Tube Amp on a PCB

RE: Tube Amp on a PCB

dang74 — Tue, 25 Jul 2023 19:50:07 GMT

Nice. I am too afraid to play with high voltage so the 273V output you created at the transformer scares me. I was thinking of doing a pre-amp using the 12AE6 or 12AX7. That would keep things below 30V. I was then thinking of having a solid state output amplifier. Not sure if that approach is ridiculous from a hi-fi point of view, but that's what's inside my comfort level. Cool project and the 60s tunes featured in the video definitely suit a tube amplifier. [emoticon:c4563cd7d5574777a71c318021cbbcc8]

RE: Tube Amp on a PCB

three-phase — Wed, 28 Nov 2018 21:00:01 GMT

Great project, thanks for sharing.

Kind regards.

RE: Tube Amp on a PCB

genebren — Wed, 28 Nov 2018 16:45:35 GMT

Very cool experiment/build. Looking at the schematic was a really flash of the past. As a high school student, I was exposed to a whole bunch of radio broadcast equipment. Those schematics really made my brain work, as I was learning transistors and reading tube schematics at the same time. I never was able to fully comprehend the tubes, but it was interesting anyway.

Gene

RE: Tube Amp on a PCB

jw0752 — Wed, 28 Nov 2018 03:36:17 GMT

Hi Doug,

Great build and good nostalgia. I remember seeing inexpensive 5 tube radios built on circuit boards much as you have done. This was in my early days of servicing and I remember it as I was able to remove the back, take off the knobs and the whole board would slide out of the case.

John

RE: Tube Amp on a PCB

dixonselvan — Wed, 28 Nov 2018 02:58:09 GMT

I am not an analog person right away and your project kindles the interest towards analog. This project really takes me back to analog days!

RE: Tube Amp on a PCB

kk99 — Tue, 27 Nov 2018 18:23:21 GMT

Really interesting project. Congratulations.

RE: Tube Amp on a PCB

shabaz — Tue, 27 Nov 2018 17:23:48 GMT

Hi Doug,

Wow - that looks fantastic!!

RE: Tube Amp on a PCB

jc2048 — Tue, 27 Nov 2018 09:34:40 GMT

Well, that's certainly 'Back to Analog'. Somehow it looks wrong having tubes on a pcb, like we've stepped into an alternative universe where the transistor didn't get invented.

I'd be quite interested to know what the overall linearity is like (this is prompted by the discussion about class A transistor amplifiers over on the 'Audio Op Amp' thread). A quick way to look at that would be a triangle wave from a function generator going in, an resistor load on the output, and then adjust the 'scope so the traces sit on top of each other and see how well they match.

Also, I'd be interested to see how well the tone control part of the circuit works - not in great detail, just roughly what each control does as it's adjusted. Once you had it set up that would be quick to try with a swept sine wave.

But, as usual, only if you are interested and have the time to spare - it's only curiosity on my part, I don't suppose I'll ever build one.

RE: Tube Amp on a PCB

neilk — Tue, 27 Nov 2018 07:33:32 GMT

Hi Douglas,

Wow, that takes me back!!!!!!! We used to build to similar designs using ECC83 and EL84, but certainly not on PCB - what a an impressive result yo got [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-c6fc8d60-1cb9-4aee-9dd8-638a71c9cc13/contentimage_5F00_1.png:16:16].

We used tag boards and tag strips - bolted to a folded aluminium chassis.

Nostalgia....................

Neil