Ever wanted to build your own tube amp?

[Nitro Express]

It's kinda like being a chef. It looks easy and in many cases it is but getting the end result to be what you like is real trial and error. I know my dad looks at the schematics of guitar amps and just shakes his head and goes,"All you guys want is distortion." He doesn't get the concept. He's a total audiofile and will be the first to agree tubes are the way to go but he's spending a fortune on expensive transformers handwound by some dude in Japan with silver wire and looking for tottaly distortion free sound. He really doesn't get why old Marshalls and such are so coveted. He looks at the transformers and the parts and basically says, it's all run of the mill stuff. Old but when the amp was built there was nothing special to the parts and even the transformers were cheap and nothing special. That's true because Marshall went to EL-34's from 5881's because EL-34's were cheaper to buy in the UK.

Guitarists love cheap shit that sounds like it's going to break. Audiofiles don't get us at all and we don't get their cork sniffing ways. LOL!

[GAR]

EL34's can take up to 700 volts plate voltage without a strain, and some engineering data specify up to 900 other designs!

Most amps do not run 'em that high.. even Marshalls.

Musicman's do 700 bone stock.. try finding 'em though. They made grate source-amps (hint hint).

[Hardrock69]

Ahhh..I had a 65-watt MusicMan head back int he early 80s. As a matter of fact, it was the first guitar amp I ever owned, errr...I mean bought.

[GAR]

Even though it is true these amp designs are 60 years old and use "run of the mill" parts, it's about the math principles that specify what parts are used.

That's the engineering aspect of it

[Nitro Express]

Plus guys like Jim Marshall and Leo Fender wanted to give musicians good value for their money. Jim Marshall got into the amplifier business because there was a demand for Fenders but they were expensive in the UK. So he made amps out of British parts based on the basic Fender design.

We're not talking McIntosh type quality here. The Marshalls and Fenders had good quality components but they were on the level of what was being put in the average hi-fi at the time. Not cheap Sears Silvertone transformers but not McIntosh transformers either.

There's just nothing in these old classic amps that is going to make an audiofile like my dad excited.

[Hardrock69]

Haha well yeah for the kind of amps we are talking about.

But has he ever got one of those old 1960s Macintosh Tube Power Amps going? Where the tubes are breathing fire???

My Dad had one when I was a kid....sold it in the early 70s, and then just a couple of years ago he found one on eBay.

[ashstralia]

Originally posted by Nitro Express
Plus guys like Jim Marshall and Leo Fender wanted to give musicians good value for their money. Jim Marshall got into the amplifier business because there was a demand for Fenders but they were expensive in the UK. So he made amps out of British parts based on the basic Fender design.

did you all know Jim is a drummer?
he had a music shop which was
frequented by pasty pimply faced
boys with names like page, townshend,
beck, clapton, richards, moon, etc etc...

[Nitro Express]

Yeah, I have a book on Jim Marshall signed by the man himself. Like Les Paul, Jim Marshall is one of those old guys who "gets it". Most in their generations don't. Shit, I hear Jim is a top notch drummer but look at his students. Not only do they keep a beat they throw in some flash.

[Nitro Express]

I have a mint condition 100 watt McIntosh tube stereo amp with the matching solid state preamp. When my parents were selling their house my dad was just going to garage sale the thing. I grabbed it. In fact, that was the amplifier that first pumped out Van Halen when I first heard them. It's a keeper.

[Hardrock69]

Wow. Lucky bastid!

[GAR]

Originally posted by Nitro Express
.. made amps out of British parts based on the basic Fender design.

Actually most of those tube circuits Leo Fender was basing his amps on were two decades old and come right out of the Western Electric receiving tube manuals widely available..

They're simple textbook circuits. Anyone can build them.. but not everyone can get consistent results because the tolerances of component values vary so much, capacitors for example are like, plus or minus 20 percent.

Building a tube circuit is all about following the tolerances and keeping it in the specification of the print, and knowing what to do to offset those measurements when they go out by computing a compensated value to continue.

Homebuilt amps are better nowadays because the component values themselves are much better sometimes with 1 percent tolerances if you can pay extra.

[BrownSound1]

I've got access to boat loads of Mil-Spec parts...those tolerances should be well within the specs on the prints.

[GAR]

Probably, but eBays' been pretty helpful to me for parts actually!

I've been loading up on resistors, caps and diodes for example, just got in a 5000 pcs bag of 1N4148 diodes for under $15 bucks, and the sellers - HALF of them abouts, actually get the materials by dumpster diving or from salvage from "end-of-run" assembly reels.

Radio Shack ain't got shit anymore. Someone ought to throw daisies on the casket already.. ebay RULES!

[GAR]

For those in need of assistance getting their AX84 low-wattage tube amp project off the ground, I found this flowchart to be of h e l p.

[BrownSound1]

Radio Shack sucks monkey balls.

I've always loved that flowchart.