1. If your amp produces a little more 2HD than necessary, would you intentionally add a little 2HD of opposite polarity to offset it?
2. If your woofer is producing 2HD, same deal?
3. If your hifi amp is producing a little 3HD and no second, would you add some 2HD to fill in the gap?
Cool looking collection. Mine might get here tomorrow. Then again it might be Monday. UPS is not always on time here, but I'm always the last stop on their route. The driver says his truck does better on our dirt road when it's empty.
Our mail girl brought me a whole bunch of stuff today, one day early. Our US Mail is brought to us by a private contractor from Ohio in her personal car. A right hand drive 2WD Jeep in good weather, or her 4WD Honda CRV in snow. There are a few days we don't get mail, usually ice or really heavy snow. She knocked on our door this morning asking me to "come get the big box out of my Jeep." It was a 50 pound spindle sander I ordered from Amazon Tuesday night. Half of the boxes in her Jeep were from Amazon. She says it gets worse in late November and December.
Thank you for telling the community about the sale. I am curious to see what's in your box. When I first opened the box I said to myself this will take forever to organize but it only took me a few movies to do.
I have several friends that work for the USPS and they are not happy this time of year, they deliver more and more packages each year and especially around the Holidays.
Hopefully you got yourself a sled to get around in the winter. I just got my Arctic Cat all ready for the season so hopefully we get dumped with snow😱
Second-order harmonic distortion
Full cathode bypass and big, fat tone controls
Five-way Butterworth crossovers which sings
These are a few of my favorite things.
Ok, it doesn't perfectly scan, so it's not going on Broadway anytime soon. (Springtime, for cathode bypass, in my amplifier...)
In all seriousness, it doesn't matter what I like, don't like, or what I would do or not do. It doesn't matter what you think about distortion.
What we're talking about is:
(a) do carbon-composite resistors color the sound?
(b) if (a) is true, and one's goal is coloration, then where should those resistors be installed for best effect?
The ideal amplifier, as Harman-Kardon put in one of its ads, is a straight wire with gain. That is, it does not alter the input signal other than to make it larger.
Anything else is personal taste.
It's ok to like distortion. Some of it sounds warm and relaxed, like a whiskey aged in a burnt-oak barrel forgotten for a century in a broken down barn and allowed to slow age in the seasons. Other is that grating sound of nails on a blackboard that makes you want to emulate Godzilla in Tokyo and smash that amplifier into rubble.
I don't judge if you like distortion.
But I call it what it is.
Carbon-Composite resistors will distort in small amounts when used as a plate resistor, but have no value elsewhere. That's the takeaway.
NB: not that it's relevant to this discussion, but just to forestall the arguments (I think this is where it's going), I'm not the guy who rips out tone controls and pontificates about how his setup has lower distortion than anything on the planet and how his ears can hear things nobody else can. Nope. I am so not that guy.
My favorite setup for many years (and might still be) was an EICO ST-40 (a bypassed cathode bias amplifier), played into original 12" Karlson cabinets with a full-range Goodmans drivers. (All of which I still have, BTW.) If your setup has more second-order distortion (and probably higher order as well) or peculiar sonic abnormalities than this, I'd like to hear how you accomplished that. Because that would deserve a Nobel Prize.
But I also have lots of other gear with minimal coloring and that is very clean, including Bozaks. Others use germanium front ends. Don't get me started on what I think should be done to guitar amplifiers. It would keep you up at night.
So the point is that I don't hate all distortion, and I'm not a zealot about it. I just know what it is and what it sounds like. So my personal opinion doesn't matter for a practical discussion of how carbon-composite resistor distortion arises and how to best use it if you like that sort of thing. (Not that there's anything wrong with that.)
The UPS web site says "out for delivery." That means that I might actually get them today, but it's not a guarantee. The UPS guy comes back this way after dark, and doesn't always venture down this skinny dirt road for just one delivery, but maybe, he is a far better driver than the FedEx guy.
For now I'll probably just pick out a few identical resistors in the 82K to 150K range to try as plate loads.
No, but after getting each of our FWD vehicles stuck several times over the last two winters, we got a used 4WD Honda Pilot. There will still be some days when we just stay inside, except to shovel snow. Don't even have a blower yet. There was one day last year that I shoveled almost continuously for about 12 hours, in a T-shirt. It wasn't that cold, but it just kept coming down.....The year before that was when we had -12 degrees, my Honda Element wouldn't start.
I build all of my own amps.....If I don't like the way it SOUNDS, I take it apart and make another. Yes, I have gone Godzilla on a few of my own creations (or death by power supply, turn it up till it fries!).
I have SE tube amps from 2 WPC to 40 WPC, P-P tube amps from 10 WPC to 125 WPC with a 500 WPC amp in the works, P-P BJT amps from 10 WPC to 75 WPC, and class D amps from 10 WPC to 200 WPC. Those are the keepers. Dozens more never made the cut. I test and record the distortion and other performance data, but don't sweat the numbers......they are what they are. In the 20 years since individual harmonic analysis has been available, I have noticed a trend in what I like, but things like dynamics don't show up on a spectrum analyzer. Different amps suit different musical tastes, moods, speakers, and SPL levels.
Guitar amps evoke an even stronger personal preference than HiFi amps. The first electronic thing that I ever made was a guitar amp, and that's all I built in my pre-teen and early teen years, all tubes because that's what you could get for free out of the trash (1960's). At first, if it made any sound at all, it was good, but my tonal tastes developed around the surf music of the mid 60's and have been changing ever since.
Again, personal preference. The guitar sound for the 60's surf music was pretty clean by todays standards, but had loads of reverb. Most rhythm guitar playing requires a clean amp. Why? try playing chords through a cranked Marshall. The IMD created when six individual tones are run through a heavily distorted amp results in the generation of dozens of dissonant sum and difference products that just sound gross, unless severe bandwidth limitations are imposed by the amp and speakers. Hence the invention of "power chords." Its real hard to generate THD, without making IMD. Power chords are designed so the first order IMD notes are consonant. Yes, a screaming lead would sound pretty blah with out being "cranked" but clean has it's place.
About 15 years ago my daughter played drums in the high school marching band, and also played guitar and keyboards. I had made several vacuum tube guitar amps for her friends. Most were low budget SE "Turbo Champs" made with salvaged parts. Each was different and a few were made with car audio speakers that I got cheap when a local K-mart closed down. One of the last amps made was built with the JBL speakers I pulled out of my car before trading it in. It was just too clean. Nobody liked it, but it did OK for a practice amp with my daughter's Roland JV1000, so that's where it stayed for two years.
One day while I was at work the usual collection of band kids was at my house annoying my neighbors when somebody plugged their ES-335 into that amp. He was waiting for me when I got home. He wanted to buy that amp. He showed me why, and I must admit that it did sound good. The car speakers gave the Gibson just enough sparkle to sound almost like a true acoustic guitar at low volume, yet it sang out in a bluesy way when cranked (just enough distortion), so I gave him the amp. High school was nearly over, and most of these kids were going off to college. I never saw any of those amps again.
I can see that, I built my current amp using only a DMM. There are no CC except as stoppers and I haven't wanted to touch it since and that's the sign I was looking for.
The examples above were to show using the resistors as a tool to reduce distortion. There was a run on inverse distortion cancellation around the time AudioXpress began. A knowledgeable member here mentioned that CC Voltage distortion was simple in nature making it a potential tool.
In my box there are a lot of 150k but they are mostly 1/4 watt. I found maybe five 82k in 1/2 watt package.
So we know that with a lower wattage resistor we will get more distortion but with more noise. Is running a 1/4 watt resistor at 100mW-150mW a bad idea? I see a lot of newer Fender amps that use 1/4 watt resistors but they are film, maybe they use 1/4 watt to save pennies or maybe they do it for another reason. I know the hotter they run the resistance will be higher along with distortion.
Not sure if I should waste my time messing with the 1/4 watters as plate loads.
About half an hour ago the UPS guy rang the doorbell. As I opened the door I see the truck driving away and a box on the porch. Normal, it's the end of a 12 hr shift for him. Upon bringing the box inside, I see that it has been ripped nearly in two, then taped back together. This is not the first time they have mangled something. The 300 rotary encoders are in plastic tubes of 50 much like DIP chips. Most of the tubes are bent, but it looks like only two encoders are damaged beyond bent pins.
The resistor box had broken open, but the resistors had been stuffed inside the box so well, that they remained a solid brick with only a few loose resistors. I find no obvious broken ones. Now how many can I sort out during tonight's episode of MacGyver?
The resistor box had broken open, but the resistors had been stuffed inside the box so well, that they remained a solid brick with only a few loose resistors. I find no obvious broken ones. Now how many can I sort out during tonight's episode of MacGyver?
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The old rule of thumb is to operate a resistor at half its rated power or less. This is probably a safe bet with these parts that seem to vary in age.
I can't possibly count all the guitar amps I have built, or helped built in over 50 years of making music, OK, noise. I currently have one working amp resurrected from the Hundred Buck Amp Challenge. That means a lot of amps have been sold or given away over the years. The majority have been tube amps except for those built from about 1975 to about 1985. Myself and a few others made a bunch of solid state amps during that period since we all worked for a semiconductor company.
Early on I learned to design my things assuming the operator is an untrained monkey, because a small percentage of them will treat your design in exactly that manner. This often means sticking the wrong tube in the amp because someone, or some web site like Ebay will tell then that these tubes make your amp sound awesome.
This is especially true with guitar amps, so I design the preamp stages such that for the most part sticking just about any tube in the socket won't blow anything up. When someone sticks a 12BH7 into his 12AX7 socket, what fries......the plate load resistor. This is why I use 1 or 2 watt resistors for plate loads, they wont fry......There is another reason. Have you noticed the tiny size of some modern leaded 1 and 2 watt resistors? The laws of physics have not been repealed, for something the size of a 1/2 watt resistor to dissipate 2 watts, it MUST get real HOT. No problem, the modern parts are happy running at 100 degrees C. That may be OK, but the solder holding it in the board will eventually become brittle, especially when it's being shook to death by the speaker a few inches away that's powered by Captain Metalhead and the 100 Watt Monsters!
If you are making an amp for yourself a 1/4 watt resistor may be OK, but I tend to design for worst case, because often, I'm the idiot with the guitar preamp plugged into an amp designed for HiFi....I test all my amp designs this way....yes I have played my guitar through a 300B HiFi amp.
Between Happy birthday phone calls, a plate of fresh baked cookies from my daughter, and the TV set I managed to sort maybe a hundred 1 watt resistors. There are maybe 25 that are 51 ohm, a dozen 1.3 meg, eight 16 meg, eleven 39 ohm, nine 68K, seven 68 ohm, six 33K, five 240K, and a bunch of odd valued singles and pairs. That's probably 10 to 15% of the 1 watt resistors. There are less 2 watt resistors and the obvious multiples are 180 ohm and 3.0K.
I'll be gone most of tomorrow, so I won't get back to these for a while
I'll try the 150k just for measuring distortion purposes then change them out. If I like the results the amp I am using them in is mine so if I have to change them out once a year I don't mind, it gives me something to do.
I agree if I build an amp for someone else 1/2 watt is minimum to be safe. I usually use 1 watt carbon film.
BTW Happy Birthday to Tubelab!!!!
I agree if I build an amp for someone else 1/2 watt is minimum to be safe. I usually use 1 watt carbon film.
BTW Happy Birthday to Tubelab!!!!
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