Tuesday 5 August 2014

AMZ 2 channel Splitter

Had drawn this a long time ago and even build a few for my personal use. AMZ buffers are known to be very good in sound quality, so the splitter is that too. It is very modular and it can have as many output channels as needed. The most common use would still be to have simple splitter - one input and two independent outputs. I used this circuit the last time i was in studio to gain two separate signal paths to two different amplifiers. We already have mixers and other utility boards listed, so i think it's time to have this one too. It'll be nice fit to 1590A box.


67 comments:

  1. Speaking of utility boards, do you have a layout of any good A/B/Y pedals?

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    1. Should be easy enough to adapt this one. You'd just need to figure out how to wire up the switches.
      +m

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    2. I am going to run two amps and would like to build an a/b/y pedal that doesn't affect the tone so maybe a buffered one? is there anyway to make up a layout for something like that?

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    3. My cousin who is also a pedal builder drew up this good A/B-Y pedal using this AMZ splitter. Enjoy!! :)

      http://i1148.photobucket.com/albums/o574/paul_rowe2/buffered%20A-B-Y_zpsuffmrbgb.jpeg

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  2. Neat layout. In the event of encountering a ground loop would you recommend adding a ground lift and, if so, which ground connection would you break for that?

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    1. Haven't ever encountered one while using a splitter like this. So no :) I'm not recommending one.

      You could possibly use insulated jacks for both output and wire them up with crude 180 degree phase switch with 2PDT toggles. But as for ground lift, you'd still need two signal wires and that would also mean that you have a balanced device in one of the paths. Those balanced devices will need to have a ground lift. Lifting one of the three ground connections needed here will simply lift your whole signal.
      +m

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    2. Ok, thanks. I built a simple (non-buffered) ABY switch a while back but isolated one of the outputs using a 1:1 transformer. I haven't encountered any ground loop issues (yet) but there's much talk in various forums of the potential for it, and the application of a ground lift to address it, but very little info on which ground to break into. Maybe I've achieved all I need to with the 1:1 transformer already. Anyway, thanks for your thoughts (and for this handy little layout).

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    3. The two wires coming from transformer are your balanced output and you should have a ground in addition to those two wires (hot/cold). There, the ground wire is the one you might want to have the lift on.

      On unbalanced line, the signal is just frequency changes between the hot and ground. Your transformer moves the signal to be frequency changes between hot and cold. The third wire in balanced signal is ground.
      +m

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    4. I was getting a buzz in one particular amp of mine with this layout. Didn't matter which other amp I paired it with. The buzz was somewhat attenuated when both amps were plugged into the same outlet, so I figured it may be a ground loop. I added a TRIAD TY-141P 10K:10K center tap transformer to one output jack. No more buzz, works great.

      One thing to note, for bozos like myself - if an aluminum enclosure is used, in conjunction with mono jacks that allow the metal sleeve to touch the enclosure, the transformer is pointless. There negative contacts for both output jacks will connect and you will no longer have isolation between them. I made this mistake the first time I put the guts inside an enclosure. Took me a minute to realize this.

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    5. Hey, I also want to add an 1:1 transformer, but i'm not quite sure how to wire it. Do i just connect the out 2 and the ground on the one side of the transformer and then its other side staight to the isolated jack (and perhaps a DPDT to change the phase 180 degrees) ? Because in other splitter schematics there is a 1n cap in series with a 10k resistor connecting the output pins of the transformer. Thanks in advance, I'm only 2 and a half years late!

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  4. Useful, imagine a cab sim circuit on the extra output channel

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  5. I have been looking for a schematic for a mic signal splitter. Most I have seen use a transformer. I guess it has to do with low impedance - can anyone enlighten me on why guitar level splitters can be active and not use transformers, but mic splitters are generally non-active but use expensive ($100) transformers? - thank you!

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  6. cool! how could i make this have one more output? would i just duplicate the right half of the circuit?

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  7. So like the Split'n'Blend I could have one output going to effect 1, the other output to effect 2 and the blend them back together with a pot to an output right? This looks like a much more robust design with betters buffers to achieve this.

    Thanks for the layout! :)

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  8. Correct me if I'm wrong, but I think Jack's original blog called for a 0.1 uF (or 100nF) cap at C1, not 100uF...?

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    1. I think you're confusing power filter and the input cap with each other. 100µ is is added power filter to sooth out ripple coming from your power supply. This isn't present in the original schematic. The input cap is 100n.
      +m

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    2. Haha, I realized that later, felt like an idiot! That's what I get for drinking and browsing...

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  9. Thank for this, I used it In a multi effect that I built for a friend, this website is the best!

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  10. I bult this and have been playing around with over the weekend. The buffer appears to work but none of my drives/fuzzes (zendrive, jan ray and lunar module deluxe) seem to agree with it. When I have the buffer after my drives it seems to take away a lot of gain and make the eq more less useless. I also tried placing it in front of my board, at which point the overdrives seem to work fine but my fuzz loses low end. Has anyone had similar experiences?

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    1. Nope.. Mine definitely has no loss any any frequencies, before or after...
      +m

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    2. Hmmm. Must have made a mistake somewhere...

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    3. Checked everything over once more and found a miniscule solder bridge on the board. Everything works perfectly now. Love my sound right now!!

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  11. Hey Mirosol! Thanks for putting this together! I've got a quick totally noob question for you: I've not put many circuits together and am looking to try my hand at this one for a utility piece on my pedalboard. I noticed the Diode in your tagboard as well as the 100n power filter that was mentioned above by Brandt Miller – are both of those necessary for the build?

    When purchasing components I really only ordered enough for the original, so I'm wondering what those are for exactly and whether or not I'll need them to proceed with the build.

    Thanks for your help! I can't wait to put this together!

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    1. Hi.
      Diode is for series polarity protection and the 100n is definitely not a power filter. It is the input cap (as it is in the AMZ schematic). The 100µ is a power filter and i'd highly recommend using it since it'll tame possible noises from the power supply.
      +m

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  12. Dear Mirosol,
    Is it possible to substitue the 1,0uF output caps for non-polarized ones without screwing things up soundwise? Thanks!

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    1. Polarized or non-polar - won't affect the tone whatsoever. Use the ones you have.
      +m

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    2. I know some hard liners think electrolytics have no place in the sound path altogether. I doubt any can even tell the difference but.

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    3. I know synth builders don't prefer tantalums for anything, due to they possible shorting if damaged. They tend to use only electrolytics for both, power and signal paths. That's just for the local builders i know, but still..
      +m

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  13. Hi mirosol, do you think that I can use it to drive my mixer output (left- right) with 4 different powered speaker (2 for left and 2 for right)?

    Paolo

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    1. If the speaker sets are active and the signal is basic line level signal, i see no reason why not.
      +m

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    2. Thanks a lot Mirosol, and if I work with balanced signal did you have a layout to suggest to me?
      thanks again

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    3. Not really. To achieve balanced signal you'd probably need transformers for both channels and the input too. I have no idea how to do that.
      +m

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  14. Hi,

    I built this one and the volume is very, very, very low on each channel... I triple-checked everything but I can't see what's going wrong.... Any idea?

    Thanks a lot

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    1. I'm having this same issue on this build. Any solutions out there?

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  16. Here is an A/B-Y layout using this AMZ splitter. Enjoy!! Tj and I built a dual A/B and A/B-Y pedal and used the splitter on the A/B-Y portion. below are pics of the layout and pedal.

    http://i1148.photobucket.com/albums/o574/paul_rowe2/buffered%20A-B-Y_zpsdfptgcke.jpeg

    http://i1148.photobucket.com/albums/o574/paul_rowe2/4a9ff788-1574-428d-a466-7880f60e02fb_zpsshr3vf3e.jpg

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  17. I'm thinking about building this one.
    But would it make sense to run this at 18V for more headroom? Since I tend to push my amps really hard with an EP Booster. Or is there enough headroom?

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  18. Has anyone put this into a 1590A yet?
    Any suggestions on placement of all the parts? I need to place this underneath my pedaltrain 2

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  19. Hi, I have built the three output version of this off the AMZ website but I'm getting really weak signals on all three outputs, also two of the output signals are at different levels.

    I trust the circuit but i wonder if anyone could shed some light on whats going wrong?

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  20. Hi, mirosol
    Is it possible to substitute 1n5817 to 1n400x?
    thanks

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    Replies
    1. yeap..there is no problem using a 1n400x. this diode is for polarity protection

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  21. Hi! It's possible to add a tone pot and a volume pot to one of the outputs?
    Thank!

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  23. Hello. I want a splitter to use it with fuzzs in parallel but the lvl and impedance drop of splitting and buffering would mess with their inputs if not set right. So i look for someone with more experience than me here to help me out. Someone has deal with this issue and solved it?

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  24. Hi! Hope this isn't a newb question, but if I'm building an A/B pedal, wouldn't the addition of a 3pdt footswitch remove the need for two outputs from the buffer? If so, would there be any difference in sound between using the two output buffer and a single output buffer?

    Also, if I wanted the option of switching to true bypass a/b, could I put a switch inbetween the input and the board, leading straight to the 3pdt switches?

    Thanks!!

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  26. Hi! I want to split the output Signal of an organ, which is quite a loud signal. Will this circuit have enough headroom? If not, would adding a voltage divider like you would do with a normal jfet buffer help increase the headroom?
    Hope that someone can help me. :) Thank you!

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  27. Hi. I built this a long time ago, but would like to add a phase reversal switch. I guess using a dpdt on-on and Wire it like this :

    - -
    - -
    - -

    Lug 1 to lug 6
    Lug 2 to lug 5
    Lug 3 from board output 1
    Lug 4 to output

    Is that correct?


    -3 -4
    -5 -6

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  28. Hi, I build the splitter today. It works. But I does not work with 2 guitars going in the outputs and the input going to the amp. In other words it does not work backwords. Can the splitter be modified so that I can use 2 guitars and 1 amp. Thanks for your help.Leon (the Netherlands)

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    1. It will not work backwards, no pedal should. Look at the layout for a 2 channel mixer.

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  29. A normal splitter will work as you described but this splitter is buffered(meaning the signal is being pushed in one direction). You need a non buffered A/B pedal

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  30. Could someone please direct me on how to add another output? I’d like two lines going into my interface and one going to my amp.
    Any help is appreciated

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    1. Simply solder an extra 1 uF(polar or non polar) cap to the S of the J-fet on the right side of the board to where the other outputcaps are connected.

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  31. Would it be possible to run this on a 12v centre positive power supply?
    I reckon reversing the diode, polarised caps and transistors would do it, but does anyone else have any words of wisdom that I’ve not considered?

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  32. Hi, I added one kill switch after each voices to be able to kill the signal (the signal is send to the ground with a dpdt).
    It works fine when none of the signal is killed, when only the output 2 is killed, but when only the output 1 is killed,I'm loosing the signal of the output 2 as well.
    Does anyone have an idea which might causes that? Thnaks!

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  33. Hi, is this the kind of splitter where input impedances need to be high? Or can I use it later in my signal chain, like splitting a low-impedance signal to go through parallel effects? Thanks!

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  34. I'm really stumped on this build. I get signal from both outputs but at a drastically reduced volume. If I remove the input capacitor, the volume drop isn't as drastic but I'm definitely losing a noticeable amount of signal. I've inspected for copper traces and solder bridges over and over. I've replaced components. Nothing seems to work. Help!

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    1. I probed all the components and the volume drop is present all the way to the input wire. Why would that be?? I replaced the wire, thinking maybe it was broken. That didn't fix the problem.

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    2. I replaced Q1 and C1 and that fixed everything. I don't know if my first transistor was faulty or if I damaged it somehow, but the circuit works perfectly now and really sounds fantastic!

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  35. can someone teach me how to read a bloody schematic? I'm not used to this at all.

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  36. I built this and am running the signal to two separate peadal boards. Then from the amps to a mixer. Even if I unplug an amp I'm getting bleed through of effected signal from one channel to the other.. it is driving me crazy

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    1. Hello, how did you solve this problem, i have the same

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    3. If you are getting bleed it is more than likely the wiring of the switches than the circuit board itself. I would debug your switch and jack wiring first to ensure it's true bypass.

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