Cutler Duo-Control

[M Fowler]

Andy I am starting to be one of your biggest fans as I like the way you come up with a circuit and then go about building from bench scrap and end up with a nice amp.

Mark

[Andy Le Blanc]

Appreciate it, thank you. Ive been at for a long time, started with a box of
junk, a meter and a soldering iron. I've never built a kit. Once you've got
the right few tools in one spot, and fill in the technical gaps in practical know how,
there really isn't any good reason to not go for it.

There aren't any new circuits, but there is a lot to explore, and you have to build it
to get to know what things sound like.

That speaker is bizarre, can't wait to gig that one. There's always more stuff
in the bone pile, once people hear your into old tube stuff, the pile takes on a
life of its own.

[Structo]

That is real smart drilling the holes while the metal is flat.

I enjoy reading your exploits as well, I just don't comment that much because most of it is beyond my skill set.

On the Hammond box I used for my Dumbleator, I used a drill press but dang if even the new drill bits wanted to walk.
So even though I laid the pot and switch holes perfectly, now when I stand back, I can see they are not really in a straight line anymore......
Dang it!

I tried a scratch awl for center punching but that would dent the surface too much.
I chose a black powder coat so I wouldn't have to paint the box.

Probably clamping some wood that fit into the side I was drilling would have been best. To have that backing would most likely help me to keep things straight.

I never took much metal shop in school so it's all pretty new to me.
Especially since school was 40 years ago.....

[KT66]

Andy I am starting to be one of your biggest fans as I like the way you come up with a circuit and then go about building from bench scrap and end up with a nice amp.

+1. Keep 'em comin' brotha. I like the wire wheel thing you did to the chassis, I'm gonna try that. I'm sure I'm not alone in wanting to hear some of your experiments. We want clips ! We want clips !

Tom : I don't know if this would work for a powder coated chassis, but when I drill chassis holes I give the drill point a good whack with a center punch ( making sure there is a solid surface underneath ) and then drill the hole with a very small drill bit. Then I use a little bit bigger bit, and then a bigger one, etc. until the hole is large enough to drill it with the right sized bit for the hole that will keep the bit centered. I even use this method sometimes for drilling through a plastic/plexi panel attached to the chassis, but for that I drill a tiny hole in a piece of wood. and then clamp it lightly to the panel with the hole lined up to my drilling mark, and then drill through the wood.

[M Fowler]

I do like Ryan does first make my markup centerlines and then use a springloaded center punch following by a gentle tap with backing behind the surface I am punching.

When I design a faceplate I use 5/16 pilot holes in the faceplate to use it as a drilling guide then I slowing enlarge both the faceplate and chassis and having had to problems with that method.

Mark

[Andy Le Blanc]

I've had the same issues, Aluminum, you can get away with it, soft.
You still get a lot of drift, I've tried, The investment becomes the jig to hold
the bent chassis. Otherwise your just wasting time, frustration is wasted energy too.
Its a process that if things aren't performed in order, accuracy goes out the window.
So the hell with it, Thats where prefab chassis find the market, but by the
time you bought so many units you could have bought the tool in first place.
Once you have the tooling your not restricted to having to make do.

I found these bits, pilot point?, that do well. The flutes are a different angle.
Working in the flat with even a cheese drill press makes it a breeze.
Even by eyeball you get better than a 32nd tolerance, 64th's if you spend a little patient time.

I've found automotive engine paint, it withstands up to 500 degree's.
Comes in colors, like GM blue, Ford yellow, Dodge teil. Seems worth a try.
But after drilling, bending, even after paint a steel chassis is still less than
20$.....could drop it more buying wholesale, but not until sales volume
makes dealing with the state paper work worth the time.

[Cornelius]

Those drill bits are beautiful. I think they go under the name 'bullet point' here; 'Phirana' brand. With those bits, triangular holes are history, and they make very precise and clean holes.

I also use a springloaded center punch, and i always have wood underneath; both when punching and drilling.

For larger holes, i use a 'step drill bit'; a conical drillbit with 2mm steps from 6mm to 22mm. they also makes perfect holes, and eats its way, 2mm diam. at a time.

Edit:
A step drill bit are also excellent to deburr other holes...

[Sonny ReVerb]

On the Hammond box I used for my Dumbleator, I used a drill press but dang if even the new drill bits wanted to walk.
So even though I laid the pot and switch holes perfectly, now when I stand back, I can see they are not really in a straight line anymore......
Dang it!

That's why I like the Pilot Point bits. They don't wander like a regular bit. I use them whenever I'm not using a step bit.

Probably clamping some wood that fit into the side I was drilling would have been best. To have that backing would most likely help me to keep things straight.

I use a jig I made up to hold the chassis on it's side. I clamp the jig to the drill press table and then hold the chassis against the jig. Once I get the bit lined up with the center line of the face, I can slide the chassis back and forth and the bit stays centered. I use a step bit so I can drill holes of different diameters without changing bits or the setup. It works great for different size pots, switches, jacks, etc.

[img:800:727]http://img34.imageshack.us/img34/3992/chassisjig2.jpg[/img]

[img:800:645]http://img704.imageshack.us/img704/6066/chassisjig1.jpg[/img]

I enjoy reading your exploits as well, I just don't comment that much because most of it is beyond my skill set.

+1 You task my brain, Andy. I like it!

[Andy Le Blanc]

A logo changes everything. I like the "your name here" aspect.

Quick and easy with a scroll saw, a coping saw will work too.

Masonite, paperboard, old clipboards, thin plywood, it's more the fact that
there is a logo of some kind that creates the visual draw.
No need to invest more than a little time for the one off.

[Structo]

Thanks for the tips guys.

I have seen those spring loaded punches.
How do you center the punch before you release it.

[Andy Le Blanc]

One thing that I run into constantly is that with a very simple amp you have
to respect the fact that tubes work best when they see a very high impedance.
It is very easy to introduce an impedance miss-match when trying out different design elements.
I had to drop the hiwatt tone stack, so I went even simpler, The amp screams.
It has that old wards, dano, supro, silvetone tone, Perfect.

All the pots are 1M

All you do with those center punches is push, it's automatic, push bang.

I'm off to the jam, if the drummer is tasty It'll be fine in the mix.

[Andy Le Blanc]

It gig's pretty well. As much as a pair of 6v6's can give you.
The tone controls work, I wasn't all that optimistic, they are so simple.
I suffer fender-itis too, prejudiced expectations of the amps response.
The amp with it's paraphase inverter is never really clean, but it gives you color.
A modded bassman with KT66 was at the jam, the decades old RCA's in mine did well.

It was funny just how sterile fenders can be. Loud but no real tone color.

The distortion on my little amp was wonderful, The tone for a blue's solo.
That 10x15 speaker was neat, it was tight and never flab'ed out, that's one to clone.
I did want more watt's, it's easy to think that changing the bias method
would be the easiest way, but the color would be effected, 6v6 are so sweet
as they are cathode biased.