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Is a transitor the same thing as a tube found in guitar amps? Answered

If it is, could I use a tube in place of the transitor in a simple transitor amp circuit? 

I am trying to build some tube amps...  I have built many transitor amps but I just can find that tube sound...  I want to also know as the most simple tube amp circuit.  I like to start with easy and simple and then experiment...   Any advice on tubes?  Thanks...



8 years ago

before you give on solid state amps.................
go to runoffgroove.com and check out the Fetzer valve circuit. Its a FET (Field effect transistor) circuit based on a vintage Fender 12ax7 valve input stage. you could build that and add as front end to one of your many transitor amps you have made? By the way, if your just building power amp kits and putting your guitar in direct then it will sound pretty horrible-thats not a solid state guitar amp. Try adding a preamp and tone stack? heres the best site for info on building solid state guitar amps - ssguitar.com - you might be surprised at how good a well built ss amp can sound. have you built a ruby amp ( see it runoffgroove or generalguitargadgets.com) or a noisy cricket amp (based off ruby) at beavisaudio.com
If you have to ask this question-you don't sound ready to jump in and start playing with high voltage valve amps. the stuff i mention is all 9-12v stuff and works well.
good luck.


Answer 8 years ago

 Thanks,  I think I am going to stick with solid state amp building and the add the Fetzer valve circuit to my solid state amps.  And the site ssguitar.com is really good. 

Quercus austrina

8 years ago

In amplifiers, be they instrument, hifi, or otherwise, the active components are transistors or vacuum tubes. There are chip amps that are filled with transistors. As for how they work, you need to address the fact that tubes need a heater circuit to work, and the output needs to be achieved differently. While there are some output transformerless designs, most tube amps use an output transformer to change the impedance of the circuit to reflect the desired speaker impedance, ie. 4,8,16 ohm, while most transistor designs do not. Also, tubes usually run on much higher voltages than transistors. Those are the major differences between the 2 devices. There are more, but they would actually require a lengthy tutorial.

To answer your 2nd question, no, you cannot just put a tube in place of a transistor, due to the things I mentioned above.

As for advice, look around here, there are several instructables on tube amps. If you want to know more, read this FAQ:geofex.com/tubeampfaq/taffram.htm and then head on over to www.diyguitarist.com/ and look for any number of low power, easy to duplicate tube amps. Then try a search engine and look for "DIY Tube Guitar Amplifier". Quite a few matches will show up.

Good luck on your build.