Building a Clean Boost Guitar Pedal
ฝัง
- เผยแพร่เมื่อ 16 มิ.ย. 2024
- First delivered to my Music Production undergraduate students during lockdown, here I talk through the process of designing and prototyping a clean booster for guitar.
00:00 Introduction
02:02 Powering the Circuit
02:55 Measuring Battery Voltage
05:18 Operational Amplifier or Op Amp
09:04 Using a Potential Divider to power the circuit
16:09 Input Impedance
17:12 DC Blocking Capacitors
18:32 How the Op Amp functions in this circuit
19:58 The Maths (Gain)
23:20 Breadboarding the Circuit
34:48 Mistakes were made!
38:26 Testing with a Sawtooth
41:00 Using the Oscilloscope to Measure the Gain
43:44 Testing with Guitar
I am no expert in electronics, I remain a curious hobbyist. However, I have always been fascinated in learning how audio electronics works. Disassembling various radios as a kid and eventually becoming interested in designing and building guitar effects pedals. I attempt to understand how these systems operate electronically, and due to this approach, I have picked up a few bits of theory along the way. If you're unsure about it, my best advice is just get started, mistakes and corrections (and the occasionally popped component) is how we learn. You win or you learn
In this video I do my best to explain the simple Op Amp based booster circuit, build it on the breadboard and then test the prototype, using a mixture of my own DIY Lab test equipment, and a Digital Oscilloscope.
If you found this useful, want to correct my knowledge or want to know more about my DIY pedals and test gear leave a comment below.
Follow my other projects here:
/ beliefspacestu
If you'd like to support my channel and get some cool stickers, you can find my Etsy Store here (I'll be adding some electronics kits in the future): www.etsy.com/uk/shop/MusicTec...
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I'm making a pedal for my GCSE engineering project and this was very helpful
Excellent stuff. Glad it helped.
Excellent instruction! Very clear to follow.
Have been using pedals for 50 years! And now decided that I ought to understand them properly and your input is really appreciated. Got my first pedal kit, random parts and breadboard on order, so looking forward to diving in. No doubt will be referring back to your video(s) - just the right balance of theoretical and practical - many thanks.
Thanks, Martin. Excellent stuff. It's so rewarding building your own guitar gear. There's a fantastic community of helpful effects builders and hobbyists out there too, always willing to share knowledge and tips. Plus more videos in the pipeline from me :)
You explain perfectly; I finally understood. Thanks a lot!
Brilliant Tutorial. Very well explained. Thank you very much.
Thank you, you are a great teacher, keep on!
Fantastic walk-through! Very concise too. I thoroughly enjoyed the video. Looking forward to more. Subscribed!
Thanks. It's good to hear that you enjoyed it. There's a lot more to come.
You're amazing as a teacher
Thank you for helping me understand what the Bias voltage is !
This is an absolutely amazing lesson! This is the very first video I see in which I finally understand how translating an schematic to a protoboard works. Please keep making these type of videos!
This was an exciting video
This is great! I'd like to see some more of your creations on breadboard. Thanks for the nice info!
Awesome, thanks. I'm working on a few more sessions right now, including a Fuzz Face. Will be uploading this week.
The best tutorial to learn audio electronics. please continue with the work of education. thank you
Great video easy to understand the foundamental bases of analog electronics
Only 10 minutes in and loving the clear, thorough explanation. Not often I’ll subscribe before finishing a video, but this is one of those rare occasions. 👍
Finnaly an explanation that even I could understand. Nice and simpel. Will be watching moore of your uploads in the future. Thumbs up!
Thanks, Charlie. 😊👍
Great video
Nice presentation
Coming from someone who used to know all this but hasn’t thought about it in a decade or more - excellent clear and thoughtful explanations at a good pace. Thank you!
Thank you. Great instructions.
Thanks 😊. I planning some further videos for this OpAmp booster series too.
@@MusicTechknowledgy
Looking forward it. Signed up and spreading the word. Keep up the great work.
How did I only just find this channel?! I’ve played guitar for 30+years and tinkered with electronics on and off, but really want to get into making my own tones and sounds.
Thanks to this channel I just ordered a breadboard and component set.
I can well appreciate how much effort and thought goes into these vids, but please know you have a fantastic teaching style. The pace is perfect, the context helpful, the leaving in mistakes and among questions along the way - super helpful.
Please do more!
I am really interested in the filtering aspects at the moment. Both for within a circuit but also to create a customs EQ circuit 😊
Thanks for your contribution to the pedal and electronics community and here’s to more content. 💥💥💥
@MusicTechknowledgy I used KiCad to create a circuit board to this "Clean Boost Guitar Pedal".
If you are interested to share my circuit with your TH-cam users, I'm more than happy to share it with you. Just let me know to where should I upload (send) the circuit board Kicad project file so you can share it here, in your channel.
Stay safe.
This was perfect for someone like me who only recently started learning about guitar pedal electronics. Clearly explained and easy to follow - thank you!
Thanks, Bruno.
awesome
Top video
Please making electronics loop recorder 👏👏👏
Hello. Thanks for the videos. That is excellent for who wants to initiate in the diy pedals and amps. What kind of signal chain have you? The guitar straight into circuit and to the amp? What amp, the clean sound is very good.
Hi Luis, Thank you very much. In this video, I'm going from a telecaster into the circuit to my own small DIY amplifier I use in the lab! It's based on this circuit: www.runoffgroove.com/ruby.html I might make a video about it at some point. In the meantime, happy DIYing :)
Excellent vid! Where would a tone control fit in this circuit?
Hi Peter, Thank you. To answer your Q -- In this simple version (check out my other video for an improved version), I would place the tone control at the end, for example...
If you were to use a passive Resistor, Capacitor circuit, e.g. a tone stack (like that used in the EHX Big Muff), I would place this at the end and then adjust the gain of the op-amp circuit to compensate for the volume drop associated with the passive tone controls.
On the improved circuit, we would probably add an active tone control, after the boost (gain) stage using a second OpAmp. Like that used in the Ibanez Tube Screamer.
Tone controls are a great topic for some future videos in this series.
Would you be able to give instruction on how to add a gain control knob?
Hi Aaron, a volume knob can be added to the end, like this: th-cam.com/video/h-hEsnyuICU/w-d-xo.html
A gain control could be implemented more like the MXR Distortion+ circuit, found here: www.electrosmash.com/mxr-distortion-plus-analysis
OpAmp clipping, is the topic of a future video.
@@MusicTechknowledgy Thanks for the reply! I've only made it onto the troubleshooting video, so sorry about that 😅 And I wasn't aware that gain meant it was for distortion. I was saying it in reference to volume
Amazing Lesson. Really good job explaining everything step by step. I still have one question. You explained nicely the purpose of the 100 nF at the start of the circuit, but what purpose do the 10 uF capacitors serve for both the output and the other potential divider?
Thanks. The 10uF at the end is another AC coupling capacitor, it lets the AC signal through but blocks DC from getting onto the output. The other 10uF forms a high pass filter with the 100k resistor, filtering very low frequencies to the ground (roughly everything below ~16Hz) and letting any high frequencies through. The idea is to remove any low frequencies that might overload the OpAmp or cause hum or instability.
I suggest:
1. It is better to add a 0.1uF-1uF capacitor to the LM741 supply rail. Capacitor's pins connected as close as possible to pin 4 and pin 7 of LM741. The addition of a capacitor will solidify the output sound.
2. You can replace R1 to 12k and replace R2 to 47k. Reducing the value of R2 will reduce the noise. Gain will increase to about 5 volts/volts.
3. It is better to apply a 100-470 ohm resistor in series with the 10uF output electrolytic capacitor to ensure that the LM741 is stable.
4. It is better to try another several types of IC to replace the LM741. I suggest trial with CA3130, CA3140, LF351, LF355, LF356, LF357, LM301, LM318, NE5534, TL071 etc to get a sound personality that suits your art personality.
I'm a technician and I can't live without art.
Thank you
Excellent stuff. Thanks for taking the time to make these suggestions, they all make sense in improving the circuit. Some of those changes are already implemented in my Improving a Clean Boost video: th-cam.com/video/h-hEsnyuICU/w-d-xo.html Always learning.
What i don't understand is does a clean boost same as preamp. And how to make this circuit as a preamp, i want to attach on first stage guitar amp if possible. Thank for your explanation.
@@thesounddistiller preamp has 1 volts/volts (0 dB) gain. You just need to connect pin 2 to pin 6. Don't need R1, R2 and first 10uF anymore.
Try OPA134.
@@thesounddistiller Yes, in essence, it's the same thing. You could combine this with a power amp, to create an amplifier. If you want to add a gain control, check out the circuit for the MXR MicroAmp, it's similar but uses a combination of a potentiometer and resistor to control the gain, rather than having a fixed gain like this circuit.
This is a really great video, and I’m definitely going to run through this build.
I’m wondering if you wanted to add a potentiometer to adjust the boost, where would it go?
Thank you!
Thanks, Brad. Add a 10K (or similar value) between the output capacitor and the output jack. This approach attenuates the boosted signal, it's used to retain clarity in the circuit.
You can see a schematic diagram of this mod on the original circuit, at 4 seconds into: th-cam.com/video/h-hEsnyuICU/w-d-xo.html in my improving a clean boost pedal video.
@@MusicTechknowledgyamazing! Thank you so much!
I’m starting to understand breadboards but I’m having trouble understanding how to transfer them to a strip board for permanent small build. A video transferring this circuit to a stripboard would be very helpful! Thanks for your videos!
That’s a great idea. Thanks, Kevin.
I have that same problem lol. I’m up to three failed LPB-1s
@@majordabalert That sounds frustrating. One of the vey first circuits I did a transfer to stripboard on was a modified Phase 90, took me two weeks to work out that I’d mis-wired two components. I’ll get working on that video 👍
I'm working on this right now. One of the next videos.
@@MusicTechknowledgy dude how funny. I’m still trying to get an LPB-1 to work lol. At least my solder joints are starting to look cleaner
Brilliant video, very engaging. Would you maybe do a video on your triangle generator?
Thanks. Yes of course. It will be a more advanced one involving current sources, diode switches and comparators.
@@MusicTechknowledgy Ace, looking forward to it.
@@tziirkq Just uploaded it. Thanks for the idea 👍 and sorry for the 10-month wait.
@@MusicTechknowledgy 10 months is nothing. Thanks for your hard work!
Using a A500k pot in place of R2 should give me a volume knob with plenty of gain on tap. To my understanding, I would simply replace the connection on R2 with lugs 1 and 2 and then wire lug 3 to ground. will that give me the proper rotation direction or would it be the other way?
Hi Chris, Yes, you're right, replacing R2 with a pot would work, similar design to a ProCo RAT circuit. What you describe here is a voltage divider (with a ground connection), what we need here is a current divider. To achieve this wire lug 1 on the input side of the OpAmp and lug 3 on the output side, then with lug 2 to lug 3. I think I have that right. That way when the maximum resistance is reached when the pot is turned entirely clockwise.
I tried to build a buffer pedal on some of the solder boards with copper traces around each hole and never could get it to work after 5 or 6 tries LOL. I was using a TL072, iirc. Whatever the Klon Centaur buffer uses. I think I even tried it on breadboard but couldn't get it to work.
Sounds like a matrix board with the copper in a circle around the holes? Good prototyping board. It can be frustrating getting circuits to work, I've probably spent longer troubleshooting over the years than anything else, but as irritating as it is when it doesn't work, it's invaluable experience for future projects. The Klon Buffer does use a TL072 (one side of it anyway) set up in a voltage follower configuration to buffer the signal (Gain of 1, e.g. no boost). Looking at diagrams for the Klon Buffer, you do need a bias voltage of 4.5 volts, it often doesn't show the voltage divider used to achieve this. Also, bear in mind that the TL072 had two OpAmps so the pinout is different to a TL071 for example.
Trying to give into schematics and understanding currents after building pedals for about 5 years (not my PCBs). Your videos are very helpful and easy to watch. I was wondering if you could help clarify what reason to use which resistor values when dividing voltage? For example why is 2m2 used, instead of 1m, or any other? I’m sure you covered this but am still trying to understand. Cheers!
Thank you and yes. In this circuit, the input impedance is largely set by the divider. We can use AC circuit analysis to calculate it. Here we can consider it to be 2M2 in parallel with 2M2 which gives us 1M1 or approximately 1 Megaohm of input impedance. There is also a more detailed explanation about the divider and current draw in my next video Improving a Clean Boost Pedal: th-cam.com/video/h-hEsnyuICU/w-d-xo.htmlsi=CydSNRI05-U-1-Hs&t=1985
@@MusicTechknowledgythank you for the reply!
what amp are you using? the sound is clean and great. Is Diy too?
Hi Luis, Thank you very much. In this video, I'm going from a telecaster into the circuit to my own small DIY amplifier, you can see it at the top of the screen at 43:56 in the green box, the speaker is oval and recycled from an old Theatre intercom system. It's based on this circuit: www.runoffgroove.com/ruby.html I might make a video about it at some point. In the meantime, happy DIYing :)
Great video! Question: I can use any value for R1 and R2 of the potential divider (2M2 in your circuit)? If I use two 10M resistors in order to get a 5M input impedance, that would be OK?
Thanks ROD. Great question. I felt like I was "pushing it" with 2M2, it is more common to see K ohms used with Op Amps. Although the voltage remains the same, V=IR means that as we increase the resistor values, we are significantly reducing the amount of direct current flowing into the non-inverting input. This will affect the gain of the circuit. Having said that, I learned electronics by building circuits (and then later trying to apply theory) so, personally, I would experiment with it, it will likely be okay with the low gain and in the audio frequency range.
I added a tone knob at the output and I cannot get anything to work lol. Need some help
Correction volume pot not tone
@@bso6371gt Great stuff on the volume pot addition. Let's see if I can help. Was it working prior to the volume addition? Check the OpAmp is not getting hot, it should stay cool.
@@MusicTechknowledgy no. It’s not working with or without the vp pot. It will just hum. The hum calms down a little when I touch the strings but I get no guitar sound. I’ve checked everything over and over. I’ll just keep checking I guess lol
I want to create my own pedal
What does the 10uF cap do (the one in series with R1)? I built this circuit and removing it completly mutes the signal
Great question. As R1 and R2 form a voltage divide for the AC signal we need to reference AC ground. However we don’t want to reference the DC ground here, otherwise we’ll get no signal (muting the signal). Therefore we can effectively block the DC ground using a capacitor. So the end of R1 “sees” AC ground not DC ground. Like all electronics, the AC analysis is actually more complex but that’s a good way to think about it in this circuit.
A quick question about the voltage divider: When you decide and set the values of the voltage divider, choosing the 2M2 ones (instead of let's say 2x 1M) is to control the amperage into the op-amp?
As no matter what size of resistors you would put in the circuit, it would always divide the voltage in half, as long as the resistors are the same? Or calculate the sizes of the divider if there's another circuit outside this circuit on higher voltage, but that one is powering that circuit (if that makes sense) for instance to get the voltage right and aswell as the amperage?
Great question. I'll try and answer. I choose 2M2 to help set the input impedance to about 1M1. Yes, you're right, if the resistors are the same value and you use two, in this configuration, it will half the voltage. We are doing this to allow the AC signal to "swing" around 4.5volts. There are other methods we could use, such as two batteries to create + and - 9 volts. In the Improving an OpAmp video, we change we way we achieve this and I explain in more detail.
@@MusicTechknowledgy Brilliant, thank you for a good and well explained answer :)
Another question: Will you be making more videos? Yours are one of the best ones and best explained I've seen on youtube
Hi, can a volume control be added to this circuit so that you can blend in the amount of boosted signal? If so what type of potentiometer would be best and where would it go? Thanks
Hi John, yes you can. On the output, after the capacitor. Log(A) has the best audio response but linear(B) will work well here too. The value with roughly set the output impedance . My Improved circuit used a 470ohm resistor in series with a 10K linear potentiometer to set the output impedance. See here: th-cam.com/video/h-hEsnyuICU/w-d-xo.html&si=DDpBmRknXA2Uys-j
@@MusicTechknowledgy thanks for the fast reply. Very helpful as always. John
For their Radius mandolin pickup, LR Baggs recommends users plug into a preamp with an input impedance of at least 2.2 M ohm impedance. If I wanted to build a boost pedal to accommodate my mandolin pickup, do I just replace those 2M2 resistors with 4M4 resistors (or better)? Do I have to make changes to anything else in the circuit?
Hi. The quick answer is yes you can. The reason is that theoretically, the OpAmp doesn't draw any current.. In reality, it draws a little of course, but it so small that it makes no difference to the operation of the circuit. If you will use this project a lot with your mandolin, I encourage you to watch my Improving an Op Amp Booster video, where I discuss the enhancement you would make to a commercial version. I also discuss input impedance in that video at this timestamp (39m17s): th-cam.com/video/h-hEsnyuICU/w-d-xo.htmlsi=oM8JyCXD4SkdjF2L&t=2358 The MXR MicroAmp uses the same topology as that improved version and uses 22K and 10K as the input resistors raising the Zin to 6.8M ohms. I hope that helps, Stu.
@@MusicTechknowledgy This is very helpful! Thank you! It does lead me to another question though... Looking at MXR's manuals for the Micro Amp and Micro Amp+: Both manuals list the input impedance as 1M ohm. Is it 1M ohm, or 6.8M?
Is this the sort of thing where a company (such as Line6) says a pedal (say, the HX Stomp) requires a certain amount of amperage (3A), but in reality the pedal uses quite a bit less (850-890ish)?
(I'm learning here and I'm just asking questions about things I don't yet understand. Thanks for your help!)
@@JETallacksen Great question and I see what you mean about the manuals. It may be that modern versions have a lower Zin.
I’m pretty sure the original circuit was 6.8M ohms. There’s a great analysis by ElectroSmash here: www.electrosmash.com/mxr-microamp
Having said that, you can actually measure it, with a little bit of effort and some test gear, which I will later, and report back.
Also, this gives me a great idea for a future video :)
I built the Electro-Harmonix? LPB boost pedal on my breadboard for my 1st boost pedal. I also did a fuzz face on breadbaord from smallbear since they have a step by step breadboard page to follow.
That was like 3 years ago and I still have both of them lol. I also ordered those same boards and built the NPN board. Mine came from the UK. I need to order another set of them since I'm much better at soldering now. I even bought an enclosure to put the board in and mount the jacks and knobs and switch. When I got it in the enclosure, it didn't want to work so I just put it aside.
LPB is a Transistor-based Common Emitter Amplifier Circuit. Great booster and one of the excellent 'building block' circuits that you'll spot in all sorts of drives, distortions and other gain pedals.
Thanks for checking out my content and commenting, always great to read these and see what others are building.
Question! I don’t have a 220k What could I replace it with? Thank you. I love this video. I actually understand most of your teaching.
Thanks, Greg. You can replace it with another resistor value. Reducing the value decreases the gain and increasing the resistor value will increase the gain. For example using 100K, you'd have a voltage gain of 2, that's 6dB. If you used a wire instead of resistor, you'd get a gain of 1 or 0dB which is a buffer (what goes in comes out without being amplified). Hope that helps.
@@MusicTechknowledgy Thank you man! I added a 500k v pot bc that’s all I have and when i run it to my amp all I get is hum. Even skipping the v pot and going direct with everything turned down I still only get hum.
@@bso6371gt Ah, okay. Sounds like a ground is not connected somewhere, that would cause that type of hum. First thing to do is check all the grounds -- circuit, in/out jacks and and battery's negative terminal are all connected.
@@MusicTechknowledgy All of the grounds are connected to the breadboard. But they aren’t very tight. I’m looking for a thicker wire to install then put my alligator clips on to that bc they aren’t secured very well.
@@bso6371gt How are you getting on? Did you get it to work? Your questions inspired me to make this new video about troubleshooting this circuit: th-cam.com/video/EJzrh2mSOqI/w-d-xo.html
hey can anyone explain to me how could i connect jack from the amp to the circuit (to the breadboard) , any inverter connector equipments or any other way to connect jack(from the amp) to circuit and to guitar
Using two TS (Tip Sleeve) Jack Sockets. Input jack tip goes to the input (100nF) capacitor and the sleeve goes to ground (make sure all grounds are connected, battery and audio). Output jack, tip is connected to the output capacitor (10uF), and the sleeve goes to ground again. Then simply use the same cabling that you would for any effects pedals, guitar -> jack to jack -> breadboard -> jack to jack -> amplifier.
Replace R2 (220k) with a 330k to make it "one louder".
@@MusicTechknowledgy thanks a lot man
Great Video! But i think the second capacitor is actually the wrong way around! Its negative lead is connected with pin 6 of the op amp, and the positive one goes to the output. It should be the other way round i think. I wonder how the circuit is still working
Very well spotted and completely correct. It's correct in the schematic and then plugged it in the wrong way around. I even talk about that in the subsequent Troubleshooting Video but didn't spot it here. Luckily my 16v rated cap is not that fussy with 4.5ish volts on the wrong terminal, as (*see below comments) there is not enough current to cause a failure. However, as you point out, we should always connect positive lead to the higher DC potential. Great spot, thanks. I will add a note to the video.
@@MusicTechknowledgy you're welcome :) i didnt knew an electrolyric cap would work the other way around as long as the voltage of the cap is high enough, thanks for letting me know ;)
@@GuterSchenkel23 No, they don't, I am wrong, and apologies that my comment was very misleading. I was only hypothesising about my circuit, because you asked why it still works. I am only suggesting why that might be, in this circuit because, as you can see in the video, it did still work with that unnoticed error. It very likely would fail if it was left it on long enough. I would have immediately corrected my mistake if I'd noticed it at the time. Also, in a higher voltage circuit, and this is very important, they can and will explode (reverse or over voltage).
Actually, I don't know why it still worked but I will find out.
Okay, after messing around with it on EveryCircuit simulator, I believe it because there's no current on the op amp output, going into the capacitor. I will measure it later. If I'd put a pulldown resistor to ground after it, it would have been a different story. Thanks for keeping me on my toes.
When you put the first two resistors on the breadboard. How come the one end is in row 5? and the other is row 4. Does that matter?
Very sharp eyes. I had to watch it again to check. No, in this case/configuration it doesn’t matter. It would only matter if it was in the same row on the same side.
Thanks for the reply@@MusicTechknowledgy
I can only find the IC TL071CP. Is it fine also, right?
Yes, absolutely. TL071CP will work.
@@MusicTechknowledgy Much appreciated.
I'm going to assemble 4 units of this.
I was searching exactly for clean DIY pre-amp for electric guitars.
The idea is to save the electric guitars on a DAW using DI-Box (passive), so, a clean pre-amp is really needed for this. The guitar FX (distortion or any other FX) are applied in post. You have no idea how opportune this project is for me.
Thank you very much. Stay safe.
So R2 is always going to be in the feedback network?
As labelled here, yes my R2 is in the OpAmp's negative feedback path. However, you can make a voltage follower (aka buffer) by having 0 ohms (just a straight wire) in the feedback path (you would also need to remove R1 and 10uF in that buffer circuit)
I should have added in the db calculation. The feedback network resistor is always on top.
@@Ebo838 Yes, that's right, in this case R2. So, Gain in dB = 20 x log (1+(R2/R1)). Therefore increasing R2 or (decreasing R1) increases the gain.
Based on the calculation on 23:12, to make the boost pedal to 20db i just add the value of the R2 correct?
Yes. That’s correct. Adjusting the ratio of R1 and R2, will change the gain.
At some point it will clip the OpAmp but it takes a lot of gain to do that.
@@MusicTechknowledgy when it does clip, it'll start to distort the sound correct?
@@yngwieisaac7920 Yes. However, the MXR Microamp is very similar and clean boosts up to just over 20dB. In that circuit, a potentiometer and resistor are used for R1 allowing the gain to be adjusted. Great article on it here: www.electrosmash.com/mxr-microamp
@@MusicTechknowledgy thanks for the info🙏🏻 your video is very helpful too
Is there printed circuit board available?
Hi Jeff, I’ve been working on it in the background. I will also do a “build along” video once it’s ready.
Hello, i need your help.
I have a black star Id core v 3 20 watts solid state amp, can this pedal fry it? If I put a 10 k resistor at the output of the pedal, 2 1n4007 diodes in opposite polarities parallel which connect the output to ground and then a 10 k pot voltage divider, whose middle pin gets connected to the amp, will this fry it? What if I also use a 10 k resistor instead of the 100 k one at the inverting side of the opamp and a 100 k pot instead of the 220 k resistor? I am trying to build an overdrive pedal and I am wondering if it's safe .
Please help me, i already spent some money buying the components and I have just thought if this can fry my amp.
What you’re attempting to do there sounds a lot like a MXR Distortion + circuit. Have a look for the schematic online it will help answer all of your questions. This one has a good explanation: www.electrosmash.com/mxr-distortion-plus-analysis
@@MusicTechknowledgy Thanks! So if I make your booster it won't fry my amp, right?
I've never known a properly wired guitar pedal circuit, running from the correct voltage supply to "fry" a properly maintained amp.
I've built many, many pedals over the years and none of them have had any adverse effect on any of my amplifiers (Tube and Solid State).
However, I cannot tell you for sure as I don't have enough information on all the potential variables.
What I will say is, if it's all properly implemented, it's extremely unlikely that it will "fry" anything. However, personally I always test my builds on a low power DIY amp (the one in the video) before trying them on a more expensive amplifier, that way if anything adverse happens, I can easily rebuild it.
@@MusicTechknowledgy Thank you, i will be careful and maybe check the output with an oscilloscope.
I think I will make a 10 k pot voltage divider so i start from 0v and get up to a comfortable level, so i don't fry anything.
I really want to say that you are great! You are the only one in TH-cam who has made me understand the circuits and even answered my questions. Keep it up👏👏
@@MusicTechknowledgy I tried it, after adding the hard clipping diodes and the potentiometer. It sounds absolutely great!
Now I am couriouos: Why didn't you put only the 4.5 volts with no guitar in the non inverting input. I have watched Greatscott's video on opamps and I am really confused. I, and I think many more, would greatly appreciate an in depth oxplanation of the opamp part, because you talked about resistors and capacitors but not how the opamp itself works. You are a great teacher and I believe you are the only person who can make me understand this stuff. I have watched far too many videos on opamps and still don't understand it, their thinking is contorted but you are absolutely brilliant.
Is this the same thing as in a Pre-amplifier?
Hi Roberto,
Yes, it is (OpAmp-based pre-amp, you can also do a similar thing with transistors).
This one is adapted for Guitar (Instrument) level signals, with a high impedance input and low impedance output, running from 9 Volts. The circuit can be adapted for other types of signal (e.g. line, mic, etc.)
@@MusicTechknowledgy thank you! I have one more question, when using the Gain formula how do you determine how much gain is needed?
@@robertonunez6626 That is an excellent question.
A great example is the MXR Micro Amp. This is a clean boost redesign of the Distortion+ .
The Distortion+ has a massive max gain setting (about 200 or 46dB) driving it (and some clipping diodes) into distortion.
By comparison the MXR Micro Amp, designed as a clean boost has roughly a maximum setting of 20 voltage gain (26dB).
From experience, I know most Booster pedals have between 10 and 20 voltage gain. The LBP-1 is a Transistor (Common Emitter Amplifier) circuit and has roughly x20 voltage gain also, like the Micro Amp.
We usually add a potentiometer at the end to attenuate the boosted signal to give us more control over the output. I do this in my improving a Clean Booster video with a 10K pot at 48m03s.
@@robertonunez6626 A potentially longer and more complex answer is to design for the input of the next electronic device in the chain. HiZ (guitar or instrument) will present a high impedance usually 47K to well over 1M ohm, whereas a Line Input will only present about 10K ohms. So we then design the circuit for its specific application. Guitar Amplifiers and Pedals are all HiZ inputs (unless they specifically have a labelled line input).
Very clear video. Kudos - What would be power drain.. how long will the 9 volt battery last
Thanks :) It’s a simple circuit so the current draw will be minimal, a better should last a while in this one. I’ll measure it later and then we’ll be able to work out the power consumption using ohms law.
@@MusicTechknowledgy Thank you - do you think about 4 to 5 hours ?
@@PremiumExcelcom This circuit should only draw a few milliamps due to the large resistors in the voltage divider (I = V/R = 9v/2M2 = 4 microamps across each resistor) and the nature of OpAmps (TL071 quiescent or standby current is from about 1.5mA to 2.5mA). Even if the circuit's current draw was might higher, say 100mA (0.1 Amps), a decent 9v battery (rated at 500mAh) would give you 5 hours. Given by this formula (and assuming ideal conditions): Battery life (in hours) = Battery Capacity (in milliamp hours) / Current Draw (in milliamps)
However, bear in mind other factors will affect this, such as the battery voltage decreasing during use. This means that the circuit will no longer operate optimally before the battery depletes. Additionally, humidity, heat and other environmental factors can play a role in battery depletion.
So, as you already suspect, a few hours of optimal circuit performance is likely to be correct for your application. The only way to know for sure is to test it.
Bro for this circuit can we use TL072 or do we need to use only TL071?
You can indeed use half of a TL072 just be aware, when wiring, that the pin outs are very different as the TL072 has two op amps in one IC whereas the TL071 has just one.
@@MusicTechknowledgy Thank you very much
@@MusicTechknowledgy Thank you Bro.. - I finally create a buffer and boost - Thank you for saving $400 to $500 or more..
For the Distortion can we have a buffer in the front and in the same op amp use it for clipping.. - will the impedance have impact on distortion.. 'cos some pedals like Boss ds1 have buffer before and after gain stage..
@@PremiumExcelcom My pleasure. Check out my two other videos on: th-cam.com/video/cHD6klQwovE/w-d-xo.html this one covers clipping stages and, if you want a more robust version of the buffer, also check out the improvements video here: th-cam.com/video/h-hEsnyuICU/w-d-xo.html
You can absolutely cascade one circuit into the other, to have buffer stage then clipping stage and then another buffer stage if required. You can also use a transistor (FET) based buffer for a different sound, I'll cover those in a future video. You can also adapt one OpAmp stage for an active tone control too (Tube Screamer style)
@@MusicTechknowledgy Perfect Bro.. Thank you ..
Please making electronics loop recorder 👏👏👏