GUITAR DESIGNS by HIFIJOHN

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build your own electric guitar,build a bass guitar,build a guitar amp,guitar amp,
guitar amp schematic,guitar amp speaker,guitar amplifier speaker,tube guitar amplifier
vintage guitar amplifier

GUITAR AMPLIFIER COMBO

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I always wanted to build my own guitar amplifier.Even though there are hundreds of amps out there, there is still some thing about designing your own.The cabinet is ¾" plywood covered in a ruby red vinyl.The power supply, amplifier, and preamplifier are all mounted on there own seperate chassis. this is a bit unusual, but this way it is much easier to design and upgrade.

the power supply

The power supply schematic. is both solid state and vacuum tube (5U4).The solid state gives a much brighter and tighter sound while the 5U4 gives a more mellow sound.A switch on the front chassis allows the user to switch back and forth from solid state or tube.

the amplifier

The amplifier produces 35 watts into an 8 ohm load schematic. Because of its design, almost any output tube can be used.I'm currently using a pair of used EL34 Mullards .One unique feature (which I think all amps should have) is the bias meter in front. With the meter, the user can match the tubes to the correct bias and even to each other. This eliminates the need to buy matched output tubes!You can even experiment by turning up or down the bias to see what kind of sound change it creates.Just one 12AX7 tube acts as a predriver and phase inverter.I like to think I came up with this circuit but I'm sure it has been used before. One other feature that I added is feedback control.In the full counterclockwise position, the amp gets the maximum amount of feedback from the output back to the first stage. This creates the tightest sound with some loss in gain .With the control in the clockwise position,the amp gets no feedback.This creates a much looser and more open sound with a little more reverb.Most players keep the knob at the 10:00 position.

the preamplifier

The preamp is a 2 12AX7, 2 stage design. schematic. The first 12AX7 provides all the gain for the clean channel. Between the first and second channel, there is the stacked tone control. .This is the only part of the guitar amp that was never breadboarded, it was all done on a computer. The second 12AX7, is the dirty channel.Being a true audiophile it took a long time to get used to this idea!The dirty channel is essential the same as the clean channel, except it is design to intentionally clip the waveform. The output of this channel is then fed through a switch to the input of the clean channel.The result is a jazzy style of distortion which many people like.

the tubes

In the power supply,I'm using a NOS GE 5U4. Ive not experimented with other types.
In the preamp,I'm using a pair of used 12AX7 telefunkens.I'm amazed how good these tubes sound.I originally had a new pair of sovteks which sounded pretty good.But the tele's blew them away!
In the amplifier:The predriver is a used amperex bugle boy. Like the preamp, the original design had a sovtek 12AX7, but the sound of the amperex was so much better.I had the most fun experimenting with the power amp section.Grabing as many output tubes as I could find, I spent days carefully auditioning each pair for their sound.
NIB GE 6550:good bass,very forward midrange and very ringy jangly treble.
Conclusion:alot of force,but too forward and agressive sounding for me.
NIB SOVTEK 6L6:ok bass,ok midrange,ok treble.
Conclusion:I'd say there is nothing special about these tubes, their sound is just average.
used SILVERTONE 6L6:poor bass, cheap sounding midrange,cheap sounding treble.
Conclusion:I dont know who made these tubes for silvertone but the are very poor.
WESTINGHOUSE 6L6:ok bass, bit raspy midrange,ok treble.
Conclusion: these tubes are ok but I'd go with the sovteks first.
used RCA 6L6:perfect bass, excellent airy midrange,well controlled treble.
Conclusion:Wow, I can see why guitarist like these tubes, they are amazing in their sound.
used MULLARD EL34:excellent bass,very smooth midrange,very good treble.
Conclusion:second only to the RCA's,these mullards have a very smooth accurate sound.

conclusion

Overall I'm very happy with the amp.I've compared it to many amps out there ,and it holds it own very well.I've also exhibited the amp at a local guitar show ,and most people that have played it, seem to be pretty satisfied with the sound ,and most like the feedback and bias meter feature. The amp has been used ,and abused, quite a bit ,and has after 6 years never had a single failure!My only minor complaint is that it is physically big ,which makes it difficult to get into car trunks for transporting, but the weight is no more than any other amp in that power catagory.

specs

code :BV 88102597 tube : preamp-{2 12AX7}amp-{1 12AX7}{2 EL34) sound : (B+) thickness : ¾" height : 24½" depth : 11½ " length : 25½" weight : 55lbs finish : red vinyl cost : $392.67

2 WATT TUBE GUITAR AMPLIFIER

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I always liked the sound of a small wattage tube guitar amp.I wanted to build a 1 watt amp but got 2 watts instead.Its a single ended class A design with only 2 tubes.Design and construction is very straight forward. One 12AX7 for the predriver stage and a 6L6 for the output. I'm pretty happy with the results,its just a little too polite sounding for most people.I'll play with the voicing when I have time later.Click here for the schematic.

specs

code :BV11041507 tube : preamp-{1 12AX7}{1 6L6) sound : (B) height : 15½" depth : 6¼ " width : 11¼ " weight : 11 lbs. finish : cream vinyl

MICRO GUITAR AMPLIFIER

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Here is one of those 'for fun' projects-a super mini guitar amp.Made entirely out of scrap pieces I had in my junk box.The amp is the amp you find in a computer speaker.The only control is a volume knob in back.Though this was made just for fun, I'm very surprised at the sound. cost : $0.00

GERMANIUM DISTORTION BOX

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When I built my first distortion box(the red one) I was not entirely happy with the sound, so I always wanted to build another. I got lucky and got a hold of some NOS germanium transistors and decided to build a new distortion box around them.The design is much more complicated than I originally wanted but I had no choice ,if I wanted to get the desired sound this is want I had to do. The circuit is a 4 transistor design- Input buffer,2 stage distortion and output buffer.I'm very happy with the sound.It has a very cool 'blues type' of distortion sound.Although I have been in electronics for 30 years,this is the first time I have ever used germanium transistors. schematic

specs

code :BV10920721 sound : (A) height : 2 " length : 7 " width : 5" power source : 9 volt battery finish : top-gold paint,sides and bottom-copper paint cost : $37.86

THE MG GUITAR

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What would a guitar player be with out his own homemade guitar??Like the amp, there are so many guitars out there to choose from, but I still wanted to design and build my own.

The neck

The neck was bought from Stewart Mcdonald. I decided to make my job a bit easy and just buy the neck!It's a maple neck with a rosewood fretboard. The nut originally was a graphite type but I later replaced with one made from artificial tusk.(I think it's just dense plastic)The tuners and bridge are Schallers. One feature I added is a pair a pick holders on the back of the headstock.Most players seem to like this feature.

The body

The body is my own design. It made out of african paduak,which when first cut its a beautiful orange red but with exposure to sun and the air it eventually turns to a subdued red.I like the wood very much. It cuts and shapes well, it looks great, and it imparts a very warm and mellow tone to the sound of the guitar.

The electronics

The pickups are from my junk box. I spent 2 weeks carefully auditioning each pickup,both single and humbucker. Though most sounded good, the two I picked had the best sound of them all. The other unique feature of the guitar is the wiring.Each pickup has its own set of switches. One switch allows the pickup to be used in either a humbucking or single coil mode and the other switch allows the pickup to be used in or out of phase. Along with the tone control this combination allows the player a wide variety of sounds from a very thick les paul like sound to a very bright strat sound.

The conclusion

I have recieved good comments from people who have played the guitar. I am pretty satisfied with the overall sound.It has good tone and sustain and the guitar is very comfortable sitting down or standing up.

specs

code :BV88102597 body thickness : 1½" scale : 24" comfort : standing(B) sitting(B) sound : (B+) balance point : 6½" from bridge neck res : 96hz/182hz frets : 22 width at nut : 1 5/8" length : 40½" weight : 8½ lbs finish : polyurethane cost : $351.48

DISTORTION BOX

Here is my distortion box,like most out there ,its pretty simple in its construction schematic.
CIRCUIT:An opamp drives 3 silicon diodes which clips the waveform asymmetrically.I found that two silicon diodes one way,and one diode the other,produces the best sound.
DISTORTION CONTROL:this controls the overall gain of the opamp and therefore the amount of distortion.
BOOST:the boost mostly works on the bass,fully clockwise,it produces a fuller bassy distortion. fully counterclockwise,it produces a thinner lighter distortion.
COLOR CONTROL:fully clockwise,it produces a brighter distortion,fully counterclockwise,duller dirtier distortion.
OUTPUT:simply controls the output level.I generally adjust it so the clean and the dirty levels are the same.
SOUND:overall,I like the sound.It has the typical 'distortion box' sound but with a little bit more variety.
cost:$36.84

THE BASS GUITAR

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Besides a six string guitar,I always wanted to make a bass guitar. Its a basic 4 string design.The only feature that is a little unique is that the tuners are angled so they are easier to use.This is not a very original idea since I've seen basses that have this.

the neck

Mail ordered from CARVIN ,maple with ebony fretboard,and plastic nut.I put a light lacquer coating on the neck.

the body

The backside is honduras mahogany,the topside is redheart.The finish is a coat of sanding sealer and 3 coats of a satin polyurethane.To make the seam between the top and bottom look better,I used a strip of copper foil.

the electronics

Just your basic volume and tone control with an EMG bass pickup which I bought from stew-mac.

the conclusion

Overall, the comments from people have been very good.They like the light weight and the sound ,though not as deep and rich as a heavier bodied guitar would have. My only criticism is that it is a bit neck heavy and its awkward to play when you are sitting down.

specs

code :BV993152 body thickness : 1½" scale : 34" comfort : standing(B) sitting(D) sound : (B) balance point : 8½" from bridge neck res : 73hz/146hz width at nut : 1 5/8" length : 52½" frets : 22 weight : 8 lbs finish : polyuathane cost : $364.82

THE 3 GUITARS

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Here is another for fun project. I had a box full of guitar parts and alot of maple and a few necks, so I thought I would make a few guitars and give them to some of my friend's sons who were getting into guitar playing.
Building them was very straight forward.First, all the maple for the bodies were glued together, I had enough for 4 guitars but I only had 3 necks! A rabbet cut was made for the neck.A drawing for each body was drawn out and enlarged to the correct size,cut out,laid on the wood and traced.The maple was then cut on my bandsaw ,and alot of sanding followed-and I mean alot of sanding!.After that, pockets for the pickups and electronics were drilled with a forstner drill bit.After that,I sprayed 10 coats of paint and allowed the bodies 1 week to dry. Pickguard material was cut ,drilled ,and the switches, pots,and output jacks were mounted and soldered.The next step was to bring everything together,neck first,pickups,bridge,and finally, the pickguard with the electronics.The final step was to string up the guitars, tune them up,adjust the action,intonation,and truss rod.
THE REVIEW:
the red guitar
maple neck with rosewood fretboard
2 humbucker pickups
1 switch per pickup and master volume and tone control
sound:overall not bad, a bit dull and lifeless for my taste.
overall feel:sitting down or standing up, the guitar has a good balance and feel to it even though the maple is heavy.

the blue guitar
mohagany neck with rosewood fretboard
1 humbucker pickup
volume and tone control
sound:ok ,but it does have a cheap sound to it, I blame the pickup and the small maple body.
overall feel:standing up the guitar is comfortable, but as with all 'flying V' type of guitars,sitting down is awkward.

the purple guitar
Washburn maple neck with rosewood fretboard
2 humbucker pickups
1 switch per pickup and master volume and tone control
sound:very good, by far the best out of the three,not much top end but the mid and especially the bass are awesome!!
overall feel:very heavy standing up,heavy and a bit awkward sitting down.

THE BLUE GUITAR

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When I made the 3 guitars above it was just for fun, but when I played the purple guitar ,I liked it so much that I decided to build one for myself.

the body

The body is made from thin strips of mohagany I got from a friend. it came in 3/4" thick, 4" and 6" wide ,pieces of wood.To get the body, I ripped the wood 1.5" wide and glued it face to face(the top and bottom of the guitar are the edge of the wood).I found this to be a very effective way of getting a guitar body from any size of wood you happen to have.The guitar is finished in a blue metallic automotive body paint

the neck

The neck is from Carvin,which I mail ordered from their catalog.Its maple with an ebony fretboard.The nut is plastic and comes with the neck.

electronics

2 sheilded humbuckers I got from my junk box with a volume, tone control,and an on/off switch for each.

the sound

Overall I'm a little dissapointed in the sound, while the guitar is much lighter and much comfortable to play than the original, it lacks the great bass that the original (purple)guitar had.The mids are good and the notes stand out a little better than the original purple guitar,but the top end is too refined sounding for my taste.It does ,however, have very good sustain.

specs

code :BV1041262 body thickness : 1½" scale : 25½" comfort : standing-(C) sitting-(C+) sound : (C) balance point : 3½" from bridge neck res : 87hz/121hz frets : 22 width at nut : 1 11/16" length : 48½" weight : 8¼lbs finish : blue car spray paint

THE STICK GUITAR

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I remember back in the late 70's,I was walking through central park in new york city and saw a guy playing a guitar I have never seen before.It had no headstock or body!I have never forgotten it and occasionally I see something similiar to it in guitar magazines.20 some years later, I decided to build one for myself.

The body

The body is made from scraps of oak I had around the work shop,since there is very little body I needed very little wood.

the neck

The neck is from a guitar I bought at a garage sale for $20.The guitar was a piece of junk but all I wanted was the neck.

the electronics

The front pickup is a single coil and the back pickup is a split humbucker.A single switch is used for the single coil and two switches are used for each section of the humbucker.The last switch allows the pickups to be played in or out of phase.There is your basic volume and tone control after that.The aluminum bar was latter added so the guitar can be played sitting down and I can place it on a guitar stand.

the sound

It has a very interesting sound,good but a bit thin in the bass.This doesnt surprise me very much .Being bodyless, I didnt expect much bottom end,but the mids and the top end are good.Overall it has a clean and bright sound.It reminds a little of a STRAT.

conclusion

Standing up,the guitar is so light you hardly notice you're holding a guitar,its nicely balanced but it does have a unique feel and it does take a while to get use to it.Sitting down is another matter altogether,because everything on the guitar is at one end, the guitar is 'back heavy', so it does take a while to get use to it.It also takes time to get use to the fact that the tuners are at the other end and the aluminum bar does get a little in the way.Most people who have played the guitar,seem to like it but are not very enthusiastic about it.

specs

code :BV1029192 body thickness : 1½" scale : 25½" comfort : standing-(C) sitting-(C-) sound : (C-) balance point : 4 5/8" from bridge neck res : 87hz frets : 22 width at nut : 1 11/16" length : 36½" weight : 5 lbs finish : black spray paint

VACUUM TUBE REVERB UNIT

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When I built the guitar amplifier, I originally wanted it with reverb,but I ran out of money and time,so I decided to finish the amp, sans reverb, and build the reverb as a separate stand alone unit.The design is basic,and the layout is simple. The entire power supply and reverb circuit is mounted on a aluminum chassis and the reverb tank is mounted seperately.
the circuit: The signal comes from the input jack and is split in two. One signal goes to one half of a 12AX7 that drives the tank through a transformer.The output of the tank is amplified by a two stage 12AX7 circuit.The two (clean and reverb)signals are then summed by a passive summing circuit. The final stage is a buffer stage.With the level control turned down,you get the clean signal only, with it turned up you get the clean and a percentage of the reverb signal.
schematic

specs

code :BV103121302 tubes : 12AX7 sound : (C+) height : 7½ " depth : 5½" " width : 19" " weight : 7lbs finish : mohagany with copper trim cost : $117.70

THE HOLLOW BODY GUITAR

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While I have built many solid body guitars ,I have always liked the unique sound of a hollow body.Though there are many good hollow body guitars out there, its always more fun to make your own.

the body

Its a hollow body guitar without any sides.I had no desire to bend wood, so I decided to build a guitar with only pillars ,or spacers, for sides.At first ,I thought this was a strange idea, but I have seen this before.The back and front is a 1/8th inch stained birch plywood,the side pillars are mohagany.

the neck

The neck is pine I got from an old sears guitar I bought at a garage sale.I was going to restore it but it was too far gone.So I just kept the neck for a future guitar project.

the electronics

There are 2 junk box humbucker pickups with 2 selector switches a volume and a tone control.The volume and tone controls are old bakelite knobs.

the sound

The sound is big and fat with alot of resonance.

conclusion

A little to big and uncomfortable for me to play and the edge of the guitar digs into my lap when Im sitting down.Im also surprised how heavy it is.

specs

code :BV10533005 body thickness : 3¼" scale : 24" comfort : standing-(D-) sitting-(C-) sound:(C+) balance point : 5 7/8" from bridge neck res : 104hz/124hz frets : 20 width at nut : 1 3/8" length : 42½" weight : 7¾ lbs finish : stain/polyurethane cost : $35.22

THE PIANO GUITAR

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the body

The body is from an old piano I found in the alleyway.Someone had smashed it up pretty good so I took a piece of the wood home for the body,Im not sure what the species is.It looks like oak but its far too light.

the neck

The neck is from an old harmony guitar I bought at a guitar show.The bridge is from an old gibson futura guitar from the 80's.

the electronics

I used 2 junk box humbucker pickups and a 3 way switch tone and volume control,your typical controls you would find on a guitar.

The sound

The sound is very good with a nice amount of sustain and a bit of a Fender twang to it. The body is very light and the shape makes it comfortable to play whether you are sitting or standing up.

specs

code :BV10671805 scale : 25.5" body thickness:1¼" comfort : sitting-(A-) sitting-(A-) sound : (B) balance point: 7" from bridge neck res: 129hz frets: 21 width at nut : 1 5/8" length: 40" weight: 7 lbs finish: stain/polyurathane

THE ACOUSTIC GUITAR

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This is my first attempt at an acoustic guitar.I always wanted to build one.Unlike electric guitars,acoustic guitars cant be tweaked later, what you get is what you're stuck with.

the body

I had no desire to bend wood for the sides so I decided to do something different.I took a bunch of 4x4 pieces of pine and glued them together,I then cut the outside and inside of the shape. After sanding it down ,I got the form I needed.The top and bottom is made from englemann pine.The sound hole is triangular because its easier to cut than a round hole. its about 11 square inches in area , 1 less than your typical guitar would have.

the neck

The neck is from Mighty-Mite,its your standard 'strat like' neck.

The sound

I put nylon strings on this guitar because I never had nylon strung guitar before, plus nylon strings put alot less stress on a guitar body.I do believe the bracing is far too strong for the strings, so the sound is not as full and loud as I would have liked it,but I don't care ,it has a soft pleasant sound that I like, plus its very easy on my fingers.Also this guitar was designed for steel strings so in the future I can always put those on it.

specs

code :BV108816 scale :25½" body thickness:3½" comfort : sitting-(b+) sound : (c-) balance point:8½" from bridge neck res:82hz/103hz/164hz/207hz frets:22 width at nut:1 5/8" length:42" weight:5 lbs finish:cherry gel stain/polyurethane cost: $221.19

Though I have many guitar stands ,they are the generic aluminum type, so I wanted to make some nice wooden ones.The one on the right is out of oak and the other is out of pressure treated lumber.I like the oak one better and the guitars do look nice on them.

I was walking down the alleyway one day and found an old stereo from the 60's that someone had thrown out.It was a piece of junk, but it did have a cool 15" jensen woofer.I came back with a screw driver and got the speaker.since I have plenty of scrap wood around, I decided to make a small guitar speaker cabinet. I like the sound, a little thin in the bass but otherwise it sounds very good.
cost: $26.07

While I like my bass guitar, I needed a good speaker that can handle the bass.I bought this 15" woofer years ago and never used until now.The cabinet is plywood with a covering.It sounds great and makes my bass guitar really sing!

click here to hear some short songs I've made(basically just me and my little 4 track recorder).

click on the pictures to see videos of my guitars and amplifiers.

reality is merely an illusion,albeit a very persistant one