ilovefuzz.com

But, fuck it.

As someone who has built a few (less than 10) pedals, and breadboarded several dozen, is there much of a difference in difficulty between a moderately complex pedal and a relatively simple amp? Yes, I know that the huge caps can store bcbc-killing amounts of current, but I'm talking about level of difficulty/skill required.

The reason I ask is that I've had an idea in my head for quite some time about what my perfect guitar amp would be, which is a modification (and a major simplification) of a classic amp. I've trimmed down the schem to everything I think I need, and shit, it has less components than some pedals I've breadboarded. So now the question is, do I drop a little coin to try it?

Feel free to smack me down

I only built a tiny mini tube amp... it was hard... and if I hadn't traded for a large amount of stuff, really expensive.

I assume you're talking tube?

There's things like layout to worry about, proper practices, sorting a proper chassis, that deadly stuff that keeps trying to kill you.

I got shocked twice off my build, thankfully the mA is low so it just hurt a fucking lot, but it coulda been a dead Scruffie.

I wouldn't wanna do it is all i'm saying, i'd start with a kit for the first go... i'd call amps... deceptive, the schematic looks simple but they're not really and are a big investment.

If this is solid state... yeah just do it.

i say do it.

i built a few small amps and it was easy. Thats subjective enough i guess but if you have some drive and some patience id say go for it.

even if its tube, for something simple you are way less likely to run into layout problems imho. Also it is hard to get shocked unless you are completely unfocused. in which case you should just have a beer,a sandwich and go to bed.

multi_s wrote:i say do it.

i built a few small amps and it was easy. Thats subjective enough i guess but if you have some drive and some patience id say go for it.

even if its tube, for something simple you are way less likely to run into layout problems imho. Also it is hard to get shocked unless you are completely unfocused. in which case you should just have a beer,a sandwich and go to bed.

I'll admit, my getting shocked was cause I knew it wouldn't kill me, probably woulda been more careful with a power transformer... and I may have poked it one of the times just to see... but still, the chance is there and debugging with those voltages around could be tricky.

It wasn't hard per se but it was an involved build, more than it may appear... and I lack drive and patience.

I'd atleast get one build under my belt before I went full on tube though, unless I did some serious reading first, it's not something i'd step in to lightly.

Beer sandwich and bed sounds like a plan right now though.

Yeah, it is tube. It shouldn't be all that expensive, I already have the tubes sitting around, and I priced out everything else. Component-wise, maybe another 100 dollars of parts. The layout and actually building the chassis will be a bitch, that might be the main thing I might need help with. But the schem looks pretty straightforward, probably deceptively so.

I thought about trying a kit first, but they all seem REALLY fucking expensive, from my initial searches. Let me know if you guys know of any relatively cheap ones out there.

How the hell do you go about prototyping tube shit before you build the fucking thing? Do you just have the tubes sitting there in their sockets on your workbench? This is where the dumb newb questions come in. I guess that's not a big deal to just breadboard the preamp section, but how do you prototype the power section? Just build a shitty proto chassis?

Scruffie wrote:It wasn't hard per se but it was an involved build, more than it may appear... and I lack drive and patience.

I'd atleast get one build under my belt before I went full on tube though, unless I did some serious reading first, it's not something i'd step in to lightly.

Beer sandwich and bed sounds like a plan right now though.

ya its true it is more involved then you will think from looking at the schematic. i wish i had a beer. and a bed

bigchiefbc wrote:
How the hell do you go about prototyping tube shit before you build the fucking thing? Do you just have the tubes sitting there in their sockets on your workbench? This is where the dumb newb questions come in. I guess that's not a big deal to just breadboard the preamp section, but how do you prototype the power section? Just build a shitty proto chassis?

well if its SIMPLE then probably you'll just be changing component values or something basic? liek how simple is it? or is it a secret?

what i did was using those terminal strips, put 2 in parallel and use way more then you theoretically need. Or get a turret board with more turrets then you need. Then with a pencil or software actually draw the phyiscal wiring layout. If you can get that to fit on the number of turrets you have, assuming you didnt screw up, putting it together should be a cinch. And if you leave some extra eyelts then you have a bit of play to mod.

so... in short i only had 1 chasis, the final chasis. Its not liek your going to change the number of tubes in teh power section really eh? so once you figure that out and what xfmrs your using the output stage probably wont change?

if you are doing some design i would point you here:

http://www.freewebs.com/valvewizard/

if you have a calculator and time to read you can pretty much design amps from scratch. Also if your trying to learn someo f the explanations go pretty deep so its a good site. maybe one of the best i have ever seen.

maybe ebay a second hand fender chassis to build it in . Building an amp circuit is one thing, being a skilled metal worker is another!

Yeah, re-using an old chassis is a good idea, thanks for your input guys!

It'd be similar mentally, but BUILDING it is a different story... depending on what you're building.

http://tubedepot.com/kit-british18whead.html <-- there's a video on that page of a guy building the kit, which sorta gives you an idea of what goes into it. Sorta. Yogu can see it's pretty involved, though.

If you do the amp with everything mounted to PCBs, it won't be a TON different, but there tends to be a lot more hardware because of the transformers and such.

Moreover, amps are just bigger-- which makes them harder to work with. Like, I can build a simple pedal in the it takes me to wire a guitar just because the guitar is so big and awkward to work with.


The only dangerous part of tube amps when they're off is the filter caps-- just discharge them through a big assed resistor (or a big screwdriver if you like sparks) and you're good. Check for voltage with a meter just to be sure.

yeah throw a 5w 1M resistor in your next parts order, I use a screwdriver on caps when I salvage old TV's but I never see sparks. some people have a 24 hour rule about caps discharging themselves while the equipment is unplugged. I have never trusted that 24 hour thing with my life, but I have never seen sparks doing it that way either. I almost built a ceriatone but did not have the money to do it.

http://www.ceriatone.com/

http://www.tedweber.com/ <----- click on Amp Kits

information and forum
http://www.ax84.com/

tubedepot.com <------- I have made purchases in the past. if you call and ask for a tech he can talk to you a little about what tube to buy to meet your requirements or to chase some kind of sound. they do hand picked tubes for an added fee. I got 5 high gain 12ax7's for my mesa and it was screaming the blues.

Your troubleshooting skills get put to the test on amps way more than pedals,
be prepared for some very unpleasant noise if you don't ground the chassis properly on a 60 watt tube amp!

soundboy.massacre wrote:Your troubleshooting skills get put to the test on amps way more than pedals,
be prepared for some very unpleasant noise if you don't ground the chassis properly on a 60 watt tube amp!

This is an excellent point! While the skills you learn from building pedals will be an enormous help in building an amp, the consequences for making a mistake are much greater. Exploding caps, blown speakers, fried transformers... these can all be expensive "oops" moments. Forgetting to drain the caps before you touch anything... that can cost you your life.

I know they can be expensive, but I would strongly suggest building a kit first. I built a Mission 5E3, and was rewarded with the best sounding amp I own plus hours of fun during the build process. I was probably a bit paranoid about making a mistake, so whenever I was unsure about something I put down the iron and did some searching or asked questions on forums. I learned a TON. Just like building pedals, there are all sorts of little tricks that amp guys seem to know and take for granted. Getting involved in some of the amp building forums will help bring you up to speed. I'm certainly no amp expert after building one relatively simple kit, but I feel like I now have enough base knowledge to tackle a more involved build.

These are the three most important things I learned to stay safe when working on amps:

1. Make yourself a "lifesaver" tool: 5w 1M resistor, soldered to some alligator clips. Clip one end to the chassis FIRST, then clip the other end to filter caps.
2. After they are drained, check them with your meter. EVERY TIME.
3. Take off all rings and jewelry. When probing inside the chassis, keep one hand in your back pocket.

Call me paranoid, but I think having a healthy amount of respect for lethal voltages is a good thing. :-)

Lastly, here's an idea to help you get started AND save some cash: build a kit that is similar enough to the amp you have designed that you would be able to reuse the chassis and transformers for it.

You're safe once you've ensured the caps are discharged. Really, just flipping the power switch on will discharge them a lot since they're right on the power supply. Then you can use the resistor just to finish them off.

If you have to work inside the chassis while it's plugged in, you could use electricians gloves to be safe. And it's always a good idea to keep one hand well away (although one hand in your pocket could mean you can't catch yourself if you fall over-- I'm pretty clumsy so I have to worry about such things)

Always check with a meter, though. Those things can be like 400 volts which will totally fuck you up.

Interestingly, BYOC announced today that they have released a Fender Champ kit. It's 350 bucks, but BYOC is about as fool-proof as you can get. Now I'm torn.

One of the reasons many people are drawn to traynor yba-1's as a platform to mod is that many of them are built so that the chassis lid comes off to give access to guts while the chassis is still in the head cabinet. The design saves you a lot of snapped pots and broken tubes you might get otherwise.