You might dig this... and I have questions.

[ioginy]

Hey all. I got it into my head to build an amp a little while back and found sanctuary here for all my information wants and needs. I've stuck mostly to the tube101 area, but I think I should expand my horizons and show you what i've been up to with all your kind and generous help.

Here's the story.
The amp is based off a Deluxe ab763 circuit. I was able to salvage most of the parts needed from an old Bell & Howell powered speaker. Came with a late 60's jenson alnico 12" and a really nifty cabinet all for $80.... CANADIAN! So, after that I found a frikken saint of a man here in edmonton who runs a small amp repair shop called C4 audio works. If you guys ever need a guy, he's where it's at. I got most of my remaining parts from him and the whee stuff from a wonderful electronics store just down the road from my house.

I didn't want it to look like a fender so i strayed REALLY far from their design and made the entire chassis and enclosure out of acrylic. It looks really neat.

I wanted to make everything myself if it was possible, so I got some blank one sided coper covered pcb board, stripped the copper off it and cut it to size. I then found out that they use copper rivets to fasten skate blades into their holder thingy's and it just so happened that I work in a giant bike shop with a skate sharpening department. So I went down and asked them for some rivets and low and behold, I had turrets. All I had to do then was drill the centers out and I was ready to rock.

I made a guitar about a year ago and had a bunch of the wood left over so I used some fretboard wood (pau farro) and made a nice little control panel out of that.

Another cool thing I found in my research was on the Angela amp site. They have a design for a super single ended 6l6 amp features an octal and a 9 pin socket connected together to a really wide variety of swapping for preamp tubes, specifically between the 12ax7 and a 6sl7. So, I ran with that and did the same. I haven't put it together yet, but I am going to make a relay box to allow remote switching between the tubes so i don't have to actually pull the thing and replace it when ever I want to get that different sound.

Alright, enough blathering. Here are some pictures.






My only issue now is figuring out how to ground it with this acrylic case. I've posted a few places asking for help but am still on the hunt. If anyone has ideas I would appreciate it. Keep in mind, this is my first amp ever and I have very little knowledge (comparatively) of how to do it. So in short, use little words and maybe draw a picture. I do well with pictures.

Thanks all. Hope you like the amp.

[nyazzip]

excellent! i got a bunch of free plexiglass about a year ago, still has the protective layer on it. i think at least one sheet is smoked grey color. i've been kinda scared to try tackling it. i don't know how to go about cutting it....what did you use? also what can you use to glue it with?

ps thumbs up on the tegan and sarah in the pic

[ioginy]

Thanks, i just went and saw them a couple of weeks ago. Been meaning to for years but never got around to it. Man they put on a good show!

I used a 6" band saw. I have a rather fine blade on it right now which caused some resisdual melting, but did not effect the sheets at all. It just melted the plastic dust (for lack of a better term) which collected on the under side of the plexi. After cutting it, the melt just cracks off nice and smooth leaving a nice cut. If i were to do it again though I would use a courser tooth blade.

As for Glue, I really could only speculate that a fiber glass epoxy would be dandy. Probably something marine grade would be ideal. I just put it all together with bolts and it worked dandy. Makes it look kind of industrial as well.

[ioginy]

my roommate also pointed out that aquarium silicon would probably do a really good job of gluing it together.

[ioginy]

Alright, the amp is all together. I just have to take it down to C4 Audio Works so Chuck can do a little diagnostic work on it and then I'll be able to put up sound clips... if it sounds good that is.

I was going to just do a smoke test but I thought better of it. Impatience would and probably would kill me.

Here are some photo's of the finished product. I can't think of a name for it right now sadly, but I'm sure one will present its self.

[dhuebert]

When I worked in research I built lots of things out of plexi. Go to a plastics supplier, they will have the correct glue. It came in a blue tube and was runny like super glue and was really really permanent. It gave a transparent bond that looked great...

Get a propane torch like you use for copper plumbing, run the flame lightly over the edges, they will turn transparent.

With chamfered edges, flame treated ends and the right glue and some practice pieces to get it right, getting a professional look is pretty easy.

The only problem I see is shielding the input from the power supply.

Don

[ioginy]

I was hoping it wouldn't be an issue by keeping the input as far from any wires as I could, however it is pretty tight quarters. Would you have any suggestions on a good way to shield it?

[nyazzip]

i like the torch idea...
hey IO can you post a close up of one of the "ice skate" turrets? i am always interested in turret alternatives

[dhuebert]

Does it buzz unacceptably? With the tag board approach, the only shielding I can think of is an aluminum box around the power supply.

Don

[ioginy]

Does it buzz unacceptably? With the tag board approach, the only shielding I can think of is an aluminum box around the power supply.

Don

I haven't tried it out yet. I'm taking it down to my tech so he can do a diagnostic on it to make sure everything is kosher before I plug it in. Being my first amp I have faith in my work, but am still wary of destroying it on the first power up.

The "ice skate" turrets. I like that.




Here is a photo of how it turned out. The bases of the rivets are epoxied in, and then I put another layer of board under them to secure them in case of the epoxy failing, as well as to stiffen the board up. Drilling out the center of these rivets is essential.

This was taken before I put the second layer on. I believe one of the rivets fell out the bottom promptly after taking this picture.



In hindsight, the rivet washers designed to actually hold the rivets together when mounting the skate blades would probably have been the best option for securing them. Oh well, Now I know for next time.

[nyazzip]

that's cool; i bet they would be very pricey if you had to buy them, they look beefy
i have a box of little copper nails i might sacrifice as turrets. i kinda am reluctant to as i have scoured the local joints and have not seen copper ANYTHING for sale, at least not hardware
as you probably saw, i used 3/32" brass tubing segments with success on 2 boards but the labor was pretty insane

[ioginy]

Check in at your local skate repair place. Those ones I have are actually used and discarded ones. The new ones are three times longer, but that length is really unnecessary. They hold onto them to take in for cash when they get enough. I bet they would give you a bunch if you ask real nice.

I like the copper tube setup, but yeah, lots of work involved with those.

[nyazzip]

Check in at your local skate repair place.

ahh that is amusing: i'm in the midwestern USA, people don't skate or do anything but drink and watch football 10 months of the year. no such thing as skate repair shops unfortunately, that i am aware of

[ioginy]

hahaha, that is funny. Well if you get desperate I could send you some. I have about 80 left over from what I snagged from our shop.

[ioginy]

Well, the amp is done. I want to thank you all for your help.

Here is a little video demo.

http://www.youtube.com/watch?v=ovEe2cAz59M