Recent content by drew.spriggs

12x7x2". Not socketing them - the footprint is pretty big so if they ever need to be replaced it won't be too bad Found my miter saw was busted, so a circ saw and speed square did the job! No finger joints, but there are some internal braces added that should be strong enough. Still needs a lot...

If you are designing from scratch, there is absolutely no reason to use a 555 these days - it's noisy and shockingly inefficient. Even if you were going to for some crazy reason, the IRF740 is a terrible choice as it's more expensive option than other MOSFET choices that have half the Rds or...

Nothing like some half-assed measurements to drill an enclosure from. Enclosure is a laser cut, CNC bent job from 1.5mm steel I had a friend whip up. If I was doing it again I'd probably use 1mm steel, but this will do the job. It looks like shit, but hammercoat covers all mistakes :ROFLMAO...

It's not finished yet. These are the inverter modules. They have a lot of input noise which can be solved with a good electrolytic, and their switching frequency is about 60khz so output noise isn't terrible. They do need mechanical isolation from any sensitive circuits.

Yep, but it's got onboard rectifier diodes so you can grab an unfiltered DC off of it

Probably. The carrier/amp boards are 125x75 and 150x75 in total, but if you wanted to compress it to a single board you could easily get there.

317 technically doesn't even require a heatsink with that dissipation and anything below a 40 degree ambient so I'm not too concerned. The matching was with a gain response, not frequency response - plate impedance/etc is all totally different so if you wanted it sound as identical as possible...

NTC/ICL info: wanted a better way to manage tube inrush, so grabbed a stack of ICL's when I did my last Mouser order. Some didn't have a hot resistance so needed to test them. Setting up some 20w resistors to get 900mA of draw through the heater circuit, I got the following info: ICL cold...

Howdy, Thought I'd document some of a build I'm doing here in case anybody is interested in how you approach making custom boards/etc for an amp. I've got a stack of submini tubes, and a guy has been harassing me about making him a mini Trainwreck-inspired head for a while. Decided to see what...

Idles at 300v with ~6w or so of draw

G'day, Uploaded all my Kicad libraries into a .rar file - there's symbols linked to footprints linked to 3D models for just about everything you could ever need to build a pedal or amp. All basic parts have suitable fab house/CNC option for footprints, and have a much wider range of stuff than...

Make the 10k resistor to the power rail a 50k trimpot. Pro tip: you can also add a 1k pot between the power rail and the emitter of Q3 and you've got a nice little octave control pot.

It does, but it also forms a RC filter with adjacent components

These are all from memory, so please consult the board/schematic before trusting anything I say. Remove the cap connected to the AC output to isolate it (should be C2, 22nf ceramic) Bridge B/C pads Drill a small hole in the D pad Connect C2 + 1/2w 470k resistor between B/D (massive noise...

https://a.aliexpress.com/_mKX6pn1 With a little bit of finagling (and some much needed safety features added) these are a very compact, shockingly quiet HV supply for running tube preamps (and even power amps up to about 5w). I've been running them for a few years with zero failures