Custom OT Impedance Question

[Austin]

Champ 1000 Watt Tube Amp that'll do it

I dunno why the guy in this link calls this a "Champ" becuse it is pp, arn't all champs se?

[imaradiostar]

I guess if it's his own design he can call it whatever he wants!

Jamie

[Enzo]

If you are making a totally outrageous, over the top amp, it increases the irony to name it after the most minimal of amps. Like naming the most destructive weapon ever made the "peacekeeper."


(Note: that is not intended as a politcal statement, please do not assume it is and get off into policy)

[J M Fahey]

Like naming the most destructive weapon ever made the "peacekeeper."

You are not exactly wrong .

Not Politics, just light History:
This Colt revolver, was called .... "The Peacemaker" .....


And the Romans said: "If you want Peace, you must be ready for War"
Or, in Latin: "Si vis Pacem, para Bellum"
100 years ago Germans fell in love with the word, so they created their own version of "Para Bellum"


So, in a nutshell, when somebody starts talking about Peace, get bhind a thick wall first and only then ask him to explain what he really means.
Just sayin'

[Alan0354]

Call me a holier than thou pompous prick but I have to say I side with RG on this. While I'm no Randall Aiken, RG or Steve Connor (those guy's have probably forgotten more than I'll ever know), I've noticed an increasing trend of guys starting up amp shops who claim to be "designing" their own amps yet they don't even have a basic understanding of the elementary basics (i.e. Ohm's/Watt's Law, electron flow vs charge flow, transformer voltage/impedance ratios, basic tube theory, DC load lines, how to read schematics, etc etc).

Then everytime those of us who've paid our dues by learning all of this say something about it, those guys feel compelled to attack with personal attacks, brag about how many big name people are playing their amps, how they have "golden ears" compared to guys who actually understand amp theory, and somehow think we feel "threatened" by the fact that "hobbyists" are starting up their own shops and getting the same recognition we do.

Threatened? Not in the least.

Feel like the public is being misled to think that these guys actually have electronic basics down and really know what they're doing and WHY certain component values affect the tone of an amp the way they do in a given circuit? Feel like undeserved credit is being given to someone who hasn't paid their dues to earn it? That's more like it!

Guitarists think that anyone owning an amp shop actually knows how amplifiers work. Why? Because anyone running an amp shop SHOULD know it. Then once the cat's outta the bag as to the limitations of one's knowledge, guitarists ask "Well how can we tell which techs really know their stuff?".

I mean think about it...would you want to be going to a doctor that had no concept of human anatomy but follows the "tried and true" methods of real doctors who paid their dues by learning the required knowledge to be a doctor and actually know what they're doing? Do you take your car to a mechanic who is little more than a "parts changer"?

Most of these guys are starting shops and riding on the coat tails of those who designed certain circuits. There's another message board that has lots of mods floatin' around and guys are just using those same mods to build and sell amps. Every so often I get emails from these guys who've done a certain mod, the mod didn't quite go as planned, and due to their lack of knowledge they email me and expect me to walk them through how to fix it. And these problems they have are VERY basic...getting the OT primary/PI grid drive out of phase, forgetting to ground the bias supply, not grounding cathodes, etc etc. If your working knowledge of electronics is limited to the point that prevents you from troubleshooting even the most basic problems in a given circuit on your own via a schematic, you have no business running an amplifier shop IMHO.

Now from time to time those of us who have a genuine working knowledge of electronics will run into a problem that we cannot solve and hit up another tech for help. However, we're not expecting the other tech to "do the work for us" and the nature of the issues we typically hit up other techs for are a bit more complex than the basic "wiring the OT primary out of phase". On top of this, by the time we hit up other techs, we have voltage readings, schematics, etc etc...to supply them and we kinda go through it together...not "one telling the other how to do it".

Just my $0.02.

Call me crazy and it is actually against all my practice as I am the one that really get into the theory and all. I have to come to the defense for the OP. There is something about guitar amp that you can just step onto a winning formula. I did!!! 1979, I modified my Twin to the way I like it, I did not know electronics, I sure did not know how transistor works, just common sense of physics and barely a little about guitar amp. I mod my amp, I still have an old cassette tape made on one of my street jam with a hand held recorder. I am working to get back the sound I got. Of cause this time, I studied before I try......as I have been studying RDH4. That was the time before I got my first half a$$ electronic field service job. Just purely by a little common sense. I was actually doing true channel switching using a SPDT foot switch into either a cascade gain channel and a clean channel( I did not know anything about relay!!!). Point is, you can stumble into something good and make it a product.

I quit music right after that, sold it to a friend for cheap which I since lost touch. Did not really pick up the guitar till the late 90s. I dump a black face Fender Deluxe and a Bassman 100 head into the garbage can when I move in 86..........I am dead serious, Too much to move, just dumped them all in the trash.

[Austin]

I quit music right after that, sold it to a friend for cheap which I since lost touch. Did not really pick up the guitar till the late 90s. I dump a black face Fender Deluxe and a Bassman 100 head into the garbage can when I move in 86..........I am dead serious, Too much to move, just dumped them all in the trash.

[deci belle]

Guitarists think that anyone owning an amp shop actually knows how amplifiers work.

I was one of those guitarists that thought anyone owning an amp ought to know how it works!!

[Alan0354]

I have been kicking myself since. I did not even listen to music for 6 or 7 years during that period of time. Deluxe was considered cheap amp!!!! Nobody want that!!! All of a sudden, small amps are hip!!! I was kind of a mild hoarder before, I determined to change when I bought my first house......that was really the wrong time to change!!!

[Steve Conner]

Believe it or not, during the metal era these little amps were considered junk! Nobody wanted them.

[Alan0354]

I was one of those guitarists that thought anyone owning an amp ought to know how it works!!

That's what I thought, it's so natural to open the amp and start tinkering on it. Never thought about "cascade", all I know was I want to drive it harder and I don't use reverb, so I started by copying the first stage using the 12AT7 socket and drive the normal stage harder!!! Then if I don't like the sound, start monkeying with the resistors and capacitors. I got the idea of variac because I was from Hong Kong, I shipped my Marshall Plexi triple stack from Hong Kong, and it has 110/220 select switch. I put it on 220 accidentally and got distortion at low volume. Then I start monkeying around that too!!!

That's how I launched my entire career, starting with tinkering. I found electronics was......and still IS my ultimate passion. I quit music because because I just didn't have time.........and I grew up, got married. If I have the knowledge on patenting, I could have been rich. I don't care whether anyone believe this or not, In 1988, me and my step son was B.S ing one night about suit case with bigger wheels and retractable pull up handle. I actually drew up some diagrams, we laughed and dropped it. The rest is history. That's the reason I was here for a little bit last year, quit playing with electronics for almost 6 months, just concentrated on learning how to write patent application.

Everyone, ask yourself, I am sure you have ideas one time or the other and laugh it off.........then turned out to be a hit years later..........and kick yourself why you did not do something about it!!! I found learning and writing the patent very exciting, it really help you focusing your mind too on the design.

[Alan0354]

Believe it or not, during the metal era these little amps were considered junk! Nobody wanted them.

The kicker was I actually had to buy another Bassman 100 AGAIN in the late 90s and monkey with it. Luckily, it has no reverb and I only paid $250 at the time.

[Alan0354]

I want to share something really funny. Want to know how I even got into electronics and tinkering? I bought the Twin right before I went back to Hong Kong for summer vacation in 1975. I was so excited I want to carry it back. It was way too heavy as luggage, I took out one JBL and the power transformer and carried it on the plane. I lost the transformer in the Airport!!!! So when I was in Hone Kong, I had to buy a Chinese made transformer, tinker with the bias and all, had it in a wooden box hanging out at the back of the amp when I was performing. That was the first time I got into the amp tinkering. I bought the correct transformer after I came back. You can't buy parts in Hong Kong like here!!!