Gotta Split? Lehle P-Split 2

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Too Many Notes
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In the studio, being able to split a signal is simply a fact of life. It's often also a source of multiple problems: ground loop hums and buzzes, signal loss, phase alignment problems, bad tone, etc. The Lehle P-Split 2 is a nifty and inexpensive solution, and it's made for high-impedance connections, such as a guitar, pedals, and guitar amp.

Let's say you need to take the output of your guitar or pedalboard into an amp but also a direct box so you can possibly reamp later, or combine the signal with a modeled amp. And if you reamp, you need something that can take a balanced signal and output an unbalanced one.

Or maybe you want to run two amps. Or an amp and a modeling box.

In either case, what you don't want is hums, buzzes, ground loops, loss of tone, or phase reversal.

Basically with this box, you can do all that stuff and avoid all of the above problems.

Lehle is a German company whose owner absolutely "gets it" and all of its products are built with the very best parts. Even the enclosures are beyond solid, and come with thoughtful touches like top-mounted screws, so that you can use the two provided additional screws to attach the base plate to your pedal board, reattach the top, and have an attachment that is better than velcro (this isn't necessary to do, however, rubber feet are also mounted on the product or you could always attach velcro). I didn't attach mine to anything because I see it as a solver of studio problems of many kinds, as I will explain further.

I could go on and on about what this thing does, but here's the important thing: it's the best of its kind I've found in 25 years of recording work.

Most AB or ABY boxes have no way to lift the ground. So if you want to use two amps on stage or in the studio, whether combined or one at a time, you will get lots of hum and noise. Whether on stage or in the studio, ground loop noise is absolutely unacceptable.

Most AB or ABY boxes also can't solve the problem of two out of phase signals causing phase cancellation that can make the sound thin (this doesn't always happen, but when it does, it makes you want to pull your hair out). This is also not something you want to have with your audio.

Most AB or ABY boxes alter your tone in bad ways. This is because they either provide too much resistance, or if they have transformers to isolate both signals, most have transformers that sound really bad. And I've had boxes incorporating some of the known "standard" transformers that just killed my tone. After all, transformers often have a "sound," and that isn't a good thing if you've worked carefully to create your personal sound.

The P-Split 2 does no bad things to your tone. In fact, it's absolutely transparent; at least, I was not able to hear a difference in my tone with the box in the signal chain. No difference in tone is good.

To test the isolation transformer's ability to kill ground loop noise, before installing the box in my chain, I used a standard AB box to send the signal to both amps. As expected, there was quite a bit of hum and buzz simply by virtue having both amps connected to the AB box.

I then replaced the AB box with the P-Split 2. With the ground lift switch in, both amps were dead silent, the ground loop noise was killed completely. Switching the ground lift off made the hums and noise return. This thing works.

It has both balanced and unbalanced capability. You can find a manual explaining how to use this feature that can be downloaded as a PDF by googling the product. A balanced signal lets it be used as a direct box with a recording interface or sent to, say, an effects box with balanced line inputs. It also lets it be reversed and used as a re-amping box.

The important thing is that the tone of the signal is unaffected. You can even use it in a single amp rig, between amp and pedal board, if attaching your pedal board is making your amp hum (this assumes, of course, that your pedalboard isn't having its own hum issues just from the pedals being connected to each other or a power supply or two).

This box has no footswitches. They make one that does, but you may not need switches so you might as well save money. This thing runs only $169. That's a good price for a gadget this good.

So if you're running two amps and only want to hear one, either put the second amp on standby or turn its volume all the way down. Lehle makes one with switches that does all the same stuff, but in the studio that's not something I need. Switches are expensive, and the Lehle that has them costs $229 and has to be connected to a power supply. The Fulltone box, which is the only other one I'd recommend, is $239.

The P-Split 2 needs no power supply at all, nor does it need batteries. It's 100% passive.

This is a great tool -- if you have a studio, it's a must-have. And because it costs $70-80 less than the only other decent switchers out there (namely, Lehle's own product with switches, and the Fulltone ABY) it's a bargain.

A lot of players like the competing products by Radial. While I think Radial makes good stuff, I have found that their similar product gives my guitar a "crinkly" tone. I can't describe it any other way. That may just be my guitar and amp combinations, but that's my finding. So for studio use...not for me. Fine for live.

In the past, I haven't liked to record more than one amp at a time, because usually it's more trouble than it's worth, but today I got some beautiful tones combining my two amps while testing this box out in my rig, and I can say for sure that it will get a ton of use. This is what it looks like. As you can see, there's nothing to break or wear out, it should last forever:

 
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I have one of those, it's pretty cool. I don't have time to post on how I used it but it's a nifty sucker, way better than trying to use a ABY or something.
 
Yes it is!

Hey, when you have time, if you feel like sharing how you're using it in your rig, that'd be a fun read.
 
Hey Les, thanks for the write-up. And John, I too would like to hear how you use it in your situation.

I don't have multiple amps (well, not counting tiny practice amps etc), so I don't need this yet. But if/when I do get another amp, I will seriously consider this product - it seems to do exactly what I would want.
 
I don't have multiple amps (well, not counting tiny practice amps etc), so I don't need this yet.

I'm thinking that a practice amp is the ideal amp to use clean for delays, etc., along with a bigger, dirty amp. :top:
 
I've heard good things about these. As walkways, solid review Les-Meister!
 
Hey Les this is great stuff, i wonder though since you're using
2 amps at once, did you get the chance to use the EBTECH HUM X?
I saw few demos and it seems a good solution for buzz and ground loops
I'm asking this because i have too much 60 cycle hum in my new house
(Here in Lebanon there's no dedicated ground cable inside power outlets)
So i'm agonizing every time i pick up my 513 and unless i keep my
Both hands on the guitar i'm plagued by this noise even on clean channel
And this wasn't apparent that much with my previous CU22'S with
57/08's which begs the question is 513 pups more prone to hum and buzz?
It is present in SC and HB modes alike ,sorry for the long writr up
But i'm frustrated by this...:redface:
 
Hi G, I haven't used the Ebtech HumX, I've only used their other product. The HumX looks to me like it's designed to be used with grounded plugs and to lift the AC ground in some way, as opposed to lifting and/or isolating the signal ground, which is what the Lehle product does.

Grounding is a science unto itself, and I'd check with local recording studios to see how they're handling the issue. What could be tried is use of a grounding block attached to a true Earth Ground (such as a water pipe that goes deep into the ground) on one end, and to something like a screw on the amp chassis at the other end. Grounding Blocks are commonly used in studios to create a star grounding system, and it is something I used with certain equipment here in the US to reduce signal noise when I had a ton of analog gear all interconnected by patchbays -- certain gear needs a better earth ground than even homes with typical grounded plugs are able to provide.
 
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I know about the water pipe solution Les ,but i live on the second floor
And the way things are i can't hook a wire from a faucet or something to my playing room
So to what extent i can remedy this problem if i used one of these ground loop killing
Devices?
Thx for any additional advice i appreciate it
 
I know about the water pipe solution Les ,but i live on the second floor
And the way things are i can't hook a wire from a faucet or something to my playing room
So to what extent i can remedy this problem if i used one of these ground loop killing
Devices?
Thx for any additional advice i appreciate it

I'm the wrong person to ask about this. The Lehle will certainly eliminate ground loops using either its isolated or ground lifted jack, but I have no idea if the problem is merely a ground loop, or insufficient grounding at the amp itself. Lots of amps (and other equipment) are designed to use grounded plugs, and their grounding schemes will not work properly otherwise. So you could buy something thinking the problem is between, say your pedalboard and amp, and it turns out that the problem is the amp needing to see a solid earth ground, and humming because it doesn't see a good ground at the wall socket.

100% of my experience in the studio is with grounded AC outlets, not ungrounded ones. US buildings haven't had two-prong AC outlets in 50 years.

In fact, both of the recording studios I booked for sessions in Europe had their AC outlets converted to US style grounded outlets (Wisseloord in The Netherlands, and Plus XXX, Paris), and that was a decade ago.

I'm not saying this is necessarily the problem for you. I'm saying I have no idea whether it is or not.
 
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I'm the wrong person to ask about this. The Lehle will certainly eliminate ground loops using either its isolated or ground lifted jack, but I have no idea if the problem is merely a ground loop, or insufficient grounding at the amp itself. Lots of amps (and other equipment) are designed to use grounded plugs, and their grounding schemes will not work properly otherwise. So you could buy something thinking the problem is between, say your pedalboard and amp, and it turns out that the problem is the amp needing to see a solid earth ground, and humming because it doesn't see a good ground at the wall socket.

100% of my experience in the studio is with grounded AC outlets, not ungrounded ones. US buildings haven't had two-prong AC outlets in 50 years.

In fact, both of the recording studios I booked for sessions in Europe had their AC outlets converted to US style grounded outlets (Wisseloord in The Netherlands, and Plus XXX, Paris), and that was a decade ago.

I'm not saying this is necessarily the problem for you. I'm saying I have no idea whether it is or not.

Hello sir! Curious if you think the Lehle P Split would help in reducing interference from single coil pickups... I just moved into a new studio and have had at least 5 electricians verify there is no ground loop or issue with our power. Isolation transformer did nothing. Ferrite chokes did nothing. The power company has verified something in the neighborhood is amplifying the EMI on the street... Thanks so much for your help!
 
Hello sir! Curious if you think the Lehle P Split would help in reducing interference from single coil pickups... I just moved into a new studio and have had at least 5 electricians verify there is no ground loop or issue with our power. Isolation transformer did nothing. Ferrite chokes did nothing. The power company has verified something in the neighborhood is amplifying the EMI on the street... Thanks so much for your help!

No, it is designed to isolate signal ground from two devices plugged into AC outlets.

Totally different problem than pickup noise, which has absolutely nothing to do with grounding. Single coil pickups get their noise from electromagnetic induction.

In other words, if you’re in a house where there are appliances, AC wiring, refrigerators, fans, heating and cooling - that is, nearly every home and building in America - you’re going to get single coil pickup noise to one degree or another.

Guitar pickups work on the principal of magnetic induction; they’re like little radio antennas for electromagnetic noise. So they pick up noise. And appliances, AC wiring, dimmers, anything electromagnetic in the vicinity, AC power wires near your house, will generate electromagnetic noise.

That’s why they invented humbuckers. Humbuckers “buck” noise by having two pickups wired in parallel and 180 degrees out of phase. The out of phase thing is noise cancelling, like a balanced audio line. Though even humbuckers will pick up some EMI.

Those single coil suckers are going to pick up noise regardless of whether your amps and other equipment are properly grounded.

Usually there’s a room in the building where EMI is lower. For example, in a basement, where you’re near the furnace, the AC, the fuse box that sends power everywhere in your house, there’s going to be more noise. If you’re in a room near computer monitors, televisions, refrigerators that have electric motors (all do), there’s more noise. If your house is near power lines, more noise.

Etc. To prove this, turn in a circle with your guitar volume full up. Some positions will be noisier than others. With single coils, you need to face directions where there’s less noise.
 
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Thanks for the info. Unfortunately the EMI is throughout the neighborhood, confirmed by the power company. Unfortunately Im the only one it bothers, as most people aren't a running a newly opened recording studio. : (
 
Thanks for the info. Unfortunately the EMI is throughout the neighborhood, confirmed by the power company. Unfortunately Im the only one it bothers, as most people aren't a running a newly opened recording studio. : (

As a studio guy, believe me, I get it.

I suppose you could have a Faraday shield put inside your walls, if you really want to be a madman...

They do make noiseless single coil pickups that could reduce the issue, or you could migrate to humbuckers. Or you could be That Guy Who Moved Because of Guitar Noise. ;)
 
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