LeftyBassist.com

ok ok, so it's not strictly an effects box, but my adventure of the last two weeks should be shared with y'all.

Bought the mixer on 03/01. The reason for buying it was to allow me to not have to schlepp two amps to gigs where I double on synth bass. I wanted some kind of pedalboard mixer so that I could combine the signals from my bass and my synth and only use one amp.
Overall the construction and attention to detail of the pedal are top notch, as is the case for all of Lehle's products. and of course you get to pay the price for all that goodness, but I digress ...

I take the pedal to the gig. Two nights at the same location, 9:30PM to 1:30AM on both nights. Everything is going smoothly until about an hour to go in the last set of the 2nd night. I'm really digging this pedal cause it's dead quiet operationally-wise, and I can dial in different volumes for either channel. what more could a guy ask for, right?

Suddenly in mid-song, a sound appears that resembles a slowly oscillating LFO. and it's LOUD!! After some mild panicking I realize it's ME and not the P.A. or my synth. There was no time to diagnose the issue, so I whip off the wireless and plug my bass straight into my amp and the mystery LFO goes away ....
The next day I start diagnosing the issue and come to realize the LFO came from the Lehle mixer. Long story short, I wasn't using a power supply, just yer typical 9V battery. When the battery discharges below a certain amount of current the LFO signal appears. it took me a couple of days and a couple of batteries to get to the point where I could capture the issue when it occurred.

Off I go to contact Lehle support ... they are in Germany so there's a huge delay in communication due to time zone differences. After chewing through a couple of batteries, I was able to reproduce and film the issue. Joki - the support guy at Lehle - is astounded at my discovery. He's never heard of such an issue and wants me to return the pedal to Germany (or at the very least Dana B Goods who is the distributor). Meanwhile I'm in contact with the local vendor and Dana B requesting a replacement, 'cause this must be a defective unit wouldn'tcha think? And again the clock is ticking. By this time it had been 10 days since I started this process. My frustration level is mounting daily ....

Two days ago, Mr. Burkhard Lehle himself finally chimes in and tells me this is an expected behavior of the mixer!! And I quote: "A battery life can be in the range of 5 to 16 hours. the Parallel L has a charge pump that doubles the 9V supply to 18V, this pump has a pumping cycle of 23KhZ which you don't hear. when the battery comes to an end the voltage drops and through that the pumping cycle drops too, in that range you can hear it. the solution is to use a power supply or frequently change the battery."

So Dana B is being a champ and sending me a Lehle PS for all the grief I've been through. but hey, I wish I'd have known about this before I bought the mixer.

When I get home tonight, I'll see if I can attach a couple of Dropbox files that'll demonstrate the issue.
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All I can say is Good Frikkin' Grief Charlie Brown!

Great read and an amazing job and finding the root cause, nice to have the designer contact you and hopefully they will create a enhancement request to prevent from happening. Personally after years of playing I almost never rely on batteries unless I do not have a choice. If I have an option I always use a power supply. It kills me when I see all the Duracell adds about all the changes they are making but in reality I wish a 9V battery would stay nine volts then simply die rather than go into an unstable state.

True enough. I'm in the process of getting a Temple Audio pedalboard built, so for now it's either batteries or a bazillion little wires cluttering up the stage - which for me is a safety issue as well as a PITA to manage.

Also, I can't attach or reference the Dropbox video. I'll post it to Photobucket when I get a spare minute or three.

I stopped using batteries a long time ago. The only pedal I have them in (IIRC) is my Boss a/b pedal. The battery only powers the channel indicator LEDs.

video of the offending whine

http://vid32.photobucket.com/albums/d14/mrberger/20150315_174943_zpscgkxx45n.mp4

Sorry to hear it didn't work out for you, Marc. Are you planning on keeping it and running with a power supply from now on? I also haven't relied on batteries in my pedals for years now since I bought a 1Spot. Lots of guitarists still love how the old Boss pedals sound right at the tale end of a battery's lifespan especially their overdrive pedals), but I don't think you want that out of a mixer pedal.

Considering what you intend to use the Lehle for, have you considered the Boss LS-2 at all? IMO, it's one of the most invaluable pedals I own. When I sold off 95% of my pedals a few years ago, I kept that one because it has SO many different routing functions. You can actually route 3 different sources into it if needed, so it's like a mini 3 channel mixer with 3 ins/3 outs, with the option of blending two sources (It has 2 on board channel level controls). I haven't found any other company that offers this kind of option or versatility in such a small footprint. Now I'm using it in my latest band with two bass sources - My main bass (currently my '76 Tele bass) + my Roland GK3B equipped Carvin midi bass. And I actually did run it off a 9v at my last gig.

I ended up mounting a pair of Cioks power supplies to my board, so yes I've kept the Lehle and spent way too much'es munnies on other pedals as of late Had I known about the LS-2 I likely would have gone that route. And that's not to say I won't in the future but for now my needs are being met.