Firstly, Happy New year!
Secondly, sorry the pictures aren't very good/clear in this post, I should have taken them in the daylight, but I forgot and it's impossible for me to get good close ups with a flash indoors ... but I will try to describe things the best I can.
So, anyway after making my LPB-2 'true bypass' I decided later that I would like to add an LED too, I've been asked how I wired this, so this post will explain that clearly, hopefully.
The negative wire from the LED is going to the top left of the 3pdt as usual (see switch diagram below) the positive wire from the LED is going to the middle left pole on the slide switch (with a resistor in between to stop the led blowing) the led will turn on and off when you slide the switch. There is also 2 resistors on the same lug of the switch.
The Negative battery wire goes to the top left lug of the slide switch and the positive goes to the ground lug on the output jack... don't ask me why, that's how it was! To be honest it's pretty confusing looking at the mess of wires and parts inside this thing.
The rest of it is wired as it was before but with a 3pdt..
If you have any questions about specific wires and where they are going it might be easiest to leave a comment below and I can look at one thing at a time and answer quickly.
you can find the original post about the LPB-2 and other related posts about bypass here.
I think your blog is wicked. Happy New Year. I'm into synths and drum machines etc but like to use fx pedals on them - I'm following your blog posts and bought the parts and built the first 'getting started' pedal you described. Keep up the good work. Nick.
ReplyDeleteOne question if you have time - do you use a drill press or get by with a hand drill? I'm thinking of getting either a little vice for my table or cheap fold-away work bench with wind in grips to hold the boxes and just using a hand drill. I'm really tight for space in my flat. Cheers.
Hi there, thanks for the kind words. yeah, I still get by with the same £10 hand drill I bought from argos in 2010 when I first started this blog, if you click the 'drilling' label at the side there there's a few posts about how I drill my cases and what I use. I use a cheap fold away work bench to hold the cases when I drill them, it all works fine for the small amount I do, if I was drilling cases everyday then I might invest in a press but I only do about 1 month at the most so it's not really worth it for me. I don't have a lot of room either (well no 'workshop' or anything like that) so I usually drill mine in my garden. (or my kitchen if the weather is really bad!)
ReplyDeleteThanks for that.. I didn't notice you had drilling info at the side of your page. Doh!
ReplyDeleteWill have a read of that now and I think I will pick up a cheap work-bench soon as well. Cheers. Nick.
hi mel, jack here. thanks for this
ReplyDeleteso i tried to just add this on to the wiring i did from your 1st lpb2 post but it didn't work. i rewired according to the abouve 3pdt sketch and it works now but there are 2 issues:
1] there is nothing attached to the ring of the trs input jack
2] the led isn't working. it's old and maybe it's shot. how do i test it without blowing it? just hook it to the battery terminals with the resister at 1 end?
also, as it's wired now, does the battery stop draining when the input's unplugged or only when the slide switch is off?
Hi Jack, on mine I don't have a stereo jack on the input, I never really noticed this until the other day, I presume it's original (both jacks look original) and I presume this is because it has an on/off switch, the way it's wired the battery is disconnected when the switch is in the off position, so it doesn't matter if a jack is inserted or not it just matters if the pedal is turned on or off.... does that make sense?
ReplyDeleteyeah, to test the led just open the legs out slightly, hold a resistor on the positive leg and touch the resistor and the negative leg of the led to the battery terminals, or use an unsoldered battery clip with the loose wire ends, I made a little tester to make things a bit less awkward ... I got a battery clip, soldered a resistor on the positive wire then soldered mini crodile clips to the ends, so I can just clip led's in to test them (I seem to have all my colours mixed up all the time!)
also try switching the wires round on the led in case you have them the wrong way round, it's easy done... need help, just shout.
melx
ok, i'm up and running. there were several factors that made this harder than it should've been for me and my limited electronic abilities. 1st off, i was confused by the fact that i have a trs input, figuring true bypass always does (i guess the slide switch eliminates the need). secondly i had rewired according to the screddypedals diagram above. that is different than the wiring you describe on your earlier post and i couldn't seem to get the led to work with it, even after i switched the leads as (3rd) they were reversed. i re-rewired to your original instructions and added the led to the 3rd row.
ReplyDeleteso now all's well except for 2 things: 1] i was going to ebay the thing off and buy something else but i really like it...very cool, warm sounding boost that compresses a bit. i'll have to try it in a few situations and see if the $$ for that new mic might have to come from somewhere else.
and 2) i can't remember how to log in so that i don't come up as anonymous.
p.s.- just rewired the pedal board. i use a 1spot on this one so the boxes are all daisy chained. i used a battery jumper adapter for the lpb2. no boxes lit up. i unplugged the lpb2 and they did light up. oddly, they''ll all light up if the lpb2 is plugged into the power without the input or output jacks plugged in but the whole board goes dead if either are inserted. i guess the lpb2 is positive ground?
ReplyDeleteYeah, the thought did cross my mind when I saw that the positive wire from the battery was connected to the ground lug on the jack on mine. I must say that I never knew the circuit was positive ground before, the many clone layouts I've seen around the web aren't usually. But I guess those are using NPN silicon transistors, where as this must be using a PNP transistor. To be honest I wouldn't worry about it I've had the same battery in mine since I've owned it (over a year) and of course the on/off switch means you don't have to worry about pulling the jacks out to save battery power, just turn it off when you aren't using it.
ReplyDeleteHi there ..... First of all A Big thanx for all the information About stompboxes you are sharing... I got one of these LPB - 2 and its the´same positive ground ....The One I got is older than this one . and it has Xicon Greenies ( .1 Uf. ) The Transistor is A Siemens BC 239 C
ReplyDeleteCheers ... Greetings From Copenhagen Denmark
Thanks for the kind comments and the info. Yes this one has a BC239 also, I just checked. Does yours have the older style (more plain looking)graphics? Nice to know people are reading all around the world, it makes it all worthwhile.
ReplyDeleteHello again.... Yes mine has the more plain looking graphics here are 2 photos http://www.staalfx.com/2011/12/elektro-harmonics-lpb-2i.html
ReplyDeleteKeep up the cool Work Cheers !!!!
Sweet, that's a really old one! very cool.
ReplyDeleteoh, and I'll be following your blog now too!! you've made some really cool stuff by the looks of it. :)
Thanx....And Thanx for your comment...
DeleteKeep on Rocking....Cheers
interesting. mine must be a transitional one as it has the newer graphics but the big, green thing inside. jack
ReplyDeleteAS this is Electro Harmonix we are talking about here (who aren't exactly known for consistancy in parts)I'd suspect that they just had a big bin of Caps of the same value, all random sizes and colours and the builders just stuck their hand in and pulled one out. The best way to date an old pedal is by pots codes (well it will give you the date of the pot anyway)
Deletehttp://melxfx.blogspot.com/2010/10/how-to-part-five-dating-pots-in-guitars.html
my LPB pots date is '77 so I'd imagine the pedal was made in either 1977 or 1978, what about you guys??
Hello again i´ve been giving my EHX - LPB - 2 a close look and the numbers for your Mel XFiles are XM 2184 and on the other side of the pot it reads 1377602
ReplyDeleteWhat can you make of this ?
Those guys at EHX could really learn something from the guys who made Vintage Tube Amp Like HiWatt - Carlsbro - Simms Watts Etc.
This Booster is really a Mess inside ..
Cheers And have a Cool Week - end
Yep, that's an easy one... '1377602' the pot was made by CTS (137 is their manufactures code) the next two numbers are the year, so that's '76 and the '02' is the week so it was made during the second week of the year, so that pot was made in January 1976, so you can presume your pedal was made early the same year (presuming the pot is the original pot) the other code is not related to age or anything, could be type of pot, a CTS batch number or something like that probably.
Deletelol, yeah it is a bit of a mess inside really... it's pretty funny when you show people the insides though and they are like "does that really work!??"
Oh PS I have solder on top of my 'week code' that's why I didn't mention it while talking about mine ... I might desolder it one day to have a look though.
DeleteFunny .... the guy who made mine used 1/2 ton of solder wire rigth on top of the Date number ...All I could see before I desoldered it Was 137 It was actually a lot of work sucking all that solder Wire Away so I could read the rest of the number ... I Removed the Pot to Clean it...and then later I put it back ....And its Back in Working order again
ReplyDeleteOnce Again ....Thanx