The guitar itself is a factor in how much output the pickup will have, and its construction is the first set of (fixed) tone shaping control that occurs in the amplification process. A solid body guitar made from a "dead" wood like poplar is assumed to be relatively neutral. The two poplar bodies that I made produced very little unamplified sound, being almost inaudible in a large high school woodshop classroom. Make that same guitar body out of yellow pine and it is quite audible with the same neck that I used on the poplar bodies. the large pine guitar was quite loud, and I could hear the maple / mahogony uke over it in an unamplified classroom jam session. This difference translates to slightly more output from the pickups and a longer sustain time. Make a hollow. or semi-hollow body guitar with that same hardware and it will be even louder with more sustain and have a different harmonic output due to resonances in the body itself.
Guitar pickups come in all sorts of configurations with varying output levels. The biggest difference is the cheaper single coil VS the bigger, more expensive hum-bucker with two coils wired out of phase electrically, and magnetically. In this manner the vibrating strings contributions to the two coils add, but stray 60 Hz fields cancel. In the early days of the Hundred Buck Amp Challenge, some forum members that had never built a guitar amp before asked about the electrical output from a typical guitar. I simply connected a scope across the input of an amp that I had on my bench and plugged in every guitar that I could get my hands on. The hottest guitar I had at the time was an old Guild with DiMarzio Hum Bucker pickups. With the switches and controls set for maximum output, and by running through a series of SINGLE NOTES from low to high and finding the loudest one I got an output of about 1.5 Volts peak to peak. This is well beyond what most people in the thread expected including me. Note the TEK scope has a non TEK probe on it so it does not recognize the 10X setting. The real vertical sensitivity is 200 mV / DIV. Some other guitars can't hit 1 volt even when playing 6 note chords as hard as possible. Single notes are in the 500 mV range with all controls set for max output and all three pickups on.
The "setup" of an electric guitar involves adjusting everything for best intonation and best playability for the player that will actually use the guitar. One of these adjustments is pickup height. The closer the pole pieces are to the strings, the louder and brighter the sound out of the amp will be. If the pickup height is too high the strings may touch the pickup in the hands of a heavy handed player, making an ugly POP sound. If the pickup is too low the sound will be quiet and dull in the hands of someone casually strumming some chords.
It has been said that half of all electric guitar players will simply set the controls on their guitar to max volume and wide open tone and expect the amp or FX boxes to do all the work, and that IS a valid strategy for someone who uses a pedal board and likes a loud distorted sound. I admit to being one of them most of the time. The little 4 tube amp I built for the HBAC taught me to use the volume knob on the guitar to set the level so that lightly plucked strings are clean, and harder picking increases the distortion without raising the volume much. The input stage in that amp is a high gain pentode with only 150 volts of B+.
A 1.5 volt peak to peak signal can push the typical opamp input stage in a cheap SS amp into its ugly distortion range, from which there is no return.
I can't say that I'm an expert on guitar speaker boxes, but they obviously have a huge impact on the tone and loudness of the whole system. Back when I made a lot of guitar amps, mostly for coworkers and friends, I would get the person and his guitar to go with me to a big music store that let us "play with the toys." I would tell them to find an amp and speaker combo that they liked, then we copied it. Speaker cabinets were clones of what we used in the store, with some driver changes based on budget. Amps were either built from a schematic found in a book or acquired by tracing out an amp, and tweaked to suit, as the internet didn't exist, or was still in its early years (1980's through about 2000).
Guitar pickups come in all sorts of configurations with varying output levels. The biggest difference is the cheaper single coil VS the bigger, more expensive hum-bucker with two coils wired out of phase electrically, and magnetically. In this manner the vibrating strings contributions to the two coils add, but stray 60 Hz fields cancel. In the early days of the Hundred Buck Amp Challenge, some forum members that had never built a guitar amp before asked about the electrical output from a typical guitar. I simply connected a scope across the input of an amp that I had on my bench and plugged in every guitar that I could get my hands on. The hottest guitar I had at the time was an old Guild with DiMarzio Hum Bucker pickups. With the switches and controls set for maximum output, and by running through a series of SINGLE NOTES from low to high and finding the loudest one I got an output of about 1.5 Volts peak to peak. This is well beyond what most people in the thread expected including me. Note the TEK scope has a non TEK probe on it so it does not recognize the 10X setting. The real vertical sensitivity is 200 mV / DIV. Some other guitars can't hit 1 volt even when playing 6 note chords as hard as possible. Single notes are in the 500 mV range with all controls set for max output and all three pickups on.
The "setup" of an electric guitar involves adjusting everything for best intonation and best playability for the player that will actually use the guitar. One of these adjustments is pickup height. The closer the pole pieces are to the strings, the louder and brighter the sound out of the amp will be. If the pickup height is too high the strings may touch the pickup in the hands of a heavy handed player, making an ugly POP sound. If the pickup is too low the sound will be quiet and dull in the hands of someone casually strumming some chords.
It has been said that half of all electric guitar players will simply set the controls on their guitar to max volume and wide open tone and expect the amp or FX boxes to do all the work, and that IS a valid strategy for someone who uses a pedal board and likes a loud distorted sound. I admit to being one of them most of the time. The little 4 tube amp I built for the HBAC taught me to use the volume knob on the guitar to set the level so that lightly plucked strings are clean, and harder picking increases the distortion without raising the volume much. The input stage in that amp is a high gain pentode with only 150 volts of B+.
A 1.5 volt peak to peak signal can push the typical opamp input stage in a cheap SS amp into its ugly distortion range, from which there is no return.
I can't say that I'm an expert on guitar speaker boxes, but they obviously have a huge impact on the tone and loudness of the whole system. Back when I made a lot of guitar amps, mostly for coworkers and friends, I would get the person and his guitar to go with me to a big music store that let us "play with the toys." I would tell them to find an amp and speaker combo that they liked, then we copied it. Speaker cabinets were clones of what we used in the store, with some driver changes based on budget. Amps were either built from a schematic found in a book or acquired by tracing out an amp, and tweaked to suit, as the internet didn't exist, or was still in its early years (1980's through about 2000).
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Got some stuff at the show. Very Lucky this year. I paid $30 and $40 for the tube amps, $10 for the short midi keyboard. Which caused the guy to give me the cab and mic pre box for free. I bought the Panasonic AM / FM cassette for $1, cause I recently read they're "in fashion". OK.
The Bogen one uses 7868s, which were both there. We'll see if I need to buy new ones, or punch out those sockets for octals. 3 microphone trannys in there too. The other one is a Thomas. Looked like 6BQ5s, but 6973s. If it's a concertina phase splitter, that box has 5 triodes upstream. Yum! Busted socket on one of the 6973s though...
The Bogen one uses 7868s, which were both there. We'll see if I need to buy new ones, or punch out those sockets for octals. 3 microphone trannys in there too. The other one is a Thomas. Looked like 6BQ5s, but 6973s. If it's a concertina phase splitter, that box has 5 triodes upstream. Yum! Busted socket on one of the 6973s though...
A lot of the older piezo pickups exhibited a screechy sound, or "piezo squawk", so they fell out of fashion on most solid body electric guitars. They are still seen on acoustic guitars with jacks, and some hollow body and semi hollow body electrics.
There is a neat solution, and I have one of these systems on a Strat body that still in a box somewhere. The GHOST pickup system puts the piezo element inside the string saddle. The reason I used them is they provide a separate output for each string. This can be useful for guitar to MIDI converters which was my application. The Ghost system also provided a guitar output (all six strings) that did sound quite like an acoustic guitar. The piezo element output must be fairly low and high impedance as an opamp based preamp in the guitar is needed. Simply connecting a saddle pickup to a guitar cord and plugging it into an amp makes for a weak and muffled sound. The tiny little wires coming out of those saddles are easy to break too.
https://graphtech.com/pages/ghost-pickup-systems
There is a neat solution, and I have one of these systems on a Strat body that still in a box somewhere. The GHOST pickup system puts the piezo element inside the string saddle. The reason I used them is they provide a separate output for each string. This can be useful for guitar to MIDI converters which was my application. The Ghost system also provided a guitar output (all six strings) that did sound quite like an acoustic guitar. The piezo element output must be fairly low and high impedance as an opamp based preamp in the guitar is needed. Simply connecting a saddle pickup to a guitar cord and plugging it into an amp makes for a weak and muffled sound. The tiny little wires coming out of those saddles are easy to break too.
https://graphtech.com/pages/ghost-pickup-systems
Yes, I used that setup quite often several years ago until I stole the neck off of it for another project. The public school system in Florida has a program where they open a few schools at night for "adult education" classes. These are one off weekly classes usually of a vocational, remedial (GED), or ESOL nature for a fee based on the cost of running the class, its subject, and the ability of the prospective student to pay. There were woodshop classes available in my area for a reasonable fee which once a new student completed two simple build projects, became a 4 hours per week shop rental with an expert in woodworking available. I went to the woodshop class one night a week for several years where I made guitar amp cabinets, HiFi amp chassis, speaker cabinets, guitar bodies and a few other projects. A coworker at Motorola joined in for a year or so to make three nice electric Ukeleles. The fun ended when that teacher retired from the public school system and was not replaced. The picture seen in post #141 was shot with my phone when both of us happened to have our DIY instruments in playable condition at the end of class one night and a few of us sat around the classroom playing and singing a few old Beatles songs since they were the few songs that both of us knew.
Yeah, I remember the ads for those devices in the 60s. I'm sure the guy next door with the side TV repair had them. Just thinking out of the box on this; interesting the ADA unit ran their tubes heaters hot like that - and dared to make a product, Something I see in that schematic (thanks!) are the attenuators between each stage, which is something I suppose one could do to make use of more stages, but without so much gain as they would otherwise provide. Another tube-sound-shaping scheme?
The Bogen amp I got works and the output tubes dont red plate immediately. Looking to gut it and make it into something "different".
Sort of amusing, on the same terminal strip as the speaker impedance outputs are 3 terminals labeled "remote". Each has a 470k going to +250V, another 470k going to a 0.1 (or so) to ground, and another 470k to an input tube plate resistor. I guess grounding those terminals allows one to kill a channel in the mix with a switch...conducting ~0.5 mA. As long as it's not my finger! That circuit will be among the first to go.
I read HiWatt amps have some atypical phase splitter, which give them their sound distinguished from a Fender or Marshall. Claim is the latter's bias slip-slides around under transient conditions, while the HiWatt design does not; stays cleaner longer. I'm chewing on the idea to put the phase splitter up front and run differential stages with as many triode stage pairs as I have back to the output tubes. Up front the signal is so small, it wont knock the bias around with someone chugging chords, as it may way back there at the signal levels just before the output tubes.
Running differential circuitry allows one to play with further ridiculous notions on top of that. Like separate power supplies for the "inverting" and "non-inverting" gain string. Something a real manufacturer would never do. With a control allowing a user to dial down either side, which would change the gain and also the signal curve of those strung-stages. Change the overall sound, as it goes from fully right-on-the-schnops balanced to more than a hint of SE?
Then to really go nuts, one could make a tube static phase-shifter along the way within those gain strings, so a user could rock the phase, making, say, the non-inverting gain string slightly lead or lag the inverting string, with a panel control. Coming back together again within the OPT, I'd assume it would comb filter there. Adjustable change to how it sounds? (The digital guys would do a precise time delay of some concert-pitch note, making the amp appear to actually favor amplifying some in-tune notes over others. Unsure what that effect would be like)
Well, it's nice to dream on a Sunday afternoon.
The piezo pickup impedance reminded me of my brother. He has been in design/production of control equipment for over 30 years. But for some reason he could not get an accurate signal from the pH sensor amplifier he built. It was only later when he found out a 10M input impedance just did not cut it when your source is across a piece of glass. For a piezo 10M really should be a minimum.
Actually, the tubes are run cold. The 8 volt source is wired across pins 4 and 5 which is the 12.6 volt connection. Google up the schematic for the Soldano SLO 100 for a good example of gain stages chained with attenuators. It was also the first time I saw LDR's being used as switches.
Got it, thanks. Looking at the schematic for a Fender Princeton, the Tremolo function modulates the bias voltage on the output tubes, in turn AMing the guitar signal. So I suppose there's room to play like that.
One time I tried to make a "floating resistor" out of a couple LDRs; one in a control loop, the other making a - supposed - copy of what the first was doing resistance wise. A voltage controlled floating resistor.
No one used it, because the techs could tune the control loop with their decade boxes just as fast as the computer could controlling the LD resistors via some algorithm... My contraption only had the advantage of a much, much shorter wire connection to those SMD pads ;')
One time I tried to make a "floating resistor" out of a couple LDRs; one in a control loop, the other making a - supposed - copy of what the first was doing resistance wise. A voltage controlled floating resistor.
No one used it, because the techs could tune the control loop with their decade boxes just as fast as the computer could controlling the LD resistors via some algorithm... My contraption only had the advantage of a much, much shorter wire connection to those SMD pads ;')
"One time I tried to make a "floating resistor" out of a couple LDRs; one in a control loop, the other making a - supposed - copy of what the first was doing resistance wise. A voltage controlled floating resistor."
One of the LDR / LED based opto isolator companies makes or made a "linear optocoupler" that did exactly that. Vactrol Maybe? I have the data sheet somewhere in my 12 terrabyte garbage collection that began with my first PC in 1983.
I have started tinkering with some simulation of the "MetallicAmp" design that I plan to make with parts that were available before the early 50's. Spice models for old metal tubes don't exist. It's a lot harder than I thought to design stuff using only parts from before I was born. Now if I only had all those notes from when I was a kid and actually used parts from the stone ages. It would be a lot easier to make stuff if I could stick some mosfets and LED / transistor based optocouplers in it. LDR's existed then, but LED's did not. Vacuum tubes don't like to directly drive an incandescent bulb in a linear manner without blowing them up either.
One of the LDR / LED based opto isolator companies makes or made a "linear optocoupler" that did exactly that. Vactrol Maybe? I have the data sheet somewhere in my 12 terrabyte garbage collection that began with my first PC in 1983.
I have started tinkering with some simulation of the "MetallicAmp" design that I plan to make with parts that were available before the early 50's. Spice models for old metal tubes don't exist. It's a lot harder than I thought to design stuff using only parts from before I was born. Now if I only had all those notes from when I was a kid and actually used parts from the stone ages. It would be a lot easier to make stuff if I could stick some mosfets and LED / transistor based optocouplers in it. LDR's existed then, but LED's did not. Vacuum tubes don't like to directly drive an incandescent bulb in a linear manner without blowing them up either.
Actually, I have neither. MetallicAmp will use only metal tubes from the 40's and I have collected about 80 of them in 20 different flavors. The 6L6s and 6V6s have been confirmed good in working amps. The metal tube thing rules out blue stripes and magic eyes. I'm currently playing with basic ideas in LT spice and building cabinets outside when the weather permits. It's not hard to make a tube compressor with a 6H6 and 6SK7. Unfortunately, I have none of either tube but the biggest hamfest in the world is about two months away.
As above, I spent my limit on all I could carry out. There was more, if I brought more $ and dug a little deeper. Had to bring the car around to pick up as it was! Bring your wheeled tote and may it be filled with all you're willing to spend, this time!
Well, it would be interesting just to see if it'd actually work. How cool are those old photo tubes for the projector sound pickup? One would think they'd have made a metal one with a glass window; ground the case for lower noise - I imagine those are pretty High Z sensors.
Compression - whether built in as an additional circuit with adjustable parameters, or via a fixed tuning of time constants in the power supply - is a character making aspect of a guitar amp's behavior when played. I keep catching info that supports this, reading how David Gilmore used it a lot, perhaps an effect heard on some of the most famous guitar lines in rock history.
I have an idea that I'll be trying in that Bogen amp I got, but I'll start another thread for that. I'm just glad I was able to get a couple "opportunity" amp hardware bits at that show. It'll be a while, as I'm cleaning off component wire attachments to the tube sockets, I realize "what am I doing" and I should just order new ones for $2 each and simply replace the whole thing, rather than fight with all those wire crimps.
The open mic last night had a new keyboard player. Guy told me he picked it up after the arth started bugging him playing guitar. He's pretty darn good at it too, just a year into it he said. Said he's working on starting / stopping the Leslie effect in his organ phrasings... Had his left hand so much on the effect control, I thought he could only play with his right for a bit. Got a lot of groove, for little movement in that right hand.
"As above, I spent my limit on all I could carry out. There was more, if I brought more $ and dug a little deeper. Had to bring the car around to pick up as it was! Bring your wheeled tote and may it be filled with all you're willing to spend, this time!"
The Dayton Hamfest is only a 4 hour drive for me since I left Florida, so I go every year. I don't take a wheeled tote to the show, I take a Ford Transit Connect cargo van and park it inside the flea market. I have been selling stuff at Dayton off and on for about 15 years. I limit myself to spending only the cash that I bring in from selling my stuff, and since the van is stuffed beyond its capacity when I get there, I can only come home with the same or less cubic volume than I left home with. It has been said that the flea market regulars just keep passing each other's junk around.
I went to 42 of the 45 yearly Miami hamfests and sold stuff at most of them when I lived in Florida. The Miami Hamfest was big, and it was the first of the 5 or 6 mega hamfests. There are now only 2, Dayton and Orlando. Being in early February it attracted a lot of tourists that needed an excuse to come to Miami. Unfortunately, the NFL kept extending its schedule and as (bad) luck would have it, the Superbowl landed on hamfest weekend when the brand new football stadium built for the Miami Dolphins opened. The Superbowl was held in Miami on hamfest weekend for two consecutive years. Even a low budget dive-motel gets $500 a night on Superbowl weekend, so the Miami Hamfest was locals only for two years, and died.
I went to the Orlando Hamfest probably 15 to 20 times and sold stuff there about half of the time I went. It was also a 4 hour drive when I lived in South Florida. I have driven a van load of stuff there three times since I moved here. It's a 16 hour drive.
I just realized when I was looking at a site I used to visit often that the site owner passed away nearly 20 years ago and many here have probably never seen it. Those 20 years have certainly flown by. Fred Nachbaur had a web site for his electronics adventures, many of which involved vacuum tubes, and another site for the music he wrote, performed, and recorded. They are still being hosted. The electronics site has a Vacuum Tube Projects page, that includes some guitar amps. The Dogzilla is a must see. It will probably hold the record for the most tubes in a guitar amp forever at 18!
http://www.dogstar.dantimax.dk/
The Dayton Hamfest is only a 4 hour drive for me since I left Florida, so I go every year. I don't take a wheeled tote to the show, I take a Ford Transit Connect cargo van and park it inside the flea market. I have been selling stuff at Dayton off and on for about 15 years. I limit myself to spending only the cash that I bring in from selling my stuff, and since the van is stuffed beyond its capacity when I get there, I can only come home with the same or less cubic volume than I left home with. It has been said that the flea market regulars just keep passing each other's junk around.
I went to 42 of the 45 yearly Miami hamfests and sold stuff at most of them when I lived in Florida. The Miami Hamfest was big, and it was the first of the 5 or 6 mega hamfests. There are now only 2, Dayton and Orlando. Being in early February it attracted a lot of tourists that needed an excuse to come to Miami. Unfortunately, the NFL kept extending its schedule and as (bad) luck would have it, the Superbowl landed on hamfest weekend when the brand new football stadium built for the Miami Dolphins opened. The Superbowl was held in Miami on hamfest weekend for two consecutive years. Even a low budget dive-motel gets $500 a night on Superbowl weekend, so the Miami Hamfest was locals only for two years, and died.
I went to the Orlando Hamfest probably 15 to 20 times and sold stuff there about half of the time I went. It was also a 4 hour drive when I lived in South Florida. I have driven a van load of stuff there three times since I moved here. It's a 16 hour drive.
I just realized when I was looking at a site I used to visit often that the site owner passed away nearly 20 years ago and many here have probably never seen it. Those 20 years have certainly flown by. Fred Nachbaur had a web site for his electronics adventures, many of which involved vacuum tubes, and another site for the music he wrote, performed, and recorded. They are still being hosted. The electronics site has a Vacuum Tube Projects page, that includes some guitar amps. The Dogzilla is a must see. It will probably hold the record for the most tubes in a guitar amp forever at 18!
http://www.dogstar.dantimax.dk/
Thanks for sharing that; I'd never seen it before. That Dogzilla amp was quite a project and contains some interesting stuff, like the compressor, the progressive diode limiter and the "small amp emulator" all inside that big 70 lb construction. Fred sounds like he would have been a fun fellow to talk with, about amp building. I'd ask him about those 3 neons, coming off the 12AT7 plate; what is that, a bias power supply?
I see two places where three series neons are connected to the plate of a 12AU7. Both are in very similar DC coupled "preamp" stages. At cold tube turn on both of the plates will be a the B+ level. The neons will have enough voltage across them to fire, so they force a positive voltage on the grid of the bottom tube in the LTP, which forces a proper startup of the DC coupled circuit, settling out as the neons extinguish and the CRC network slowly discharges.
I use a single neon to ground on the shared cathodes of the LTP in my Universal Driver board. It clamps the cathode voltage to a safe H-K breakdown value when the CCS chip drags it to the negative supply rail during cold tube startup in a "universal" application where the negative supply voltage may be unknown. Once the tubes are hot, the neon goes out and becomes a 1 pF cap.
His "small amp simulator" was what got me building small tube amps with big solid state boosters for a few years, back when Fred was developing this thing one stage at a time on his blog (or whatever they called it then).
I use a single neon to ground on the shared cathodes of the LTP in my Universal Driver board. It clamps the cathode voltage to a safe H-K breakdown value when the CCS chip drags it to the negative supply rail during cold tube startup in a "universal" application where the negative supply voltage may be unknown. Once the tubes are hot, the neon goes out and becomes a 1 pF cap.
His "small amp simulator" was what got me building small tube amps with big solid state boosters for a few years, back when Fred was developing this thing one stage at a time on his blog (or whatever they called it then).
From the cant effin sleep dept...
Given all you know about analog synth's and guitar amps, why not take the two technologies, put 'em in the jar and press "blend"?
After all, that Fender tremolo is just a LFO with a VCA; two common components of an analog synth.
Another base component is the envelope generator. With guitar, that wouldnt necessarily be initiated via a trigger signal, but you can otherwise get an envelope. I once made an envelope follower that was 2nd order, with advantages like faster attack speed, resonance and LP / HP outputs.
Fred had a "Timbre" control, and he could have used the envelope from his compressor to change from the clean signal to the single ended amp emulator output "automatically".
Unsure what the circuit would be, but I'm sure you could get a CV from roughly where you're playing on the neck, just through an analog signal analysis. That would be the (nearest) equivalent of the keyboard CV, without needing a special guitar. You could then change the tone bandwidth of the amp, chasing the spectral content of what you're playing.
Heavier would be the 'ol ring modulator effect, which is just the LFO turned up into the audible range, driving a VCA. I can imagine having that as a percussion, similar to when on a synth you tune one osc up a 3rd, followed by a fast decay, to get that Hammond sound. The percussion envelope could come from the HP output of the envelope follower. Super nuts would be to set the modulation frequency by playing a brief note on the guitar and a foot tap on a switch...
These control voltages could otherwise be used to modify the operation of the tube circuits in more subtle ways. Could have the envelope change the bias on the output tubes, such that with no guitar signal the bias decays down to cool, when you start playing it comes up to normal and playing really hard it goes to a level one wouldnt want to leave set continuously.
Unsure what the classic "sample and hold" as a CV would get you, perhaps that's a bit too far. I'm sure you get the gist of the idea. Even a '64 Princeton Reverb has analog synth elements within it. There's a lot more one could do, that I'd bet someone could weave into their playing in a musical way.
Given all you know about analog synth's and guitar amps, why not take the two technologies, put 'em in the jar and press "blend"?
After all, that Fender tremolo is just a LFO with a VCA; two common components of an analog synth.
Another base component is the envelope generator. With guitar, that wouldnt necessarily be initiated via a trigger signal, but you can otherwise get an envelope. I once made an envelope follower that was 2nd order, with advantages like faster attack speed, resonance and LP / HP outputs.
Fred had a "Timbre" control, and he could have used the envelope from his compressor to change from the clean signal to the single ended amp emulator output "automatically".
Unsure what the circuit would be, but I'm sure you could get a CV from roughly where you're playing on the neck, just through an analog signal analysis. That would be the (nearest) equivalent of the keyboard CV, without needing a special guitar. You could then change the tone bandwidth of the amp, chasing the spectral content of what you're playing.
Heavier would be the 'ol ring modulator effect, which is just the LFO turned up into the audible range, driving a VCA. I can imagine having that as a percussion, similar to when on a synth you tune one osc up a 3rd, followed by a fast decay, to get that Hammond sound. The percussion envelope could come from the HP output of the envelope follower. Super nuts would be to set the modulation frequency by playing a brief note on the guitar and a foot tap on a switch...
These control voltages could otherwise be used to modify the operation of the tube circuits in more subtle ways. Could have the envelope change the bias on the output tubes, such that with no guitar signal the bias decays down to cool, when you start playing it comes up to normal and playing really hard it goes to a level one wouldnt want to leave set continuously.
Unsure what the classic "sample and hold" as a CV would get you, perhaps that's a bit too far. I'm sure you get the gist of the idea. Even a '64 Princeton Reverb has analog synth elements within it. There's a lot more one could do, that I'd bet someone could weave into their playing in a musical way.
The window of opportunity for working outside with wood and power tools got slammed shut yesterday afternoon when a 4 X 4 foot sheet of thin Lauan plywood levitated off the picnic table that wants to kill me and was recovered about 1000 feet away. The cold front that brought the high winds also dropped the temperature below freezing this morning. One of two speaker cabinets was far enough along to be completed in the basement.
The amp head was built a long time ago for the HBAC challenge and has some issues. I coated the cabinet in the same "Tolex in a paint can" finish that I used on the speaker and will likely reuse it though possibly with a different front panel depending on what "guts" I wind up using.
Synthesizer circuits in the ultimate guitar amp......Yes, that's a given. The current plan is to use at least one hex pickup on the guitar, probably a stick on Roland or Graph Tech saddles in the bridge. That will feed six analog circuits to create six square, and possibly triangle (or something with similar harmonic content) waves using analog chips. A simple compartor with a floating trip point can be used to create a trigger for 12 ASDR envelope generators. Six for the VCA, and six more for the VCF. I would do most of this stuff in a microcontroller like a Teensy, because I have already done most of the work. I have two working "virtual analog" poly synths built using Teensy boards. Both were cleverly designed for 6 note polyphony. The VCFs may wind up being fully analog since only a Moog ladder filter sounds like a Moog ladder filter. A well known German company has already cloned the Model D in SMD, so I just cloned the clone.
The amp head was built a long time ago for the HBAC challenge and has some issues. I coated the cabinet in the same "Tolex in a paint can" finish that I used on the speaker and will likely reuse it though possibly with a different front panel depending on what "guts" I wind up using.
Synthesizer circuits in the ultimate guitar amp......Yes, that's a given. The current plan is to use at least one hex pickup on the guitar, probably a stick on Roland or Graph Tech saddles in the bridge. That will feed six analog circuits to create six square, and possibly triangle (or something with similar harmonic content) waves using analog chips. A simple compartor with a floating trip point can be used to create a trigger for 12 ASDR envelope generators. Six for the VCA, and six more for the VCF. I would do most of this stuff in a microcontroller like a Teensy, because I have already done most of the work. I have two working "virtual analog" poly synths built using Teensy boards. Both were cleverly designed for 6 note polyphony. The VCFs may wind up being fully analog since only a Moog ladder filter sounds like a Moog ladder filter. A well known German company has already cloned the Model D in SMD, so I just cloned the clone.
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Years ago I experimented with a GR-33 guitar synth. It could output midi into a DAW. Then the pitch, string number, and or velocity could be used to do whatever that can be done with midi. It didn't end up doing anything I really liked, although some of it could be used in a show to give different sounds from the guitar player.
More recently, I did some work on my speaker cabs. Tapped on them with my finger to see what frequency they resonated at in different spots. One cab is pine, which pretty resonant. The other plywood. Both cabs needed a lot of internal bracing to control their resonances. I used some clear maple boards from Home Depot, mabe 3/4" x 1-1/2" on their tall edge. Used maple because it wasn't expensive and its a tone wood. Well, it ended up taking a lot of bracing to get the cabs sounding the way I wanted. Then I put fender speaker cab tilt-back legs on both cabs to better hear the sound coming out of the speaker. Most recent thing has been to figure out guitar volume and tone settings that sound especially good, and the effect on guitar cable capacitance on the sound that can be gotten. Turns out for both guitars I tried, a fender nashville telecaster, and a gibson es-335 studio, a cable with about 330pf sounded better than cables with more capacitance. Best guitar tones were often with guitar pickup volume controls midway or lower, and tone controls to find the quacky tonal areas and also the very mellow jazz tonal areas. Amplifier for this is marshall 18watt clone. Speaker in the plywood cab is celestion gold 12". I will say, it sounds very good.
Why mention the foregoing in the context of this thread? Just to illustrate that sometimes its the subtle things that matter a lot, not just dramatic differences. Seems to me that other people have probably already tried making a guitar in to a synth by various means. IOW, its an idea that's not altogether new. Wondering if anyone has made interesting music that way, which is sort of to say wondering if its there is any gold in them there hills? Or, maybe its mostly just for fun. Do it because it something interesting to do.
More recently, I did some work on my speaker cabs. Tapped on them with my finger to see what frequency they resonated at in different spots. One cab is pine, which pretty resonant. The other plywood. Both cabs needed a lot of internal bracing to control their resonances. I used some clear maple boards from Home Depot, mabe 3/4" x 1-1/2" on their tall edge. Used maple because it wasn't expensive and its a tone wood. Well, it ended up taking a lot of bracing to get the cabs sounding the way I wanted. Then I put fender speaker cab tilt-back legs on both cabs to better hear the sound coming out of the speaker. Most recent thing has been to figure out guitar volume and tone settings that sound especially good, and the effect on guitar cable capacitance on the sound that can be gotten. Turns out for both guitars I tried, a fender nashville telecaster, and a gibson es-335 studio, a cable with about 330pf sounded better than cables with more capacitance. Best guitar tones were often with guitar pickup volume controls midway or lower, and tone controls to find the quacky tonal areas and also the very mellow jazz tonal areas. Amplifier for this is marshall 18watt clone. Speaker in the plywood cab is celestion gold 12". I will say, it sounds very good.
Why mention the foregoing in the context of this thread? Just to illustrate that sometimes its the subtle things that matter a lot, not just dramatic differences. Seems to me that other people have probably already tried making a guitar in to a synth by various means. IOW, its an idea that's not altogether new. Wondering if anyone has made interesting music that way, which is sort of to say wondering if its there is any gold in them there hills? Or, maybe its mostly just for fun. Do it because it something interesting to do.
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