the diodes on the switch are soldered properly checked it, somewhere something in the circuit is not ok, which portions to check? What schematic did you use in this layout? Are there two leads coming off drive 1 - one that goes to the board and the other that goes to the switch? Lower that value to something like 18K, 22K or 27K. Have you tried this thing called the internet?+m, The new versions of AC, RC and BB seem to have one additional transistor, maybe a FET that's part of the clipping circuit. john what did you use in labeling your bb clone? So it's gained 1.5V ish somehow, despite the fact that the only other thing pin 6 connects to is pin 7 via a cap and resistor, but pin 7 only measures 4.656V.Something doesn't look right to me around there. Maybe socket those positions so you can experiment to make it perfect for you. The customer will be happy :) I recommend if possible that IvIark modifies this layout with 220pf instead of the 51pf and the 47k replaced with a trimpot. How do you go about wiring your components?Got a Paisley drive under way as well. The BB Preamp offers awide variety of sounds. Schematic can be found here. Put it in front of any Boss effect and you'll sound just like Dave Gilmour. Replace 22n cap to 220n on input section. The wires they wire the 9v adapter with are rediculously thin though as I broke one trying to have a nosy at what was inside. They have the same pinouts. John, your build looks pretty neat. The Bass BB Preamp distortion booster was designed to retain the original attack sound and tonal spectrums and produce a variety of gain structures for all bass players. hi,I'm looking to make this for bass, and i see some suggested changes listed above. Do you tend to fasten the board with hot glue or something when mounting it upside down? Changing it to 94p decreases the frequency to 1.6K and changing it to a 220p creates a rolloff frequency of about 700hz. and if not corrected please send me the corrected image veroboard ..thanks. I can already tell that this was has a little bit more growl. I really love the sound of this one. Oooops, I've got the diode switch going to Drive 2 and 3 instead of Drive 1. to get it to go down to 34hz, you increase that cap to a 1u, and it is supposed to be connected to the vbias when you do it. Between the RC, AC, and BB, you can cover all your boost, overdrive, and gain needs! keep learning! i get most of my components from mouser (they have the biggest selection and give the part dimensions). short answer is no. Many thanks in advance! I\m starting to think that , the 47K resistor is wrong! Pro Quality. or change some resistor value (R3?). i'm not sure. swapping for a ~ 220p. The only differences are that the cut at the top of the 470K from Q2 base has been removed, so if you've already placed that cut you'll have to make a little bridge over it. Excellent John, glad you got it going. Does it need to be absolutely not polarized ? That's weird, from the top IC pin 1 output you've measured 4.55V. does anyone know what changes have to be made to turn it into the bass version? This is a library of perfboard and single sided pcb effect layouts for guitar and bass. That then goes through a 100n cap and 10K resistor to the inverting input, pin 6. Something went wrong. Q1 base voltage also looks high to me, the 470K attaches to vbias but it shouldn't be anywhere close to 4.1V. Better. I've seen two different diode arrangements, one with just two back to back which would be more compressed, and one with two series pairs, so I've included a switch so that you can choose either, and also have a centre diode lift mode for a cleanish boost. Aah right. Reducing it to 2.4k or 1k you should increase the gain, but even change the clipping frequency, maybe you should increase a bit the 47nF (C4) next to the "Sw1-5" wire, too.Then, I'm not sure, but maybe you could try to increase 1k resistor R11 and 47k R16. this baby's done and sounds great. i built this one this evening but it's not working properly yet. changing the ceramic cap value in the clipping amp. Bastardized versions can be found in Ampeg, Orange, Tweed Fenders, Sunn amps and more. You can usually do this if the cap is in the signal path, and not going to ground. Only when the diode clipping is engaged I have to turn the volume to the max to get unity. Check the soldering and for any small burrs or something in the cuts under the IC. i'm also going to just use a two way DPDT clipping switch to go from two and four diodes since the dirt without any diodes is pretty harsh & bright. thanks Mark. Dimitri's build blog, recommended reading for anyone wanting a DIY walkthrough, - Freppo's blog Parasit Studio. hi all ... a question .... the veroboard which is published as is with all corrections ???? It would probably be easier to have a single wire to the board, a single wire to the pot, and both other ends joining at the switch where you can wrap them round the solder lug to make it easier to make the daisy chain.To keep the leads shorter you could mount the board upside down - track side up, that does make things easier IMO.