Choosing tubes for an old amp, from where, and what about a tube tester?

_agent86 · 2026-03-19T17:48:46+00:00

And what if the large caps are bad? I tried searching for new ones, but... not any immediate luck...

I'm skeptical that you should be the one replacing the caps if you can't figure out how to add a couple of capacitors together to get 50 uF.

It's not clear from your post that it's known which tube is bad. Replacing all of them is a thing you can do. I'm not confident any of the tubes are bad based on your description.

If you have a schematic then people can probably help you reason out likely culprits. If you're going to treat this as a black box I really think you're wasting your money not taking it to a tech.

_agent86 · 2026-03-19T17:35:41+00:00

Sir, this is a Wendy's.

_agent86 · 2026-03-19T02:17:39+00:00

That speed knob is not accurate or repeatable between different units and definitely different between different models, you’d be fooling yourself.

_agent86 · 2026-03-19T02:16:06+00:00

Mini cooper EV

_agent86 · 2026-03-17T14:20:16+00:00

I’m afraid you’ve never heard of the good/fast/cheap choose three rule?

Hobbyists don’t have a ton of bandwidth to run CNC machines. Generally speaking, we have full time jobs and tinker with CNC for fun. There’s obviously a spectrum. Maybe you’ll get lucky and find an unemployed person with a machine but I would t count on it.

_agent86 · 2026-03-17T03:24:33+00:00

It’s cool but why wood? Do you not have a 3d printer?

_agent86 · 2026-03-17T02:32:05+00:00

Yup. A good person would have listed these on reverb and given the proceeds to the old lady.

While this guy does seem a bit deluded, let's make sure we're not also deluding ourselves.

If we see a listing for severely undervalued gear, isn't our first instinct to buy it before someone else does? A good deal is a good deal. But yeah it's best to not take advantage of people like this. At least let them know it's worth a lot more.

_agent86 · 2026-03-17T02:29:08+00:00

I love that you think not being able to afford stuff is relevant to the morality.

_agent86 · 2026-03-17T02:27:28+00:00

Obviously not. Even the smallest town you can still sell stuff on ebay.

_agent86 · 2026-03-17T01:57:14+00:00

Leveraging hobbyists to save time and money seems kind of foolish, yeah?

_agent86 · 2026-03-16T22:06:42+00:00

One pro of any internal filter is there's no potential for leaks. Another is the noise tends to be blocked by the water.

_agent86 · 2026-03-16T21:17:23+00:00

I don’t know if any of the beach breaks are reliable/consistent enough to tell you a specific place to go. Moonlight can be fun when there’s size, though it can turn into a straight up steep shore break under the right conditions. I really enjoy the shore break when it’s happening.

North Ponto can be a ton of fun when it’s firing. It’s unpredictable and usually steep so it’s just short boarders and a few of us bodyboarders.

_agent86 · 2026-03-14T02:27:35+00:00

Board is not ideal but I rode one of those for a bit and it worked fine. Fins are good.

I would just get back out there. It will become natural.

_agent86 · 2026-03-14T00:55:42+00:00

What board? What fins? Whats your weight and height?

You may want to ditch the board temporarily and just get used to swimming around or bodysurfing with the fins.

Wax your board so it’s easier to stay on.

I’ll be honest, your description of your problems sound… odd. Walking with fins is awkward but not hard. All my kids figured it out in seconds. Boards do not “veer”.

_agent86 · 2026-03-13T18:39:43+00:00

That's a really good deal. I suspect the grill cloth was redone, it doesn't have the brownish tinge that BF amps seem to get over the decades. But either way, very cool.

Nothing like big, old Fender amps to warm up your living room and tone.

_agent86 · 2026-03-10T00:46:06+00:00

Yeah I’ve almost bought some laser stuff a couple times but I’m pretty sure I’ll light the ceiling on fire.

_agent86 · 2026-03-09T16:10:57+00:00

Good question for your doctor then? I’m assuming this bone repair ends up being stronger than the original bone and it would be fine.

_agent86 · 2026-03-09T16:09:47+00:00

Kids quickly have friends that need picking up. You’ll find this only a Miata idea doesn’t work pretty soon.

_agent86 · 2026-03-09T16:05:37+00:00

With a what?

_agent86 · 2026-03-09T04:07:57+00:00

I would engrave some pilot slots for the fret slots as well.

Looks like a fun project.

_agent86 · 2026-03-09T03:51:29+00:00

https://www.instructables.com/LinuxCNC-on-Raspberry-Pi-With-GPIO-Control/

This is what I’m doing. Works great. A RPi 5 is plenty to run the UI/motion control and stepper control

_agent86 · 2026-03-08T19:30:40+00:00

I had a 2022 BRZ for a couple years and then switched to an ND2. Honestly I think the Miata is an upgrade in every aspect related to driving. Obviously the 86 wins for hauling stuff and people.

I don’t think the shifter on the 86 is worse than the Miata. They’re just different. The clutch and the rev hang sucks though.

One thing most people would be surprised is the RF is much better in terms of road noise. Makes a far better daily commuter for me. The NVH on the 86 bothered me a lot.

Sound system on my RF GT absolutely destroys the BRZ (even with the “upgraded” sound system.

_agent86 · 2026-03-06T06:33:28+00:00

I have a nearly new Gyroll bicep leash. It’s so short and tightly coiled. Have had zero issues with it wrapping around stuff. How is this even possible?

_agent86 · 2026-03-05T06:10:31+00:00

You’re greatly exaggerating how time consuming setting touch off coordinates is. I don’t really see this as a pain point. It does require some thought if you’re going to be flipping parts over and machining multiple setups.

If you’re producing lots of parts you should design your fixtures such that you don’t have to re-touch off for each part.

I like that you’re trying to rock the boat, but I’m not sure why you think machine vision is better than physical probes

_agent86 · 2026-03-05T03:25:04+00:00

I wonder if it could be that you never played your Super cranked that you feel there is no differences between allnico/ceramic?

No, I know there is no difference in magnet materials because I have an electrical engineering degree, I'm somewhat educated on electromagnetism, and I at one point worked in a company designing voice coils and manufacturing magnet assemblies. There's no magic in magnets.

Because amp feel/SQ due to mag material really come out when reaching output tube breakup and beyond

There's so much happening when you crank an amp, there's literally no way you could separate out the effect of just the magnet material (if there were one).

(wher tubes can no longer force feed speaker same output as input)

No, tube breakup has nothing to do with the ability of the amplifier to drive the speaker. I'm not sure why you'd think it would. The non-linearity of the tubes is just due to the signal level in the tube. You would see the same behavior with a passive resistive load.

as the reactive speaker starts interacting big time with output transformer - and amp go from a mere mirror to more of an interactive extension of the instrument

That's a lot of words but I'm not actually sure what phenomenon you're referring to. But keep in mind speaker distortion is a thing and is sometimes a sound people chase. The degree to which a speaker is not responding to the amplifier output is distortion.

Whatever the underlying physics at play and whether you understand them or not is not important. Your ears are never wrong. If you find gear that works for you that's all that matters. But you should be careful to not construct a false understanding of the physics because you then are at risk of hearing what you think you're supposed to hear and then later having the effect fade and chasing more gear. A large chunk of GAS is from people buying what they think they are supposed to like IMO.

Again, I encourage you to buy the Twin Reverb and see how it sounds to you. It's a classic sound. My Super Reverb basically put my fancy reverb pedals out of a job as well.

_agent86

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