Hi, great videos and great project, you see a lot of completely wrong videos on how to connect your guitar to a phone or tablet, and they completely ignore the 2.8v dc ....which is noisey as hell....so good job man.
OMG! I think building an iDevice guitar interface myself is awesome but you can even improve its tone quality!! You're genius and I love your videos so much! They're useful~
Thank you so much from latinamerica. You have this amazing a simple easy way to explain things, especially electronics, here turn to be to expensive to buy an Irig.
Thanks a lot for the great videos! I followed your schematic and used a bf245c and it works great! Good job on putting it in such a small box. I put everything in a 5x3.5x2.5 cm box so I'm very satisfied :-)
i know im asking the wrong place but does anybody know of a method to get back into an Instagram account..? I stupidly forgot my account password. I would love any tricks you can give me!
@Adan Jayce Thanks so much for your reply. I found the site thru google and im in the hacking process atm. Seems to take a while so I will get back to you later when my account password hopefully is recovered.
First off, Excellent video. Thanks for all your hard work putting this 3 part series together. I wanted to ask you a question, I'm looking to record only audio from the line output of my DJ Mixer going into my iphone headphone jack when recording video. Basically like the (Line In Headset Buddy which is a $22 device) My question is: do i need a resistor between the sleeve which = iphone mic and ring 2 which = ground to make this work? I know what cable I need, but not the electronic components needed to fool the internal mic of my iphone and trick it by recording the audio line out of my mixer. Any help would be greatly appreciated.
You could use the same circuit shown here, but with changes to the resistor values. A line level input expects a low impedance, so set R1 to something like 10k instead of 1M. A line level is around 2v. Experiment with R2/R3 until the signal avoids clipping/distortion. A google search turned up another circuit example: gmondada.wordpress.com/2017/03/28/using-ipadiphone-headphone-jack-for-audio-input/
Hi John i was planning to build a piezo pickup preamp and had already bought some JFET when I saw your video and decided that an iDevice preamp might be more fun. It took me a while to understand that the ground from the iPad needs to ground the circuit but that's probably just beginners idiocy and your tutorial could not have been more verbose. The weird thing I encountered was, the guitar sounded really out-of-tune. No amount of tuning could fix the offness of certain tones up and down the fretboard. I put a 1microF capacitor on the drain and the detuning disappeared. I had no diodes on hand so I left them out. Do you think the diodes in your circuit are de-oscillating the input from guitar? I had to use Toshiba 2SK369 as no other JFET was available here in Germany. I can really recommend them. The low noise is spooky. Nothing comes through the preamp until you touch the strings of the guitar and then there's so much signal it's too much for the headphones. I used my studio monitor instead. Thanks for the great tutorial. Phelim
Hey there- I can't imagine the zener diodes would have any effect on this. They are purely there as static discharge protection. I'm glad you experimented with the circuit and were able to get a satisfactory result. Nice work!
Thank for this nice instructional vid. I was wondering if your circuit design can be used for pc as well without any modification? or if not, can you design something similar for pc. like having minimal parts and requires no extra power source. I wanted to build one for pc but all of the circuit designs I found requires extra power from a 9volt battery. Can you help me please. Thanks
I really like your videos and find your knowledge of electronics fascinating. I know this is an old video, but i have a couple of questions, and was hoping you could provide an answer or two. My first is if this could be used with a computer, only using a separate headphone and mic cable. My second is if, instead of adding a permanent 10K resistor to the circuit, could a 25k trim pot be used instead to vary the resistance for different output pickups and also add some more headroom to the circuit. I use both single coil and humbucker pickups and, although turning the input volume up on the amp sim is easy enough, I think that might be a good tweak to the circuit.
This circuit requires a voltage to be provided from the the host jack, to power the FET. If your computer has a line-out, then it won't provide the required voltage. A trim pot would be fine instead of the fixed resistor, except that it will require a separate project box, rather than fitting inside the plug.
Yea, I'll have to test the mic jack on my soundcard to see if it supplies any voltage, if not could it be powered by 2-3 AA or AAA batteries? And I realize it wouldn't fit in the jack, I intended to use a seperate box for it. But with the trim pot, would it work like the volume on the guitar and suck out some of the brightness?
Drew Webster - no this trimpot would not be wired like a volume pot and wouldn't affect brightness. Take a look at Tillman's preamp designs for ideas on powering the circuit with a battery.
hi john great tutorial and i'm reallly super intrested to build one on my own... well i'm still preparing the component and i have a question about the zener diode since i'm not good at electronic component... is it 5 or 6 V on both of the diode or is it the value of each diode so the total of 2 diode will be 10 or 12 V... and um when i try to buy, the sales asked me whether it's 1W or 0.5W... i'm really sorry for my lack of knowledge but your help will be truly appreciated...thanks
hi john, MPF102 is difficult to find here in my area.according to your schematic, i can use 2N5457 as a substitute which luckily the shop here have some stocks left. what will the value of R2 if I use this kind of JFET? I need help pls. Thanks for your wonderful tutorial. cheers!
See the discussion in the comments at my blog: www.planetz.com/simple-jfet-preamp-for-an-idevice-guitar-interface. Some people had luck with R2 between 10 and 30k with the 2N5457. You could experiment with a 50k trim pot until you find a value that works well, then measure it and replace it with a comparable resistor.
I doubt there will be the necessary voltage on the output of your pedal. Unlike a laptop or computer, a guitar pedal isn't expecting a microphone/headset to be plugged in.
@@johnplanetz thanks for your reply, ive ended up making a modified irig circuit, which kind of works, but had to add a dpdt switch for record and playback to avoid dc crackle on the record level pot.....a work around, i just need to record vid, audio on a tablet.....cheers .
Hello sir, i am VERY inexperienced with electronics so i may sound a bit dumb here but while digging around i came across a bag of BC337-25 transistors. i looked up the data sheet and have no idea what i'm looking at but was wondering if it would be possible to use it for this preamp if the other parts were modified to work with the BC337-25?
Hi John. Thanks for sharing your knowledge and helping all of us less experienced musicians. I'm hoping you can help me with a simpler cable. I want to run a cable from my guitar to my cell phone , but only for tuning. I won't be using my cell for recording so I hope i really don't need the cable you showed in your video. Any suggestion for me ? Thanks and have a great weekend. : )
+Rik J. Smith - yes tuning should work fine without buffering. That's what the Griffin GuitarConnect cable is. If you want to make your own, you just need a TRRS male plug, and 1/4" male plug for the guitar-side, and connect the appropriate leads - as shown in part 1 the video: ruclips.net/video/p1T8QmQowVQ/видео.htmlm46s
Are your Zeners Flipped? The schematic you drew has cathodes facing away from each other and it seems you have cathodes facing each other on the circuit. Does it matter? One of the diodes is going to get activated with anything over .7V, meanwhile the other will still wait for the reverse breakdown voltage. I know it's a failsafe for static discharges, just wondering if the orientation matters.
A line level signal may be too hot and can clip, especially if it exceeds the zener breakdown voltage of the esd diodes.
10 лет назад
thanks a lot for this great tutorial. but i couldn't made this i think. o i used wrong transistor. the seller give me F254C fet. he said "i do not have MPF102 but F254C is the same with MPF102" is that right? the pin structure of F254C is D-S-G while the structure of MPF102 is G-S-D.
The JFET in this circuit requires power. If your laptop has a powered mic input, it might work. But not if you only have a line-in. Check the input with a multimeter to see if it carries a DC voltage.
If the computer's 3.5mm jack has a voltage (to power an electret mic) ,then this same approach would work. Test the jack pins with a multimeter to determine what's available.
I haven't tried, but you should be able to do this without circuit modifications: amp send to preamp mic input to ipad/iphone processing to preamp headphone output to amp return. You may find it too noisy- but you could try.
i'm not into electronic components, but i found a circuit and it comes with a resistor(the R1 from your circuit) of 39k instead of the 1M that you put in your circuit, do you think 39k is enough? these are the resistors in the order of your circuit, R1= 39k, R2= 1.2k and R3= 4.7k and they also use the MPF102. and these are the values of the caps 22nf, 100nf and 470pf. here is the circuit guitar-gear.ru/forum/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=16412
A higher resistance would be better for R1, to make this a high impedance input. A lower resistance to ground will excessively load your passive pickups, causing treble rolloff and a dull sound. Try it and see!
+Julien Ghanimeh - I guess it will work, since the voltage to drive an electret mic is standard. But I don't have an android device to try. The only way to know for sure is to measure the voltage at your jack using a multimeter.
Hi, great videos and great project, you see a lot of completely wrong videos on how to connect your guitar to a phone or tablet, and they completely ignore the 2.8v dc ....which is noisey as hell....so good job man.
OMG! I think building an iDevice guitar interface myself is awesome but you can even improve its tone quality!! You're genius and I love your videos so much! They're useful~
I 've never really had any interest in plugging a guitar into an idevice but if that amplitube app is free I'm definitely building one of these.
yes! you're back. missed your vids!
Thank you so much from latinamerica. You have this amazing a simple easy way to explain things, especially electronics, here turn to be to expensive to buy an Irig.
@Erik Henriksson - the MPF102 is the JFET I used in my circuit
@johnplanetz awesome. cant wait for part 3. I'm going to go to radioshack and then find my ipod touch.
+1 the coolest dude on youtube!
I don't seem to find the transistor you used.
Could you point me out some alternatives that might work?
Great vid. How about a vid showing how to build a Stratoblaster with a JFET that goes under a flat plate jack like with see on Alembic's site?
Thanks a lot for the great videos! I followed your schematic and used a bf245c and it works great! Good job on putting it in such a small box. I put everything in a 5x3.5x2.5 cm box so I'm very satisfied :-)
i know im asking the wrong place but does anybody know of a method to get back into an Instagram account..?
I stupidly forgot my account password. I would love any tricks you can give me!
@Darius Aarav instablaster :)
@Adan Jayce Thanks so much for your reply. I found the site thru google and im in the hacking process atm.
Seems to take a while so I will get back to you later when my account password hopefully is recovered.
@Adan Jayce it did the trick and I now got access to my account again. I'm so happy:D
Thank you so much you saved my account :D
@Darius Aarav You are welcome :D
you're the coolest dude on youtube.
First off, Excellent video. Thanks for all your hard work putting this 3 part series together. I wanted to ask you a question, I'm looking to record only audio from the line output of my DJ Mixer going into my iphone headphone jack when recording video.
Basically like the (Line In Headset Buddy which is a $22 device)
My question is: do i need a resistor between the sleeve which = iphone mic and ring 2 which = ground to make this work? I know what cable I need, but not the electronic components needed to fool the internal mic of my iphone and trick it by recording the audio line out of my mixer.
Any help would be greatly appreciated.
You could use the same circuit shown here, but with changes to the resistor values. A line level input expects a low impedance, so set R1 to something like 10k instead of 1M. A line level is around 2v. Experiment with R2/R3 until the signal avoids clipping/distortion. A google search turned up another circuit example: gmondada.wordpress.com/2017/03/28/using-ipadiphone-headphone-jack-for-audio-input/
Hi John
i was planning to build a piezo pickup preamp and had already bought some JFET when I saw your video and decided that an iDevice preamp might be more fun. It took me a while to understand that the ground from the iPad needs to ground the circuit but that's probably just beginners idiocy and your tutorial could not have been more verbose. The weird thing I encountered was, the guitar sounded really out-of-tune. No amount of tuning could fix the offness of certain tones up and down the fretboard. I put a 1microF capacitor on the drain and the detuning disappeared. I had no diodes on hand so I left them out. Do you think the diodes in your circuit are de-oscillating the input from guitar?
I had to use Toshiba 2SK369 as no other JFET was available here in Germany. I can really recommend them. The low noise is spooky. Nothing comes through the preamp until you touch the strings of the guitar and then there's so much signal it's too much for the headphones. I used my studio monitor instead.
Thanks for the great tutorial.
Phelim
Hey there- I can't imagine the zener diodes would have any effect on this. They are purely there as static discharge protection. I'm glad you experimented with the circuit and were able to get a satisfactory result. Nice work!
Thank for this nice instructional vid. I was wondering if your circuit design can be used for pc as well without any modification? or if not, can you design something similar for pc. like having minimal parts and requires no extra power source. I wanted to build one for pc but all of the circuit designs I found requires extra power from a 9volt battery. Can you help me please. Thanks
Hi johnplanetz, do you show the values of the resistors which you use in the video? Thank you in advance.
I really like your videos and find your knowledge of electronics fascinating. I know this is an old video, but i have a couple of questions, and was hoping you could provide an answer or two. My first is if this could be used with a computer, only using a separate headphone and mic cable. My second is if, instead of adding a permanent 10K resistor to the circuit, could a 25k trim pot be used instead to vary the resistance for different output pickups and also add some more headroom to the circuit. I use both single coil and humbucker pickups and, although turning the input volume up on the amp sim is easy enough, I think that might be a good tweak to the circuit.
This circuit requires a voltage to be provided from the the host jack, to power the FET. If your computer has a line-out, then it won't provide the required voltage. A trim pot would be fine instead of the fixed resistor, except that it will require a separate project box, rather than fitting inside the plug.
Yea, I'll have to test the mic jack on my soundcard to see if it supplies any voltage, if not could it be powered by 2-3 AA or AAA batteries? And I realize it wouldn't fit in the jack, I intended to use a seperate box for it. But with the trim pot, would it work like the volume on the guitar and suck out some of the brightness?
Drew Webster - no this trimpot would not be wired like a volume pot and wouldn't affect brightness. Take a look at Tillman's preamp designs for ideas on powering the circuit with a battery.
Nice One Bro.. wait is it ok to try BF245C or(J201 )?
hi john great tutorial and i'm reallly super intrested to build one on my own... well i'm still preparing the component and i have a question about the zener diode since i'm not good at electronic component... is it 5 or 6 V on both of the diode or is it the value of each diode so the total of 2 diode will be 10 or 12 V... and um when i try to buy, the sales asked me whether it's 1W or 0.5W... i'm really sorry for my lack of knowledge but your help will be truly appreciated...thanks
The zener breakdown voltage should be around 5v for each zener. Either 0.5W or 1W is fine. There is very little current in the guitar circuit.
hi john, MPF102 is difficult to find here in my area.according to your schematic, i can use 2N5457 as a substitute which luckily the shop here have some stocks left. what will the value of R2 if I use this kind of JFET? I need help pls. Thanks for your wonderful tutorial. cheers!
See the discussion in the comments at my blog: www.planetz.com/simple-jfet-preamp-for-an-idevice-guitar-interface. Some people had luck with R2 between 10 and 30k with the 2N5457. You could experiment with a 50k trim pot until you find a value that works well, then measure it and replace it with a comparable resistor.
Great video! I Have a doubt. Will this work for a passive pickup in a electro acoustic ukulele (epiphone les paul ukulele) ??? Thanks!
Ivan Ernesto Gordon - Yes, it should work
great circuit can i use direct box
Quick question, will this be ok coming from the headphone out of a multifx pedal? I dont use apps, i just need to record...thanks.
I doubt there will be the necessary voltage on the output of your pedal. Unlike a laptop or computer, a guitar pedal isn't expecting a microphone/headset to be plugged in.
@@johnplanetz thanks for your reply, ive ended up making a modified irig circuit, which kind of works, but had to add a dpdt switch for record and playback to avoid dc crackle on the record level pot.....a work around, i just need to record vid, audio on a tablet.....cheers .
Hello sir, i am VERY inexperienced with electronics so i may sound a bit dumb here but while digging around i came across a bag of BC337-25 transistors. i looked up the data sheet and have no idea what i'm looking at but was wondering if it would be possible to use it for this preamp if the other parts were modified to work with the BC337-25?
Using that transistor would require a different circuit design. To use the circuit presented in this video, you should use a JFET.
Hi John. Thanks for sharing your knowledge and helping all of us less experienced musicians. I'm hoping you can help me with a simpler cable. I want to run a cable from my guitar to my cell phone , but only for tuning. I won't be using my cell for recording so I hope i really don't need the cable you showed in your video. Any suggestion for me ? Thanks and have a great weekend. : )
+Rik J. Smith - yes tuning should work fine without buffering. That's what the Griffin GuitarConnect cable is. If you want to make your own, you just need a TRRS male plug, and 1/4" male plug for the guitar-side, and connect the appropriate leads - as shown in part 1 the video: ruclips.net/video/p1T8QmQowVQ/видео.htmlm46s
Are your Zeners Flipped? The schematic you drew has cathodes facing away from each other and it seems you have cathodes facing each other on the circuit. Does it matter? One of the diodes is going to get activated with anything over .7V, meanwhile the other will still wait for the reverse breakdown voltage. I know it's a failsafe for static discharges, just wondering if the orientation matters.
It doesn't matter in this case- one protects against charges from positive to negative. The other protects against charges from negative to positive.
It doesn't matter in this case- one protects against charges from positive to negative. The other protects against charges from negative to positive.
Hi John! Is this preamp for guitars only? Or any type of line signal?
A line level signal may be too hot and can clip, especially if it exceeds the zener breakdown voltage of the esd diodes.
thanks a lot for this great tutorial. but i couldn't made this i think. o i used wrong transistor. the seller give me F254C fet. he said "i do not have MPF102 but F254C is the same with MPF102" is that right?
the pin structure of F254C is D-S-G while the structure of MPF102 is G-S-D.
Hola, sos de Argentina? Vi Irig en mercadolibre a menos de 200mangos. Igual lo que muestra este chabon esta bárbaro y es mucho más barato.
I was thinking through an issue I'm facing and thought of your video. Would this be good for running a guitar into the mic in port on a laptop?
The JFET in this circuit requires power. If your laptop has a powered mic input, it might work. But not if you only have a line-in. Check the input with a multimeter to see if it carries a DC voltage.
***** Can I assume that it does if I have the option to turn on DC coupling?
Very interesting. Will the circuit work for plugging my guitar o the mic input in the notevook?
If the computer's 3.5mm jack has a voltage (to power an electret mic) ,then this same approach would work. Test the jack pins with a multimeter to determine what's available.
@@johnplanetz Yes I thought I had to do that, I'll try later, many thanks!
@@johnplanetz I measure 2.6V so it would work. What if I add the optional R3 10k resistor, just in case, while it is not necessary?
@@rva1945 I would just experiment on breadboard with the resistors, to see what works.
@@johnplanetz I can't find the MPF102. Do you know about replacements? Will a BF246 do?
Nice.... big difference!!! Good job doode!!! :-)
Hi, about the zener diodes, are they 5v/1w?
Thanks so much mate.
If I want use it in my send/return amp I must do a modifications or I can plug in the guitar-in the send of my preamp?
I haven't tried, but you should be able to do this without circuit modifications:
amp send to preamp mic input to ipad/iphone processing to preamp headphone output to amp return. You may find it too noisy- but you could try.
Hi. Is it the same on Android?
can this work if im using a headphone?, or is it really necessary to use speakers?
+Brynh Delos Reyes - I prefer headphones.
i'm not into electronic components, but i found a circuit and it comes with a resistor(the R1 from your circuit) of 39k instead of the 1M that you put in your circuit, do you think 39k is enough? these are the resistors in the order of your circuit, R1= 39k, R2= 1.2k and R3= 4.7k and they also use the MPF102. and these are the values of the caps 22nf, 100nf and 470pf. here is the circuit guitar-gear.ru/forum/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=16412
A higher resistance would be better for R1, to make this a high impedance input. A lower resistance to ground will excessively load your passive pickups, causing treble rolloff and a dull sound. Try it and see!
thank you.
can i use jfet bc547
can I use this for an android device...what I mean will there be any difference in voltage outage than the ipad
+Julien Ghanimeh - I guess it will work, since the voltage to drive an electret mic is standard. But I don't have an android device to try. The only way to know for sure is to measure the voltage at your jack using a multimeter.
You're awsome man thanks for your reply
can i use bjt
what the hell ...