# Buffered/Transformer Isolated Splitter



## JamieJ (Nov 20, 2021)

This is an isolated splitter pedal that is really good at dinging hum.

It's a simple TL072 buffer into a transformer with a phase reversal switch. The transformer isolation aspect of the circuit seems to be inspired by some of RG Keens ABY isolated splitter circuits. I used a different transformer to the original but they have the same specs.

I haven't actually properly tested this out yet so it may be a tad premature. I really enjoyed building the circuit on Vero. I might try and build a few other pedals this way.

I decided to not bother with any designs/name for this build as it will just be under my board. When I was thinking about names I did a bit of googling for name inspiration and urban dictionary made me piss my pants and emailed @jjjimi84 straight away - see below. I was tempted to call this build Dans Dinger for a while but changed my mind.




I'm a big fan of the TPS show. I haven't ever bought anything from the gigrig before but love their stuff so I feel bad about building this but I might buy a bit of TPS merch as an offset.


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## Bricksnbeatles (Nov 20, 2021)

Kudos to Dan.


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## giovanni (Nov 20, 2021)

I would like to build one of these, would you mind sharing the schematic?


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## jjjimi84 (Nov 20, 2021)

Well it is the same color and girth.


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## JamieJ (Nov 21, 2021)

@giovanni - I got the schematic from this site 





						Humdinger V2 - EasyEDA open source hardware lab
					

In EasyEDA open source hardware lab, open source square pools all kinds of electrical design engineerings together to realize resource sharing easily.



					easyeda.com


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## giovanni (Nov 21, 2021)

Thank you!


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## giovanni (Nov 21, 2021)

No protection diode on the power?


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## JamieJ (Nov 29, 2021)

giovanni said:


> No protection diode on the power?


Sorry I missed this. No there isn’t and I didn’t bother adding one. I might add one though - good spot.


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## Dan0h (Nov 29, 2021)

Dude thank you for sharing this. I might give it a go. Please let us know your thoughts after using it.


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## Dan0h (Nov 29, 2021)

This gets even better. I have a pile of tl072s and an extra 1:1 transformer I bought in error. Sweet.


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## fig (Nov 29, 2021)

Dan0h said:


> I have a pile of tl072s


Have you ever considered heaps? [I can just hear the groaning]

Righteous execution Jamie! ✊


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## giovanni (Nov 29, 2021)

Heaps and piles and stacks.


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## Dan0h (Nov 29, 2021)

fig said:


> Have you ever considered heaps? [I can just hear the groaning]
> 
> Righteous execution Jamie! ✊


When I visited Australia 🇦🇺 they used “heaps” a lot. Now when I hear that term it takes me back. 👍🏼


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## Klhnikov (Jul 3, 2022)

Hello, and thank you Jamie, I just finished my version of the ABY Box shematic you provided ( with 3PDTs + phase switch + diode )
Here is the schematic...
The pedal works perfectly well, just needs to mention that there must be something plugged into A output before I use the B out, should never use only B plugged in because it needs some ground, and B output is transformer isolated. I can now split my sound between my tube amp (A output) and an Audio interface on my laptop (B output). Thank you again


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