first build - Bass version?

[lexington125]

Although I have been playing bass through tube amps since the mid-70s, I'm a total novice when it comes to really understanding how to design / build my own amp. While I'd like to someday build an amp large enough for regular use, I've decided to take on a very simple 'minimalist' design as a first project / learning experience. But most of the simple, low power, "first amp" designs that are easily found online are very suitable for guitar use, but (intentionally) break up far too early for bass use.

I thought about starting with a small existing amp and then tear it down / rebuild, but that makes it too easy to just install components because they are on the plans, without really understanding why it was designed that way. If you begin with a clean sheet of paper and only add things that you fully comprehend, there should be fewer surprises.

But I don't want re-invent the wheel with this project, so has anyone documented any similar project? (tailored for bass use) I was thinking something like:

• FEATURES
• single channel, single input (optimized for passive bass)
• 1 volume control - no separate controls for input / master volume
• 1 'tone' control - save the use of separate bass & treble for the next amp
• power switch (is a standby switch still a good idea on a simple, low power amp?)
• thats it for controls - on the back panel there would be an IEC connector, a fuse and a single speaker output (no FX loops, line outs or other fancy stuff)
• built as an amp 'head' as I'm not interested in locking into a specific speaker configuration

• INNER WORKINGS
• although smaller, and simpler than a full size amp, I'd like the circuitry to somewhat resemble a 'real' amp, so that I get the experience of working with all of the following components:
• power transformer
• tube rectifier
• both filter caps and a filter choke
• preamp tube
• output tube (a single KT88 ?)
• output transformer (depending on what is available, either 4 ohm, 8 ohm, or both 4 & 8 ohms)

Assemble it all in a small lunchbox or rackmount chassis, hand wired on eyelet board or similar. Does a similar bass amp project exist, well documented online? If not, does the description above seem like a sensible direction? I realize that the experienced guys here must get tired of the endless succession of 'first build' project proposals, so if there is an existing bass amp version, I'm happy to try and start there.
Thanks

[eschertron]

Nice, I like! You can make a real amp at any size power, but it will have its own set of engineering challenges!

So what's the difference between a low-power amp and a 'bigger' one? Not those lunchbox grind machines, but an actual low-power unit. There are a few factors in play here (a couple off the top of my head):
1) lower volume means the Fletcher-Munson curve plays a bigger role in how we perceive the sound. Tone shaping may have to take that into account.
2) sag is also a big part of the 'big amp' sound. 'Faking' sag might be an interesting experiment.
3) don't for a minute think that a small amp sounds good through small speakers

The big difference between bass and guitar is headroom -> speaker cone excursion -> fairly big OT compared to similar-sized guitar amps.
Compression/sag before the power stage can help. Most small guitar amps get compression through driving the preamp tubes hard. This is not what you want for your bass amp. Look for other methods. A search on these fora or others might turn something up.