Iono-21 Greening Of Man

Greening Of Man

track listing:

01: Saturday Outing In Spring......................................6:19 min

02: Birch Tap................................................................8:38 min

03: Discussing Life With Green Man..........................7:40 min

04: Detroit Terminal.....................................................6:35 min

 Through out time man has created and distorted himself and his surroundings. Just like the changing of the seasons with it's inherent death and rebirth cycles, we are only to connected to this through observation and practice. Like a story being played out in front of us, we face it's harsh realities all the time. The one who is at the center of this epic story is the one we call "The Green Man". The king of rebirth and death is symbolized by a leafy skinned man. Having cast away into a deep slumber in autumn - only to rise again in spring. Green Man is waking up his kingdom with dubly sounds.

  Telegraphy shares with us his deep connection with the natural world with awakening beats and atmospheric vibes. Just in time for spring.

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Marche Du Nain Rouge 2016


words, photo and sounds by:Telegraphy

  The crocuses start to rear their wonderful heads up from the ground, the robins coming back from a long winter hiatus, all of which signals the start of spring. These suttle hints of the changing weather is in no comparison to the events that occur on the third Sunday of March. A march as you will in the month of March. Coincidence? Hum....maybe, but in this case the Marche Du Nain Rouge is Detroit's way of signaling the start of the warmer weather seasons by vanquishing all bad things the devil as kept during the cold winter months. Marching down the Cass Corridor, Detroit's citizens chase the devil and all of his negative thought's out of the city by dressing up in strange and confusing costumes.

 The many years I have attended this charade of confused costumed colleagues bent on only doing good for a city buried in negative stereo-types, I have never seen so many people dressed to impress. What I'm saying is, Detroit put it's freak on when it came to outer wear. Not only were the costumes out there but the people as well. I heard of cabin fever, but I never knew it effected Detroiters on this level. The freaks were definitely out on this day.

  Blessed with glorious spring sunshine, this Sunday in Spring was a repeat of last years weather conditions. Nice and warm in the sunshine but cold and formidable in the shade, like it was reminding use that on a moments notice the Michigan climate could change for the worst during this time of year. But this wouldn't happen here on this parade, not when the weirdo's are strutted their stuff. I arrived in the Cass Corridor, Detroit's premier college community of hipsters turned punk. The DIY movement was quite apparent in the part of town. Off the bat, while walking down the main drag I came across an old run down Victorian house with a curious looking small vehicle that looked like a toy sized "Mystery Machine" with equally sized trailer fitted with industrial grade propane tanks mounted on. The show it put on for a passing photographer was the reason why it had built in tanks. 50 foot high flames blow out of a tall pipe protruding from this flambeaus micro bus

 Strolling down the street making my way to the crowd, I past numerous twenty-somethings dressed up in alternating red and black costumes. A cross between steam-punk and just play'en punk, most of which are hand made apparel that shouted "I am here to party and to through out the Nain Rouge from Detroit".  But every once in a while you come across someone that make such a statement outside the boundaries of accepted interpretations, that you can't help but only take photo's of, knowing full well that you many never see a sight like this for the rest of your life

 Dancing on the edge of the sidewalk where it meets the street was a gentlemen dresses as a angel. White gown, halo, wings and all.  Dancing to the sounds of modern funk blasting from a radio stuffed inside a tipped over trash can with garbage pouring out all
over the ground, this heavenly soul made a show for passer-byers. Slowly swinging his arms from side to side, all the while not having care in the world about making such a scene with parade goers. Not to mention the trash he was trampling over while wearing a spotless pure white gown

 Finally making it to the crowd, I pulled my trusty Canon 35 mm SLR out from the depths of my wool over coat. Hastily loading a fresh roll of black and white film into my camera, hoping not to miss a great photo op (kind of difficult to do around here) I begin noticing the variety of characters flaunting their colors of red and black in one's own individualistic way. From old Victorian "Steam-punk" to post modern fairy tail cartoon, it was all here. The customs sent the innocent by-standard on a visual acid trip. Was it the mild sunny day in spring that triggered this hypnotic reality? Or was it the alternating colors of red and black that confused the mind? In any case, I was mesmerized by the shear complexity of humanity out on display


 Walking through the crowd, grabbing numerous photo's of strange and weird people. "Yes, I do believe the abbreviated theme of this years marche is - weird", I thought to myself as I was looking through the viewfinder at a clown juggling bowling pins. Weird might not be a tenacious enough statement. Maybe elderly man turned yellow "Sunflower king"  weird might be more appropriate. But then again the people around here love the basking attention they receive from their handcrafted outer ware.

 The D.I.Y. concept is one of the staples of this marche. Homemade four wheeled bikes, flame throwing mini cars, and horror/syfy film insect vehicle. You won't find any prefabricated cookie cutter parade floats here. Only handcrafted in some ones basement or garage. Have a steel drum band - no problem, just build a trailer to fit - ten of them. Two person tandem bike to crowded for four of your friends - add two more wheels for a foot power car
download "Marche Du Nain Rouge 2016" here

 So what can I say! This years Marche Du Nain Rouge was a trip



A Guide to Piezo Pick-ups (What you don't want to know)

words and photos by: Telegraphy

  One of the greatest inventions in modern times for the sound experimenter is the advent of the Piezoelectric Sensor or Piezo pick-up for short. These little disks of sonic discovery opened up a door to a whole new potential of recording sounds from solid and liquid objects. In the old'en days, if grandpa audio engineer wanted to record with in a violin or under and ocean, he was limited in the placement of and the types of microphones to be used. Non of them really came close to capturing the brilliance in sound as an internally instrument mounted microphone. Having a microphone directly placed on a sound surface  will produce a more brighter sound, Piezo pick-ups are perfect for the job.

 So what are these mysterious microphones and how do they work? In 1880 Pierre and Jacques Curie discovered that by applying mechanical stress on such materials as tourmaline, quartz, topaz, cane sugar and Rochelle salt, they were able to measure a surface charge or voltage on these elements. This is what has become known as the "Piezo Effect". Any crystalline element will in some magnitude, give off an electric charge when stressed. Weather it be physically stressing it, thermally (changing it's temperature) or electrically.

 A Piece of quartz (through scientific experimentation) was found to have the most surface charge then any other element. It's sensitivity to mechanical, thermal and electric stresses made it an excellent candidate for electronically detecting pressure changes in the environment.

 The first real scientific application of the  Piezo Effect was made during world war I, when in 1917  P. Langevin and French co-workers devised an ultra-sonic under water submarine detector. A mosaic of thin quartz crystals was sandwiched between two metal plates. The worlds first "Pick-up" as it can be regarded, had a resonant frequency of 50Kc (that's 50 kHz for all of you kids out there).

                                                                The basic's

 Enough of my history lesson. As someone important so gracefully said, "The only thing we've learned from history is that we never learn from history". Lets investigate closer of how a Piezo Pick-up works. Your typical Piezo element uses a thin wafer of barium titanate and lead zirconate . Now, I'm not a chemist but when it comes to big long names like this,  I go for the short and sweet definition - Piezoceramic. Ahh, that's better. A piezoceramic wafer is sandwiched between a brass base plate and a silver top electrode. The base plate is the mating surface in which the sound energy is passed from the source to the piezoceramic material. The top electrode's job is to electrically connect the piezoceramic to the + hook-up wire. The other - wire is connected to the brass base plate.  Sound pressure hits and vibrates the brass base plate. This sound vibration is transferred to the piezoceramic wafer, where it mechanically stresses it and produces a surface charge proportional to the amplitude of sound pressure. Simply said, sound enters through the brass base plate as a mechanical force and ultimately exits out the silver electrode as electrical energy.

 Now lets get physical! Investigating deeper into the mechanics of these playful Piezo Pick-ups, we find out that the sound energy impresses a longitudinal force upon the piezoceramic wafer. This means the whole disk bends laterally with the sound energy, squeezing and expanding the disk long it's axis. It's better understood view then described in words.

from Wikipedia
 A positive mechanical force will induce a positive electrical charge only on one side of the piezoceramic wafer, as too a negative mechanical force will induce a negative electrical charge only on the other side. This is why Piezo Pick-ups have specific polarities. The alignment of the crystalline atoms all have "Electric Dipole Movements" facing in one direction(much like the poles on a magnet). This direction is based on what material the piezoceramic wafer is made out of.

                                                          Mine's bigger!
 Size matters guys! Yes the size of your package makes a difference in performance. Because when it COMES to satisfying your --------EARS? Well what did you think I was talking about? Hee hee. Yes the size of the Piezo Pick-up has a lot to do of how well it responds to different frequencies. The Pick-up's basic constructed is similar to a capacitor. You have two metallic plates sandwiching a ceramic insulator, just like in a capacitor. If you took a capacitor and measured it's "resonate frequency" you will find out that they respond quite well to high frequencies.  This is why most smaller Piezo Pick-up's sound tiny. Not because there cheap or manufacture poorly. They are just responding well to high frequencies. The stiffness of your package (Oh, here I go again). also determines it's natural frequency. As sound pressure pushes against the ceramic wafer, an opposing electrical and mechanical force from within counter acts the lower frequencies but higher ones resonate it with ease. The more the area, the greater the mechanical elasticity, the better it responds to low frequencies. This is a general rule of thumb to abide by when designing your own pick-up system. So to find a nice sounding Pick-up, try using the biggest one as possible. See, size does matter.
                                                     Resistance is futile

 So, now that brings us to the last lesson of the inner workings of these perplexing Piezo Pick-ups. One of the most asked questions of the human race, besides what is the meaning of life, what are the impedance of these devices ? Eeehhhaaaa.......the truth is going to hurt most folks. The nominal impedance of a Piezo Pick-up is high......very high. We are talk'en up to one million Ohms of resistance. Impedance is the measurement of the electrical opposition to audio frequencies. The more opposition - The more impedance. So it is crucial for the output of a pick-up to be properly matched with a different impedance on the input of an amplifier. You want the electrical energy from the Piezo pick-up to flow evenly to the amplifier. The most common and easiest method to match the high impedance of the pick-up to a low impedance input of a amplifier, is to employ a "low pass filter" circuit in between the pick-up and the amplifier. Failure to match properly will result in poor sound quality that will sound tiny. This is one good reason to use a tube amplifier, not just because it sounds better but because of their characteristic high input impedance is perfect for amplifying Piezo pick-ups.

                                                       and now........A cheap pick-up line. 
  In my opinion, you should always use balanced cable to hook up Piezo pick-ups to any other piece of gear. Why? Balanced cable characteristically has lower capacitance per foot then unbalanced shielded coax. Piezo pick-ups are essentially a capacitor with a high resonant frequency. Adding coax with a high characteristic capacitance per foot will only increase our Piezo Pick-up's capacitance and therefor rise the resonant frequency (what we don't want to happen). Plus you gain the benefit of having a balanced system that isn't susceptible to ground loops, radio and electrical interference.

                                                          .....and finally

  So what do you do with a pick-up ? Here are some suggestions of various uses for these profiting Piezo pick-up's:

 1. As a guitar microphone. Experiment positioning them on the body of your acoustic. Closer to the bridge gets you more volume. Away from the bridge achieves a softer warmer sound.

2. The ultimate spy microphone. Jealous of your neighbors? Tape them on the window to hear their complaining about your dog or cat..........or child.

3: Cool body sounds are always a treat for an experimental sound. Stick one in your mouth and sing or burp but don't swallow. After a meal, tape it to your stomach to hear low frequency gulps and rumblings.

4: Can't go without whale sounds from the ocean for your ambient sound track? Well, if your like me and only have a small lake filled with carp, catfish and clams. Through one in with a small sinker attach to it. The water shouldn't harm it - that is if you are recording in the salt water of a ocean. Then I suggest getting some kind of a water proof container, attach the pick-up to the inside wall......the "inside wall" folks, not the outside. Gee's.

5: Attach them to a steal girder of a busy highway overpass and listen to creeks and bumps made by the bridge.

6: A steal radio tower will make whooshing noises on windy days.

7: Record your phone calls pleading to the IRS. Attach them to the receiving end of your phone. Yeah, it's the end closest to your ear.

8:Oh yeah. Use them for your next plate reverb project.           

Over The Time Cliff 2015

Eggie teaches us a thing or two.

words and photo by: Telegraphy

  It's back to school with you! As I was driving from work the other day, I stumbled across an abandoned building in Detroit. OH MY. AN ABANDONED BUILDING YOU SAY! IN DETROIT!!! Yes, of course there are a lot of derelict buildings in Detroit. What made this building stick out from the rest was that it was part of the growing phenomena of abandon schools. So I figured what a good place to hopefully catch  a glimpse of Detroit's most mysterious character - Eggie Kishnoshky . Wondering around these empty halls which previously echoed the voices of children on their way to class, I was drawn to one classroom on the third floor. Empty with a few school amenities still left alone from vandals. I set up my camera, awaiting his arrival. After spending more then a few nervous minutes staring at the blackboard, thinking about being robbed at gun point or worst, I took a snap shot of the scene, packed up and left in a hurry. Disappointed about the no-show of Mr. Kishnoshky, I went searching for another place to hopefully catch him.

 Driving around the outskirts of downtown Detroit through old manufacturing communities with their rotting factory's and crumbling bridges and roads, only to be sharply contrasted with newly developed condominiums and lofts sitting beside reclaimed walkways and alleys. So, this got me thinking about the state of Detroit and how it's changing landscape has influenced Ionosonde Recordings.

 In the past two or three years, yours truly have noticed a change in the landscape. Old burnt drug houses have finally made way to the wrecking ball. Vandalized businesses that were left to decay, have now been plowed under. New businesses on the other hand, are setting up shop in places that wore over looked for many years. Yep, things are changing. Just recently, travel publications have took notice and reestablished Detroit as a vacation spot worth visiting. REALLY?

  Getting back to our enigmatic figure. My search for him gained more determination as I wondered into factories and warehouses which were being renovated and transformed into stylish lofts and business space for a new generation of young productive adults. One of these warehouses is situated up above of what was once an old railway. Dug below the ground, this "cut" as it is affectionately called, runs under a hand full of major road-ways. This Dequindre Cut was featured in Ionosonde Recordings popular video Somewhere In Detroit. Sampling imagery of this old railway before, one can see the dramatic change in scenery.
The Dequindre Cut as seen in
"Somewhere In Detroit"

 So the question that arises; "Is Detroit rebounding?" I think the answer to that is written on the chalk board. Our mystifying man of Motown can only give the world subtle hints to what is beyond the horizon for Detroit. But from what I can gather, the younger generation is taking notice of the blank canvas of opportunity which is Detroit. Hum? Starting over, that may be the direction Ionosonde Recordings should be going in. Discovering new sounds - going in a different direction - starting fresh. "Out with the old, in with the new" I think it say's on the chalk board? Ether that or "Eastman was here" I think my vision is going.

 Change is good for both of us and Detroit. After developing the film I used, I was surprised to see Eggie Kishnoshky in front of the blackboard - teaching as you will. Teaching what? Change? Letting go? What ever subject this course is about; we're all paying close attention to our professor because the future depends upon us.

 Writing this last blog entry minutes from twelve midnight, when the calendar year ends and the grandiose machine gun fire starts here in Detroit. I rise my glass of cheap, spiked eggnog with whiskey to a new beginning. Not just for Ionosonde Recordings, but for Detroit and you and as always, I leave you with an image of one of Detroit's most mysterious characters (taken at a warehouse being renovated) . Burying the past in ankle deep snow and presenting the new year with a gift in his hands, Eggie Kishnoshky is just another figment of our imagination that slips through time in a city that's decaying back into sand. Or is it?

download "Detroit New Years Eve 2015" here

                                                Solitudes from Detroit

Dedicated to the loving memory of my aunt Virginia who passed away Dec 31, 2015 at 3:05 pm
                         (a graceful snow shower
outside my back door signaled her departure)

Build A Vacuum Tube Preamplifier

words and photo by: Telegraphy

  Rise your hand if you think digital sampling is superior in sound quality to analog vacuum tubes
..........anybody? Well for those of you that didn't rise your hands continue reading, all others lower your heads back down in front of your laptops, because today we're going to build a tube microphone pre-amplifier.

  Ah yes, the old debate amongst audio engineers and audiophile's. Does analog sound better than digital. The short answer (if you were to ask the almighty) - Yes it does sound better.  But why?

 Analog is defined as ": Something that is similar to something else in design, origin" which in our case of the "great debate" - analog vacuum tubes are replicating natures sound waves precisely as it is detected by our ear's. Digital on the other hand (keep your heads down laptop people) chops up the smooth natural sound into millions of steps. These steps makes our reproduction sound rough. Just as digital sampling uses "Solid State" devices to detect and reproduce sound. Though they are highly susceptible to distortion; "hollow State" on the other hand (which is referred to as tubes) are much more forgiving towards strong harsh sounds.

 The first vacuum tubes made (around 1902) were actually intended for radio reception and not audio amplification.  It wasn't until 1925 when the Western Electric Co. developed a complete electronic recording system, where by capturing, refining, and amplifying audio. This method employing tubes, revolutionized audio recording. For the first time in history, it was possible to tailor the quality of sound.
 Tube preamps are great pieces of gear to have in any home recording studio. There is no better option to obtain high quality audio from low level devices such as microphones and phonographs. So when I built a plate reverb (a low level device) I realized I was in a bind. "How am I going to get enough gain out of this plate reverb and yet still retain excellent audio quality", I thought to myself as I was driving to one of those big ticket item music stores (Ehheemm!! guitar center  ) I've always dreamed of having one of those expensive one or two tube mic preamps that retails for almost a THOUSAND DOLLARS!!! Seriously, if you can show me a capacitor or resistor that cost more then $20, I see no reason why these simple circuits with the minimal amount of components being used, should cost as much as a root canal. Anyways, I digress. Strolling through our un-named music store (hee-hee) I found a rack mounted mic preamp. Now my first though was, "Wow, a rack mounted piece of equipment"
I have a strong proclivity to when it comes to rack gear. It's neat and clean, always where you want it, and it just looks cool.
Looking at the very low, low price on the tag of this mic preamp ($50) How could I not resist. Being un-wise to spotting cheap equipment (They call that being young and stupid) my stupid behind bought myself a Behringer mic2200  Yes, some of you who are familiar with this so-called "tube preamp", can attest to it's crappy noise floor. In fact, others say it has a special knob which is marked "gain" but in reality varies the amount of noise gain. Powerhouse Mega from forums stated that it only makes a good serving platter. And hey, it works great as a serving plate. My dinner parties turn out great after using the mic 2200 serving platter with auto gain noise knob. My friends are happier, drunker and I almost had a chance to have sex. Thanks Behringer mic2200.

Behringer mic2200 as a serving platter.
  So at this point I've decided to gut the insides of this skin crawling, abomination of a mic preamp and build my own using it's cabinet. So enough about me. Lets learn how to build a vacuum tube preamp. Shall we?
The following article is a step by step description of a home built vacuum tube  microphone preamp.
Lets examine the construction of a vacuum tube. As you can see from the cut-a-way view that it is physically hollow. Hence the term "Hollow State". Your basic run of the mill tube has two elements. 1) Cathode  2)Anode. This tube is called a "Diode". It's job in life is to allow current to pass one way and not the other. Much like those gates at the train station you pass though which are eerily similar to cattle fencing at a cattle farm. (It's a conspiracy man!!)  Between these two elements is a space or a vacuum. Tubes work on the principle of charged electron amplification. A small change in electron flow at one end of the tube effects a bigger change in charged electrons on the other end. This electron flow starts at the Cathode, flies through the vacuum and hits the Anode. Now in order for this effect to happen (The Edison Effect) the Cathode needs to be heated to the point where electrons fly off. A filament much like used in incandescent lamps is placed inside of the cathode to heat it up. This is what you see glowing inside of a tube and this is way it takes a few moments for the tube to turn on. Now we have flying electrons coming off of the cathode, it would be nice if we could put'em to good use. Like those holiday meal left-overs. You hate to just through them out - but you don't want to eat another piece of ham or turkey for another load'em on your in-laws!

 The Anode or plate as it's called, is placed some distance from the cathode. Made out of metal or graphite, it is the final element in our tube. Electrons flying off of the cathode are attracted to the plate. The reason why these electrons are attracted to the plate is because of the higher voltage with respect to our cathode. We're talk'en high voltage folks. Nun of this 5 volt digital sissy pules (keep your heads down computer people) At least 200 volts !!

 Now that we have a conducting tube where electrons flow from the cathode to the anode, we can reproduce sounds from it by varying the flow. This is done by placing a third element in between the cathode and plate to act as a check valve. We shall call it - The Farnsworth Circular Modulated Multiplexed Coherer  Radiant Stimulator......just kidding folks, it's simply called a "Grid". It is used to control the electron flow and can be used to  modulate the plate voltage. In other words (our dubious digital dudes) a small signal voltage from a microphone impressed on the grid will vary the electron flow in the same manner and ultimately effect the bigger plate voltage (remember....BIG plate voltage).  Without the grid, we only can use this tube as a simple "current gate" or diode.

  Alright ! We know how a tube works. Now designing a accompanying circuit to make the tube work the way we want is a whole different ball game. Briefly put....

                                              Ionsonde Recordings presents..,..
                                          How to design a vacuum tube circuit.
( the analog deficient's version)

  This exclusive guide will teach the digital junky in four easy to follow steps, how to design and modify your pre-virtual reality analog vacuum tube microphone pre-amp. Learn how to....calculate bias, plate loading, cathode resistance and much MUCH MORE!!!  We're so confident that you will learn the art of designing a vacuum tube pre-amp's that we gave it a 30 day money back guarantee. If at anytime you feel that you haven't grasped the concept of analog reality, just simply send back your guide and 12ax7 tubes via particle beam transporter too...port 80 ip address    

Step 1) Choose your tube. The most common audio tube is the 12ax7. So we will use this one. Now look up the spec's for this tube and you will find a really, really scary looking plotted graph. Yes the  type you dreaded seeing first thing in the morning on the chalkboard in physics class. This graph is a analog computer (Do I have your attention computer people?). Believe it or not this graph, which is called a "load line graph" is able to calculate grid voltage vs plate voltage, grid and cathode bias residences. Basically you can design a complete circuit just by drawing a few straight lines on this ghastly of a graph.

Step 2) Choose a plate load resister value. A good starting value is around 100,000 ohms. We will use 150 k ohm. Using simple Ohm's law, we figure out the idle plate current. This means the amount of current draw of our tube at rest - No amplification. Calculations are.... now computer people can follow along using their Windows Calculator application. All others use your abacus or slide rule. 200 volts / 150,000 ohms = 1.33 milliamps. Hey! I see 1.33 milliamps on the right side of this graph! Hey!!! I see 200 volt down at the bottom......Well, draw a line connecting this two points. This is our load line of a 12AX7 tube. That wasn't so bad.     

Step 3) Now that we have formed a plate load line, we can use it to calculate values of other components or figure out different voltages and currents throughout our tube.  Most importantly we will calculate the cathode load resistance but first I have a secret to tell. I think you've noticed all of the animosity toward you computer people. Yes, I'm a little biased to when it comes to digital vs analog. And I'm sorry for all of the joke cracking. Us analog folks love your virtual ways (even though you can only count to 1). Yes I am biased. Biased to covering our next subject which is biasing our tube. It's alright, this will be just as easy as figuring out the loadline.

 Cathode bias - is the voltage present at the cathode which allows the tube to conduct and amplify in a set fashion. Picking any old biasing voltage from the plotted graph would work but our tube would run the chance of distorting our audio signal. We want the best audio quality. To do this, an amplification class known as "Class A" is to be used. Simply put "Class A" amplification in a tube has the best reproduction quality with the least amount of distortion. But, like all things in life there is a trade off. "Class A" isn't very efficient. Yes it's like driving a Bentley because you want to look good but when you want to race that annoying prick with his souped-up ghetto cruiser, blasting heavy base from their rattling trunk lid, your not going to do it! So we will sacrifice speed for class. For a 12AX7, a good all around cathode bias voltage (for Class A, don't forget) is 1.5 volts. Now back to our graph - look up the -1.5 volt curve and place a dot where the plate load line intersects. This is the biasing point. Now pay attention computer people. Draw or read across to the left hand side. You should read 0.5 mA. We have volt and now we have current. Both of these readings can be used just like our calculation of the plate load line. 1.5V/0.0005 A =  3000 ohms. This is the value of the resister off of the cathode. Draw a straight line from 0 volts and 0 mA through the bias point. This is our tube's cathode load line.

Step 4) PUT AWAY YOUR DAMN SLIDE RULER!! We are done. Now it's time to stop number crunching and start constructing.

 OK step back, take a breather. Drink some tea. That intense coarse study in analog computation is like a acid flash back to calculus class in high school. We're all done. Now it is time to have some fun with electronic components, wires and tubes.

The lone 12ax7 with
back lit LED's
Are you kidding me?
The design of this preamp is by Norman L. Koren  His "Spice preamp" is the design I choose for this project. Now, first thing on the list is build a power supply.

 Before I do that - a little bit more ranting about the Behringer mic2200 preamp. After discovering it's eccentricities, I opened up the cabinet only to find one (count'em one)12ax7 tube. I've also notice how the designers included a handy see through window on the front panel mounted just in front of the tube just to show off the fact that this is a "tube preamp". With only one resister and one capacitor on a printed circuit sub board where the tube is mounted, I was a bit concerned. Looking at the schematic diagram, I found a disturbing sight. The one 12ax7 tube in question, was only designed to be used as a cathode follower. What that means (computer people) that it doesn't amplify the audio signal what so ever. All it dose is transform a high impedances down to a low impedances. The amplifying is all done by cheap solid state op-amps. What a joke!

 Tubes as you know, require high voltages. To obtain several hundred volts means we need to build our own power supply. Running to your local radio shack isn't going to help or will it? Radio Shack offers an old school power transformer but it's output voltage is only 12 volts. That's OK, we can get around that. By using two of them connected back to back and using a few diodes and capacitors as "voltage doublers", we can obtain the required 250 volts.
Ripping out the Behringers power supply which only puts out 48 volts (way to low  to power a decent tube) I managed to fit my own built power supply in the space left by the old one. I mounted the two Radio Shack 12 volt power transformers, which are coincidentally enough the right height to fit perfectly inside of the chassis. A small perf board where all the components of the power supply are mounted on, is just to the left.

The old power supply
 Warning:  This supply is capable of producing lethal high voltages. So be cautious when building and testing this power supply. (DO NOT POKE OR PROD WITH A SCREW DRIVER or paper clips for that matter) We know how computer people love using paper clips to hack things.

My own power supply (note the two Radio Shack power transformers)

 "Telegraphy"? "I know how Optimus Prime transforms. Is this the same as the Radio Shack 12 volt transforms?"...........silly computer people..........

  No that isn't how it works. Think of it as a voltage multiplier and divider. Inside of our 12 volt transformer is two coils of wire wound around a central metal core. One coil connects to the house hold mains or 120 volts A.C. This is the input or "Primary winding". The second coil is the output or "Secondary winding". This secondary has a unique property where by however many winding's there are, determines the amount of voltage present. The more winding's - the more voltage. The least amount of winding's - the lower the output voltage will be. It steps up or down the house main voltage, all done by the ratio of primary winding's too secondary winding's. So the first 12 volt transformer; the primary connects to the 120 v house mains and we get 12 v on the secondary where it is sent to a circuit to convert it from 12 volts A.C  too 12 volts D.C.. The second transformer's secondary winding (remember - back to back) is connected to same secondary winding of the first transformer. So through ratio and proportions, the primary voltage of the second transformer goes back up to 120 volts. Hard to follow and strange in design but it works. If it's ugly or atypical and it works - just have faith in it.  So now we have 120 volts A.C. coming out of the primary winding of our second transformer. At this point we can not simply apply that to our tubes. Like a small child  tasting Castoria for the first time, our tubes won't take well to that. They need D.C. voltage. So the power supply is fitted with a circuit that will convert the 120 v A.C. to D.C. (no not the band!..go back to your onion routers) A few silicon diodes does this job perfectly. They only let the alternating current pass through one way to produce a pulsating D.C.. Next some capacitors are needed to filter out the bumps and ridges left by the diodes to turn it into pure D.C.. At this point we have 120 v D.C. Just about enough voltage required for our tubes but we want more power! The voltage can be doubled by using a special circuit called a "voltage doubler". This circuit uses a combination of silicon diodes and capacitors to double the voltage to a higher level. But of course with everything in electronics, there's a trade off. Sure the amount of voltage goes up but that the same time the current handling capability goes down. In other words, our power supply puts out 120 volts D.C. with 500 milliamp current handling capability before using the voltage doubler. After the voltage doubler, the voltage goes up to 240 volts but the current drops down to 250 milliamps.  This means we have to be careful how many tubes we can use with this power supply. 

  With 240 volts ready to use, we can now start on the tube amplifier itself.  As you can see from the schematic diagram below, the pre-amp I decided to build has quite a few components. Most of them are used has ether filtering out high frequencies generated by the pre-amp itself, or used as a feed back network to control the amount of amplification. But keep in mind, the basic theory I covered earlier on how to design a tube using a loadline is the same and can be seen here. You probably noticed by now that there is one input and one output - you've guessed it! This a mono pre-amp. So If you want stereo, you need to build two.

 Taking the grand tour of the pre-amp; our first stop(if you please direct your attention to the left, ladies and gentlemen)  is the phono input. R1s, R1g, and C1g make up a filter network, while R1gs is the grid stopping resistor. What is a "Grid Stop Resistor" you should ask? Well, Johny a grid stop resistor works in conjunction with the input filter network to stop any high frequencies parasitic oscillations. Ha, ha! In other words Johny, our tube likes to oscillate on it's own. The grid stop - stops it from self oscillating. As you can see connected to the bottom  and top of the first tube is the familiar cathode bias resistor R1c and plate load resistor R1p. C1m is a negative feed back capacitor. This also controls the amount of amplification and insures the tube doesn't break into self oscillation. (Now if you shall follow me over to the next capacitor. Watch your step, please) C1p is called a coupling  capacitor. It's job is to transfer the amplified audio energy from the first tube, over too the second tubes grid.....continuing on!.... The second tube operates just like the first, it just amplifies the signal even more. (And finally, we conclude our tour with) The third and final tube. This called a"Cathode Follower".  Transforming impedances is the name of it's game. It takes the high  impedance from the plate of the second tube and transforms it to a lower impedance without sacrificing gain. You might notice the output is coming out of the cathode instead of the plate. That's why it's called a cathode follower. The last components are feed back and filtering circuits. (Tours over - please visit our gift shop on your way out)

Point to point wiring.

The traditional way of constructing a tube circuit is to use point to point wiring on a tube socket.  By all means, it's a good time tested method of construction. For a stereo pre-amp your going to need three 12AX7 tubes. Each of them can be mounted horizontally, side by side.
Tube socket brackets 
Neatly mounted.
 To mount those tubes, I had to fabricate my own tube socket brackets. Made out of 1/8 inch thick aluminum sheet. One thing the Behringer engineers did do well is the back connector interface board. Well done!..........but I can't use it. So I ripped it out and reinstalled all the connectors to the back panel.

  Oh yes baby, we're at the home stretch. Now all needs to be done is connect the back connectors to the tubes. Install all three 12AX7's and plug in the A.C. cable for the initial "Smoke Test". Once again, do I have to explain everything computer people......hum. A smoke test is the first time a home built piece of equipment is powered up. If you find no burnt fuses or burnt components after the power switch is turned on - then it's a successful build. Oh, also if anytime during the test you DON'T see any smoke leaving the unit.....Thumbs up dude!!    


Un-soldering the connectors
Removing the back interface board.

Useless board removed. 

 As an added touch, I improved upon Behringer lackadaisical attempt to justify a working tube. It's back lighting with a solid state LED's was ridiculous. So I put in an old school incandescent  light bulb. Ah yes, a nice warm light to remind you of the warm sounds that comes out this pre-amp.
Kids, you might want to ask your parents what a incandescent light bulb is.
Real tubes light up.

  Let talk about tubes before I close out. Yes I know, I discussed tube theory up the wazoo earlier but I want to cover what type and where you can find tubes. Remember, you can't go wrong with N.O.S. (new old stock) tubes. They might be dirty, covered in dust or god knows what, but they work almost like the day they were born. I've had great success with these new fangled Russian made 12AX7's tubes. Their easily found on Ebay for as little as $15 each. Another thing to consider when purchasing tubes is when your project requires several of them, always buy "Matched Pairs". These are tubes that have been dynamically measured so that each matched pair conduct evenly between each other.
Well, hope you learned a thing or two about analog electronics. Hey it's fun and you get knocked on your @$$ with high voltage......Just kidding folk's. Be safe out there in the real "analog" world. And if I offended any computer people. I'M SORRY! Your just to easy in the analog world.
Digital? Any idiot can count to "1"
                                              Bob Widlar

I like electron tubes!