6ak6-tone-experience?

[Gnobuddy]

then my @$$ is a banjo.

Come on, Chuck, surely you can pick something better than a banjo!

Which reminds me of a joke: What's perfect pitch?
Answer: A perfect pitch is when you throw a banjo in the dumpster, and it lands on an accordion!

I've got some tinnitus too - in my case, probably from driving a too-loud muscle car in my twenties. Hearing damage is cumulative, another reason I watch my exposure to high SPL these days.

Sorry to hear about the RSI - been there, done that, got to the point where I couldn't even drive a stick-shift without severe pain. I switched jobs, and stopped using computers almost entirely for a year or so. That let my arms, wrists, and hands recover enough to resume somewhat normal activities, cautiously at first.

It's been years now, but I still have to watch that I don't type too much, or spend too much time on high-speed guitar picking practice exercises.

-Gnobuddy

[bob p]

Say what?

[Justin Thomas]

Damn the torpedoes or give me deaf!

Justin

[Chuck H]

Eh? Speak up! I couldn't hear you.?.

Yes I have mild tinnitus. Believe it or not you actually learn to ignore it at my level and I don't have any trouble with jumbling or peripheral noise. Sometimes you just have to gauge the level of damage against your lifespan I wink, but I'm not kidding. Live till you die or die so you can live. It's a choice. I deal with it every damn day since I'm a service industry contractor with multiple repetitive motion disorders

Whatever OSHA decides is going to be the lowest common denominator because they hate when people file law suits. Most ears are more resilient than that. I'm living proof if ever there was. And if I'm worried about a two watt amp (or even a fifteen watt amp) then my @$$ is a banjo. Damn the torpedoes (thanks Tom) I'm going to enjoy my guitar while I can.

[Justin Thomas]

"Using a compressor or limiter like this can be pretty interesting, I think it's easier to control the acoustic feedback this way..."

Control? Where's the fun in that? Not to mention, CHEATING!

I think this can all be settled by acknowledging that we're all in this together, but we're all different. Myself? I'm more the "Sonic Youth Approach" than the "Santana Approach..."

And nothing is too loud when you had the chance to CRANK a Sovtek Mig-100, a 1978 JMP-100, a VT-40, and a Super Twin...

Justin

[Gnobuddy]

It's still a guitar amp and it SHOULD make some noise

I understand your point of view, it's a very popular one among electric guitar players.

But then you look around, and notice that all the surviving disciples of "the godfather of loud" - the ones who played through 50W and 100W and 200W guitar amps on stage, turned up to full - are now either deaf, or have severe hearing loss and tinnitus to torment them. (Imagine a sound like a small jet plane taking off inside your ear - all the time, all day, every day. )

Me, I enjoy music better if I don't have ringing ears and a headache - and hearing loss - at the end of the evening. Evolution never designed our ears to cope with 100 dB sound levels, never mind the 115 dB you can get from a 15-watt amp and a 103 dB sensitivity speaker. 200W amp? Horrors. You can probably hit 130+ dB with a 4x12 cab or two. That's loud enough to cause virtually instantaneous "permanent shift of hearing", as the medical profession calls this type of permanent hearing loss.

OSHA says you can tolerate 85 dB SPL for several hours a day - but most people don't realize that (a) that assumes dead silence for the rest of the 24 hour day, and (b) OSHA was heavily biased in favour of factory owners, who don't like to spend money on reducing SPL levels.

So the reality is that several hours of sustained 85 dB SPL music (which takes only 0.1 watt into a 95 dB speaker!) is loud enough to cause some hearing damage over time. No way around that, short of wearing earplugs - you can't argue with the limitations our evolutionary past wired into us.

Not trying to tell you what to do, of course. Just trying to look out for another musician.

Acoustic feedback! It's part of what makes an overdriven amp sound right.

Throw a compressor (or distortion pedal) in the chain, turn up its gain, and you can get acoustic feedback without ear-splitting SPL. Using a compressor or limiter like this can be pretty interesting, I think it's easier to control the acoustic feedback this way.

-Gnobuddy

[Justin Thomas]

A-FRIGGIN-MEN TO ALL OF THAT!

Justin

[Chuck H]

You guys! With your milliwatts and such... Christ on a rubber crutch, are you practicing in the lobby of the municipal library? It's still a guitar amp and it SHOULD make some noise

No, you're not playing it cranked up at midnight. But it should still be fine with appropriate timing (read: wife isn't home right now, or whatever) but you still need that thing I talked about earlier. Acoustic feedback! It's part of what makes an overdriven amp sound right. The idea behind a two watt amp isn't that you can play it at midnight (or in the moonlight if you're at the AX84 site). Rather it's more like "Well, it's not a cranked fifty watt amp". That's got to be better. At some point you reach diminishing returns. I absolutely REFUSE to practice with headphones. That $h!t is worse than sex with a condom.

[Chuck H]

...for example, you can see that the output transformer is actually one of those inexpensive 70V audio line transformers. Given the strong bass in the MP3 clip, I wouldn't have guessed that - those little audio line transformers often have very low primary inductance compared to "real" valve OPTs, and there are frequent mentions online of thin bass in DIY builds because of that. But it seems the combination of OPT and speaker that Printer2 used has no shortage of adequate bass.

Indeed! I started looking into it the moment I read the thread It seems there's a lot of useful iron out there for less $$$ than the boutique stuff. Of course that's because it's made by the barrel so guys can buy eight of them over the counter without falling over from sticker shock. That extra five percent of goodness from OT duty specific transformers starts to fade when you realize you can get a nearly equal unit to the task for ten to fifteen bucks!?!

[Chuck H]

Make a 6cl6 pp amp. I'll mail you a few, i have a 100 and will never get to that project until about 2025.

Too many watts! And what's up with that .65 amps of heater current? I'm planning a 2W amp here with about 40mA available from the HV wind and 1.2A from the filaments.

Looks like a neat tube. Supposed to process video with low distortion. I'll guess that's going to be at much higher frequencies than we deal with normally Still, could be a great tube for a pair of mono blocks and home listening

[Gnobuddy]

...we have to admit that if you've got efficient speakers it only takes milliwatts to make something "too loud" for someone else's ears.

A few years ago, I discovered that I could hear ten microwatts of 1 kHz sine-wave into an old Weber speaker. The speaker was on my workbench, and I was sitting on a chair pulled up to the same bench, with my ears two to three feet away from the speaker.

I was living in a rented suite on a 20-acre farm at the time, and it was a very quiet environment. Still, I hadn't expected to be able to clearly hear microwatts of power into a speaker. I thought I must have made a mistake in my AC voltage measurement, or my math. But when I calculated the estimated SPL, it all made sense. Ten microwatts - that's 10^(-5) watts, or (-50) dBW. Put that into a speaker with 95 dB@1W@1m sensitivity, and it will make an SPL of +45 dB. According to typical SPL tables (like this one: Noise Level Chart: dB Levels of Common Sounds), that is somewhere between "babbling brook" and "light traffic". Quite audible, and in fact, that 1 kHz test tone was loud enough to be annoying after a few seconds!

That led me to sit down and do some calculations on guitar amp power vs expected SPL. I decided on 70 dB SPL (about as loud as a vacuum cleaner) as the loudest sound that would be acceptable in an apartment. How much power does it take to generate 70 dB SPL at 1 metre distance from a speaker with 95 dB@1W@1m sensitivity? Three point two milliwatts!

As another data point, I once briefly owned a VOX AC4TV, and found it too loud to use at night on the 1/4W (250 mW) setting.

So there you go, with a typical guitar speaker, the "right" amp power for overdriven guitar tones in an apartment setting is somewhere between three and three hundred milliwatts!

it's an interesting idea to build something smaller and smaller until you find that magic micro-amp.

Been there, failed to do that...when the output power was the limiting factor, either my overdriven guitar sounds were too loud, or my clean tones were too quiet. And other physiological (Fletcher-Munson) and psychological (loud sounds have more emotional impact) factors came into play. I never was able to get guitar sounds I really liked with that approach.

So I re-thought the plan, and decided to have a preamp that generated the timbres I wanted, and a master volume, and a mostly "clean" power amp with a whopping two watts power capability. For me, that approach has been a lot more successful. I can get guitar tones I enjoy at SPL levels comparable to playing on an unplugged acoustic guitar.

I understand how hard it is to not build something when you've got an oddball piece of iron there, just taunting you...

I have a few 6LY8 triode-pentodes and a couple of 70V audio line transformers lying around. I keep thinking I have to turn those into a two-bottle mini "18 watter" some day. The triodes are the same as the ones in the 12AX7, so just two 6LY8s should be enough for both a push-pull phase splitter, and the output pentodes. Add a 6JW8 in the preamp and you can have both a triode and a pentode channel...no overpriced EF86's necessary!

(Actually I think both the 6LY8 and 6JW8 have little beam tetrodes in them, not true pentodes.)

-Gnobuddy

[Gnobuddy]

I don't need to see the pics. But thank you. I know what a build looks like I haven't read his build article yet. Going there now.

Oh, I'm sure you know what a traditional build looks like!

But I should have been clearer - one of the pics (he posted a GIF file) is a schematic (without part values, but may be useful). Another pic is a screen capture of a spreadsheet bill of materials (which, of course, does include component values).

Some of the build pics are also revealing, for example, you can see that the output transformer is actually one of those inexpensive 70V audio line transformers. Given the strong bass in the MP3 clip, I wouldn't have guessed that - those little audio line transformers often have very low primary inductance compared to "real" valve OPTs, and there are frequent mentions online of thin bass in DIY builds because of that. But it seems the combination of OPT and speaker that Printer2 used has no shortage of adequate bass.

-Gnobuddy

[mozz]

Make a 6cl6 pp amp. I'll mail you a few, i have a 100 and will never get to that project until about 2025.

[Chuck H]

I agree about the volume. Doing some short math I figure my attenuated practice level right now is about one watt (probably just shy of that). So two watts (probably a hair more) is going to be comparatively loud. But there's that level of volume that allows for some acoustic feedback which I would like to get. It's probably good that I've developed a skill for dodging flying objects and I keep a pillow in the shop.

[bob p]

the problem with low-wattage amps is that they still produce a decent amount of power, as far as getting too-loud-for-the-neighbors goes. as much as we like to crank amps, we have to admit that if you've got efficient speakers it only takes milliwatts to make something "too loud" for someone else's ears.

it's an interesting idea to build something smaller and smaller until you find that magic micro-amp. and i understand how hard it is to not build something when you've got an oddball piece of iron there, just taunting you...

for me an attenuator has been a good enough solution to the too much power problem. let us know how it plays out, chuck.