-Heavy bottom. Rich harmonics. High tone which is not too peaky. JBK-1.0 is what all guitarists have been waiting for. In today's music scenes, players are often required to make all kinds of sound with given amplifiers. JBK-1.0 will help you in such situations.
-It covers quite wide range from soft and delicate crunchy overdrive to rock-crushing hard overdrive. Set it as a hard driver with a clean setting amp. Set it as a clear booster with a overdrive setting amp. You will feel sharp sound coming out of the P.A. system at your body.
-Today it is naturally required for professional guitarists to control the color of sound with adjusting the guitar volume. You are lucky! With this JBK-1.0 you feel as if you were controlling the distortion directly with your guitar volume.
-Try it in loud, anyway. You can get the chopping sound even with a clean amp. You can also adjust the "HEAVY" knob to change that chopping feeling.
-This new lineup of Boot-Leg, JBK-1.0 can be used as an amp simulator. This is a big news!
F*ck, I'm out of 50k pots!, hope on this coming week I get my tayda order with a bunch of them as I'd like to build this effect.
ReplyDeleteA quick question, for pedals building purpose, when using rectifier diodes like this (1N4002) you can use use any 1N400X?
As we don't use the power rectifier featura of these diodes, just the V drop, it seems logical that we can use any diode of these series, isn't it?
BR
P.S. Yes, I have a TON of 1N4007s and don't want to buy more of this class if not mandatory :P
1N4007 should be just fine. Main difference is the rated maximum voltage those can handle. The 1N4001 is rated at 50V, while 1N4007 is rated at 1000V. All the other specs are the same. Expect for junction capacitance. That's the reason why 1N4001 (15pf) and 1N4007 (8pf) may sound different when used for clipping... So sadly.. You need to stock up on 4001s too to have a decent stash:)))
DeleteIt should sound fine with any 1N400X, but the capacitance is half for 1N4005, 6 and 7.
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Thanks Miro, I'll order another ton of 1N4001s too :P.
DeleteBR
Good thing those are really cheap :) I have a bunch of 4001s, 4002s and 4007s.
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Yeah! I've just ordered 100x 1N40001. € 1.11 s&h included, nice price!
DeleteI have just built this but only get a very broken low level signal; a bit more with a humbucker than single coil but neither useable. The voltages look reasonable. I tried injecting a 1k sine wave audio at various points and the thing is pretty dead, ie a whisper at the output, until pin 7 when op 3 comes to life.
ReplyDeleteI have tried to reverse engineer the schematic it but its a bit of a brain frizzling exercise which I have probably got wrong or misunderstood. It seems that the Non inverting input of OP2 is connected to the inverting input of op3 which seems weird to me. i.e pin 9 via two 10k resisters to pin 5 which are split halfway and connected via 5.6k and 1uf to the inversting input of OP2 (pin 6.)!
I tried to find the schematic via google but got referred back to this site with a reference to Tonepad. I looked on Tonepad but could not find the schematic there. Could you provide a URL for the schematic please. It way well be right and my soldering is more likely at fault but I cant see any obvious problems that I havn't already fixed.
Schematic is available at FSB for registered members. I will double check everything once i get back to my desk.
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The pin 9 is connected to vref....
DeleteJust had a quick look and don't see anything wrong with it. Mark?
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There's a 10K resistor between 9V and ground instead of Vref and ground.
DeleteThanks.
DeleteI was looking at the wrong part of the layout. The vref network won't work as is, so i'm putting this on hold. - And fixing it asap once i'm back home.
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Norwichbadger: desolder the middle 10K of the three and solder it back from the top row to ground.
DeleteFixing this will take some rejigging...
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I think I was following the same train of thought. Even though I saw it wasn't the case, for some reason I kept thinking top row was 9V and pin 4 was Vref, probably because we both often have 9V on the top row.
DeleteOh well. These things happen. I fixed it already, but i can't export it to png with this machine. I'll post the fix in about 24 hours.
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If you want to win get a Finn! It now makes the sort of horrible racket that a young person playing electrified guitar in a popular music combination might like to make. In other words your mod has fixed it. Thanks Miro.
DeleteKeith
Good to hear you got it running.
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Layout fixed by the way...
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Forgive me if I don't rebuild this but eyeballing your elegant re-working I can't see any problems. I canabalised another effect to try this and have ordered more bits to make it permanent and will box it asap. It goes from heavy to light OD just using the volume control. Recommended. Thanks again.
DeleteNo worries mate. I'm just not sure enough.. Let's wait until we get another report in...
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unverify
ReplyDeleteDon't have a slightest idea what you're trying to say.
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yes cause I really2 did't yet finish to verifying this layout, still to find the way out
ReplyDeleteIf you build the original with an error, you should just desolder the middle one of the three 10K resistors and take a new 10K resistor from top row to the second. That's how you can get it to work.
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I built it and it's not working. All I get is a very high pitch squeal when turning the "Break" knob. I can hear that the other knobs are working although no signal goes through. The "heavy" seems to be backwards because when I turn it back, the high pitch squeal gets louder.
ReplyDeleteI am sorry to note that your build does not work and in view of your considerable experience in getting these effects working I reverse engineered the schematic from v2 as I did with version 1. It seems to be the same as the corrected V1. The circuit is basically:- OPamp 1 a unity gain buffer, OPamp2 is a distorting stage like that in countless overdrives eg SD1 with diode clipping in the feedback loop and a parallel variable resistor which in other units is called "Gain" but here is called "Break". OP3 is an amplifying stage which feeds a simple tone control (Heavy) and then a Volume control (Level.). OP4 is not used.
DeleteYour fault description of the squeal getting loader when you back off Heavy is consistent because tag 1 is fed from the output of OP3 (pin 8) via a 2.2k resistor and a 10uf cap and tag 3 is earthed via a 10 nan cap. Tag 2 goes to Tag 3 of Levels o as you turn heavy back the treble cut is reduced and the volume goes up. I can't be of much more help except to note that when I built mine I forgot to put in the under chip links before I soldered the socket on. What a joy it was to fix that! If perchance you did a similar thing or have a dodgy connection between pins 1 and 2 that would account for the symptoms you describe. There would be no feedback from the OP1 output (pin 1) to the OP1 inverting input (pin 2) but pin two would still be connected to pin 5 (non-inverting input of OP2) via the 39nan so the OPamp1 would be free to oscillate and share it with the following stages but no guitar signal would get past OPamp1.
I have now boxed this and its still verified but I owe Geiri an apology. I had previously just briefly tested Miro's fix to the first version with all the bits spread out on the table. I should have boxed it before giving an experienced builder advice! When boxed it squealed like a good'un until I took the back off and pulled the board out of the 110 x 60 x 30 box. When I tried to wiggle it to find my "intermittent fault" it squealed again when I had thumb and forefinger across the board lengthways. I put some insulating tape on the sides of the box and under the lid and refitted it. Crazy squeal went away.
DeleteWhen the manufacturer says "Amp Simulator" maybe they meant "Amp" because beyond about 11 o/c it's way too loud! Level at 8 is unity and 9, is a good lead level. Mine still squeals a tiny bit at high gain (Break) settings with single coil guitar at full guitar volume but that disappears with the guitar volume backed off a bit. With Level and "Break" well backed off it's stable if a bit fuzzy but with the guitar backed off as well it gives a useable o/d sound.
The "Heavy" control doesn't do much beyond a "Tinny to Muffled" basic tone control. I use mine at about 3 o/c.
I shall probably keep this because I know it can drive almost any old amp if needs be but if I was going to sell it on I would get a signed disclaimer and maybe put one of those Nuclear Radiation warning signs on it! I call mine "Lawbreaker".
Just to confirm, this can definitely be tagged as verified. For me this circuit shines most when boosting a tube amp, with the amp set for breakup and the Jawbreaker set for low gain it sounded really sweet. My 15 watt Blues junior will never sound like a Marshall stack when overdriven and I've built all kinds of boosters to see what I can get out of it, the Jawbreaker doesn't really push the amp that hard but it adds a bit of body to the sound that seems to compliment my set up. To be honest with the amp set clean and the gain cranked on the pedal I wasn't really a fan, it almost gets into fuzz territory and it's incredibly noisy, though this could be a bad tl074 I guess.
ReplyDeleteGeri: I got a little squeal at one point but it turned out to be some debris across the pins on the pot, I reckon you've probably tried that but if not it may be worth a try, also you're spot on about the heavy knob but I think it's designed to work backwards, maybe just to mess with out heads ;)
Cool cheers matey
DeleteThanks Madferret.
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No problem guys.
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ReplyDeletegonna have a go at this today.....I don't have a 1uf cap and thought i did (should go to spec savers) will a 10 uf do or 220 nf..or none.....thanks
ReplyDeleteforget my last comment found them......Spec savers for me..wife's glasses worked a treat
ReplyDeleteSqueels really bad I have used a 100k pot instead of a 50k could that be something to do with it???
ReplyDelete