Lamprey - jubal81's SFT in a 1590B

[lincolnic]

Over the weekend, I finished up three projects: twin1965's V Fuzz, midwayfair's Rustbunny, and now jubal81's Lamprey (the SFT). This build wasn't super eventful, but it's worth noting for a couple of reasons.

The PCB was intended to fit into a 125B, but I much prefer 1590Bs. I asked Jason if he thought it would still fit, and he said it would, so I dove in. Turns out, it does fit...barely. After some very careful measuring and drilling, I still had to flip the PCB component side-down, but otherwise it fits over the jacks and under the backplate without touching either. Since everybody always says this circuit sounds so much better at 18v, I also made sure to leave room to include a spare Road Rage I've had sitting around for a while. Double-sided tape insulates it from the enclosure and holds it in place.

The enclosure is Laser Navy from PPP - it's actually a little bit darker with a more subtle sparkle in real life, but my camera's flash made it pop a little bit more. I labeled it with a metallic silver Sharpie, though it looks white here (again, due to the flash).





You can see how tight everything is in the gutshot, but there's no pressure or stress on the board when I close it up, so overall I'm fairly pleased with how it came out. It sounds good, and I intend to use it for home bass recording. Thanks to Jason for the nice PCB!

[jimilee]

Man that's tight! Nicely done...

[muddyfox]

ok that settles it... mine is going in a BB!

[jubal81]

Wowser that's tight! Great job, though. It's funny because the 125b doesn't look that much bigger than a 1590b - until you're trying to mount things inside it.

[lincolnic]

Thanks, guys. If I was doing it again, I'd be less stubborn and put it in a 125B -- if only so I could use PCB-mounted pots. I've been spoiled by some recent builds and forgot how annoying it can be to wire those guys up!

If you guys think this is tight, wait'll I get my 1590B Death By Audio Robot up and running. It's giving me some weird issues right now, but I'll get a tech help thread going soon enough...

[thesameage]

I've been playing one of these for the past few weeks and I find that it's really the last 1/4 turn of the volume and gain knobs have the most effect. Before that, it's kind of subtle. Is this normal or do I need to do some mods? Or just run it at 18V?

[jubal81]

I've been playing one of these for the past few weeks and I find that it's really the last 1/4 turn of the volume and gain knobs have the most effect. Before that, it's kind of subtle. Is this normal or do I need to do some mods? Or just run it at 18V?

That's how it's designed - dial in gradual distortion until you want a lot. I actually love it this way. If you want a more linear response, try a linear 1M pot for gain and an Audio taper 100K for volume.

[thesameage]

Good to know. I'll play it with this in mind and see if I still want to change things.

[lincolnic]

I will say that if I was going to build another one of these, I'd go for the alternate pot values. I'm fine with the pedal as it is, but a more linear response feels more natural to me.

Plus, a real B-15 will tend to break up anywhere above 9 or 10 o'clock.