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У меня лет 10 назад JJ ECC83 из ТТ разделась сама)) чего меня дëрнуло не включить свой Сло, а полезть потрогать лампы - Х. З. но когда тронул лампу - колба осталась в руках,  а кишки в панельке торчат
Хотя предыдущее включение было штатно, поиграл и выключил

Last year I spent… countless hours designing some guitar pedals that I still haven’t built yet… but in the process, learned a lot of new quirks of vacuum tube behavior. And while designing & prototyping those pedals (which I will finish the next time that I get the urge to solder), I realized that some of those weird quirks explained why my amps never sounded quite the way I wanted to sound.

For example:

Did you know that the gain factor of a triode changes depending on the impedance it has to drive? And that’s in addition to whatever signal loss you’re going to be seeing when you consider its own somewhat high output impedance? For example, a 12AX7 common-cathode gain stage loaded with 50k only generates a little more than half as much gain as it would with a 500k load, and you’re still looking at a 38k anode impedance running into that load. So it produces a smaller amplified signal and then attenuates it more. Consider the final preamp triode in the classic Fender AB763 circuit: at a glance it looks like its output just runs through some mixing resistors on its way to the phase splitter, but then you spot that pesky Tremolo intensity pot hiding further down in the schematic. Oh, and those mixing resistors and the other channel’s anode resistors all form a big complicated network of AC paths to ground, acting in parallel with the more obvious parts of that load… and right before that triode is the big signal-attenuating reverb filter. So that last stage isn’t spitting out a great big signal and slamming the phase splitter like I thought it was in 2014: it’s taking a very manageable signal, spitting out a small signal, and then throwing even more away on its way to the splitter. No wonder my Fender-inspired build always seemed too dirty and never did the spanky-clean funky stuff properly.

I rebuilt the entire pre-amp in the Fender-y amp and now it’s just dandy. Added some more options too, so now it convincingly covers the entire Fender clean spectrum, certain Dumble settings, and the Mesa Mk1, Lonestar, and Blue Angel pre-amp circuits. Very flexible. Lots of mini toggles.

Another example:

I was - and remain - power tube agnostic when it comes to BS like “American power tubes sound glassier and cleaner than British power tubes!” No they don’t. That’s how the preamps and speakers are voiced. It has nothing to do with the power tubes.

Buuut

That “they’re all the same, just different power levels” attitude made me miss that different models of tube have different levels of input headroom.

For example, it turns out that a 6v6 starts to distort at about the same level of input signal as an EL34 does, which means that the power tube distortion start at an appropriate level for my Fender and Marshall styled amps when they’re cranked up loud, but an EL84 offers much less clean input room before it hits its maximum output and distorts. So the Vox styled amp, with the 6v6 output section I gave it back when there were no trustworthy manufacturers for EL84s, was completely incapable of pushing its output tubes into the kind of saturation demanded by Queen. So I ended up rewiring the power transformer to nerf the voltage, replaced the output transformer to an EL84-friendly value, and popped in new sockets to use the right tubes. Luckily JJ makes good EL84 tubes now and so the reliability problems are solved and the amp sounds right again.

Okay, one more example that has nothing to do with the tubes:

When I chose my speakers for these amps I based my choices on what kind of aftermarket speakers people were putting into their amps at the time, and alnico blues were extremely popular. So sure, why not? Jensen alnicos it was. Fast forward ten years and I’ve realized: that’s not what came in Fender amps in the 60s, and that’s part of why my Fender-ish never sounds properly Fender-ish. Bought me a proper cheap ceramic Jensen, wired it up in the speaker cabinet, and voila: the crisp dare-I-say “ice-picky” trebles that were always missing were there. And to think, this wouldn’t have been a problem if I had originally gone with the same “we chose this one because it was cheap” speaker the things shipped with half a century ago.

… . .

Yeah it turns out if you want to make something that sounds like the amps you’ve been listening to from the last 60 years of recordings, the best way to do that is to pay careful attention to what was inside those amps instead of trying to reinvent the wheel.

А кто этот чувак, открывший для себя азбуку, через 10 лет работы?