Tags:
Tube Depot is a good place to start. Tube amps are challenging, but do-able. Just remember that the voltages inside the circuit can reach or exceed 450 volts...one wrong move and it's over...as in DEAD.
If you want to start small, look at Doberman Amplifiers (AX81 project) or look into the Noisy Cricket tube amp.
Otherwise, the Fender 5E1 and 5F1 (champs) are straight forward circuits.
Happy soldering...
Decades ago, tube radios that would be found in homes were powered by large batteries. Guitar amps are altogether a whole different beast.
I am not aware of any guitar tube amps that would not use 117v or 230 volt ac power to operate. There are usually 2 power transformers...one changes the wall outlet (i.e. house power) from ac to dc...then that electrical current flows through the various components (capacitors, resistors, tubes, fets, and such to shape the "sound" of the amp) and then to the output transformer, then to the speaker(s).
So "yes", I believe you must have access to wall outlet to operate tube amp.
The battery killer with tubes is the amount of power it takes to run the filaments.
As an example, a typical preamp or input stage tube commonly needs 6.3 vac @ 0.6A or 12.6 vac @ 0.3 A for it's filament or 'heater' . That's about 3.5 W. A 2 or 3 tube amp needs roughly 2-3x more. The high voltage side (plate/anode/grid/screen, etc) might need (another rough arbitrary example) 150-300 VDC for input stage tubes at 5-10 mA each. That's a few more watts typically. This rules out a single 9V battery or maybe even several.
The 450 and up VDC scenarios are usually larger power tubes or the rectifier tube supplying power to the other stages. When an amp has a minimal number of transformers, typically 2, as mentioned, one is for the power conversion from the wall to the levels needed, and another, the output transformer, to convert the high output impedance tube output stages have to the typically low impedance of a speaker voice coil.
There are some 'starved plate' tube electronics (might be preamps rather than power amps) that run a very low voltage for the plate/anode/grid, but you cannot starve the filament...they rely on the proper amount of filament power to get hot enough to work.
Also check out the Audio Asylum and DIY Audio websites. There are some 1-5 W tube amps that can be done pretty inexpensively with surplus transformers, but they DO need transformers. Small toroidally-wound power transformers
have been used as audio output transformers, but they're not as prevalent in surplus sources in the US as in Europe, so they cost a fair amount.
It's possible with a lot of hassle & hacking (and safety) knowledge, to recycle a DC-AC power inverter to supply usable voltages to run a tube amp from a still-hefty battery source, but I think it would someone's personal goal to prove it can be done and not a very practical one. (Sorry, no promises when).
Take a look at www.runoffgroove.com
There are a few excellent amp circuit diagrams there that will fit your needs.
Bob Danielak's tube amp pages...
http://www.reocities.com/bobdanielak/projects.html
It's nice to see some practical amps that prove armchair advice wrong (often mine!). The cricket was kind of interesting. I had forgotten what to call those 70V line output transformers...I bought a few of those...have them somewhere...from an eBay seller in Pennsylvania, in large part because he had specific details of what tubes he used them with and at what current. I would not have assumed I could run single-ended tubes with such a transformer...but that's another unfinished project...
Many online electronics stores have amp components and DIY amp kits for battery-powered applications. QKits is one I know of...they have a 7 watt mono amplifier kit that works for guitars. One thing to realize is the higher the power & the louder the output, the more juice that gets drained from the battery. One variation to consider and recommended to save battery life when the amp is being used in home...add a wall wart input to the circuit.
If you're not familiar w/ term wall wart...its an ac/dc adapter that changes house outlet power ( 117volts a/c to a lower voltage...maybe from 9-18volts d/c).
The 7 watt amp kit will operate within a range of 9-18volts dc...but don't assume that using wall wart w/ higher dc output is better..in fact, that specific unit sounds better when juiced w/ 12volts dc.
The circuit I build is only 1/2 watt, runs on a single 9 volt battery, uses minimal components, and can fit, as a head, into your pocket. As a "combo" style...with speaker, I use cube shaped cigar boxes that wont make good guitars.
Started by BrianQ.. Last reply by BrianQ. May 18, 2020. 6 Replies 0 Likes
Started by James Conder. Last reply by James Conder Aug 27, 2019. 4 Replies 0 Likes
Started by Denis U. Last reply by Richard Haas Dec 3, 2016. 4 Replies 0 Likes
Started by Scott aka Farmer Ted Nov 17, 2016. 0 Replies 1 Like
Started by Paul Craig. Last reply by Paul Craig Nov 3, 2016. 31 Replies 0 Likes
Started by Primitive Acoustics. Last reply by Primitive Acoustics Mar 9, 2016. 3 Replies 0 Likes
Started by Erik Bell. Last reply by Scott aka Farmer Ted Dec 20, 2015. 4 Replies 0 Likes
Started by Surly. Last reply by Alan Steeg Oct 27, 2015. 1 Reply 0 Likes
Started by Coventry Halfpenny guitars. Last reply by Pickedmoor Jon Oct 20, 2015. 3 Replies 0 Likes
Started by alectron. Last reply by Zac Ray Sep 2, 2015. 10 Replies 0 Likes
Started by Henry S. Last reply by Henry S Mar 25, 2015. 4 Replies 0 Likes
Started by Scott W. Last reply by Henry S Mar 24, 2015. 6 Replies 0 Likes
Started by wormil. Last reply by wormil Sep 2, 2014. 2 Replies 0 Likes
Started by Greg Potts. Last reply by Ron "Oily" Sprague Jul 1, 2014. 1 Reply 0 Likes
Started by GARAGE HERMIT. Last reply by GARAGE HERMIT Apr 29, 2014. 108 Replies 1 Like
Started by MichaelS Country Boy Guitars. Last reply by Henrik Johansson Mar 10, 2014. 34 Replies 0 Likes
Started by HarleyTodd. Last reply by Bernie Mango Feb 26, 2014. 18 Replies 0 Likes
Posted by Vlad on March 6, 2024 at 2:32am 5 Comments 2 Likes
Posted by billy jones bluez on February 28, 2024 at 2:09pm 0 Comments 0 Likes
Posted by billy jones bluez on February 17, 2024 at 11:00pm 0 Comments 0 Likes
Posted by Vlad on February 11, 2024 at 1:06am 1 Comment 1 Like
Posted by billy jones bluez on February 8, 2024 at 4:05pm 0 Comments 0 Likes
May 11, 2024 from 11am to 8pm – Speakeasy Grill
0 Comments 0 Likes© 2024 Created by Ben "C. B. Gitty" Baker. Powered by
Cigar Box Nation is presented by C. B. Gitty Crafter Supply, your one-stop-shop for Cigar Box Guitar parts and accessories!