. But it had some issues, mostly with hum. Various folks have mods that fix these, but Dennis Cronin as done a really nice job of both modding the amp and putting up a great webpage that explains various things with nice clear pictures. (Update: you can now get a head version of the Epi Jr.!)

Plus: using light bulbs for attenuation and compression. Nice work Dennis!

http://www.valvejunior.com/

    

ToneCrafter: I'm Speechless

Here' the idea. A box with the basic stompbox controls. Plus a breadboard. Plus a bag of components and instructions to make up to 7 different pedals. And get this, when you order one, you can specify which effect you want pre-wired and they'll do that for you too. So you get it ready to run.

How much would you pay for this other-worldly product? $500? $400? No friends! This is 99 clams. Unbelievable. Might have to order one...

http://www.killertone.com/

    

Quite Lovely Hand-built Tube Amp Head

"EF86 input, ECL86 triode gainstage and pentode output stage, EZ90(6X4) rectifier, and EM80 magic eye output power meter. Thanks to Tom Schlangen in Germany for sharing the EM80 circuit! Play hard, and the EM80 lights up brighter (fans out like a little radar screen)... play soft and it dims, comes to a fine vertical line. Here's a closeup of a beautiful mesh-screen Siemens EM80."

http://artifactaudio.com/

    

Dualish Logic Drive: Combo Blue Box, PWM, Uglyface, Idiot Wah, Booster

Processaurus over at the StompBox Forum has designed and built a very nice looking box that has some pretty imaginative circuitry.

"It's the blue box based thing where the two channels you pan between get the logic signal processed by two Tim Escobedo circuits, and then get mixed together. One side gets the PWM, and the other gets the Ugly Face. There's some photo resistors hooked to the CV input on the 555. "

http://www.diystompboxes.com/smfforum/index.php?topic=43469.0

    

Hand-made Pedals and Synths from Peru

Effects, modulators, oscillators, synthesizers and modifications, all from Peru. Handmade cool stuff. Check out the sound samples.

Brought to you by Carlos Garcia and Eduardo Larres, two musicians/electronics dudes from Lima, Peru.

Check them out:

http://www.zebranalogic.com/indexdos.htm

 

MohoMods "Multi-Screamer" Pedal

These guys have come up with one of the cooler mods to the venerable Tube Screamer. Switchable between TS-808 and TS9 layouts, and with switchable op-amps. How cool is that?

"An actual TS9 tube screamer board repackaged in a new enclosure with switches to allow total control over the OpAmps, Mod, Bass and increased gain. No more opening cases to change out OpAmps!!!"

http://www.mohomods.com/store.htm

 

6 in 1 all analog multi-fx under $100

Guy re-houses low-cost Danoelectric effects in a home brew enclosure. Figures out how to make them true bypass and ends up with a unique pedalboard. True genius in the best DIY tradition.

http://thegearpage.net/board/showthread.php?t=130262

 

Best use of Chrome on Cool Effects

When I grow up and build pedals for real, I want to be just like ToneCzar. Highly regarded analog delays pedal, long waiting list, pricey but supposed to be well worth it. Also wins the slickest website award and the use of thick lovely chrome plating takes it all home.

http://www.toneczareffects.com

 

Sonosaur Analog Bass Pedal Synthesizer

$99 kit to build your own monophonic synthesizer. Designed as a bass pedal synth, you add your own footswitches. Looks be be pretty controllable (eight pots!). Designed by the highly respected Howard Cano. How could I turn this into a guitar pedal?

Cano Electronics

 

WTF? Got a two by four?

The DIY ethic at its most primal form. The sheer ingenuity. Nails on goddamn piece of wood. This is Zen dude, this is real and earthy. This is the way we should build effects. Props to this guy--he's different.

http://www.diystompboxes.com/smfforum/index.php?topic=36392.20

 

 

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