Stickman builds his first tube amp

Aite. So, the speaker I chose was too deep for the enclosure I bought.

Not by much, mind you. I only needed about a quarter inch.

Well...the back panel doesn't *need* to be 9mm. Problem is, I didn't feel great about spanning the entire back of the cabinet with 3mm plywood. I wanted something a bit stronger.

So, I cut a piece of 3mm carbon fiber, created a couple of 1/4" stand-offs, and viola.

Then comes the needing to make it match the rest of the cabinet. So, my first try with applying tweed.

Once the glue is cured, I'm gonna lacquer it.


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Asdrael said:
For standby switches almost everyone uses regular 250V ones. Some “protect it” with a cap in parallel. Having one is not needed thought. Plenty of amps were built without one and were perfectly fine, and it has been demonstrated that tubes amps fare better without one anyway. Just have a mute switch for the functionality and you’ll be just fine.
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Just read up on this, thanks!
 
JohnnyCreepy said:
Inrush current isn’t a problem with a tube rectifier as it slows current while warming up, but you’re limited to smaller value caps on the first filtering stage.
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I had seen that as well.

The only extra little mod I've added is a pair of protection diodes on the tube rectifier. These are there just to "pre-rectify" the B+ in case of tube failure in the future.

A traditional standby wouldn't really help with inrush even with solid state rectification: switching the B+ on will lead to inrush regardless.

Though it makes sense if you've got a resistor of sufficient size across the terminals. Typically I see an NTC thermistor take this role in SS designs.
 
Re: musicalpowersupplies — I did email them a couple weeks ago and got a response. I used [email protected] and had a quick response.

If that falls through, Edcor is quite good, really really good specs and well like, but definitely not cheap.

Standby switches and b+ has always worried me. But somehow they work. Like magnets
 
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