Search found 39 matches

by Craig B
Sat Aug 22, 2026 12:48 pm
Forum: Fender Discussion
Topic: Solid State rectifier for 5E3 build
Replies: 2
Views: 4701

Re: Solid State rectifier for 5E3 build

Yes, check the PT specifications. But you should be fine with a tube rectifier. 6 preamp tubes in a Deluxe Reverb. Only 3 preamp tubes in your proposed design. The B+ must be sky high in your Tweedle Dee! The best excuse I can think of for switching to a solid state rectifier would be heat reduction...
by Craig B
Wed Oct 22, 2025 12:04 pm
Forum: Technical Discussion
Topic: Musings on the State of the 5e3 Art in 2024
Replies: 35
Views: 17145

Re: Musings on the State of the 5e3 Art in 2024

No 1790EP when I search Hammond website. Are you using a 1750EP output transformer?

Just being hyper critical trying to understand why the output tubes do not distort :?:
by Craig B
Sun Oct 19, 2025 1:37 pm
Forum: Speakers and Cabinets
Topic: Turquoise Shower Curtain
Replies: 4
Views: 32147

Re: Turquoise Shower Curtain

Very interesting, Carlsoti. Do you have any photos and details of Phoenix Trim fabrics you have used on amplifiers or or speaker cabinets? I'm always looking for a unique but classy covering.
by Craig B
Sun Sep 21, 2025 12:40 pm
Forum: Fender Discussion
Topic: Champ Reverb Build
Replies: 58
Views: 40112

Re: Champ Reverb Build

Old thread but those faceplates are gorgeous! The rest of the build is top-notch too.
Update from the original poster please. Maybe final schematic, voltages, pics, satisfaction... ;-)
by Craig B
Sat Apr 12, 2025 3:14 pm
Forum: Fender Discussion
Topic: Vibro Champ Clone wants some breakup
Replies: 17
Views: 21490

Re: Vibro Champ Clone wants some breakup

I like that your design has an extra node of power supply filtering compared to the original fender design. That really reduces hum and reduces the (my opinion) excess B+ in the ab764 version of the Vibrochamp. If you want power tube distortion :D you need even lower B+. To reduce the excess voltage...
by Craig B
Wed Mar 26, 2025 12:07 pm
Forum: Fender Discussion
Topic: '67 Deluxe Reverb Rectifier change
Replies: 11
Views: 7029

Re: '67 Deluxe Reverb Rectifier change

I use a 5R4GYB in my DR clone with a Weber power transformer. It puts out 408 volts. A Sovtek 5AR4 puts out 458 volts.

I am very pleased with the performance using the 5R4GYB.
by Craig B
Wed Jan 29, 2025 10:58 pm
Forum: Fender Discussion
Topic: '65 Princeton Reverb Reissue Randomly Detunes Notes
Replies: 35
Views: 18556

Re: '65 Princeton Reverb Reissue Randomly Detunes Notes

I am totally ignorant of oscilloscopes so take my idea with a pound of salt.
Does the output of the phase inverter stage show the same signal change? How about the stage before that??
Good luck with your brain teaser!
by Craig B
Wed Jan 01, 2025 1:46 pm
Forum: Fender Discussion
Topic: Dlx Rvrb, 360v vs 450v plates
Replies: 16
Views: 6811

Re: Dlx Rvrb, 360v vs 450v plates

I used the same PT with my modified deluxe reverb. Needed to use the 125 volt primary wiring to get the heaters to 6.5 volts. I have 1 fewer premp tubes to draw current. Get 348 B+ volts with a Sovtek 5AR4. I prefer the slightly softer sound of 404 volts with a 5R4GYB and adjusted string dropping re...
by Craig B
Wed Jun 22, 2022 12:21 pm
Forum: Technical Discussion
Topic: Fender 600 champion reissue complete rebuild
Replies: 122
Views: 24433

Re: Fender 600 champion reissue complete rebuild

Yup, I find that a CLC filter is necessary for all single ended amps when using a speaker with any bass response at all. Using only a capacitor for B+ filtering makes too much ripple (hum). Some deluxe reverb chokes are only rated for 40ma. If I was going to drive this amp HARD I would opt for the l...
by Craig B
Fri Feb 18, 2022 6:20 pm
Forum: Technical Discussion
Topic: Modded DR Too Much Filtering?
Replies: 44
Views: 7296

Re: Modded DR Too Much Filtering?

That's a real dilemma. Your 100k feedback resister made for good tone but allowed too much hum. Your 1k feedback resister cancelled the hum but caused sterile tone. Neither one sounds acceptable. It seems that you have to put the 100k back in there and find the cause of the hum. I vote for removing ...
by Craig B
Fri Feb 18, 2022 1:24 pm
Forum: Technical Discussion
Topic: Modded DR Too Much Filtering?
Replies: 44
Views: 7296

Re: Modded DR Too Much Filtering?

My ears hear that you have far too much negative feedback and that makes your amp too sterile. 1k feedback resistor into 5k presence pot. Try setting your adjustable feedback resistor to it's other extreme (100k) and see how it sounds. 101k into that 5k pot would be about perfect.
by Craig B
Fri Jan 21, 2022 1:14 pm
Forum: Marshall Discussion
Topic: Need help with TAD 18-watt TMB Build
Replies: 17
Views: 5422

Re: Need help with TAD 18-watt TMB Build

"White to live and black to neutral ideally" NOT IN THE USA!
by Craig B
Thu Aug 19, 2021 2:59 am
Forum: Technical Discussion
Topic: Tweedle dee PT question
Replies: 16
Views: 4094

Re: Tweedle dee PT question

Mojo's way of describing the specs is confusing to me. I "think" they mean it is a 330-0-330 at 150 ma. If I were building with 6V6GT power tubes, I would not want any higher voltage or amperage than that. I will be curious to see what others think.
by Craig B
Wed Jun 16, 2021 6:08 pm
Forum: Technical Discussion
Topic: Rectifier Tube Swap
Replies: 16
Views: 4862

Re: Rectifier Tube Swap

I love these builds cause I had so much fun with my first one-a Newcomb record player conversion. The beginning of an addiction. The heat issue and more gain issues are complicated to answer. The amp running too hot could result from modern line voltage being higher than when the power transformer w...