DiY Buffer

Craig Baker · Post by **Craig Baker** » 4 Jun 2016 5:00 pm

Georg,
Why there is no difference when the switch is closed is puzzling. It sounds like the 27pf is shorted, but that seems highly unlikely.
(Wasn't he the Emperor of Ethiopia?)

Craig

Dave Hepworth · Post by **Dave Hepworth** » 5 Jun 2016 7:12 am

Just been to Maplins and defo got some 390k resistors ,also another 100 k and the two caps so will rebuild the the feedback loop.See what happens.

Craig Baker · Post by **Craig Baker** » 5 Jun 2016 9:10 am

Dave,
I just discovered "Gorilla" double-sided mounting tape. They claim it holds 30 lbs. That should support your battery.

Craig

Dave Hepworth · Post by **Dave Hepworth** » 5 Jun 2016 9:37 am

Thanks Craig .Will give it a look at.

Bob Lawrence · Post by **Bob Lawrence** » 5 Jun 2016 9:22 pm

@ Craig Baker:

re:While everyone knows that black steel guitars sound better, for a buffer to work well, it must be in a blue case.

Craig, I'm not sure how accurate you statement is however, it may be just self promotion LOL and to show why I pasted in a few quotes from color-meaning.

"Use blue to suggest precision when promoting high-tech products."

re: Black guitar's sound better

Maybe it's the the mood that the color puts you in, thus you just play better when playing a black guitar.

"Black denotes strength and authority; it is considered to be a very formal, elegant, and prestigious color "

Source:
http://www.color-wheel-pro.com/color-meaning.html

On the serious side , I once read that you were using transistors in your early buffer design. I also read that Jack Stoner took one of your units apart and it had an opamp's . Did you start with transistors and evolve to op-amps?

2. What year did you start selling your Liâ€™l Izzy?

Bob VE1RLL

Dave Hepworth · Post by **Dave Hepworth** » 6 Jun 2016 1:35 am

Hi,
For what it's worth ......There was a food programme on uk tv recentlly where they put students in a room which was lit by different coloured lighting.Red then yellow then green.On each occasion they were given the same food ,only the lighting colour changed.Each different colour brought out different tastes ,eg sweeter,spicier etc.The food industry recognises this phenomenon as a real entity and it will reflect in new culinary ideas both in manufacture and in eating experiences.
I am not surprised that in sound and music differing colours of our tools of the trade will impart a more or less preferential effect.Our senses are all intertwined quite literally in the brain.
Thats why my Mullen is Black.

Dan Haas · Post by **Dan Haas** » 6 Jun 2016 2:49 am

Wow a lot has happened on the post since the last time I looked, that's awesome

10MEG resistor would give about 10db of gain at ~280Hz.
Should hear a difference in the low end.

Another thought....
The resistors may be read from the other direction violet, green, black black brown 75K ohms? (hard to tell from pics)

If they are then there would only be ~3db of gain centered at ~ 19Khz. My old ears wouldn't hear any difference with the short on the 27pf. 3db is not much change to hear.

I also have a BLACK Mullen

Craig Baker · Post by **Craig Baker** » 6 Jun 2016 5:36 am

Bob,
Thank you for the color link; very interesting reading. I hope the "stay-on-topic" police don't ticket us.

The first experimenting I did with low impedance buffer circuits was probably around 1973. In the beginning I used a two transistor circuit in a totally different case and sold a handful to local friends. The present configuration was developed and advertised in 1977.

The circuitry has changed very little over the years, but the appearance has had several make-overs. The first units were a two-tone blue-grey, then blue-white, etc. Here's an early one:

Concerning the color blue, It's like reverb, it's nice, but can be overdone. Every major network uses blue heavily in their news and sports sets. I recently saw a game show where the audience was lit with blue overhead floods. Too much.

Now, let's see how Dave's buffer is working today.

Respectfully,
Craig

Dave Hepworth · Post by **Dave Hepworth** » 6 Jun 2016 6:09 am

Hi Craig ,George and everyone else who cared to look and talk on this thread.Daily buffer report is as follows........
Remade resistor network ,and found little change SO ...took 120p cap out and substituted it for a .002mf cap .Result was dramatic .The sound with cap was really crisp and several db louder .This is a very usable option now ,and is totally acceptable to me.I put the network onto a switch as shown in photos.I may put the new buffer into a proper aluminium project box at a later stage .
This has been an excellent thread folks and I have learnt quite a lot of interesting stuff on the way and wish to to thank you all.Shame it is coming to a close .

Bob Lawrence · Post by **Bob Lawrence** » 6 Jun 2016 6:23 am

@ Dave Hepworth

Good job Dave. Everyone learns from a post like this.

re:Shame it is coming to a close .

It won't be long before you'll tinker some more. Once you get the bug you don't have control anymore. Just ask Craig LOL

Now you need to find a FET based Op-amp and experiment with a similar design .

Dan Haas · Post by **Dan Haas** » 6 Jun 2016 6:24 am

That will give you ~ 13db of gain @ 1.4kHz that is right around the pickups resonant pk. That's quite a bit of drive in that area. Around 700mv of input you will start to see some clipping of your signal (with a 9V battery). As the battery voltage drops clipping will increase. I have measured peaks around 1.4V from a pickup with a 1 MEG load. (firm picking)

This is a good thread keep on tinkering

Craig Baker · Post by **Craig Baker** » 6 Jun 2016 7:02 am

Dave,
Your case appears to be a brighter shade of blue in the most recent posts. That may be why it's sounding better. LOL

Craig

Dave Hepworth · Post by **Dave Hepworth** » 6 Jun 2016 7:03 am

Hi Dann,
Thanks for info.See how it performs on hard picking.I don't play particularly hard though.
Would you say the 120p is about correct then ? With the switch in place it is lot easier to swap caps out.
I like the change the .002mf is giving ,didn't realise I could be potentially falling fowl to square waves !!
,

Dave Hepworth · Post by **Dave Hepworth** » 6 Jun 2016 7:06 am

Craig,
We are having some very sunny days here in UK ......probably sound is controlled by amount of sun .....interesting ! Lol

Dave Hepworth · Post by **Dave Hepworth** » 6 Jun 2016 7:53 am

Will do George ,it will be Friday before I can get the cap,then I have a couple of non PSG gigs over weekend so will report back after.
Regards

Dan Haas · Post by **Dan Haas** » 6 Jun 2016 8:28 am

Hi Dave,

120pf gives a slight boost. I think the circuit is more about not loading the pickup down and keeping the highs.

I agree with Georg my taste likes a little boost 5-6KHz.

I think keep tinkering and testing to suit your taste.

Just be aware that more gain will bring you closer to clipping, as the battery drops in voltage the clipping will increase. The original values will work with the battery dropping down to ~5.5V.

When using the .002uf you can tame the gain by increasing the 100k resistor. 330K give about 6dB of gain.

Good idea Georg it gives him some options to see what he likes. He may want to build a couple of these things

The 820pf will give ~12db @ ~2KHz

On the other subject...
If the sun makes the blue brighter it works for me:)

Dave Seddon · Post by **Dave Seddon** » 10 Jun 2016 12:33 am

Dave, I have spent hours building different buffers and boosters but always come back to the first one I ever built, I've yet to find anything simpler or better. All parts available from Maplins or even cheaper on the net. If you have any trouble getting J201's I got loads.

Dave Hepworth · Post by **Dave Hepworth** » 10 Jun 2016 6:31 am

Hi George and Dan,
Just put a 330k resistor in place of the 100k .I found the gain was not as much but totally usable ,and as you said less likely to overdrive the amp etc. I will keep this value in place and consider this particular buffer done .
To Dave,
Would you consider sending me a couple of these transistors so I could make one of the Buffers you built How much would you want? Did we do a deal some time ago via BSS? Was it some Sho bud parts?
Regards Dave.

Dave Seddon · Post by **Dave Seddon** » 10 Jun 2016 6:38 am

Dave, yes you are right, I can't seem to find your address so if you pm me your address I'll get some in the post for you. No charge. Cheers.

Dave Hepworth · Post by **Dave Hepworth** » 10 Jun 2016 6:42 am

Hi Dave,
Many thanks ,and most appreciated.I looked at Maplins before for the trannies but couldn't see any.Will PM my address.
Regards Dave

Peter Wilson · Post by **Peter Wilson** » 1 Aug 2023 3:38 pm

I just built this buffer - it's based on the Cornish LD-1 but with a different transistor (2N2222, because I already had one), a second output for a tuner, some more usual resistor values, and built in a form factor that works for PSG - leg clips and power LED on the top.

This is the circuit I ended up with...

I built it in a standard stomp box...

And used these 20mm clips from Amazon - https://www.amazon.com/gp/product/B08CQZMNZ1

It works great...

Larry Dering · Post by **Larry Dering** » 2 Aug 2023 5:30 am

Nice job on that buffer. Looks great. Thanks

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DiY Buffer

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