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Comment by kpgraham | Hacker News Reader

I've built a half dozen Fender Bassmans and a few Fender Super amps over the years. I thought the article would be about this kind of amp building, but evidently not many hacker news readers play blues harp through a tube amp.

Low tech tube amps are quite easy to build, although they cost a few hundred because the transformers, chassis and tubes can be pricey and the cabs and speakers aren't cheap. The results are great, though, and I'd say go for it if you are thinking about trying.

Get everything you need from Tubes and More dot com or eBay.

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The nice thing about these old tube amps is that the schematics are freely available (Fender ships a copy of the schematic with their amps). There are also quite simple in term of number of components.

However, there are dangerous, with 400/500V DC for the tubes. Definitely not something you should try without being extremely cautious and without previous experience.

On the topic of music hardware, another fun thing to build is effect pedals, these are much much safer, and permit to gain valuable experience with a soldering iron.

There are also a few kits available out there, either for effect pedals and tube amps.

For people in Europe, I can recommend https://www.musikding.de

* Tube amps: https://www.musikding.de/guitar-amp-kit-tube-amp-kit-valve-g... (I've built the A15 kit in the past, the components are a bit cheap, specially the power transformer, but it sounds quite nice, and makes for a great 15 Watts dual channels amp).

* They also sell a lot of pedal kits: https://www.musikding.de/guitar-effect-kits

They also sell parts (specially those a bit harder to find at a good price like footswitches, sockets, a wide variety of knobs etc).

Another shop I can recommend for components: https://www.banzaimusic.com/home.php

Another good place for tubes, especially NOS weird ones, is ESRC: http://www.esrcvacuumtubes.com/

Tube amps are also much more dangerous than 9V battery operated headphone amps. For people that are just starting out those cmoy style projects are awesome. btw there is also 1W guitar amp in style of cmoy.

Are Bassman amps actually better at reproducing and projecting lower frequencies? I have a fender amp for my regular electric, and a bass amp for my bass guitar. I also have a baritone and wanted an amp for in between.

Originally the Bassman was a 50 watt amplifier with a pair of 6L6 tubes, this is enough power to allow a solid-body bass guitar to play cleanly only about as loud as a regular acoustic string bass.

For bass guitar, there was no need for reverb or tremolo so those tube effects were not included on Bassmans. 6-string guitarists sometimes found these Bassmans more gainful at maximum volume than the non-bass Fenders having equivalent power and tube complement. A single pair of 6L6 (about 50W) for guitar will be loud enough to keep up with an acoustic drum kit for lots of blues and soft rock, while bass guitar actually needs about 300W.

With a loud drum kit and a heavy-hitting hard rock acoustic drummer, then I naturally recommend a 100W fullstack for guitar and 400W for bass.

The circuitry of the Bassman is not designed for big differences in frequency coverage compared to the non-bass vintage Fenders. The Bassman was primarily a regular no-frills 50W head, and for actual bass use within its power level (like in studios) it achieved lower lows because of use with a closed-back cabinet.

Thanks for helping explain the name and history.

As I understand it, the frequency response of a tube power amp is influenced by the output transformer, and to a lesser extent by minor design parameters such as the value of coupling capacitors. To a very rough approximation, lower frequencies need more iron.

On top of this, the preamps in some historic amplifiers tend to have a decidedly non flat response curve when the "tone" knobs are centered.

From my understanding the frequency response of the amp is designed by the gain stages and the capacitors and resistances used. This changes the so called "voicing" of the amp.

A good resource I can recommend are the books by Igor S Popovich. At least volume one and two.

Personally I don't think they (the old tube Bassman) are that much better than any other guitar tube amp. Old Marshall amps (JTMs) are based on that same design, btw.

Any recommendations then?

Try different closed-back cabinets and speaker cones with your baritone.

Do you have any links to resources on building the said amps?

https://music-electronics-forum.com

ax84.com is a great resource for guitar amp information too.

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