DiY Buffer

Steven Paris · Post by **Steven Paris** » 19 May 2016 9:49 am

Whilst on the subject of buffers, WHAT is the voltage output of various pedal steel guitar pickups? I am lead to believe that it is higher than most 6-string pickups--how much and why? Is it more windings? Some have posted that the outputs of some pedal steel guitars "overload" the front end of old Fender amps---is this true? Anybody done any research on this?

Lane Gray · Post by **Lane Gray** » 19 May 2016 10:26 am

Our transients can easily exceed 1100mV from a single note.

Dan Haas · Post by **Dan Haas** » 19 May 2016 10:46 am

I thought I would provide some values for Georg's modified buffer. They should be a good starting point, pretty level through range peaking between 5K-6Khz. (6-8db)

Steven Paris · Post by **Steven Paris** » 19 May 2016 3:01 pm

Hmmmm......I thought we were talking about a BUFFER, not an EQUALIZER!! That circuit, as drawn, will provide about +7.5db boost at ~5.8KHz. That's a pretty fair amount of mid-high boost to be puttin' in!!

Lane Gray · Post by **Lane Gray** » 19 May 2016 6:02 pm

Also most of our favorite speakers start precipitous drops an octave below that.

Steven Paris · Post by **Steven Paris** » 19 May 2016 7:07 pm

Also most of our favorite speakers start precipitous drops an octave below that.

Yes, Lane you are correct (as usual). After I looked at the response curves of some Eminence speakers, I realized that +7 1/2 db @ 5.8K ain't so much after all! The speakers' curves I viewed were down >20 db at 6K!

Mark Smilor · Post by **Mark Smilor** » 23 May 2016 8:02 am

I made these little guys over the weekend from a board I drew up but haven't hooked it up to the steel yet. It was a schematic I found for a company in Italy that went out of business a few years ago and left their schematics available for use and thought it would work good on the steel. They had it set up for a 3PDT switch but thought it should stay on at all times so I left it out of my CAD drawing. Plus I wanted to fit it in the smallest enclosure I could.

John Gould · Post by **John Gould** » 26 May 2016 9:36 am

Well my favorite sounding buffer that I have built is a tube buffer.
It works well in front of a sterile sounding solid state amp . I like it better than any of the op-amp or J-fet bufffers I have built . I don't use it on Pedal steel , I have it on one of my guitar pedal boards .

Craig Baker · Post by **Craig Baker** » 26 May 2016 10:07 am

John,
Just curious, what tube did you use and why aren't you using it on pedal steel?

Craig

John Gould · Post by **John Gould** » 26 May 2016 10:21 am

I built one around a 12AU7 and one around a 12AX7 .
I don't mind , if fact like he sound of my solid state amp for Pedal Steel but for my 6 string I like the harmonic stuff that comes off the tube even though I'm not asking it for any gain. It's a subdued change in the sound but everyone comments when they hear me use it. I just keep tinkering around with stuff, keeps me out of trouble.

Craig Baker · Post by **Craig Baker** » 26 May 2016 12:36 pm

Great ideas John, and never stop tinkering, been doing it as long as I can remember. I've always been sort of a child prodigal.

Craig

Dave Hepworth · Post by **Dave Hepworth** » 31 May 2016 8:24 am

I am currently building the modified Buffer with the 5/6 kH boost as quantified by Dann Hass 's reply .Will post when done.Hope it works lol !!

Lynn Kasdorf · Post by **Lynn Kasdorf** » 1 Jun 2016 7:19 am

I found this nice discussion of types of buffer circuits.

http://www.muzique.com/lab/buffers.htm

I built my own 741 opamp buffer back in the late 70s. I built it because I was an electronics geek and too cheap to purchase a goodrich buffer box, since I knew it was just a simple buffer amp. I stopped using a buffer amp when I went to a Hilton pedal.

However, I think I may build a JFET buffer and see what that sounds like. I have an old Sho-Bud amp that uses JFETs and I love the tone of that amp.

Dave Hepworth · Post by **Dave Hepworth** » 1 Jun 2016 7:33 am

Hi folks,
Here is my "upgraded" DIY buffer.Made from a sweet tin and sprayed up.I followed Dann Gass's values ,but left the filter out of power in ,as I use a battery.I put a 2.2 mf cap non electrolytic across the output and I got nothing! I took a 1.1 mf electrolytic out of an old guitar pedal and parraled that (as shown on photo).This time it worked !
I have to say it certainly gives a more crisp sound than the first buffer and is really good sounding and would probably use this more than the other.
Why does the circuit suggest an electrolytic and a non electrolytic together ,and can someone explain the difference please.
Thanks for looking Dave

Dave Hepworth · Post by **Dave Hepworth** » 1 Jun 2016 8:11 am

Thanks for the reply George,
Does that mean my 2.2 mf film cap on its own was faulty .Perhaps burnt by the soldering iron ,doesn't appear burnt .I got no signal initially.

Dave Hepworth · Post by **Dave Hepworth** » 1 Jun 2016 2:27 pm

Hi again George,
I think I now why buffer gave no signal initially.
I got the wrong value output cap.It was 2.2 pf not 2.2 uf .it was very small value.Would that have caused the no start up?
Incidentally could I use a 2.2 uf tantalum on its own on output rather than an electrolytic plus another in parallel .
Thanks for looking .

Dave Hepworth · Post by **Dave Hepworth** » 2 Jun 2016 1:32 am

Thanks George ,will get these values from Maplins today.I will let you know how I get on.
Regards.

Craig Baker · Post by **Craig Baker** » 2 Jun 2016 5:02 am

Dave, you did an excellent paint job.
It's not often that I disagree with Georg, but for the best sound a buffer should be a brighter shade of blue. I can't explain it.

Craig

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