Building a tube amp: kit questions

[pater familias]

Howdy, I'm a new member that needs a good tube amp for practice and regular gigging with a guitar-bass-drums-vocals band doing everything from old blues to 60's garageband to R.E.M. and LZ covers.

I prefer the Vox tone/sound. I like plenty of clean headroom, but also want some good tube-based overdrive - I don't care for all the modern extreme-scream distortion stuff at all.

The brand-name stuff is either too expensive for the point-to-point stuff or suspect quality for the printed-board PAC-rim made versions. And the boutique amps might as well cost $20K they're so far out of my range. I mean I play Danelectro guitars if that sums it up.

So, I want to build my own amp. I have built a mandolin and a dreadnought guitar, so I am fairly handy. However, admittedly I'm as dumb as a bag of hammers with regard to electronics. So, I thought the pre-wired components from CeriaTone might be a good way to build my first. I am fortunate to have a electronics engineer cousin to use for some help as well - though with the big modern stuff he works on everyday he might chuckle at the old, quaint vacuum tube technology.

Thought it'd be a good idea to list what I think I want and get input from some experts around here.

Here goes:
1. 30 watt head - figured that'd be min. req'd for gigging. Keep it small if possible. I like how some can be used to practice at only 15 or 18 watts.
2. either one or perhaps two separate relatively small cabinets with only one 12" speaker in each. I thought that would give me ideal portability and flexibility for home, rehearsals, and different gigs. I could use one cabinet or two and even separate them around the stage to widen the sound, etc.
3. As far as speakers and tubes I recognize some names but that's about the extent of my knowledge. What tubes and speakers would be best for lots of clean headroom but tend most towards that classic AC30 tone.
4. Re: channels, controls, etc. Simpler is better to me. I think I'd like a tone control, a volume control, and maybe a master volume if that'd be the best way to use max overdrive of tubes but still be able to play at lower volumes if need be. I don't think I'd care for the bright or presence or other eq-related controls - in fact I might very well just use an EQ pedal anyhow.
5. I like good reverb and tremelo, but if I could get better quality of these effects for the $$ with pedals or some other outboard gear I'd be happy leaving them off the amp.

That's all I can think of at the moment. I'm anxious to hear everyone's advice and opinions. I realize I may have listed some impossibles or mutually-exclusive goals, but that's part of this learning process for me.

Thanks.

[hopy]

Hi, well, the first thing you need to do is read, read, read, read, and then read some more. In particular, safety. These amps can be very dangerous if you're not extremely careful. Learn how to properly discharge the capacitors.

I would begin the journey, and it is an extremely rewarding journey, by studying basic electronics theory, ohm's law for example.

The next thing to explore is transformers. Understand how they work and how they connect in the circuit. Get the wiring wrong and BAM!

Then learn about capacitors, how they work, the difference between polarized and non-polarized, and what their purposes are.

Then you need to understand the pin layouts of vacuum tubes. Learn the difference between preamp tubes and power output tubes. I would recommend http://www.nj7p.org/Tube.php for pin diagrams and tube specs. Understand what the heaters are and what they are there for. Learn why powering up an amp in Standby mode is good for the tubes. Learn about the difference between tube rectifiers and solid state (diode) rectifiers. As for tube brand selection, I've found that JJ Electronics is about the best quality/price choice on average, but that's just my opinion. There are tube snobs out there that will say "Oh hell no! My brand choice is XYZ and anything else is crap!" Your choice is your choice. If I was gigging or recording with an amp, I might go with some of the expensive ones, but like I said, your choice.

Then I would spend some time exploring the different amp kit sites. taweber.com and ceriatone.com are just a couple examples that are easy to explore. Pay particular attention to the layout diagrams, understand what each component looks like in the drawing. Compare the layout diagram to the circuit schematics, find the schematic symbol for each component in the layout diagram. Understand what each component connection is, and where it is on the component. In particular, jacks, pots, switches, etc. Learn what T, S, and G means on the guitar and speaker jacks. Learn about proper grounding.

Learn about speaker impedance and why an output transformer (specs) is mated to a particular speaker impedance. And learn about connecting multiple speakers in series versus parallel.

Once you feel you have a basic understanding of the above items, it's time to learn the skills needed to perform the build, and acquire the proper tools for the job.

Tools:
Soldering iron and supplies. I would recommend you watch a few youtube videos on proper technique. And get at least a 40-watt soldering iron, you want the connection to be soldered hot, but not too hot.

Hand tools - needle-nose pliers, wire strippers, clippers, crimps, magnifying glass, hemostats, screwdrivers, small flashlight, all valuable. I also find a long spring hook is handy for many little tasks.

A good digital volt/ohm meter is mandatory. Get some good meter lead clips, alligator clips, alligator or spring-clip jumpers. A meter that has a continuity test function is invaluable when testing your soldering job.

Once you have all your connections and soldering done, start at the beginning of the circuit and do a continuity test for each solder joint. Test the resistors all the way through the circuit, it doesn't take very long. Another thing to remember, I found this out the hard way, when looking at the layout diagram, you are looking at it as if you were inside the chassis looking out, not outside looking in.

Learn why shielded wire is used for some connections, and why twisting other wires are suggested for others. (I'll spoil it for ya, it's to reduce ambient noise.)

Now for choosing the first project... Everyone usually says "start with something small." And I agree completely. I would suggest a Fender Champ or Deluxe, 5E1, 5E3 and the like. They are simple circuits, easy to understand, they REALLY sound good, and it's and amp you can enjoy forever. Not like one of those cheap hobbyist kits.

All this being said, and it may sound like a lot to learn, but the reward is fantastic and you really only have to learn it once. I first caught the bug by just doing a cap-job on a 40 year old Harmony H400. The results were so amazing that it dawned on me, I could build them from scratch as well.

Hope this helps, if I've left anything out, sorry, maybe someone else will add it later. Remember.... SAFETY SAFETY SAFETY!!!!!

[pater familias]

thanks for that in-depth response.

Safety and lack of hands-on electronics knowledge is one reason I was thinking about one of the CeriaTone pre-constructed boards/chassis. I'd rather pay a little more to know the layout and soldering are done correctly, and mostly what's left is me to assemble everything into a whole. Then next time actually try my hand at soldering myself.

I hear you 100% about safety.

[hopy]

Originally Posted by pater familias

thanks for that in-depth response.

Safety and lack of hands-on electronics knowledge is one reason I was thinking about one of the CeriaTone pre-constructed boards/chassis. I'd rather pay a little more to know the layout and soldering are done correctly, and mostly what's left is me to assemble everything into a whole. Then next time actually try my hand at soldering myself.

I hear you 100% about safety.

Keep in mind a couple things, you may have to do a bit of soldering with the Ceriatone kits, depending on what degree of completed kit you purchase. And also, you might want to make sure you check their shipping cost table, they are very up-front with it, but it can add more than a few dollars to the price, they are located in the south Pacific. I have read many good things about their quality also. Good luck!

[TD_Madden]

By the way, power-wise I really like the 5F4 (tweed Super) circuit.....nice and clean at low volumes, but the overdrive tone is outstanding as well.

[kldguitar]

if you have little electric experiences , but you have many ideas in sound, want make your self sound. in fact , you can start from assembled kits. many parts of amp have been assembled on chassis. you only change some important place, OPT, IMPORTANT cap, little change in circuit, many simple and dangours works were done by other people. it save time largly