Search found 59 matches

by jbrrrrr
Tue Sep 22, 2026 3:04 am
Forum: Technical Discussion
Topic: voltage divider for screen grids
Replies: 98
Views: 47222

Re: voltage divider for screen grids

If e.g. the voltage across the 220k is 450V, it draws a current of 2mA and causes an additional voltage drop of 1V across the 500R. So removing the 220k would increase the screen voltage by 1V only. Thanks, Martin & Helmholtz. It always sounded a little odd to me but I'm game to try any weird arran...
by jbrrrrr
Mon Sep 21, 2026 9:46 pm
Forum: Technical Discussion
Topic: voltage divider for screen grids
Replies: 98
Views: 47222

Re: voltage divider for screen grids

This old Mullard trick gives you one more design option. A common divider with individual screen resistors off the divider. To fit the discussion above that would mean a 500 Ohm / 220K divider with individual 1K screen resistors from the divider. That would give similar sound to the individual divi...
by jbrrrrr
Sat Aug 29, 2026 8:23 pm
Forum: Technical Discussion
Topic: Now for some bright/treble cap snakeoil trials
Replies: 19
Views: 6312

Re: Now for some bright/treble cap snakeoil trials

I would recommend recording your trials, keeping as much consistent between takes as you can besides the caps: guitar, pickup selector, tone and volume knobs, amp setting, position of pick from bridge and where the stroke happens in relation to the pickups, etc. The mind is a curious thing and will ...
by jbrrrrr
Mon Aug 17, 2026 3:47 am
Forum: Technical Discussion
Topic: More happy use of AI in amp designing...
Replies: 17
Views: 5006

Re: More happy use of AI in amp designing...

It's great, in the hands of people that can do what they're asking the model to do for them.

It's a horror show in the hands of people that are using it to do things they aren't able to do themselves.
by jbrrrrr
Fri Jul 03, 2026 3:42 am
Forum: Technical Discussion
Topic: Benson B700 bass amp
Replies: 4
Views: 7191

Re: Benson B700 bass amp

I have so many conflicting feelings about this.
by jbrrrrr
Wed Jun 10, 2026 9:38 pm
Forum: Technical Discussion
Topic: Building Power Supplies for 2 X 12ax7 pedals
Replies: 90
Views: 40767

Re: Building Power Supplies for 2 X 12ax7 pedals

Cool, thanks! They look to be sold out, but they have the schematic and parts list which is handy. Just found this other one, but you don't get any info about it till after you by it: https://frogpedals.com/index.php/product/frog-smps-high-voltage-tube-power-supply-bundle-of-5/ I've used the C2C on...
by jbrrrrr
Wed Jun 10, 2026 7:57 pm
Forum: Technical Discussion
Topic: Building Power Supplies for 2 X 12ax7 pedals
Replies: 90
Views: 40767

Re: Building Power Supplies for 2 X 12ax7 pedals

Check out the power supply that C2C Electronics uses for their PCB pedals.
by jbrrrrr
Tue Jun 02, 2026 6:33 pm
Forum: Technical Discussion
Topic: New circuit design tool
Replies: 25
Views: 17032

Re: New circuit design tool

Awesome! Did you receive the code in your email as well? I wasn't able to resolve that issue until this morning, but it should be working now. If you need it, I think I can resend. Yeah, I spoke too soon - I didn't receive the code, but the checkout worked at least. Would you mind resending when yo...
by jbrrrrr
Tue Jun 02, 2026 6:27 am
Forum: Technical Discussion
Topic: New circuit design tool
Replies: 25
Views: 17032

Re: New circuit design tool

Just an update - I was able to checkout successfully, and yes - I can hit the https://workbench.epic-devices.com/ URL as well. Looks like whatever Stripe trouble you were having has been resolved.
by jbrrrrr
Mon Jun 01, 2026 1:45 am
Forum: Technical Discussion
Topic: New circuit design tool
Replies: 25
Views: 17032

Re: New circuit design tool

Hey, I get a "failed to fetch" error at the cart after inputting my name and email and trying to check out. Can't complete it. When I try to register a new account on your site (seeing if I could bypass the error that way), it sends a confirmation email. The link of that confirmation is to localhost...
by jbrrrrr
Sat May 30, 2026 12:47 am
Forum: Technical Discussion
Topic: Carr Trail Rider - New 5w Amp
Replies: 0
Views: 10918

Carr Trail Rider - New 5w Amp

https://www.youtube.com/watch?v=CeSWd6XPVNc&t=9s Carr Amps - Trail Rider Product Page Sounds *real* nice, to me. I'm seeing 5W + the onboard attenuator, 2x 12AX7, 1x 12DW7, 1x EL84. Guessing a single ended circuit with a cap-coupled reverb tank using the 12DW7, and maybe the V and T "channels" each...
by jbrrrrr
Wed May 27, 2026 3:13 am
Forum: Technical Discussion
Topic: MEF first page changes
Replies: 5
Views: 4069

Re: MEF first page changes

WHAT! YES! MEF is back!
by jbrrrrr
Tue May 12, 2026 7:56 pm
Forum: Fender Discussion
Topic: Adding negative feedback to a '57 Deluxe
Replies: 7
Views: 11350

Re: Adding negative feedback to a '57 Deluxe

Thanks for sharing this, Martin!
by jbrrrrr
Fri Apr 24, 2026 5:26 am
Forum: Technical Discussion
Topic: Transformerless Reverb
Replies: 16
Views: 2649

Re: Transformerless Reverb

There's quite a few projects around here and EL34world that utilize 6BM8 single-tube no-transformer reverb circuits if you do a search for that as well as ECL82 - you can find some starting points that might be a decent place to start tinkering from.
by jbrrrrr
Thu Apr 16, 2026 12:17 am
Forum: Trainwreck Discussion
Topic: Ordered some Fishman Fluence Pickups; will these ruin my TW Life?
Replies: 28
Views: 78685

Re: Ordered some Fishman Fluence Pickups; will these ruin my TW Life?

As far as using cable length to try to mitigate harsh top end, I received one of these cables as a gift - it's a pretty cool idea if you need to add some variable capacitance often, works great - not to mention that Eric Valentine has some pretty golden ears. Undertone Audio UTA Vari-Cap Cable I mea...