Matching input/output loads in series with pedal switcher(s)

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Joined: Sat Oct 24, 2009 4:24 am

Matching input/output loads in series with pedal switcher(s)

Post by shai-ann » Sat Oct 24, 2009 5:54 am

Hi there one and all.. my first time at this so please bear with me!!

I have a stereo setup: Guitar into a Teese Picture wah, then a passive Tonebone A/B splitter, then
A channel- Pedal switcher, (use a Commander) then into A input of Voodoo Lab Amp Selector
B channel- No effects ( except when wah on of course ), and into B input of amp selector.

I have a few pedals I use, but should I only have one effect per switcher loop??,

Loop1- Keeley Java Boost, (and going to add a JMI or D*A*M Mk2 tonebender)
Loop2- Mad Professor Phaser, then a Fulltone Choralflange, then a Fulltone DejaVibe.
Loop3- EP3 Echoplex
Loop4- Mr Springgy reverb into Maxon AD900 delay

Could I be getting impedance load/buffer issues between these eg Java boost and Springgy reverb pedal (loops 1 & 4 active?). Or just between the phaser and chorus on loop 2, even tho they are all supposedly true bypass when not on?

I also notice that when I have the Java Boost ONLY (loop 1) engaged, that it has a serious impact on tone (turns muddy, significant volume drop in my B channel (clean), unless I use the buffer input on the switcher- but after watching the great and informative clip on having two switchers in series, I realise that all germanium type effects should not be buffered at the input, but like to see a buffered load at the output??! Correct, or not?? I think a second switcher is definitely on the cards, but need some advice/ideas on this! And what about the buffers on the amp selector? What impedance loading are they showing the pedal switcher(s)? I could put the proposed second switcher onto channel B,(unbuffered input) instead of in series in Channel A, with my fuzz and java boost on it? And then A/B both switchers on loop4 and do away with an amp selector altogether?? But don't really want that as I like one dry channel, and one wet (again except for the wah)??

Also am getting some hum (ground loop?) thru the switcher when I power up the echoplex...

Finally, a little unrelated but amp output 3 on the amp selector breaks up intermittently with some serious bad noise sounding like a faulty contact?? Moving the volume level, although REALLY scratchy when I move it, sometimes rectifies this, sometimes not?? I have four amps plugged when at home, so can't just switch to amp 4 output to fix....


BTW all pedals are powered up with a Burkey Flatliner, so no problems there..

Thanks for your patience in hearing me out!


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Re: Matching input/output loads in series with pedal switcher(s)

Post by JohnClark » Fri Oct 30, 2009 4:37 pm

Wow, that is an impressive rig setup. I'm afraid I have to give you the age old response first however, and suggest simplifying this down to the simplest setup that still yields the problem.

"impedance load/buffer issues"- One thing I see is that you are trying to not buffer some effects yet split the signal post most of the effects. This passive split will likely result in loading down your pickups if its used as a Y... I assume that is what you are doing when you say this is stereo, right?

"hum (ground loop?)"- Not sure how this could be other than to scrutinize how it is powered and how it is all mounted. Is there metal to metal contact between the two chassis somehow, or is there a proximity effect that will go away if you move some gear around? Again, really the way to start here is to simplify untill the problem goes away or you are left with only one thing left and the buzz is still present.

For the Amp Selector, you can try your luck cleaning the pot but it may be best to arrange an RMA to send it in for us to take a look at it. This is of course after simplifying it down to ensure the noise is the Amp Selector output itself rather than an interaction with some other device.

Good Luck, and take some pictures of this setup for us, would you!
---------==Voodoo Lab Magician & Tech==---------

Posts: 9
Joined: Sat Oct 24, 2009 4:24 am

Re: Matching input/output loads in series with pedal switcher(s)

Post by shai-ann » Sat Oct 31, 2009 5:27 pm

Hey, thanks so much for the response! I'll certainly do as suggested when I rebuild my board, and attempt to isolate the buffering issue, esp. with the Java Boost. Might be a month or so ( I'm in OZ 4 a break right now! ), but when I return to NZ I'll get back into it, and send you a pic or two of my rig.

I'm going ahead with two pedal switchers, and a Ground Control Pro now!!

I'll keep you posted on the Amp Selector issue also...

Many thanks,

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