Klon buffer, Cornish Buffer or JHS Little black box? I need one for bass.
The one that kills the most unicorns for its magic.
I use the Klon one most of the time since I have the parts on hand most of the time.
Cody
maybe like this?
(https://3.bp.blogspot.com/-rg0ueSgyL00/WIZ38BgRCmI/AAAAAAAABG0/pSjk_ZQgiMIQm_8KbxKPya7Ux4IdYjAcQCLcB/s1600/Ultimate-Buffer-System.png)
credits to azilts/coldcraft
Simple Op Amp buffers like the Klon buffer are fine in my experience. I prefer them over transistor versions, mostly because I understand them better.
Jacob
Hmmm.. Probably just the klon buffer, but I've used all sorts. I get a substantial amount to top end increase using it with some builds (Superjudge), but I haven't done any great research into the effect of different buffers on that.
This is a great question and got me thinking... buffer project time! I use the Unicorn Breath Klon buffer and really notice its positive effect on my signal. Never tried the Cornish buffer to see the difference.
I like the cornish buffer, but haven't tried it on bass.
My friend makes a pcb with both the Klon and Cornish buffers on it. You can select them with a switch. Best of both worlds. I like the Cornish for most things and use it all the time. This is exclusively with a Strat though. I do like the Klon as well and have noticed that a little more bass gets through compared to the Cornish. Therefore, Klon for bass IMHO. Of course it's all pup > gtr > amp dependent. My 2 Canadian cents worth.
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
Wait are you telling us that it's a hornless unicorn, thereby making it just a horse? But what about magic?
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
Wow. I used to think there couldn't be new Klon developments that would out "smug" the last thing I had heard or read - I was always wrong.
This definitely adds to the list of just absurd info about that pedal/piece of gear folklore. To think about how many people go ON AND ON about the wonderful buffer in there.
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
But its more fun to imagine a mythical beast that gives birth to buffers.
Cody
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
So then, a better question would be opamp or transistor buffer?
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Quote from: jimilee on January 24, 2017, 05:06:00 PM
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
So then, a better question would be opamp or transistor buffer?
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i vote opamp buffer
transistor have very poor power supply noise rejection, unless youre battery guy
Quote from: mrclean77 on January 24, 2017, 04:26:27 PM
Wow. I used to think there couldn't be new Klon developments that would out "smug" the last thing I had heard or read - I was always wrong.
I mention it in any thread where somebody references "the Klon buffer", but I don't seem to be getting any traction. ;D
Quote from: jimilee on January 24, 2017, 05:06:00 PM
So then, a better question would be opamp or transistor buffer?
Right. Or more specifically, op amp or JFET or MosFET or BJT buffer.
BJT is, in a lot of ways, the worst of the lot, but it's also the cheapest and takes up very little space.
Op amp is best if you need headroom, high input impedance, and bandwidth because you can just use a better op amp if you need to. A TL072 isn't the best buffer in the world, but with guitar you aren't likely to notice any shortcomings. Current consumption is higher than a single transistor. Output impedance is so low you have to add a resistor to the output.
A BJT is good if you don't need sky-high input impedance but you do want lots of headroom and can sacrifice a tiny bit of bandwidth (in part from cable capacitance and lower input impedance). You can get 1M input impedance from a BJT which ought to be enough for any bass player to be happy. Current consumption is very low. I strongly disagree with CultureJam that it's the worst of the lot.
A JFET is good if you need very high input impedance (for our purposes effectively infinite) and bandwidth but don't need headroom. A JFET can be set up with gate biasing for more headroom but you are still contending with a device-level problem. Current consumption is very low.
A MOSFET is a truly lousy source follower buffer (try it and see), but if you can live with an output impedance of, say, 1K (I think that's about as low as I'd go on the drain and source resistors), and don't need to conserve current (i.e. you aren't using a battery), you could use it as a unity gain inverter and get the extremely high input impedance of a JFET, excellent bandwidth, and tons of headroom.
Hybrids: There are lots of two-transistor buffer arrangements, but that might be more complicated than you need.
Positive feedback: You can use a bit of positive feedback to make up for low input impedance. You usually get less noise and can correct the bandwidth loss from the cable capacitance... sometimes. IIRC the Cornish buffer does this.
If it were me doing something for a bass, I'd just use a BJT with a 1M at the base tied to a 22K/22K voltage divider and a 10K emitter resistor, and run it on 18V (two batteries if it's going inside the bass) if I managed to distort it and just live with the imperfect nature of such a simple device. Basically the second thing on Jack Orman's basic buffers list.
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
Is there a good location to view example applications of op-amps? It seems like a surprising number of big-name manufacturers used an example design in this fashion.
Quote from: midwayfair on January 24, 2017, 05:40:22 PM
I strongly disagree with CultureJam that it's the worst of the lot.
I should have qualified my statement a bit. I don't personally think BJTs are lousy buffers. But the general perception, at least from the many articles and forum posts I've read, is that they aren't as "good" because you get a little less than unity gain and the input impedance is not has high as an op amp or JFET. Do these things matter in most designs? Probably not.
I actually use them all the time in my designs. And it's probably just psycho-somatic, but I swear BJT buffers are not quite as "bright" as op amp buffers or JFET. I've not scoped anything or done any waveform analysis, so I might be full of shit on this.
Quote from: culturejam on January 24, 2017, 06:15:44 PMbut I swear BJT buffers are not quite as "bright" as op amp buffers or JFET. I've not scoped anything or done any waveform analysis, so I might be full of shit on this.
They aren't. The input impedance isn't as high no matter how big you make the base resistor. It's a device limitation. Some BJT-input op amps are marginally better than a single device (and some are far worse), but there you can run into problems if you make the bias resistor too large anyway.
Quote from: midwayfair on January 24, 2017, 06:26:30 PM
Quote from: culturejam on January 24, 2017, 06:15:44 PMbut I swear BJT buffers are not quite as "bright" as op amp buffers or JFET. I've not scoped anything or done any waveform analysis, so I might be full of shit on this.
They aren't. The input impedance isn't as high no matter how big you make the base resistor. It's a device limitation. Some BJT-input op amps are marginally better than a single device (and some are far worse), but there you can run into problems if you make the bias resistor too large anyway.
Having great success using these in distortion circuits in places other than the input stage. Few parts, outstanding headroom and the slight low-pass is actually a bonus. Very nice putting one of these after the tone stack and before the volume pot, for example.
Jon's on point. For standalone, can't really beat opamps. I like using the second in parallel for lower noise and more power. Even better would be with a split supply ...
(https://s23.postimg.org/73o1exeuj/Screenshot_2017_01_24_10_54_33.png)
I need to learn how to take schematic to vero I think. Googles, here I come!
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Quote from: jimilee on January 24, 2017, 07:10:47 PM
I need to learn how to take schematic to vero I think. Googles, here I come!
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I'll lay out a PCB for you. Share it on OSH.
You want a switch? Toggle? Footswitch?
Foot switch would be great! Thank you sir!
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Quote from: jimilee on January 24, 2017, 07:14:59 PM
Foot switch would be great! Thank you sir!
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3PDT or DPDT/Optofet?
3pdt would work
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Quote from: jimilee on January 24, 2017, 07:17:41 PM
3pdt would work
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How's this look?
(https://s27.postimg.org/ef8hrrvyr/Screenshot_2017_01_24_11_46_26.png)
That's really sharp, thank you.
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Quote from: jubal81 on January 24, 2017, 07:47:18 PM
How's this look?
(https://s27.postimg.org/ef8hrrvyr/Screenshot_2017_01_24_11_46_26.png)
the buffer will be always in the circuit and you can switch something behind it on/off if I'm not mistaken. Was this the purpose of the application here? your schematic is 100% correct (although imho C6 and R9 are overkill), but I'm not sure that's what Jimi intended. I thought the switch was to toggle the buffer on and off.
I have the
regular opamp buffer used in the klon in my oshpark projects (useable as 2 buffers), altough without a toggle, if that helps.
Quote from: m-Kresol on January 24, 2017, 09:21:56 PM
Quote from: jubal81 on January 24, 2017, 07:47:18 PM
How's this look?
(https://s27.postimg.org/ef8hrrvyr/Screenshot_2017_01_24_11_46_26.png)
the buffer will be always in the circuit and you can switch something behind it on/off if I'm not mistaken. Was this the purpose of the application here? your schematic is 100% correct (although imho C6 and R9 are overkill), but I'm not sure that's what Jimi intended. I thought the switch was to toggle the buffer on and off.
I have the regular opamp buffer used in the klon in my oshpark projects (useable as 2 buffers), altough without a toggle, if that helps.
Yeah, misunderstood what Jimi wanted. Going to redo it as a standalone buffer pedal with the buffer on a footswitch.
Quote from: culturejam on January 24, 2017, 03:11:08 PM
There really is no such thing as "the Klon buffer". The buffer in that circuit came straight off the op amp datasheet in the "example applications" section.
Might as well call at the National Semiconductor or Texas Instruments buffer. ;D
I've heard that both the Cornish and "opamp-in-the-klon" buffers are straight up Text Book buffers. Would love to find the old British data sheet or electronics mag that Cornish
sourced-nicked-borrowed his design from.
Quote from: ShredderNemo on January 24, 2017, 05:46:43 PM
Is there a good location to view example applications of op-amps? It seems like a surprising number of big-name manufacturers used an example design in this fashion.
Here's one: https://www.sparkfun.com/datasheets/Components/General/LM358.pdf
Starts on page 11. "Klon buffer" is on page 13. There are a buttload of applicaiton circuits in that PDF (more than the usual op amp datasheet).
Quote from: JC103 on January 25, 2017, 12:22:49 AM
I've heard that both the Cornish and "opamp-in-the-klon" buffers are straight up Text Book buffers. Would love to find the old British data sheet or electronics mag that Cornish sourced-nicked-borrowed his design from.
There's only so many ways to make a buffer, and all of them come from textbooks and application notes on data sheets. The basic building blocks are spelled out by the semiconductor manufacturers so that people will know what they can do and want to buy them. No shame in reading the damn manual, you know. ;D
And to be fair to Bill F, I don't ever recall him saying that the Klon buffer was some kind of special sub-circuit that he invented. It's the Klon-worshipers that made that leap of faith. ;)
As for Cornish, it looks to me like a simple BJT buffer (off the datasheet) but with the input impedance adjusted downward and some RC filtering going on at the output. Definitely not a "clean" buffer that seeks reproduce the input precisely. And that's probably why some people like it. The filtering/impedance adjust part is that makes it sound different, and I kinda doubt he copied that out of a textbook, since most books try to avoid signal degradation. Schematic is attached, and *yes* I did "steal" it from FSB. ;D
Same goes for overdrive and fuzz. You don't find that kind of thing in an electronics book or datasheet because the general idea with amplification is that it *doesn't* distort/clip the input signal.
One more thing on Cornish...
When the G2 was traced, the schematic showed that the bypass setup is buffered all the time. And when the effect is on, there is also a fixed buffer on the effect circuit. So you have an input buffer with some filtering going into an input buffer with some filtering...going into a fancy Muff. Profit!!
I mentioned the 2 buffers because they seem to be the ones people reference and use the most. I don't know that much about buffets as far as differences between them but I do understand what they do. I just didn't know if there was one that would be better matched for bass because of the frequencies.
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Quote from: jimilee on January 25, 2017, 01:53:47 AM
I just didn't know if there was one that would be better matched for bass because of the frequencies.
Higher headroom is better for bass. At least as far as I understand things. So I would think an op amp buffer running at 18v would be optimal, but that's just a guess on my part.
Quote from: culturejam on January 25, 2017, 01:58:25 AM
Quote from: jimilee on January 25, 2017, 01:53:47 AM
I just didn't know if there was one that would be better matched for bass because of the frequencies.
Higher headroom is better for bass. At least as far as I understand things. So I would think an op amp buffer running at 18v would be optimal, but that's just a guess on my part.
I was thinking that. If it's a standalone pedal, then there's plenty of room for that. Split supply and ground bias would squeeze a little more noise out of the system, too.
Quote from: jimilee on January 25, 2017, 01:53:47 AM
I mentioned the 2 buffers because they seem to be the ones people reference and use the most. I don't know that much about buffets as far as differences between them but I do understand what they do. I just didn't know if there was one that would be better matched for bass because of the frequencies.
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R-C values on that workup more than plenty low to get all the bassy goodness.
Yeah, actually running at +/-9V might be better than +18v with virtual ground. Would allow the use of more types of op amps and not have them running right at the upper limit of the positive rail max.
I'd love that osh park layout to add to a compressor>fatpants pedal I'm building for bass.
Quote from: culturejam on January 25, 2017, 01:09:56 AM
Quote from: ShredderNemo on January 24, 2017, 05:46:43 PM
Is there a good location to view example applications of op-amps? It seems like a surprising number of big-name manufacturers used an example design in this fashion.
Here's one: https://www.sparkfun.com/datasheets/Components/General/LM358.pdf
Starts on page 11. "Klon buffer" is on page 13. There are a buttload of applicaiton circuits in that PDF (more than the usual op amp datasheet).
Quote from: JC103 on January 25, 2017, 12:22:49 AM
I've heard that both the Cornish and "opamp-in-the-klon" buffers are straight up Text Book buffers. Would love to find the old British data sheet or electronics mag that Cornish sourced-nicked-borrowed his design from.
There's only so many ways to make a buffer, and all of them come from textbooks and application notes on data sheets. The basic building blocks are spelled out by the semiconductor manufacturers so that people will know what they can do and want to buy them. No shame in reading the damn manual, you know. ;D
And to be fair to Bill F, I don't ever recall him saying that the Klon buffer was some kind of special sub-circuit that he invented. It's the Klon-worshipers that made that leap of faith. ;)
As for Cornish, it looks to me like a simple BJT buffer (off the datasheet) but with the input impedance adjusted downward and some RC filtering going on at the output. Definitely not a "clean" buffer that seeks reproduce the input precisely. And that's probably why some people like it. The filtering/impedance adjust part is that makes it sound different, and I kinda doubt he copied that out of a textbook, since most books try to avoid signal degradation. Schematic is attached, and *yes* I did "steal" it from FSB. ;D
Same goes for overdrive and fuzz. You don't find that kind of thing in an electronics book or datasheet because the general idea with amplification is that it *doesn't* distort/clip the input signal.
We decided to make a CSOD with a buffer on to get around it's problems of operating like an old fuzz (doesn't like wah's/they don't like it, etc). Tried the Klon and it coloured the sound of the CSOD too much. Used the G2 buffer in the end and tweaked a few parts here and there (imp and filtering funnily enough) to get it to the point where it sounded right next to an unbuffered CSOD. It's a lot more handy in that sort of circumstance. Also the Klon one only seems to do bright, which isn't always what you want.
Quote from: culturejam on January 25, 2017, 01:09:56 AM
As for Cornish, it looks to me like a simple BJT buffer (off the datasheet) but with the input impedance adjusted downward and some RC filtering going on at the output. Definitely not a "clean" buffer that seeks reproduce the input precisely. And that's probably why some people like it. The filtering/impedance adjust part is that makes it sound different, and I kinda doubt he copied that out of a textbook, since most books try to avoid signal degradation...
Nope. The cap from the emitter to the bias resistor (C3) is there for bootstrapping and
increases the input impedance. With a BJT with mid-high gain, you can get >1 M input impedance, which is as good as essentially all op-amp designs commonly used. The filtering is designed to be flat too.
It's a good design, and I very much doubt I could tell the difference between it and an op-amp buffer in a blind listening test...
Which leads me to my answer to the OP - use whatever you have handy as you probably can't tell the difference.
Quote from: 287m on January 23, 2017, 09:41:27 PM
maybe like this?
(https://3.bp.blogspot.com/-rg0ueSgyL00/WIZ38BgRCmI/AAAAAAAABG0/pSjk_ZQgiMIQm_8KbxKPya7Ux4IdYjAcQCLcB/s1600/Ultimate-Buffer-System.png)
credits to azilts/coldcraft
I like the adjustable output impedance, I keep meaning to breadboard an opamp buffer with switchable (via relay) impedance for the input section of a looper i'm working on... slowly. Any more details on the circuit?
I find that this buffer adds incredible shine and sparkle...
(https://s26.postimg.org/h8uuum0d5/makita.jpg)
Quote from: samhay on January 25, 2017, 10:03:51 AM
Nope. The cap from the emitter to the bias resistor (C3) is there for bootstrapping and increases the input impedance.
I was actually thinking of the interplay between C4, R7, R8, and R39 when I said "filtering at the output". But now that I look at it again, you're right. It's almost exactly flat.
So yeah, I guess the Cornish buffer really doesn't do much of anything other than act as a buffer. Which makes me wonder why he used so many parts to do what an op amp can do with half the parts? Maybe it's part of the mystique of "Class A discrete buffer" that he talks about in marketing literature. Here's an interesting thread on the topic: http://www.diystompboxes.com/smfforum/index.php?topic=33241.0
Quote from: culturejam on January 25, 2017, 04:33:27 PM
Quote from: samhay on January 25, 2017, 10:03:51 AM
Nope. The cap from the emitter to the bias resistor (C3) is there for bootstrapping and increases the input impedance.
I was actually thinking of the interplay between C4, R7, R8, and R39 when I said "filtering at the output". But now that I look at it again, you're right. It's almost exactly flat.
So yeah, I guess the Cornish buffer really doesn't do much of anything other than act as a buffer. Which makes me wonder why he used so many parts to do what an op amp can do with half the parts? Maybe it's part of the mystique of "Class A discrete buffer" that he talks about in marketing literature. Here's an interesting thread on the topic: http://www.diystompboxes.com/smfforum/index.php?topic=33241.0 (http://www.diystompboxes.com/smfforum/index.php?topic=33241.0)
If you're building at quantities, the cornish buffer is a lot cheaper, too.
Mouser pricing at quantity:
BC549: 4 cents
Resistors: 10 cents
Caps: 15 cents
Total: 28 cents
And these are parts he's already buying anyway, which makes a big difference.
K, here's the updated version:
(https://s23.postimg.org/5czzgqu2j/Screenshot_2017_01_25_09_05_26.png)
Looks good
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Quote from: culturejam on January 25, 2017, 04:33:27 PMWhich makes me wonder why he used so many parts to do what an op amp can do with half the parts?
I think it might be old enough to simply say "op amp chips sucked and were expensive at the time."
Quote from: midwayfair on January 25, 2017, 06:15:06 PM
I think it might be old enough to simply say "op amp chips sucked and were expensive at the time."
I thought of that, but he didn't start selling pedals until the late 70s, and op amps had been widely available for 20 years at that point. But I guess there is a lot of value in designing around parts you are very familiar with, especially if they are cheaper.
^
FET input op-amps (much better for high input impedance) came along in the mid-late '70s and would have been relatively expensive, so the cost argument makes some sense.
BJTs are also more tolerant of input abuse (e.g. through ESD) and as Cornish was making kit for touring musicians, he may have figured they were more likely to survive a tour of stadium rock. This is actually still a valid reason to choose a BJT as the input buffer to your pedal board.
Quote from: samhay on January 25, 2017, 09:27:47 PM
^
FET input op-amps (much better for high input impedance) came along in the mid-late '70s and would have been relatively expensive, so the cost argument makes some sense.
BJTs are also more tolerant of input abuse (e.g. through ESD) and as Cornish was making kit for touring musicians, he may have figured they were more likely to survive a tour of stadium rock. This is actually still a valid reason to choose a BJT as the input buffer to your pedal board.
Both very good points!
Didn't end up too awful big. 50mm X 36mm.
Now about a name?
Bottom Muscle
Iron Glutes
Lightning Eel
It's your's Jimi, name it what you want.
(https://s27.postimg.org/u13evaisz/Screenshot_2017_01_26_10_05_10.png)
Thank you!!
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Shared on OSH
Order it here (https://oshpark.com/shared_projects/LQcJJpBW)
How about "Signal Lube"?
Oooh, buffer with charge pump... handy. Is the buffer in the chain regardless of bypass?
Quote from: Willybomb on January 29, 2017, 02:46:10 AM
Oooh, buffer with charge pump... handy. Is the buffer in the chain regardless of bypass?
Nope. The switch bypasses the buffer.