Newb wants to build his first amp

[manticus]

Hey All,

This is my first post but I've gleaned a fair amount of info from the forums. Thanks

Anyway, I've wanted to build my first tube amp for quite some time. I'm not a stranger to working on electronics, soldering, replacing components, troubleshooting etc... But I'm by no means over an intermediate level in any area.

I've been doing some repairs for a local and he gave me an '82 Carvin 60 watt 1x12 that was going to cost more to fix than it was worth. I tried to fix it myself, but there was lots of carbonization on the board, burned traces, etc... So I did some parts recovery of the stuff worth keeping and want to do a build.

I'm not too worried about outward cosmetics so I'll use the chassis an cab I have left from it. Here are some parts I recovered:

PT & OT
Bunch of 1/4" jacks
About 40 various value Sprague orange drops
10 pots, various values, 4 of them are push/pull
Tube socket
5 new tubes (6l6's and 12ax7's)

I'd like to build something relatively straightforward with 6l6's and 12AX7's that has a decent overdrive sound and is more touch sensitive than your typical SS or cheap tube amp. Love Fender cleans, hate (maybe too strong a word) Fender OD.

Does such an animal exist? Any help would be hugely appreciated!

Andy

[M Fowler]

Welcome Andy,

That Carvin 60 does that have volume, treble, mid, bass and presence holes?

What other features are you looking for in the circuit so we can recommend?

Mark

[manticus]

Thanks

The pic is of the amp I have. I'd like a master volume, but not necessary. Definitely B/M/T controls. No need for an effects loop. I have a nice Hammond 3-spring reverb tank but I can go without.

I guess Id like a good circuit to learn on, but capable of clean to mean with my guitar volume and my pick attack. (Yes, I'am aware there can be a large gap here. All about the happy medium...)

Obviously I not ready to build them yet, but love the sound of the TW Express, Sommatone OD35, Roccaforte 18. That idea.


Andy

[JazzGuitarGimp]

With all those fried innards, are you sure the transformers are good?

[manticus]

Yep, transformers are great. These amps had a bit of a bad design and the hi-wattage resistors were too small and didn't dissipate enough head, so they wold eventually char the board if they were pushed too hard.

Before I took everything apart, I rebuilt that section of the board on a small Radio Shack board, cut the old traces and wired it in. Worked great, but after about half an hour, my new board started to discolor from the heat of the resistors.

Couldn't stand the thought of it catching fire in the middle of a show or practice, so I dismantled it.

Andy

[manticus]

Here are a couple pics.

[M Fowler]

It already looks like a Mesa Boogie so why not make it one either turret board or by the PCB from ebay.

[manticus]

LOL, I never even thought of a Boogie... I love some of their older amps. Thanks Ever done a Boogie build?

[manticus]

Also, does anyone have a process they like for coming up with a good board layout based only on a schematic?

Andy

[Super_Reverb]

Here's one way:

1) Figure out how large the turret board can be / needs to be
2) Cut turret board to size
3) drill mounting holes in board and chassis
3.5) Use a tested ground scheme - I use a modified Hoffman ground scheme with Tube Wizard's ground guidelines and a central bolt to bring preamp, power amp, filter cap gnds, and power tube cathodes, etc. to a central point.
4) use graph paper or print your own in Excel - complete floorplanning (plan for placement of components)
5) Can also create objects in excel (use group objects to group component bodies and pins together)
6) Finalize layout
7) Cut paper and tape to turret board
Drill turret holes
9) stake turrets (don't confuse front and back of board

You need to do your homework, and study classic layouts to make your first build successful.

Your layout should flow from 1st gain stage to power amp left to right or vice versa. If you deviate from this, you can have parasitic oscillation (unintended feedback).

Take your time and don't rush into it until you are comfortable.

Sometimes, simplest circuits are the best.

rob

[statorvane]

You need to do your homework, and study classic layouts to make your first build successful.

Yep. That's how I learned.

I'd try looking at your basic 5F6-A circuit (2 x 6L6/5881). May not be exactly what you want to build, but if you like tweed OD, I think that'd be hard to beat. Classic amp anyway, and you could always morph it into a JTM45/50 at some point.

There are a number of schematics and layouts on the web so you can see the translation from schematic to layout. I think pretty much all the tweed and BF amp schematics/layouts are out there for you to peruse. And there are TW Express/Liverpool schematics/layout available here too.

[manticus]

I'm working on a '51 Valco Supro for someone and it's soo much fun. I'm ordering 2 sets of tubes for it. One for replacement the other for my build. This is a pretty simple amp, but sounds so good. Anyone ever build one?

Andy