Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter
Well it's pretty much a generic common drain amplifier. I did that layout a while ago and have had a look to see if I saved the exact schematic I used (I usually keep them in a "done" folder where I store my layouts) but I can't find it for reference. Looking at some other buffers though, the layout seems to line up, but some use a 10uF instead of the 100nF output capacitor so if you're having issues that is the only significant difference. Check out the transistor buffer on the Beavis site:
http://www.beavisaudio.com/techpages/Buffers/
Apart from that, are you sure you're using a JFET with the correct pinouts?
I will be building this tomorrow. I ordered the parts thursday nite so when I get all the parts in(should be Monday), I'll let you know if I got it. I ordered everything on the diagram above. I will also tell you if it works!
So i built the buffer just like the layout above. The results were that I lost a small bit of high end. Not very noticeable, but in the end, I felt like i had lost the piercing shimmer of my Gretsch Penguin.
I guess you can say it works but, You cant say that because its not really doing its job in keeping the pure tone.
Am I right on this? Or will I never find a buffer that doesnt take away from my signal even just a little?
Did you try it with the 10uF or 100nF output capacitor?
At the end of the day all a buffer does is convert a high impedance signal to low impedance which helps with losses caused by long runs of cables, multiple short patch leads etc. I'm sure with some guitar/effect/amp combinations buffering your signal just doesn't sound quite as good as when it's unbuffered and this may just be one of those cases.
It may be worth trying a generic opamp buffer layout like this one:
I just used the 100nF cap. I suppose I could try a 10uF. Would that reduce "resistance" in the signal? I am also going to have a couple guitarists put this on their boards. Im going to see if they think they lose anything by having it.
I just am running 25ft mogami cable from guitar to board(board runs through 5 pedals) then another 25ft mogami to my amp. So if anything, I guess I expected to have more highs in my signal... or is that not supposed to happen after going LowZ
also, what type of IC should go in that first buffer? perhaps a TL072?
Hello, what is the purpose of the 100R input resistor? The Beavis Jfet buffer does not use one... Also what happened with the discussion about the output capacitor? should I try the 100n or the 10u?
Hello, what is the purpose of the 100R input resistor? The Beavis Jfet buffer does not use one... Also what happened with the discussion about the output capacitor? should I try the 100n or the 10u?
Hey, do you know if this buffer works?
ReplyDeleteHi
ReplyDeleteWell it's pretty much a generic common drain amplifier. I did that layout a while ago and have had a look to see if I saved the exact schematic I used (I usually keep them in a "done" folder where I store my layouts) but I can't find it for reference. Looking at some other buffers though, the layout seems to line up, but some use a 10uF instead of the 100nF output capacitor so if you're having issues that is the only significant difference. Check out the transistor buffer on the Beavis site:
http://www.beavisaudio.com/techpages/Buffers/
Apart from that, are you sure you're using a JFET with the correct pinouts?
I will be building this tomorrow. I ordered the parts thursday nite so when I get all the parts in(should be Monday), I'll let you know if I got it. I ordered everything on the diagram above. I will also tell you if it works!
ReplyDeleteCool, thanks Jacob
ReplyDeleteSo i built the buffer just like the layout above. The results were that I lost a small bit of high end. Not very noticeable, but in the end, I felt like i had lost the piercing shimmer of my Gretsch Penguin.
ReplyDeleteI guess you can say it works but, You cant say that because its not really doing its job in keeping the pure tone.
Am I right on this? Or will I never find a buffer that doesnt take away from my signal even just a little?
Did you try it with the 10uF or 100nF output capacitor?
ReplyDeleteAt the end of the day all a buffer does is convert a high impedance signal to low impedance which helps with losses caused by long runs of cables, multiple short patch leads etc. I'm sure with some guitar/effect/amp combinations buffering your signal just doesn't sound quite as good as when it's unbuffered and this may just be one of those cases.
It may be worth trying a generic opamp buffer layout like this one:
http://i76.photobucket.com/albums/j6/IvIark_2006/Layouts/Vero/ICBuffer.png
or the Klon buffer I just posted on the blog, just to see how you feel your gear responds to them.
I just used the 100nF cap. I suppose I could try a 10uF. Would that reduce "resistance" in the signal? I am also going to have a couple guitarists put this on their boards. Im going to see if they think they lose anything by having it.
ReplyDeleteI just am running 25ft mogami cable from guitar to board(board runs through 5 pedals) then another 25ft mogami to my amp. So if anything, I guess I expected to have more highs in my signal... or is that not supposed to happen after going LowZ
also, what type of IC should go in that first buffer? perhaps a TL072?
hey, would this work to balance the impedance mismatch between a piezo pickup with a magnetic one do you think?
ReplyDeleteDamn you. I was going to take this one down next.. :) Well. I think i can call it a day..
ReplyDelete+m
Ha ha, sorry mate, I found someone who built it on FSB
DeleteHello, what is the purpose of the 100R input resistor? The Beavis Jfet buffer does not use one... Also what happened with the discussion about the output capacitor? should I try the 100n or the 10u?
ReplyDeletebest
Hello, what is the purpose of the 100R input resistor? The Beavis Jfet buffer does not use one... Also what happened with the discussion about the output capacitor? should I try the 100n or the 10u?
ReplyDeletebest
It's a current limiting resistor. Some people like to included them, others aren't bothered but it can help with switch popping
Deletebut if you intend to leave the buffer on all the time, instead of turning it on and off, would it be ok to remove it?
Deletethanks
I ran out of mpf102 and 2n5457, so I used a j201, would that be ok or this one will give me higher output impedance?
ReplyDeletethanks
also I removed the 100R and 1M resistors (I assume that the last one is a pull-down resistor right?)
Deletethanks
what i have to do to turn the phase 180 ° so that i have a buffer that inverts the phase?
ReplyDelete