What is the difference between the circuit board version 1.0 from 2020 and the current version of the current version dated 2025? I purchased a board off of eBay and the seller failed to disclose that the board was version 1.0 dated 2020.
Hello everyone! I'm building the SLO 100 for a friend, and I am really struggling with finding appropriate transformers. What are you guys using?
I'm in the US. I found an EU seller, but he doesn't ship to the states.
I could purchase the Onetics set from C3, but they're over FIVE HUNDRED DOLLARS. That's (respectfully) insane.
I've emailed Hammond to find an appropriate set, but they don't have anything that matches the specs for the Power Transformer. Any help is greatly appreciated. I'm willing to step this build down to 50 watts or literally anything that makes this cost effective but still fully functional.
You can try inMadOut (write directly to info@inmadout.com). The owner, Mr. Savino Luce, makes boutique transformers specifically for tube amp, used them in several of my builds.
Just share the schematics and he can give you a quote - probably way cheaper than those $500 😅
Hi
I have noticed that all the Dumble boards don’t have HRM tone stacks. I understand as space is limited.
Do you recommend making a daughter board to accommodate the HRM caps and pots?
Thanks for your assistance
Regards
Mark
I was wondering if the LED polarity for the E-lator could be added to the layout image. Looking at another build on the forum, assuming that in those images, the red wire is positive and the black is negative, when looking at the component side of the board, with the tube socket on the right, the left-most LED connection would be positive? I know that I can measure the voltage with a multimeter, but it seems that it might be easier for folks if the PCB or the layout specified.
The positive (anode) of the LED goes to the cathode of D4, the negative of the LED (cathode) goes to R1 (330 Ohm).
Hi Jla,
this is Andrea, owner of AAElectronics. Your board is basically as the current one. There have been some minor improvements over the years, but nothing major. You can follow the documentation on website
Happy building :)
Best
Andrea