Anybody here into tube amps?

The design will be much easier if you use a Class A output like a radio rather than Class B (push-pull) like a powerful stereo amp.

It's vastly easier to recycle an old transformer of adequate core cross-section for your planned output power. You get the right size of bobbin to wind your own wire on. jsw

Gawd, reaching back to Coleman College in 1987, IIRC, the stuff is called lamination steel. Low hysteresis + high permeability. Googlit.

If you get tired of trying to find stuff, here's a 12x12W kit:

- To change one's self is sufficient. It's the idiots who want to change the world who are causing all the trouble. --Anonymous

TedWeber.com

Yes, but my entire shop is covered with plastic sheets till the roof is replaced. the entire 1200 square foot flat metal roof has to be removed and replaced.

I built one in that series for the magazine articles in the late '60s, but I have some high power signal generators like the TS-382F/U and some high power solid state PA amplifiers. The meter was destroyed in my HP331A, and I am designing a digital replacement, rather than scrap another 331/332/333/334 series for the meter.

Till they tore it down to build the World Trade Center.

High silicon steel.

look at

try ax84.com - I think it is still active.

Imported -- who knows who made it then, or what modifcations to the design.

Doesn't the FCC get upset if the modulation frequencies push the bandwidth too far out? Or was it less critical in the '70s?

Enjoy, DoN.

Write a letter to Obama. Maybe he'll give you a grant. ;)

Suckage!

- To change one's self is sufficient. It's the idiots who want to change the world who are causing all the trouble. --Anonymous

It had to be powdered iron made for low frequency work. I've used a standard variac to match an amp to speakers, and some PA volume controls are tapped autotransformers.

If he wants to try winding a transformer, small APC UPS have a nice laminated core, and scrap units are around for free. I currently have about 25 with bad batteries.

The FCC would have to catch someone using that radio. Since it was mainly used to listen, it didn't matter. The only downside was that you could hear some adjacent channel crap as high pitch noise if the transmitter was close enough. That radio didn't use ceramic IF filters.

Greetings Dan, If I decide to wind my own laminations I'll let you know. Thanks for the offer. My local scrap yard is good but I cannot recall seeing and xmfrs there. Eric

Gunner Asch on Tue, 21 Jan 2014 00:21:49 -0800 typed in rec.crafts.metalworking the following:

Just be sure to mention that it will be environmentally friendly and "forward thinking".

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

TWO POINTS! ROTFLMAO.

If you ever run across something from McIntosh, in almost any condition, that would be a good bet.

Best regards, Spehro Pefhany

So I could either re-build the old McIntosh or just use the transformers and any good tubes to build my own? Probably rebuilding would be best, and I bet there are schematics available online. Thanks, Eric

Mostly it is the electrolytic caps that dry out. Some are power and some are Bias or bypass / blockers - filters of all types.

Foil and mica don't go bad unless really high voltage is generated.

Good idea. Most tubes last and last.

Mart> >