• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Who is into musical instrument tube amplification?

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who is into instrument tube amplification?

just wondering, everyone seems to be into home audio stuff, anyone into instrument tube amplifiers? They seem to be much easier to build for the beginner, as they are not meant to have pristine sound and use very few, cheap parts. (for some models at least)

i bought an organ chasis for $25.00 on ebay and bought all my parts from a local surplus store for another $15.00... now all i have to do is build it this weekend. its gonna be a fender princeton clone or a smoking mess:hot: when im done with it! wish me luck.
hi there,
I'm into both...

Can't go wrong with a fender princeton. Are we talking the PP blackface era or the really early SE princeton?

Just take it slow and check everything many times and you should be able to avoid the smoking mess scenario. Do check out fender's original layouts (avail online) as that may help with avoiding hum pickup or other problems from the physical layout of parts/wiring.

there are also some nice people on the ampage forums and ax84 project forums that talk only about instrument amplification, so you can check there too.

good luck, enjoy, be safe..

Hey Guys,

I'm into both as well. I just built the Allen Amps encore, and have been EXTREMELY pleased with the sound! It wasnt cheap by any means, but the experience gained was well worth the cost. The design is based around the mid 60s Fender Vibrolux Reverb. I love it!

I am planning on building a few more guitar amps when I finally finish a tube pre that I am working on. These will be built from the ground up.

I believe there are afew bulletin boards that deal with mostly guitar amps... I'll do a search and post what I find.

Good luck with the build... Take it slow, double-check all the joins, and stand back when you fire her up! A variac is a great tool for this application.


If you look farther down the table of contents here, you will find a Musical Instruments section. But I think most of us who like tube guitar amps will also read this section.

If you are interested in that topic in particular, also visit www.ampage.org and explore the links from there. You might like the AX84 site for example.
Guitar amp

I have also built several guitar amplifiers from a simple 4 watt 6V6 single ended Champ clone to a 150 watt push pull amp. I have recently prototyped a 200 Watt single ended guitar amp using an 833A. I realize that it is not practical for gigging due to the fragile nature of the 833A's filament, but it sounded so cool that I just have to build one.

For info and pictures see http://www.tubelab.com/833SE.htm

I found an old Guild Ultraflex amplifier at a flea market for $35 USD, it worked perfectly with the original 7591 (4X) tubes. I have been using this amp for 5 years without incident and it sounds awesome. That is why I haven't built any amps recently.
I Am Into Musical Amps more so Vs Stereo, But I love both!

I have built several tube amps lately, Love some of the stuff at the AX84 site,

Right now Im about to try building a SE 6550 guitar amp. Just because I have the parts laying around.
I also have a nice Field coil guitar project planned for winter, Nice little gibson PP 6V6 setup similar to the EH150, Have a stunning 12in speaker 950 ohm coiled Jem :)
Sign me up........

I roll tubes & speakers in guitar amps. I like Raytheon 12AX7 or 6EU7 blackplates. Tubes vary & some amps do like the Telefunken 12AX7 in the first preamp position. The Sylvania 12AX7 are quite lively & RCA 12AX7 are polite for a clean presentation at less than full volume.

Speakers? Easy- vintage Jensen P12N or P15N. Sonics to die for, well almost.

Can't afford the P12N or P15N high cost? Vintage Rola Alnico are good & stock in many older Supros.

Worst vintage speaker? Vintage CTS with a voice coil gap as wide as a barn door (nasty).
Worst vintage speaker? Vintage CTS with a voice coil gap as wide as a barn door (nasty).

interesting you say that. I had some fender labeled ceramic CTS 10" speakers in a vibrolux reverb. They were horrible. I replaced them with weber C10NT (ceramic mag, treble cone) and these sound great.

I don't have much experience with the alnico speakers, though I hear a lot of people like them. Maybe I'll try some out. Maybe with a 5E3 tweed deluxe with some mods. Or something else, if I get time for a build.
No Celestion Fans? Interesting.

Hey, I got a bunch of beleive it or not, GE long plate 12AX7's in an amp here, 1963 tubes out of an old wurlitzer organ.

These tubes are the most crisp sounding puppies I think I have ever owned. My Rca blackplates come close, For Get Dullards completely ooops,, I meant Mullards.

I have a few Sylvania Black Plates also, The 6EU7's are great, I have the Gold Pin 12AX7's but They rarely see anything other than the caddy. I felt, at least in my amp they tended to be a tad muddy on the bottom end.
:cool: Yep, I'm into tube amplifiers for guitars. Have converted my Marshall JCM 800 2205 into a Bassman/P1extreme dual-preamp cathode-biased 50 watt monster. And yes, it's still Class AB.

I've also designed/built a PP Class A 15 watter, with a Plexi-inspired preamp & a Vox AC15-inspired outputstage. It postively rocks your socks off.:cool: :D

I got a soundclip somewhere... here it is

Yeah I know, I suck at playing..:eek: :D
Emminence/Celestion fan

I have operated under the probly false impression that Emminence and Celestion are the same speakers. I love the Legend 1028P 25 watt instrument speaker. I use them in glued-together cabinets that don't come apart to replace speakers without a lot of work (design flaw?). Love the eff. and tone from them although they are somewhat over-priced. I also respect the old CTS boogers because they are so reliable. Not the most eff. but I usually have more amp then I need. I want to hear more about Trout's 4-wire speaker project. If the coil/coil cone mover is reliable, think of the wieght it would remove from, say, a sub or a bass main. A guy in college was talking about using a 4-wire set of theatre speakers on his guitar amp and thought he could do it with a hand-wound output transformer. He lost me on the theory back then but it sounded good, under the influence.
4 wire speaker

Back in the late 1960's I built a guitar amp that used a field coil speaker out of an old organ. I used this speaker because I had it, and didn't have the cash to buy a real speaker. The amp was solid state (I robbed the output stage from a dead stereo) about 20 watts. The problem that I had with this setup was that it was real easy to bottom out the voice coil which made a loud, nasty pop, and eventually destroyed the speaker. These old speakers had a paper spider which did little to control the cone movement. The SS amp probably had response down close to DC so that you could see cone movement by bending the strings, without ever playing a note. On the other hand the speaker was extremely efficient and this was the loudest 20 watt amp that my friends had ever heard. It really screamed. This might not be a problem with a tube amp with limited low frequency response.

How do you connect the field coil an a SS amp? Being a high school kid who didn't know better, I simply connected it directly ACROSS the output of the power supply. About 50 volts, I think. The speaker did get warm after the amp was on for a while. Probably why it was so efficient.
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