Sure - the kit of parts cost around $250, the speaker another $250 (I went high end for that) and I will be spending at least $300 on a combo case. Add to that some one off purchases of tools etc. I could probably have saved some money along the way by sourcing the components myself, a cheaper speaker and making the case, but even then this is not a cheap way to get an amp, but its a lot of fun and helps you understand what goes into them. Plus, in theory it should be a little better than a mass produced amp due to good component selection and point to point wiring.

Though if I was building it I'd have to factor in the cost of the amp tech's time and new parts redoing my bodged job and the trips to the hospital to sort out the burns/scars from the soldering iron .

Looking good Andrew - can't wait for the sound clips when she's ready .

Cheers,
Tony

Wow Andrew! Great start! I think i would never dare to start building something like that! Can't wait for the result!

Update:

Cool - my PTFE coated wire arrived early this afternoon allowing me to swing into action!

I don't have a permanent electronics lab yet - need to move before I can get that, I set up a table in the garage, looks pretty technical if I do say so myself!



In the picture above, you see the tagboard just before I started to solder all of the board mounted components on it.

About 2 hours of hard work later, I ended up with this:



Although I had done a lot of soldering in the past, I had never used an eyelet board like this. I would have preferred a turret board actually, but this is what came with the kit of parts and turret boards are hard to fabricate without the right tools, chief among those being a drill press which I do not posses. It all went well, including soldering of the underside wires that you can't see in the picture. Next step will be to wire he board up to the chassis components and a whole heck of a lot of other wiring. I am planning to make a start on that next weekend, for now I am pleased with progress.

In other news, I have been corresponding with Mojo Sound about a case for this beast - I have narrowed down what I want and I am waiting for a quote. I am now expecting it to be around $400 because we are into custom cases - their off the peg case wouldn't quite do it.

This post has been edited by Andrew Cockburn: Sep 5 2007, 08:57 AM

Woo, gettin' expensive Good progress though my man!

Yeah, this definitely isn't a cheap route to an amp ... but it is a lot of fun

And as you've said you'll come away with a real understanding of how (the) amp(s) works and be able to repair it if it's ever necessary - priceless.

Cheers,
Tony

Wow, this is looking all great!


Your desk looks arranged though, an open plier placed there to live things up. Too obvious!

Thanks for the answer Andrew-Its actually alot cheaper than i thought!

Maybe you can build me a 'dumble' inspired amp if things go well?!

-Ben

This post has been edited by benhowell: Sep 5 2007, 07:00 PM

Heh, maybe The designs are out there!



Cynic!

Update:

Having thought about it a little more, I'm not 100% happy with my efforts above. The joints were fine and electrically sound I am sure, but I did not like the eyelet board much. It will only get worse as I start attaching wires - some of those holes are already running out of space. Add to that I am using 18awg wire - only necessary for the heater circuits but I figured thicker wire would be better so decided to use it throughout.

After some thought this morning and a little research, I decided to redo this part of the project as a turret board. In terms of time this is a setback - a waste of 3 hours yesterday, and an additional wait for parts and another couple of hours to make the board and another hour or so to re-solder it. But I am not in a rush, and I am treating this as a learning process. I want people to be impressed with my amp, and I am just not happy with the look of the above board, it looks amateurish. In financial terms this isn't a big deal. I'll have to re-order all the parts that went on the board, but they are fairly cheap - resistors are about 5c, even the larger caps will only be a couple of dollars each. Probably the total for new component will come to $15, so no big deal. Turret board and turrets are pretty cheap, the only real expense will be a drill press - you can get those for $50 and up, which was cheaper than I thought, plus I will be able to use the press to drill my own chassis for my next project whatever that is.

With a little luck, if I order the parts today I will have them for the weekend. If not, there is some chassis wiring I can get started on even without the board.

In other news, Mojo have been very helpful in working up a cab spec for me, and the final cost is $352.50 which was cheaper than I thought, although shipping will probably add a fair amount to that.

Update:

Sep 6th, 2007

Today I ordered a drill press. Its got a laser so it must be good. I sent an order to Mouser Electronics for new board components - the big caps were about $10 each - ouch! So I revise my estimate to about $50 of components and some more for the turrets and board. It will probably be after the weekend before I get all of this together, so my weekend task will be to wire up the chassis, I can use my existing board as a guide, I just won't hook it up. Once all the wiring is done, it shouldn't take long to hook all the wires up to the new board when I have built it.

Sep 8th, 2007

A big push today - I spent the day wiring up the chassis, ready to drop the new board in when I have it done. Still waiting parts for that, but the wiring went well. All told it took me about 6 hours to do this - partly because I was getting used to making the twisted looms, but also because there is a lot of nitpicking, and I wanted to do a good job of routing the wires. It doesn't look a lot for 6 hours work, and looks messy because there are a lot of loose wires waiting to be soldered to the board, but I'm pretty pleased with it. The hardest part was the heater filaments (green and grey twisted wires) - I didn't get those perfect but they should work fine.



Next step will be to make the new board - first I have to drill it and fix the turrets in, then wire all the components in place. It will be probably 3 weeks before I get around to that as I have a vacation planned and I'm still waiting for parts and the drill press, but another couple of weekends and I should be all done

Looks like its really coming together.. have you thought of a logo to put on your amp.. like a giant cool written A/C or something

I discussed this on chat with Rokchik a couple of weeks ago - my first amp will be called the A.C. 1 . I'll probably add a logo for Cockburn Amplifiers or something as well - I want it to look as good as possible!

Im impressed with your efforts Andrew. Had that been my soildering, it would of ended up being sold as "outsider art" like when homer simpson cocked up making his DIY BBQ

your a braver man than i.
ive always wanted to make my own amp and guitar but i havent had the money, knowledge or skill to do so.

if i were to buy all the expensive components and screw it up i wouldnt be able to live with myself lol.

cant wait to hear your finished amp. good luck

Thanks guys I'll be posting clips as soon as I get it working - assuming the whole thing doesn't explode in my face when I turn the power on

This post has been edited by Andrew Cockburn: Sep 10 2007, 02:41 AM

Looks like it's coming on really well Andrew. What type/s of knob/s are you going to put on it when it's ready- chicken head/knurled metal etc - are you going for a vintage or a more modern sort of aesthetic?

Cheers,
Tony

If that happens we'd want a clip of that too, video if possible

Looking real good so far!

Heh, maybe I'll video the big switch on and post the highlights as an amp building lesson



It came with chicken heads, so I see no reason to change, they are in keeping with the tweed cab after all I'll also probably go for a plain face plate with white lettering, but not for a while. My plan is to build the basic amp then add some unique mods - on my list for thinking about are:

1. Switchable cascode boost stage - should give me something approaching a high gain sound
2. Swithchable triode/pentode - I'll try this but people have reported that it doesn't sound too good on this amp
3. Switchable Bypass capacitor - Fat, normal, bright
4. Switchable EL34/EL84 - a tough one this as I have to figure out a way of dropping the anode voltage by 100v
5. Effects loop - simple serial unbuffered would be easy, or maybe I'll use an additional 12ax7 and buffer it

All of these are moving away from the safe world of tried and tested schematis though, so the most likely thing that will happe is that I'll blow something up!