i really wanted to build a 1-2 watt tube amp, but as im looking deeper into it i see all these warnings.
now im getting scared. is it just a normal 110v shock? one guy told me to expect to launch out of my chair doing 3 backflips, spilling my beer and prying my dick out of the sheetrock on the other side of the room ! is it really that bad ? im thinking of staying with the "tiny" build now :o
DC voltages in tube amps can be lethal. Plate Voltages are frequently around 400V. Not a project you'd undertake lightly :)
Have to admit when I built my amp I was super methodical due to the voltages involved.
Built it over a few days.
As I'd been staring at it for a few days I then had Cleggy go through it step by step with the schematic to make sure I hadn't done anything stupid (I had a switch wired backwards, but nothing serious).
Checked all the grounds were good.
Powered it up without valves and went through a test sheet getting voltages. Which is the first scary bit to be fair.
Then again with the valves in.
Only after I was 100% certain it was solid did I consider it done.
I do recommend it though. It's very satisfying and lethal voltages aside, easier than doing pedals as everything is just so big. I had a friend go over mine who builds amps for a living and the only thing he really picked me up on was the capacitors slammed next to the biasing resistors. He said that at some point they'd likely fail as the resistors will get exceptionally hot. So when they do I'll put the new caps in and give them a little distance.
Pedal building tends to be the gateway drug to amp building :)
When I built mine I went so far as to attach a short wooden dowel to the test lead for the DMM. I kept one hand in my pocket, and used the dowel when probing around for voltages :D I'd read so many warnings and disclaimers that I was SUPER nervous about touching anything. Fortunately it fired right up with no problems.
It's definitely the most rewarding thing I've built.
Quote from: juansolo on November 30, 2012, 10:24:53 AM
As I'd been staring at it for a few days I then had Cleggy go through it step by step with the schematic to make sure I hadn't done anything stupid (I had a switch wired backwards, but nothing serious).
Checked all the grounds were good.
This is some seriously good advice! I haven't gotten to an amp build myself, but when I do, I'll be sure to let somebody more experienced check it over before switching on the juice......
Amps were my gateway drug, I was far more comfortable building amps than pedals. Valves can take a second or two of abuse, whereas semiconductors go POP in a heartbeat.
Plus they tend to be nice and roomy compared to 1590B's. Well, my next build is in a cake-tin chassis, so might not be that nice.
Quote from: jeffaroo on November 30, 2012, 06:46:16 AM
i really wanted to build a 1-2 watt tube amp, but as im looking deeper into it i see all these warnings.
now im getting scared. is it just a normal 110v shock? one guy told me to expect to launch out of my chair doing 3 backflips, spilling my beer and prying my dick out of the sheetrock on the other side of the room ! is it really that bad ? im thinking of staying with the "tiny" build now :o
Your friend is right. I took it that serious and always will. You don't build when tired, drunk or both.
Also, you don't need to get shocked to put your dick into sheetrock :D
My first (and only, so far) amp build was the Firefly amp. Built it this summer and love it! Added a TMB tone stack to it. Just make sure you do one of the more well known amp builds that has a good set of instructions.
Ordered this as a first: http://www.musikding.de/Kits/Madamp-Kits/Kit-Madamp-A15Mk2-deluxe::1205.html
Time to get hand dirty. A lot of stuff are lethal around us, with proper precaution i hope i can make it out this build alive.
I have a simple strategy:
I will not put my hands in the circuit once it has been powered because i won't need to.
If i need to, then i'll keep my left hand in my pocket, discharge & check the caps before doing anything.
If i do not post anything in the next three weeks, don't be sad and consider me gone.
Wooden chopsticks are traditional poking sticks (and tapping, to see if a cap or valve has gone microphonic.)
Do continuity checks on every net before you power up (and between every net and ground, especially between B+ and ground.)
You will have to put your hands in a live amp to check voltages etc. The best advice in this thread is the hand in pocket thing. Make yourself a capacitor drain and always check for voltage on caps (electros). Other than that relax and have fun. You'll likely get bit sooner or later and it hurts, not that I'd know this from experience... Getting flustered and rushing during troubleshooting is usual breakdown of safety standards so just be aware of what you're doing.
The first time you make an amp that sounds even remotely good you're screwed because amp building is at least as addictive as pedal building. :D
"Hi...my name is Gordo...I'm here tonite because I build amplifiers..."
Quote from: gordo on December 01, 2012, 03:01:08 AM
You will have to put your hands in a live amp to check voltages etc. The best advice in this thread is the hand in pocket thing. Make yourself a capacitor drain and always check for voltage on caps (electros). Other than that relax and have fun. You'll likely get bit sooner or later and it hurts, not that I'd know this from experience... Getting flustered and rushing during troubleshooting is usual breakdown of safety standards so just be aware of what you're doing.
The first time you make an amp that sounds even remotely good you're screwed because amp building is at least as addictive as pedal building. :D
"Hi...my name is Gordo...I'm here tonite because I build amplifiers..."
It's definitely much more addictive than pedals for me. The only reason I build more pedals than amps is cost.
Keeping your
left hand in your pocket (so the high voltage will not pass directly through your heart if you accidentally shock yourself) is a very good idea. Wear thick rubber-soled shoes and be at your highest awareness. I'm not an expert by any means but I've been building and repairing/tinkering for about 5 years now (and reading for years before that) and even I slipped up a couple of weeks ago and got zapped while working on my vibro champ. It is very scary. I'm not trying to deter you but you should make sure you are comfortable with what you're doing.
Another thing is to build cleanly. The last thing you want is to troubleshoot a rat's nest of wires at lethal voltages. It will also pay off in that you will reduce risk of excess noise by keeping your wiring short and neat.
Here's my 5E3 and vibro champ guts (although I will be changing the red heater wires to green cloth-covered wire soon to match the rest of it)
(http://imageshack.us/a/img6/8731/dscn5979l.jpg)
(http://img12.imageshack.us/img12/5281/dscn2305h.jpg)
Quote from: gordo on December 01, 2012, 03:01:08 AMThe first time you make an amp that sounds even remotely good you're screwed because amp building is at least as addictive as pedal building. :D
"Hi...my name is Gordo...I'm here tonite because I build amplifiers..."
This is the truth. Built mine, sounded brilliant and my first comment was "right, which one should I build next?".
Since then I've been pondering between an Ampmaker PP-18 with SL-18 mods. Or a full on version of the amp I've just built with mods from what I think would be cool for a higher power version (a second pre-stage to bring the gain back up after the tone stack, I'd fix the fat on and remove the tone stack bypass as the extra tube should compensate (in theory), reverb, more power tubes, power scaling).
VERY impressive builds!!
Agreed, damn impressive lead dress.
I've been told, though, that that style of filament wiring is bad practice in tweed cake-tin chassis', because then the AC voltage going to the filaments is right next door to the components on the board (as opposed to Marshall-style, where it's against the outer lip and about as far away from everything else as you're gonna get in something that cramped.)
All great advice here on safe building. I would not let it deture you. Just practice the techniques mentioned and be alert and rested, and take your time. It is very rewarding when it comes together.
My advice: build a light-bulb limiter for the initial fire-up after building it. It will save valuable components if your wiring is wrong.
Funny I was going to build another amp in addition to my 5E3 but recently bought another egnater tweaker cause it is such a nice little practice amp.
Here is my 5E3 for some inspiration:
(http://imageshack.us/a/img228/6806/img12bw.jpg) (http://imageshack.us/photo/my-images/228/img12bw.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)
Interesting thread. I have always wondered, whats the benefit of twisting 2 wires together like in some of the pics. Ive done it myself in some of my pedals, the 9v wire wrapped against a ground wire. Apart from looking neater does it reduce noise at all?
Yupp. Think of computer cable (twisted pair) and that's the idea. It doesn't add "shielding" in the way coax does, but the two wires are at angles to each other (ideally 90 degrees) and aren't parallel.
Go on, I'll throw mine into the mix too:
(http://juansolo.demon.co.uk/stompage/images/amp3.jpg)
(http://juansolo.demon.co.uk/stompage/images/amp4.jpg)
(http://juansolo.demon.co.uk/stompage/images/amp5.jpg)
Quote from: Hangingmonkey on December 02, 2012, 07:50:34 PM
Interesting thread. I have always wondered, whats the benefit of twisting 2 wires together like in some of the pics. Ive done it myself in some of my pedals, the 9v wire wrapped against a ground wire. Apart from looking neater does it reduce noise at all?
Actually twisting heater wire together (green wire in my pic above) is best practice to reduce hum and noise in the circuit when amp building.
Quote from: pryde on December 02, 2012, 07:32:12 PM
My advice: build a light-bulb limiter for the initial fire-up after building it. It will save valuable components if your wiring is wrong.
YES! I forgot about this. It's a regular fixture on my bench. I smoked an output transformer I paid good bucks for because I didn't have a fuse handy and hotwired it. The amp was going to be a Trainwreck and the whole project became a
trainwreck. The bulb limiter was my next build and I use if for everything. This thing will save you a fortune in fuses alone and can be built in an old computer power supply. I'll dig up the scheme if anyone is interested.
Quote from: gordo on December 03, 2012, 02:11:36 AM
Quote from: pryde on December 02, 2012, 07:32:12 PM
My advice: build a light-bulb limiter for the initial fire-up after building it. It will save valuable components if your wiring is wrong.
YES! I forgot about this. It's a regular fixture on my bench. I smoked an output transformer I paid good bucks for because I didn't have a fuse handy and hotwired it. The amp was going to be a Trainwreck and the whole project became a trainwreck. The bulb limiter was my next build and I use if for everything. This thing will save you a fortune in fuses alone and can be built in an old computer power supply. I'll dig up the scheme if anyone is interested.
I'd be interested to see your schemo for that Gordo... I have an old PC I'm about to scrap, sounds like a handy tool! :)
+1 to the schem for the limiter.
I'm ok ...... I can quit any time I want to ........ (Denial!!!)
5e3 in sight or Marshall 18 watter!!!
Here's one version of the limiter (http://www.geofex.com/article_folders/spo_test.htm).
Here is another very simple LB limiter that will work fine and super cheap to build from any hardware store
Beautiful work!
The only thing more addicting than building amps is building guitars. Probably a blessing this house doesn't have a garage, like the last one did... :-*
lol i got the guitar build bug. im in the mid of building one and got the next 2 laid out before i finished this one. next one is gonna be a tele, maybe with a strat trem and P-90s. talk about a twist ::)
I did the opposite. Or rather I had it built as I simply don't have the facilities and Wez is a bit of a ninja. I had this idea in my head and needed to see it realised...
This is a Strat with a Tele bridge (cut in half), Tele bridge pup and a single cut Tele-style upper bout. But it's mostly Strat proportions. Wiring was interesting as I ended up doing that bit. It's a 5 way with B-BN-M-MN-N. So you can get Tele sounds on 5-4 and Strat on 3-2-1 ;)
(http://www.juansolo.demon.co.uk/misc/Guitars/stratele-1.jpg)
He's currently building me a super strat with a wrap-around on it... I had a couple of pups I didn't want to sell and nothing to put them into ;) Work in progress (wood is just wiped down at the moment to show the grain, finish hasn't been finalised yet. We're going to see how black oil looks on an off-cut first otherwise it'll get painted):
(http://i36.photobucket.com/albums/e31/WezV/js33.jpg)
Gorgeous! I did a "super" tele 10 years or so ago, a little sacreligious but it played and sounded great.
Sorry for the derail, but I'd say it was worth it...! ;). Good luck with the strat
Beautiful !