18Watt.com

So of the slew of amps that I've built since I ever started tinkering, I don't think I've ever truly kept a build thread of one. This one, I'm gonna do it.
It's going to be a standard tremolo circuit 2x12 combo, just with 36 watts.
Pine cabs with birch baffles. Pickled/Whitewashed instead of tolex.
I'm also building a 2x12 extension cab with a closed back for it to match.
Parts are amassing. Cabs are coming together. It's happening.

Looking forward to the build of the amp and the thread.

Me too! I'm looking forward to seeing this thread. You can also share photos in the gallery if you want.

So I finally settled the last few items for my build, and really got a good start this weekend.

Got a blank red perforated board that staked it myself. I had to build a little staking tool, but wasn't too hard. Just drilled a hole into the end of a bolt that I was able to attach to the table of my drill press and used a punch to stake. Once I got the jig set up it was a breeze. Decided on a blank jtm45/18w mojo aluminum chassis so I could punch out all the stuff I needed and not have anything I don't need. Mojo Trem panels look pretty good. Also I'm using a GSD 36w transformer set. Couldn't help but want a sneak peek of mustards on the board I've done a ton more documenting but want to break it up into several replies so it's not just one huge string!

I got a big order of parts from Valvestorm on Saturday and I finally had the time to lay into it!

Started with the cab feet. Gray rubber old Marshall style. Stacking up nice F&T Dual 32uF can cap and clamp ready to go. No time like the present, so I started chassis drilling. Easy one first. Marking the spots for the stand-offs. Use a punch to prevent bit walk Brass stand-offs looking good. Dry fit of the board. Starting to resemble an amp!

The knock out for the power transformer was by far the most nerve racking part of any of the chassis work. I didn't want it ending up looking half-assed so I just took my time. Started a little paper template I made to get the mount holes and corners of the knock out. Then with scored center lines to keep my row of holes straight, I just started punching holes to make cutting a whole lot faster and easier on the ears. Sure started off kind of scary, but I had faith After a few minutes with a few files and close watch, I'm more than happy with the way the hole turned out. Next I drilled the mounting holes and lead routing holes for the OT. Installed rubber grommets, pan head brass screws with self locking nuts. I was going to go with plain brass nuts and lock washers on the PT, but decided on self locking nuts for it as well.

After the hard part of the chassis was done (imo) the front panel just blasted out. Used a step up bit and just kept plowing through checking each hole size as I went. Once I was done I installed the pots, switches, jacks and light. I used an amber Marshall style indicator, Carling SPST switches with the modern dress nuts on the front. CTS pots except for an Alpha 1k trem pot (grrr. inconsistency bugs me). Cliff UK jacks. I'm gonna use Scott knobs, but they haven't arrived at this point. After a nights sleep, I decided to start punching the tube socket / can cap holes in the chassis. I got a set of conduit punches to do the bulk of the work. There wasn't a punch size that I found acceptable for the gz34 rectifier octal socket, so I ended up using a step up and a good file job for that. The first time I've used these punches. I was very pleased with the hole for sure. My final two pics for the day because I forgot to get the rest of my mounting screws for stuff, but it's shaping up to be pretty nice. Also I blasted through all the back panel holes and mounted that as well. Just waiting on a nice NOS belling lee fuse holder and vertical iec jack.

Nice !!!

Very nice work! It's all looking good.

Take a look at the info post I put in the downloads section: viewtopic.php?f=25&t=25173

The Greenlee 30.5mm (1-7/32") punch works perfectly for most octal socket holes. Also keep in mind these aren't really conduit punches, they're chassis (or radio) punches. Conduit punches lie about the sizes. Conduit punches take into account inner and outer diameter of conduit pipes instead of the actual hole size, listing the inner pipe diameter while accommodating outer piper diameter; for example, 1/2" conduit punch = 7/8" hole for conduit punches. You may already know this, but somebody else reading the thread might not.

I also linked info to the Keystone TL-8 set, or the 1715 turret/eyelet tool. The keystone stuff is available from Mouser or a couple other places. The proper turret tool will swage the bottom of the turrets, giving a nice wrap around the edge (and a better grip), instead of having a sort of flare sticking out.

Thanks,
Josh

So. I thought I could live with myself, but I can't. Chassis 1: Set aside. Chassis 2: On the way. I used a cheap set of conduit punches for my tube socket holes. I knew they weren't exactly the right size, but it's already bugging the hell out of me of the sloppiness. Josh, I had read all the build tool stuff already and I didn't necessarily disregard it, but I thought I could deal the the size difference. How I staked the turrets was just fine. It staked them tight, flared them, and I used a small ball peen hammer to tamp them down. So that's all good...but the holes, man. I bought a old set of Shark radio punches that has all the exact sizes needed for octal and noval sockets and they cut great, so once I get the new chassis in, it'll be done right. I have a buddy that can weld aluminum, so i'm going to get him to weld the knockouts back in and fill anything needed filling, and use that for a black flag 50w build i've been wanting to do. I'll just have to sand the welds down and polish it back up. Then I can punch it for the 50.

Anyway, In the meantime of me lamenting my mistake, I got work done on the board and the front baffle board and cleats for the combo cab.

Hahaha, I know how you feel! I tried, at first, to consider ordering the wrong sizes on a used set to save $$$, but I couldn't do it. Instead I tried getting a cheapo set at HFT. The cheap set convinced me to spend the money and get the correct punches...and it's ridiculous how much better they are (besides just being accurate).

BTW- the 1715 staking tool is only about $10. You can clamp it in your drill press and use it, or do what I did and put it in an arbor press:

Great job! can't wait to see it complete,have you tested the mustards for leakage?

JMPGuitars wrote:Instead I tried getting a cheapo set at HFT. The cheap set convinced me to spend the money and get the correct punches

This is exactly the cheap set I speak of. Live and learn, right?

Speaking of learning:

geoff 1965 wrote:Great job! can't wait to see it complete,have you tested the mustards for leakage?

Thanks Geoff! I haven't tested them for leakage. And hopefully this is where this thread makes me a more informed builder...what exactly would I expect from leaky caps? I understand that it allows dc to pass to the next stage misbiasing the following tube/stage...but the results are range from "it sounds bad" to "it can be catastrophic. I guess this is the first time I've used a full set of NOS mustards, but I've never as much as batted an eye with any other poly caps I've used in the past. How blissfully ignorant am I being?

yeah i used mullard mustards on my cage lite2 build with 1watt carbon films and i had trouble with the one between the volume and tone pot,adjusting the tone actually increased the volume so it depends on where in the circuit the leakage is! so until i can test them for leakage i've put mojo dijon's in which are very close to the mullards for sound and they are the self healing ones which is a bonus.the only down side to them is the range of values,with the mullards you get the full range and when i was voicing "tweaking" the amp i had 5n6,12n and 15n in the preamp but with the dijons i had to "piggyback"a 2n2 and 10n,4n7 and10n to get close to 12&15 and settle for a 4n7 in place of the 5n6.
regarding the chassis,i've been a welder for over 30 years and you will struggle with warping with that gauge of aluminium!best to just use the chassis for a project where aesthetics are'nt crucial.
keep up the good work

GlassTornado wrote: This is exactly the cheap set I speak of. Live and learn, right?

Oh god... Garbage, right? The 1/2" should be usable for the noval sockets, but it was so cheap it broke itself. I returned that junk the next day.

So this weekend was more cab work whilst waiting on my new punches and chassis.

Got the combo cab done completely except for piping, cloth, and handles which are in the mail.
I got my chassis and punches on Monday and I've gotten myself back to essentially where I was when I decided to start over. More pictures to come of the holes from the new punches!

good job! i like it,are you going to use a sealer/finish on the cab? i used danish oil on my guitar and it really brings the grain of the wood out with a nice satin finish.

It's a little hard to tell but if you compare the wood color through the back of the cab to the sides, you can tell that I used a white stain to whitewash it. On the pic of the front it's a little less apparent, but in real life it's pretty obvious that it's got a stain on it. There will be thin wipe on poly after that to "protect" it. I just haven't done the poly yet, though it's quick application and quick dry.

The Shark! The Shark was a game changer! Here's a pic of the 3/4" punch that's part of my kit of Shark punches. Old japanese set that zipped through and did a great job. All the new tube socket/can cap holes punched. Very happy with the results The 3/4" punch was was absolutely perfect The brass hardware from valvestorm didn't look too shabby either Like pretty little maids, all in a row This will be the last time you see this board in here without it being wired up! (but it's still fun to look at) All in all that turned out to be a much more successful punching session than the last. All I need to do now is open up the hole for the PT again and i'll be good to go! Here's to progress.

Nice! Good punches are amazing compared to the crap we tried. It's like going from a butter knife to a table saw.

I'm not sure if you've looked at the way other people do the PT cutout, but usually people just drill the 4 corners and then connect the outsides with a jig saw before filing.