Building Tubes AMps

[SISKO]

Hi all.
        Well last weekend i got a box of tubes. Most of them are preamp tubes, but there are some EL84, and two EL34.
        With the EL34`s I'm building a marshall jcm800.  I have a fender amp, good for clean tones and blues, but its stops there. I want the marshall for hard rocking. Now here come my question: I want to build something with those el84, Something for about 15-18 watts. I been looking some schemes and first i wanted to build a VOX AC15 because it was class A.. but then i realised it was not. So I'm asking for your help. I want something, but not the same in all my amps. I think with the gain of the marshall I'm ready, so i don't Need those mesa amps. I just want a different tone, i don't know what tone, but some with two el84 

OK Thats all
ROCK ON
BYE

SISKO

[Mihkel]

Marshall 18W?

[formerMember1]

don't know how many can help here, but try the Lounge or go to the 18watt forum,.. i think 18watt.com or something....

[Peter Snowberg]

http://www.18watt.com/
http://www.ax84.com/

The big cost is from other components so building an amp based on these tubes because you have them is a little like cooking a 7 course steak dinner because you have one of the side dishes already.

The transformers and speakers are usually big cost items. A pair of EL34s is less than half the cost of the output transformer alone.

Building amps is much like building pedals and it's just as addictive; it just costs much more! 

[jrc4558]

AC15 is a cathode biased class A1, so you are ok. Both tubes will be conducting for the full 360 degrees. That's what Class A is about, anyway.

[R.G.]

Although some of the info on tube suppliers is out of date, the Tube Amp FAQ at GEO (http://www.geofex.com) is a good, quick guide to a lot of tube amp issues. It predates all of the tube web sites in existance, and supplied material for a lot of them.

One of the things that the TAFAQ mentions is that if you're going to build a tube amp GET YOUR TRANSFORMERS FIRST. This was particularly true when the TAFAQ was written, as the cottage industry supplying tube amp transformers had not sprung up at the time. I like Peter's comment - having tubes is like having side dishes. Actually, more like having silverware 8-) 

The tube power transformer is the single most costly item in a tube amp. After that you get the output transformers and speakers, and quite a few other things before you get down to things as cheap as tubes.

[petemoore]

  I don't see 'em around so much's I used to..
  Old Console Stereos w/tubes.
  also old PA stuff Like BOGEN may have tubestuffs stuffed in it...
  gettin' fewer and farther between, but keen eyein' the prime pickin's and Garage Sales...there might even be something in your grand aunt's 'side attic' which is in her way...
  Other than that I saw some decent buys for ~inexpensive new tube amps @ guitarstore...which means Ebay used will probably get even cheaper.
  I'd get and 'de-combo' an amp, double the speaker and set the amp, as head, on it.

[DuncanM]

How about a clone of a Fender Pro Junior? Mine is 15W of joy.... 2 EL84's and 2 ECC83's but absolutely GET THE TRANSFORMERS FIRST - a surprising amount of the tone comes from the output transformer.

[SISKO]

Ok.
    Thanks! Well.. About the transformers, I have got two 50w OT, a choke  and two 2 x 375v / 6.3v / 5v PT, so with those, i think im done. Anyway, if i need anithing else, i can managed to get it, like building a PT or something similar. So im not worried about the transformer.
   Im plannig to make them  heads, since i got a 100w 4x12 cab and a 100w 1x10 cab. So it would be like amps from one side and cabinets from the other.
  And i decided to make an AC-15.
Duncan:
           I knew your page and it was on of my item to discuss, but i feel like i dont like OPamps, and felt that i was a litle surprised when i saw them in your Pro Junior.. so, maybe in another ocassion alright?
OK thats all
ROCK ON

SISKO

[Dave_B]

  I don't see 'em around so much's I used to..
  Old Console Stereos w/tubes.
  also old PA stuff Like BOGEN may have tubestuffs stuffed in it...
  gettin' fewer and farther between, but keen eyein' the prime pickin's and Garage Sales...there might even be something in your grand aunt's 'side attic' which is in her way...

I've lucked out, finding a couple of those on the curbside in the last couple of years.  One was a self-contained Motorola phonograph with a 6v6 amp.  The other was a late-50's Olympic console with a dual 6v6.  I haven't had the heart to take the amp out of that one yet.  It's just too nice.  Get aquainted with the old neighborhoods in your area and find out when the heavy item pick-up is.

The downside to the Motorola (and probably others) is that it's true point-to-point.  No turrets, no eyelets, no major terminal strips.  The amp is real compact as a result, but it's not gonna be fun to modify unless I put it in a bigger chassis.  ...like I'll get around to that anytime soon.