Tuesday, 22 January 2013

Briggs' 64 Vintage

As requested. From Mr. Briggs:
Here's another (nearly) new one from me. It's a tricked out super mod of the old Electro Harmonix LPB-1 circuit that produces some lovely singing overdrive tones reminiscent of an old VOX from their 1960's heyday. I took the Lovepedal Englishman (A supposed Vox AC30 / AC15 emulator) as a base and went from there - Firstly I wanted a little more gain, hence the 4k7 collector resistor. Along with more gain I wanted more emphasis and clipping on the higher mids to replicate that treble laden Vox overdrive hence the 82nF bypass cap and the 47k/22nF mids filter at the end of the circuit. These changes make the circuit sound livelier and give it more character. The use of the *super* low forward voltage SB340 diode in combo with the BAT46 diode produces harmonically rick asymmetrical clipping, the levels of which can be controlled using the "Headroom" control. The headroom control also allows a nice rich low end to be retained while allowing the top end to be clipped, as you roll back the clipping a nice tube like "note attack sag" effect becomes prominent - it's quite pleasing and cool to play with. The use of the 2N3565 transistor is due to some tests carried out a while ago where it was found that the 2N3565 sounded best in these sort of applications, you can replace it with a 2N5088 or BC108 or, in fact, any decent gain NPN transistor.



19 comments:

  1. Definitely gonna build this as soon as I can get a chance - slow down , man, you'll give yourself a heart attack!! What I love about Fred Brigg's site is that his schematics look like old pirate maps! Excellent!

    Mark

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    1. Haha! Small ones are quick to do :)
      +m

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  2. Tag this baby! A nice booster, it's kind of half way between a Muff Fuzz and a LPB-1, with the 'volume' knob (functions like gain) rolled back it feels like a treble booster but with it cranked full it's got some nice fuzzy dirt.

    I didn't have the 2n3565 so I used a 2n5088 and I didn't have either of the diodes so I socketed them and tried to use a 1n34 and a 1n5187, the 5187 wouldn't fit in the socket so in the end I had to use a 1n4148. Basically this circuit sounds great and it'll sound even better once I get the correct parts in there.

    Briggs, I take my hat off to you Sir.

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    1. Goddamn you are fast! That's like 2 hours from publishing to verified!

      Madferret, I take my hat off to you Sir. :)
      +m

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    2. Hahaha, like you said: the small ones are quick to do :D I'm just contemplating doing the E11even but I'm waiting on a Tayda order so I'm not sure if I've got all the pots. I think now may be the time to bust out the Green Ringer, I've been wanting to do it for a while but you guys keep on posting new layouts!

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    3. You NEED to have a Green Ringer. That's pure awesomeness with clean signal, and sinister beauty sticked in front of any fuzz circuit. I've built three finished ones and only have one left :) My band's drummer (he plays guitar for Acid Elephant) finished his first build a few weeks back - Green Ringer into Lunar Module. Mean, yet super versatile thing!

      Seems like you're building circuits for drawer too! I've been doing that for a long time. Not all circuits sound good enough to box, and internet demos are what they are. Plus verifying is very satisfying hobby :) I've hoarded some cheaper (meaning a bit lower quality) parts for just playing around. You could check out these:
      http://www.ebay.com/itm/50pcs-Potentiometer-Pot-B100K-100K-Linear-shaft-15mm-/390292703895 and/or http://www.aliexpress.com/item/50pcs-15mm-WH148-1k-2k-5k-10k-20k-50k-100k-250k-500k-Optional-Ohm-Liner-Taper/562432972.html
      If i'm not 100% sure the circuit will be good enough for boxing, i'll just use those. Some circuits have surprised me so, that i just had to rebuild with aplha pots.

      Of about 100 pieces i've used, those cheapo-china pots have had like two wonky ones. That's pretty much ok, as from ~200 alpha pots have had one DOA.

      DIY costs a lot - but only when you're sourcing. Building doesn't ever cost you anything:D

      Let me have a quick count - In my drawer, there's exactly 51 circuits that i've built and tested. Some of those will get boxed at some point, but some will never leave the drawer. I do feel sorry for those.
      +m

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    4. You're right, I've not boxed most of the circuits I've built and quite a few I won't bother unless someone listens to them and wants them. The batch on Ali Express looks like a great deal, I think I'll get one ordered. To be honest the part I like least about building is wiring up pots so I'm thinking of wiring up a test bench with a few different pots through a piece of aluminium with some sockets in it, then I'll run everything into a bread board so I can just plug in the vero to test it. These cheapo pots would be perfect for it. Thanks for the heads up.

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    5. Oh and the Green Ringer will definitely be getting built tonight!

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    6. Came here thinking "I might put this one together", after all I am a Vox user and fan.

      Think I'm going to finally build myself a Green Ringer first...!

      Day off though, so why not get them both done? :)

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    7. Definitely build them both!

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  3. Built this one using all the list parts except for the SB340 which I got but it has extremely thick legs that won't pass thru vero holes, so I used a 1N914 instead - it's nice as a clean booster, adds a little more presence and really shines as a gain booster before my favorite drive pedal - a hand built "Sweet Honey" OD. Vox-y tones at moderate settings; crank its volume up and you get into vintage Marshall territory - great for both rhythm and lead (if you're into Zeppelin, at least). Cleans up great with the guitar's volume control, and keeps the "touch-sensitivity" of my setup. The "headroom" control is not that extreme - it seems to enhance the upper-mids and tightens up the sound as I turn it up. All the way back the sound is a little looser. All in all, really nice sounding, easy to build pedal. Thanks to Fred Briggs for designing it and Miro@TagboardEffects for making the vero layout!

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  4. Built one of these with a few small component changes, sounds really good, I was quite surprises at the range of tones and gain available from it. Well recommended for a quick and easy build!
    Cheers
    Dave

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  5. Been playing with this circuit some more, its sooooo darn good, it does everything from a lovely treble boost, to just a hint of break up, to a warm soft overdrive to a dense fuzz, its quite remarkable what these little Electra style circuits are capable of, and how different you can get them to sound.
    Cheers
    Dave

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  6. "its quite remarkable what these little Electra style circuits are capable of, and how different you can get them to sound"

    And therein lies the secret of Lovepedal`s success

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  7. this build really surprised me.
    at least it nails an AC30 with 80% on all three trimpots.
    that dark hard little muddy tone, real nice :P
    cant say i can dial in so many different sounds with it but who cares!?
    one real good soundsetting is good enough to box it :)
    i maybe tweek it little bit first on my breadboard.

    with a 50k trim at Rc you can test and bias almost any tranny you like, but as he says... 2N3565 is a damn good one in this circuit. mine had 345 hFE, lowest of all i got, many was way over 450.

    strange when this site says 70??
    http://alltransistors.com/transistor.php?transistor=3343

    i lift my hat to Briggs tho ;)

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  8. I tried a couple BC108B's (rated at ~300hfe) and a PN3565 (rated at 150hfe? I can't remember anymore). Both sound really good here. The BC108 makes the effect to sound a little tighter and almost fuzz face-like at higher settings, while the PN is looser sounding, less gainy, and cleans up better with the volume control of the guitar even when gain is at high levels - and it's also more quiet. I like both a lot in here. I should experiment some more with different diodes some day.

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  9. Updating:
    I finally tried some different diodes today, and found I had a little mistake in my build which didn't allow me to get the full potential of the diodes when using the Headroom control. Having that fixed and trying a few more diodes (1N914, BAT46, 1N4001, SB340), I have to say the SB340 really sounded the best for me here, with the 1N4001 in second place. I enjoyed turning the Headroom control all the way up and using the pedal as a regular OD pedal - what adds to the versatility - since I don't have to use it "only" as a booster now. Excited to try it in conjuction with a few other pedals and with my band in a week from now. I think this is a 10/10 circuit/build.

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