Hello I am new to the forum. I am seeking some help or solutions to a problem I'm having with my guitar project. I hope there are some friendly people here who don't mind sharing some of there time or knowledge. Thanks.
I really need a simple but effective preamp and tone using 2 op amps from a tl074 or tl064 ic chip. Only 2 of them because I actually need 2 of these. This is going to be internal battery powered and it wont be externally adjustable so it will be set and then left. I really need a 7 band if that is at all possible. I have seen eq circuits that use an op amp in each band that is much to complex for my needs. And I have seen preamp with 3 band tone. like low pass, band pass and high pass using one op amp for pre amp and the other for the 3 band tone I am wondering if it is at all possible to cram 5 more band pass filters in there to make it 7 band using same style setup. Or if it's possible to use a 7 band passive eq and then boost the signal after or in the pre amp. I hope someone can help me in the right direction here. I am determined to finish this. At the end of the day I want to be able to set a tone profile with the simplest but still effective circuit using no more than 2 op amps and some resistors capacitors and potentiometers. No coils or transistors please. I read some post people made about the 3 bands being tone stacks and wondered if it works beyond 3 bands or if there is another simple but effective solution
I don't want to go too deep into the guitar part of the project. But I would like to explain I have taken a Chord stratocaster knockoff and stripped it down modified the cavities as to fit 2 p90 pickups 7.5k each. replaced the bridge with an acoustic bridge with under the saddle pickup paralleled with a circle contact piezo in the body. Changed all the pots to push pull style. changed strings to a magnetically active but still acoustic sounding nickel iron alloy. And used a telecaster selector switch. That is a double ganged 3 way switch as standard.
The switch I used as 2 switches and fed the output of each side to the outer terminals of a linear 250k with the center being the combined output making it a somewhat functional mixer knob.
guitar works like this
neck position switch:
Neck pickup < mixer pot > Bridge pickup
center position:
Neck pickup < Mixer pot > Double piezo
Bridge position:
Bridge pickup < Mixer pot > Double piezo
In the future I will re wire this to be front side of switch forward A250k and back side of switch middle A250K pot. removing the mixer pot. But it does work now so it's fine for the moment.
Volume pot pulls to swap phase of the neck pickup.
Tone pot pulls from direct output of neck pickup to an (acoustically profiled eq version) of the same pickup
Mixer pot pulls from pre amped output of double piezo to an (acoustically profiled eq version) of the double piezo.
Ok sorry for such a long description but anyway all is well. I have put the guitar together and love to play it. all works as expected. However I have not gotten to the preamps or eq. So those wires are just hanging ready and waiting.
I will be using some software to eq match a mic'd acoustic guitar and then matching the tone of the neck pickup and the double piezo. This will mostly be a mid scoop but it will be profiled as close as possible to a mic'd acoustic. I have done this before with an electro acoustic so as to get a very natural acoustic sound out of it's piezo for live performance with amazing results. Not sure why everyone doesn't do this. This is my goal to help this electric try to sound as acoustic as possible with the 2 piezo and the acoustic style strings and tone profile.
I really need a simple but effective preamp and tone using 2 op amps from a tl074 or tl064 ic chip. Only 2 of them because I actually need 2 of these. This is going to be internal battery powered and it wont be externally adjustable so it will be set and then left. I really need a 7 band if that is at all possible. I have seen eq circuits that use an op amp in each band that is much to complex for my needs. And I have seen preamp with 3 band tone. like low pass, band pass and high pass using one op amp for pre amp and the other for the 3 band tone I am wondering if it is at all possible to cram 5 more band pass filters in there to make it 7 band using same style setup. Or if it's possible to use a 7 band passive eq and then boost the signal after or in the pre amp. I hope someone can help me in the right direction here. I am determined to finish this. At the end of the day I want to be able to set a tone profile with the simplest but still effective circuit using no more than 2 op amps and some resistors capacitors and potentiometers. No coils or transistors please. I read some post people made about the 3 bands being tone stacks and wondered if it works beyond 3 bands or if there is another simple but effective solution
I don't want to go too deep into the guitar part of the project. But I would like to explain I have taken a Chord stratocaster knockoff and stripped it down modified the cavities as to fit 2 p90 pickups 7.5k each. replaced the bridge with an acoustic bridge with under the saddle pickup paralleled with a circle contact piezo in the body. Changed all the pots to push pull style. changed strings to a magnetically active but still acoustic sounding nickel iron alloy. And used a telecaster selector switch. That is a double ganged 3 way switch as standard.
The switch I used as 2 switches and fed the output of each side to the outer terminals of a linear 250k with the center being the combined output making it a somewhat functional mixer knob.
guitar works like this
neck position switch:
Neck pickup < mixer pot > Bridge pickup
center position:
Neck pickup < Mixer pot > Double piezo
Bridge position:
Bridge pickup < Mixer pot > Double piezo
In the future I will re wire this to be front side of switch forward A250k and back side of switch middle A250K pot. removing the mixer pot. But it does work now so it's fine for the moment.
Volume pot pulls to swap phase of the neck pickup.
Tone pot pulls from direct output of neck pickup to an (acoustically profiled eq version) of the same pickup
Mixer pot pulls from pre amped output of double piezo to an (acoustically profiled eq version) of the double piezo.
Ok sorry for such a long description but anyway all is well. I have put the guitar together and love to play it. all works as expected. However I have not gotten to the preamps or eq. So those wires are just hanging ready and waiting.
I will be using some software to eq match a mic'd acoustic guitar and then matching the tone of the neck pickup and the double piezo. This will mostly be a mid scoop but it will be profiled as close as possible to a mic'd acoustic. I have done this before with an electro acoustic so as to get a very natural acoustic sound out of it's piezo for live performance with amazing results. Not sure why everyone doesn't do this. This is my goal to help this electric try to sound as acoustic as possible with the 2 piezo and the acoustic style strings and tone profile.
If you need 7 bands, then the circuit necessary will be complex.
This, using gyrators, and replacing the 4558 by the TL's will do the job.
5 Band equalizer tone control with 4558 - Electronic Circuit
http://schematics.circuitdiagram.net/viewer.php?id=bwy1307627855n.jpg
This, using gyrators, and replacing the 4558 by the TL's will do the job.
5 Band equalizer tone control with 4558 - Electronic Circuit
http://schematics.circuitdiagram.net/viewer.php?id=bwy1307627855n.jpg
Thank you Osvaldo for your reply. Unfortunately yeah that would be too far away from what I'm seeking. It's not really too complex but it's using too many op amps I need a design that will you only 2 op amps one for preamp and 1 for tone or less than that is fine too. Because I will be using a single tl074 that contains 4 op amps but I need 2 of these preamp/tone control circuits on 1 battery power board placed inside of a guitar. So I don't have room or power to run a op amp for each band. I know there is always trade off for power complexity fidelity efficiency and so on. But the be realistic I need to make it work with a single chip 2 circuits on one board battery powered. So I will that what ever the best I can get with those restrictions.
I was hoping I could possible take this kind of setup that looks pretty popular with the high pass, band pass and, low pass filters and simply add in more band pass in the center. is this a feasible idea at all? I had the idea I would have to adjust capacitors to add more bands but wasn't sure if this is a working idea. I do see many guitar onboard preamps with 5 band eq surely they are using similar idea.
from this site. Though I have seen 100 other schematics nearly exactly the same. Guitar Control - RED - Page69
Thanks again for your time.
I was hoping I could possible take this kind of setup that looks pretty popular with the high pass, band pass and, low pass filters and simply add in more band pass in the center. is this a feasible idea at all? I had the idea I would have to adjust capacitors to add more bands but wasn't sure if this is a working idea. I do see many guitar onboard preamps with 5 band eq surely they are using similar idea.
from this site. Though I have seen 100 other schematics nearly exactly the same. Guitar Control - RED - Page69
Thanks again for your time.
Why not to try the TLC line from Texas (TLC084, CMOS lowest power drain), or the TLC274? They are pin to pin compatible, but 1/1000 the current of standard JFET op amps. Distortion and BW are comparable or betten than JFET, and in any case, with the large amounts of NFB you will use, this can be maintained at imperceptible levels.
Hmm I couldn't find any reference to that chip ever being used for audio I googled and no hits. I don't know much about chips but texas interments says it doesn't use 1000 times less current because that would have given me a hundred years of 10 hours a day usage from one battery. but it actually uses 50% more power than the tl074 and about 8 times more power than the tl064. But still I searched and searched and could not find anyone one at all sugesting or have used this chip for audio. I am new to these chips and don't know much so I have to look everything up online. So not sure if I am confused or you. but I have already got those 2 chips tl074 and tl064 so would prefer to use what I have. also what about the design I showed can't that be changed. it kinda looks like what you suggested just decompressed. can't we do the same but have them run into a single op amp like the other?
Since It can't find any way to make a simple circuit if I do need to make a a multi op amp one or with transistors I think it may be smarter to use a chip with it all setup that way like an LA3607 it's setup as a 7 band eq. most of that same circuit but on the chip already. Then maybe the tl074 as preamp?
You can use transistors as gyrators for resonant tone controls, and I would use the TL062 or 64 since presumably this has to run on a single 9V battery. If you use the LA3607 make sure the power consumption is acceptable for the end use.
Yeah I do have a couple tl064 and couple tl074. Because I thought I would need 1 for preamp and 1 for tone. and I need 2 channels so I got the quad. But since the tone is much more complex that is why I had started the thread for a solution.
So I ordered 5 of those LA3607 thinking to use 2 of them 1 for each channel. So as I understand it I still need to use the tl064 or tl074 for the preamp correct? for the piezo I am guessing it's a must. But for the P90 pickup if I want to eq that do I need to run that tough a preamp or just straight into the eq?
So right now what I need is to be able to eq the neck p90.
And a separate circuit for the piezo that has a preamp so I can output the piezo correctly. And after the preamp want an eq. I will use a push pull pot switch to change between the preamp piezo and the preamp eq piezo.
can anyone help me out on this?
piezo channel - tl07x or tl06x preamp running into a LA3607 7 band eq
Neck P90 channel - directly into LA3607 7 band eq (Or do I need a preamp?)
I would like to put that on a single board lol
So I ordered 5 of those LA3607 thinking to use 2 of them 1 for each channel. So as I understand it I still need to use the tl064 or tl074 for the preamp correct? for the piezo I am guessing it's a must. But for the P90 pickup if I want to eq that do I need to run that tough a preamp or just straight into the eq?
So right now what I need is to be able to eq the neck p90.
And a separate circuit for the piezo that has a preamp so I can output the piezo correctly. And after the preamp want an eq. I will use a push pull pot switch to change between the preamp piezo and the preamp eq piezo.
can anyone help me out on this?
piezo channel - tl07x or tl06x preamp running into a LA3607 7 band eq
Neck P90 channel - directly into LA3607 7 band eq (Or do I need a preamp?)
I would like to put that on a single board lol
Not quite what you asked for, but my suggestion would be to get a Danelectro Fish-n-Chips pedal (7 band EQ plus clean boost), and use it as your preamp.
These are excellent EQ pedals, and very inexpensive. IMO you are unlikely to match either the price or performance of one of these pedals with a DIY build.
If you feel like sharing, I would love to see the EQ curve you used on your electro-acoustic to make it sound more like a mic'd acoustic.
(I originally started using a Fish-n-Chips for the same reason, to improve the plugged-in sound of a cheap electro-acoustic guitar I owned at the time. The EQ pedal was much cheaper than a new guitar. 🙂)
-Gnobuddy
These are excellent EQ pedals, and very inexpensive. IMO you are unlikely to match either the price or performance of one of these pedals with a DIY build.
If you feel like sharing, I would love to see the EQ curve you used on your electro-acoustic to make it sound more like a mic'd acoustic.
(I originally started using a Fish-n-Chips for the same reason, to improve the plugged-in sound of a cheap electro-acoustic guitar I owned at the time. The EQ pedal was much cheaper than a new guitar. 🙂)
-Gnobuddy
yeah I will have to take a look at that. But yeah I was hoping for an internal solution so I am still waiting on those chips to come.
It's important to note with what I did in the past and what I am trying to do now is that most people love the electric guitar to have massive mid range with nothing else. And even plugged in acoustics also have massive mid. That is before anything happens with mixing or eq. Electric is really bad this way and that is why they scoop the mids to get more acoustic sound. Then when people mix an acoustic they have an idea that is shouldn't compete with anything else so they give it an awful high pass filter making it not even sound like a guitar anymore and then cut the volume way down so almost ever song or live performance of a band I have seen where someone is playing an acoustic usually the lead singer you can not hear the acoustic at all. Just there for looks I guess. Now I am not professional at all. And was not playing in a band this was for a birthday party in a church hall. So I just wanted the acoustic guitar to actually sound like an acoustic guitar. Not ******** needed.
I used an epiphone masterbilt dr-500mce. This is a very inexpensive all solid wood electro acoustic guitar. Got if for 275 pounds I believe. All solid can't beat that. And it has a shadow under the saddle nanoflex piezo as well as a nanomag magnetic pickup right at the neck and soundhole. So it has dual pickups and can be internally mixed or output stereo to be externally mixed.
I was usuing elixur nanoweb phospher bronze 12 strings.
Epiphone DR-500MCE
I used a 4 input presonus audiobox 44vsl as my audio interface.
https://www.presonus.com/products/AudioBox-44VSL
I ran the audio interface into a presonus studio one 2 DAW
Studio One | PreSonus
Behringer XM1800S mic's (sure sm58 copy)
https://www.amazon.co.uk/Behringer-XM1800S-Microphone-Pack/dp/B00WOPL35A
And for eq matching i used. Ozone from Izotopehttps://www.izotope.com/en/products/master-and-deliver/ozone.html
So what I did was setup a microphone about 1 foot from my guitar where the neck and the body meet. I read if it's near the sound hole you will hear all boom and if it's near the neck all string attack and that this was the right place to get the natural guitar sound. The recording sounded good. So What I took a recording of myself picking each string down like a slow strum several times and then also normal strum several times I think just open strings. Now I had the 4 channel audio interface so I recored the mic in 1 channel and then the nanomag in 1 and the nanoflex in the other. So I recorded 3 channels at the same time. Then I fed the mic into ozone as the reference and then analyze the nanomag and listened to the eq matched result. Then did the same for the nanoflex. Now the nanoflex piezo has to much attack sounds very acoustic but still to much pick on string sound. And the nanomag the magnetic has almost none. So I did the whole process again but recorded only 2 channels the mic and an internally mixed output of both pickups right at half way. And I really liked this was perfect could not really tell which one was the mic or the pickups. The eq curve was almost the same on all massive mid reduction but not a bowl more complicated. The problem I had was Ozone plugin to use that eq match live causes to much latency and runs the cpu up. I ran this on a 2014 mac book pro. Even when I wasn't analyzing, when it was just the eq curve it was a problem. So I looked at the curve and tried to copy it with the 5 band presonus eq. I ended up using 2 of those. I would create the curve and then analyze that from the same recording looking for Ozone to come out as flat as possible. So I had matched the eq with 2 built in presonus 5 band or was it 7 band lol it's been year or 2. Anyway the presonus cause no latency so I was done. now just ran my live from guitar internally mixed 2 pickups to the audio interface into the studio one and back out to the interface to my pa system. I also used an izotope noise canceling software for any white noise. And possibly a compressor. I also had noise canceling on my audio mics with some eq and compressors. It actually made me sound really good and I was pretty happy since I am not at all a good singer and this went along way to helping that out. And some others played too. The point was to make the guitar sound like a guitar and nothing more or less. So my final eq for the guitar was that matched sound and nothing else. And it sounded great for strumming, picking and finger style.
Now I know this was already an acoustic guitar with acoustic strings. The electric I have is far from that. So I am just seeing how close I can get that to an authentic acoustic sound. Not a piezo sound but a real acoustic sound.
It's important to note with what I did in the past and what I am trying to do now is that most people love the electric guitar to have massive mid range with nothing else. And even plugged in acoustics also have massive mid. That is before anything happens with mixing or eq. Electric is really bad this way and that is why they scoop the mids to get more acoustic sound. Then when people mix an acoustic they have an idea that is shouldn't compete with anything else so they give it an awful high pass filter making it not even sound like a guitar anymore and then cut the volume way down so almost ever song or live performance of a band I have seen where someone is playing an acoustic usually the lead singer you can not hear the acoustic at all. Just there for looks I guess. Now I am not professional at all. And was not playing in a band this was for a birthday party in a church hall. So I just wanted the acoustic guitar to actually sound like an acoustic guitar. Not ******** needed.
I used an epiphone masterbilt dr-500mce. This is a very inexpensive all solid wood electro acoustic guitar. Got if for 275 pounds I believe. All solid can't beat that. And it has a shadow under the saddle nanoflex piezo as well as a nanomag magnetic pickup right at the neck and soundhole. So it has dual pickups and can be internally mixed or output stereo to be externally mixed.
I was usuing elixur nanoweb phospher bronze 12 strings.
Epiphone DR-500MCE
I used a 4 input presonus audiobox 44vsl as my audio interface.
https://www.presonus.com/products/AudioBox-44VSL
I ran the audio interface into a presonus studio one 2 DAW
Studio One | PreSonus
Behringer XM1800S mic's (sure sm58 copy)
https://www.amazon.co.uk/Behringer-XM1800S-Microphone-Pack/dp/B00WOPL35A
And for eq matching i used. Ozone from Izotopehttps://www.izotope.com/en/products/master-and-deliver/ozone.html
So what I did was setup a microphone about 1 foot from my guitar where the neck and the body meet. I read if it's near the sound hole you will hear all boom and if it's near the neck all string attack and that this was the right place to get the natural guitar sound. The recording sounded good. So What I took a recording of myself picking each string down like a slow strum several times and then also normal strum several times I think just open strings. Now I had the 4 channel audio interface so I recored the mic in 1 channel and then the nanomag in 1 and the nanoflex in the other. So I recorded 3 channels at the same time. Then I fed the mic into ozone as the reference and then analyze the nanomag and listened to the eq matched result. Then did the same for the nanoflex. Now the nanoflex piezo has to much attack sounds very acoustic but still to much pick on string sound. And the nanomag the magnetic has almost none. So I did the whole process again but recorded only 2 channels the mic and an internally mixed output of both pickups right at half way. And I really liked this was perfect could not really tell which one was the mic or the pickups. The eq curve was almost the same on all massive mid reduction but not a bowl more complicated. The problem I had was Ozone plugin to use that eq match live causes to much latency and runs the cpu up. I ran this on a 2014 mac book pro. Even when I wasn't analyzing, when it was just the eq curve it was a problem. So I looked at the curve and tried to copy it with the 5 band presonus eq. I ended up using 2 of those. I would create the curve and then analyze that from the same recording looking for Ozone to come out as flat as possible. So I had matched the eq with 2 built in presonus 5 band or was it 7 band lol it's been year or 2. Anyway the presonus cause no latency so I was done. now just ran my live from guitar internally mixed 2 pickups to the audio interface into the studio one and back out to the interface to my pa system. I also used an izotope noise canceling software for any white noise. And possibly a compressor. I also had noise canceling on my audio mics with some eq and compressors. It actually made me sound really good and I was pretty happy since I am not at all a good singer and this went along way to helping that out. And some others played too. The point was to make the guitar sound like a guitar and nothing more or less. So my final eq for the guitar was that matched sound and nothing else. And it sounded great for strumming, picking and finger style.
Now I know this was already an acoustic guitar with acoustic strings. The electric I have is far from that. So I am just seeing how close I can get that to an authentic acoustic sound. Not a piezo sound but a real acoustic sound.
Though I don't have the eq curved I used before. i will be happy to post the one I create when I do all that again. However it will be for this electric setup. But I may though My acoustic on and do it again to take a screen shot of the results.
You could always take the guts (IIRC, two small circuit-boards) out of the Fish-n-Chips, and re-house them inside your guitar. You'd still get all the benefits of a proven design, with its small size and light weight.
The trickiest part would probably be cutting all those tiny, precisely spaced slits, for those tiny slider pot shafts. Maybe cut that part of the case out of the original Fish-n-Chips faceplate, and incorporate it into your guitar control panel.
Joyo makes a similar EQ pedal (only 6 bands, and no clean boost) at a fairly similar price. Biyang makes a 7-band one that costs about twice as much, but still cheaper than the big brands. Both of these have the usual brick-shaped enclosures, so may be easier to re-house inside your guitar. But I haven't used either one, so I don't know how good they are (noise, etc).
Perhaps you already know, over the years, Taylor Guitars has gone back and forth between different designs of piezo and magnetic pickups, in their search for a way to make a plugged-in acoustic guitar sound more like an actual acoustic guitar. As you noticed, piezos tend to do a better job with high treble (attack, shimmer), while magnetic pickups tend to do a better job with bass.
Some piezo systems are pretty convincing - I have a Takamine acoustic guitar with an onboard "cool tube" preamp that has a pretty realistic plugged-in sound. Whether the tube is actually doing anything or not, I don't know - but the preamp has much less of that harsh piezo sound than usual.
In my home-made recordings, I've found that the best EQ for solo guitar isn't usually the same as the best EQ when the guitar is in a full band mix. In a full mix with drums and bass, high-passing the rhythm guitars keeps the low notes from the guitar from clashing with the bass guitar and drums. My limited experience is that this produces much better-sounding mixes.
But there are other situations (say guitar and vocals only, or guitar and flute, or guitar and mandolin) when there may be no need to high-pass the guitars, because there aren't any other musical instruments occupying the lower frequencies (and therefore clashing with the guitar). Here, your method seems like a good candidate to produce a nice rich acoustic guitar tone.
Thanks for sharing your EQ method!
-Gnobuddy
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