Sourcing the correct Iron for clone AC 15 and Discussion of build

[sluckey]

Will you be posting the longboard layout on your site?

yes

[lego4040]

The buss ground is different across the top of the board too compared to old version. That's cool you can make your own chassis Ed, back when Highschools had trade classes I took everyone I could. Metal shop was one and we learned how to bend steel sheets and weld corners to make boxes.

[Ed_Chambley]

The buss ground is different across the top of the board too compared to old version. That's cool you can make your own chassis Ed, back when Highschools had trade classes I took everyone I could. Metal shop was one and we learned how to bend steel sheets and weld corners to make boxes.

I have access to a pretty nice Fab shop.  Today, I own a printing company, but before I was a metal worker and machinist.  Anyway, they have a old sheet metal break and a Tig and Mig.  The rest I either punch of drill.  It is not difficult to make a box.  On my last build I did not even make layout, I simply scribed it into the metal and folded it up.

The shop also does chroming, but that means steel which is more difficult to work with.

It looks like you have all you need as your project is coming along nicely.  The blank chassis do not really cost that much, but I will admit it is much better to build into a predrilled chassis.  I am awful about posting photos of builds as I get involved and get completed before I think of it.  I am glad you are.

I ordered some more parts and decided to go ceramic for the pf since the original was.  I also use them in lots of fender builds.  I am interested in seeing how may are going to build one and how the tones will vary.  Every amp is different.  I think it is cool.

[Tone Junkie]

I am not concerned with my Visio skills, it is the drill guide and underboard wiring I am scared to draw as I know it would be wrong.

The drill guide is a lot easier than you might think. All I do is copy the loaded board to a new page. Then I just delete all the components. All that's left is the board, turrets, jumpers, and other holes. Then I do a little cleanup with colors etc. Wala! A drill guide. Only takes about 15 minutes for a complex board like this.

The hard part is re-verifying the layout is correct. I slid some stuff around when I stretched the board and sandwiched the other caps and resistors in place. It's always a good idea to recheck the whole thing and make sure it still agrees with the schematic.

Thanks for the tip on the drill guide.  Did not think of doing that, but it is way better as it insures proper placement.

As you can see, I an typing before I think.  I am getting excited.  How weird.

(LOL) Face it ED your addicted like the rest of us . I might not be thinking 2 builds ahead like i used to but Im already starting the next one before the old one is finished.
 I cant help but watch this because I dont have this amp in my an in my jam room.
Bill

[g-man]

Deleted

[lego4040]

Chroming is nasty business I here, I can manage a blank chassis as long as I measure 8 times before I drill and use Sluckey's template guide. Also have all parts on hand to measure diameter

[Ed_Chambley]

Not to hijack this thread, but I have a Mojo 18 watt I built several years ago. I have thought about rebuilding it with a different preamp, either changing both channels, or keep the normal channel and re-build the trem channel. The OT has a 9K primary. Is it even worth considering building the AC15 front end with a 9K OT?

Sure, a 9k primary will work fine.  Even as high as 10k.  I have a couple of old Thoradson Output Transformers, organ replacements at 10K that run EL84 and do a great job.  Actually a 9k could be better, it is a tube data thing and how much voltage is present.

Anyway the Power Amp section is just that.  The character of an amp is usually determined by the preamp, but when the power amp distorts it has its own tone.  Give it a try, what is the worst that can happen?

[Ed_Chambley]

Chroming is nasty business I here, I can manage a blank chassis as long as I measure 8 times before I drill and use Sluckey's template guide. Also have all parts on hand to measure diameter

Yea buddy, you do not want to be around the chroming vats.

I don't worry about the chassis much as when I go over to make them, I make a bunch at once, then I can screw up a few.
Actually, metal work work the only thing I knew about building amps.  I could do things to them, but did not understand how they worked.
Years ago I worked at the place and the owner and I became really good friends.  I was the only employee who was sober.

It was Sluckey's riding me to use schematics and not layouts.  I did not know why at the time.  My thoughts were I am building the amp and I have to go by the layout.  Not true.  It is the schematic where you learn the signal path and what is in it.   Now I laff like hell every time I get to point someone to the schematic and it is my turn to repeat Hoffman's Law which I am sure I will get on this build.

Do you know Hoffman's Law?

  I am so glad I stuck with it and the guys around stuck with all my past and present stupid questions.  When I got to understanding a bit of the design process, I began to appreciate things like Tremolo.  Is it not cool someone figured out how to do that?  I have been attracted to some Gibson tremolo circuits lately and have been studying Point Builds.  I have a few builds now with no wire.  Simple, yes but the Cool Factor is very high.

Now the appreciation of the AC15 has really hit me.  Parts are coming and I hope I can get the board built soon.

[g-man]

Deleted

[Ed_Chambley]

Anyway the Power Amp section is just that.  The character of an amp is usually determined by the preamp, but when the power amp distorts it has its own tone.

I guess that's what I'm really asking...if the Vox preamp through the Marshall power amp will still sound like an AC15. I read somewhere that a lot of the 18 watt distortion comes from the power amp. You're right, try it and see is the answer but thought maybe someone has tried it already.

I did it the other way.  Converted an attempt at a AC15 and it did not work out well.  Way to stiff because I had the wrong iron, and filter caps.  I am learning the Vox tone comes from the circuit, low filtering, low voltage and massive choke and Output iron.

I had 18 watt iron like Doug Sells and a fender choke and tried to put a Vox up front.  I ended up with a EF86, 18 Watt Marshall.  It sounded great, but was not the greasy, lovely transparent bass and that extremely touch sensitivity without having to spin your volume knob as much.

Basically, it was a tight distortion machine that was very harmonically rich and would make Eddie a nice toy amp.  Very cool, but not for me as I already have an Eddie Plexi, just don't have a place to play it.

It sold the first weekend as I put it in a music store.  That is why I have researched a lot on Vox and hopefully I get that tone.  There is always give and take.

[TNblueshawk]

Educated me on Hoffman's law if you would Ed since I'm new here?

[sluckey]

I guess that's what I'm really asking...if the Vox preamp through the Marshall power amp will still sound like an AC15. I read somewhere that a lot of the 18 watt distortion comes from the power amp. You're right, try it and see is the answer but thought maybe someone has tried it already.

A lot of people have tried it. Ceriatone has a version with an EF86 preamp rather than the normal channel. I put that same EF86 preamp in my Matchless Lightning. It sounded OK but nothing special. I currently have that Vox EF86 preamp in a Hammond AO-39 conversion. I had originally had the AO-39 wired as a 18W Lite IIB. I didn't think the Vox sounded as good as the Marshall.

     http://home.comcast.net/~seluckey/amps/hammond/hammond.htm

[sluckey]

Hoffman's Law pertains to problems with new builds. It states "If it was wired correctly, it would be working now".

[TNblueshawk]

Hoffman's Law pertains to problems with new builds. It states "If it was wired correctly, it would be working now".

Oh hell...even I can understand that one 

[sluckey]

You would be surprised at how many times I've heard people swear it's wired correctly, only to find out later that they broke the law.   

[TNblueshawk]

Nah, I wouldn't be all that surprised. I'm usually on a pedal forum of one kind or another and many times I get the "I know everything is soldered good" right after I see cold joints and bridges 

[lego4040]

I think I can remember Hoffmans Law, Schematics are a very important factor in my work. When I was in the apprenticeship I had a one year just on learning basic electricity to being able to go to any machine and look at a schematic and be able to work on it. We learned there are three types of diagrams, a pictural(your exact layout) line diagram(looks like a ladder) can't remember the other one but you had to learn how to read them all. Do you make your chassis with the  extra lips on side?

[Ed_Chambley]

I think I can remember Hoffmans Law, Schematics are a very important factor in my work. When I was in the apprenticeship I had a one year just on learning basic electricity to being able to go to any machine and look at a schematic and be able to work on it. We learned there are three types of diagrams, a pictural(your exact layout) line diagram(looks like a ladder) can't remember the other one but you had to learn how to read them all. Do you make your chassis with the  extra lips on side?

Yes, so i can put a cage nut on them.  The last ones I folded under and thought it was a mistake, but I like the clean look and use the cage nuts on the inside.  It is cool when looking at as you cannot see what is holding them in and I can also use them in a tweed style cab.  I actually made them when I built a AB763 with reverb and tremolo in a Tweed Deluxe Cab.  Cool amp and will fool you with 40 clean watts coming from a Tweed Deluxe cab.

[SleepLess]

Hi there!
How has this build evolved? Is the amp done and purring now? 

[sluckey]

There are at least three completed amps. And Hoffman built and sold another board. Don't know if that one is completed. There's another long discussion thread with lot's more info.

     http://el34world.com/Forum/index.php?topic=16874.msg167229#msg167229

Here's my amp...    http://home.comcast.net/~seluckey/amps/VAC15/ac15.htm

[lego4040]

Mine is up and Running I used all Hammond Iron on this build and I am really Happy with it.