please educate me on vacuum tubes!

[dhsia]

I'd like to learn more about tubes. I know there are a lot of sites that provide info but specifically I'm wondering if there are tube applications that are interchangable.

For example, EL84 and 6BQ5 are the same. Are there others that are like this also?

Any help would be much appreciated. Thanks in advance.

[Colbyjack]

Hoover, Oreck, and Kirby.

[Colbyjack]

sorry....what I posted above is all I know about them.

[trpullen]

PreAmp Tubes:

12AU7 / 5814 / 5963 / ECC82
12AX7 / 7025 / ECC83

The 12AX7 or AU7 is the USA designation. ECC is a Euro designation. See http://en.wikipedia.org/wiki/12AX7 for more info than you ever wanted.

6L6 / 5881
25 Watt tubes such as 6L6, 6L6GB, and 5881 are rated for plate voltage up to 400 volts.
30 Watt tubes such as 6L6GC, 6L6WXT+, and 6L6WGC are rated for plate voltage up to 500 volts.
The KT66 tube type is a 25 Watt tube rated for plate voltage up to 500 volts.

EL34 / 6CA7 / KT77

There are lots in the same boat. Check out both Wikipedia and TheTubeStore.com for more info than you would ever want.

[Taylorplayer]

Hi David:

I recently bought a copy of this book from a local bookstore:

"THE GUITAR AMP HANDBOOK" sub titled: "UNDERSTANDING TUBE AMPLIFIERS AND GETTING GREAT SOUNDS". The author is Dave Hunter, and it was published by Backbeat Books www.backbeatbooks.com

I have already learned a great deal from this book. I highly recommend it.

Hope this is helpful to you!

Taylorplayer

[12Stringer]

lots of tubes have interchangeability, but they do have different properties. example el34/kt77, sound quite different in my amp. lots of info on the net and book are available to research. Good luck

[franchelB]

I just know what my Peavey Delta Blues amp uses: EL-84 and 12AX7 tubes. I know that Vox also use these tubes in their AC amps.

But basically from what I've read, the Fender tube "sound" uses 6L6 tubes, and the Marshall "sound" comes from using EL-34 tubes.

Finally, like what "12Stringer" stated, while some tube types can be used interchangeably, the sound will vary. Fortunately, or unfortunately, my amp will pretty much sound the same because it only uses EL-84 power amp tubes. I can only decide on the preamp tubes, (which uses the 12AX7 tubes), which can vary the degree of gain...depending on which preamp tube I use.

[HereIGoAgain]

Originally Posted by franchelB

I just know what my Peavey Delta Blues amp uses: EL-84 and 12AX7 tubes. I know that Vox also use these tubes in their AC amps.

But basically from what I've read, the Fender tube "sound" uses 6L6 tubes, and the Marshall "sound" comes from using EL-34 tubes.

Finally, like what "12Stringer" stated, while some tube types can be used interchangeably, the sound will vary. Fortunately, or unfortunately, my amp will pretty much sound the same because it only uses EL-84 power amp tubes. I can only decide on the preamp tubes, (which uses the 12AX7 tubes), which can vary the degree of gain...depending on which preamp tube I use.

Well, that's true to a point. Most Fender and Fender-mimicking amps use 6L6'sa, however, so does the MESA/Boogie Dual Rectifier. Now, the guy who taught me the most about amps hates them both equally, however, they are entirely different tones. (For me, I'd prefer the Dual Rectifer.)

Some amps, like the D-Rec and the Orange Rockerverb 100, can use both 6L6's and EL-34's. However, you have to flip the bias switch to match the type of tube you are using. The amp's "bias" must be correct for the type of tubes being used or it could sound bad.

Im some cases, a 12AX7 and the EL-84 blow away interchangeability - they'll each fit in the same socket, but the pin configuration is different. In other words, don't do this.

Now, some rectifier tubes (another animal altogether) will fit into the same sockets as some power tubes. In some cases, if you do this, the amp just won't work. In other cases, you'll toast a very expensive amplifier.

You can avoid most hassles by re-tubing your amp with the same kind of tubes that came with it in the first place. You can, of course, try different brands (Sovtek, JJ, and TAD for example), but always replace "like" with "like." For example, FranchelB can call Doug at Dougstubes.com and tell him what amp he has and what sounds he's going for, and Doug will provide pricing and suggestions to help FranchelB get there, but he'll still be using 12AX7's and EL-84's.

If replacing "like" with "like" doesn't get you what you're after, consider a different amp or taking it to an amp tech and explaining the situation.

[3rd_harmonic]

In addition to tubes that are always interchangable.....


the circuit designer may have created a circuit that does not utilize the maximum capabilities of the recommended tube. So in some cases, even though the tubes may have different properties, when they are operating within a particular circuit it may not make any difference.