Normster D style amp

[mdroberts1243]

I wonder if electrical wire for the house could be used as buss wire or is it to thick and oversized. I think 16 AWG is the size i have lying around in the garage.

Nice build Mark!

I used brass rod in the past (sometimes hardware stores have it in the welding area), but lately I've been using house copper wire 14 AWG. I stretch it slightly using a vise and pliers which straightens it and hardens it a bit and then I polish it and dunk it in tinning solution to give it a bit more corrosion resistance.

[M Fowler]

ampbldr2, thanks I like this little amp. I have used romex 12ga or 14ga household wire and buss wire. My main problem is looks, getting it straight without all the little imperfections you see on my build.

Mark (mdroberts1243) probably answered what I may need to try stretch it more then I have been. I also tried rolling between two objects as I stretched it.

I am going shopping this weekend for brass rods.

Mark

[brewdude]

[IMG:160:120]http://i40.photobucket.com/albums/e243/stumper1/BFS/th_BFS016.jpg[/img]

Is that a square wire that you twisted with the drill and used as the ground bus?

[Deric]

Is that a square wire that you twisted with the drill and used as the ground bus?

Nope. Just two wires twisted together.

[angelodp]

Can you explain...'dunk it it in tinning solution' ? How does that work?

A

[mdroberts1243]

Can you explain...'dunk it it in tinning solution' ? How does that work?

A

I have a product from MG Chemicals called "Liquid Tin" I think it is generically known as Electroless Tin. You immerse cleaned PCBs or copper wire into it for about 5 minutes and then rinse and dry them off... they come out tin-plated, and take soldering very well. You can get it at most electronics supply stores.

[angelodp]

Thanks

[Tone Lover]

Taylor I got my feet wet in the Dumble circuit with a D'lite 44 kit several years ago.

I learned a lot on that amp and I have it sounding pretty good with two Winged C 6L6GC's.

This tweaked circuit incorporates just about all the recommended tweaks that we discuss here.

Tom do you have a high resolution picture of this layout you could email me. I want to build it but I do better with a big poster size print out getting old cant see (LOL). Thanks Bill

[Tone Lover]

I thought it would bring it with the quote but I was wrong its the one labeled Tweaked layout with PI trimmer. jpg.
Thanks Bill

[Structo]

Sure, PM me your email address.

[M Fowler]

Tom

The amp is way too trebly any suggestions?

I better go back and look at the OD switch wiring because at the time I built this amp. If I ground the OD switch like the 16x8 layout shows. It goes dead when switched to Overdrive mode. So I removed the ground wire and it worked. So I left it as such. That is shown in the original pictures.

But now that I have been messing around with the amp, changed the presence wiring, caps as suggested, ran different tube types, I think I may have an issue that needs to be resolved before I go further.

Mark

[Structo]

Shouldn't be trebly if you used 10uF bypass caps on V1.

Did you install the OD entrance mod with the cap and resistor?

That slims the coupling way down, I didn't care for that.

The way the clean/ OD works is that it grounds the grid of V2 when in clean mode to silence that tube.

If you wire the OD switch just like that layout shows it should work.

Or have you installed relays?

[M Fowler]

Tom,

No OD entrance mod and I did not do the local feedback loop either waiting on 22m resistors and will use a switch like suggested.

Yes 10uf caps on V1.

No relays added.

I wonder if I increase the main filter caps from current 47uf to 80uf each if that would make a difference?

Mark

[Structo]

Usually the only thing that the large filter caps affect is the tightness of the bass.

You should have a total of at least 50uF (2 x 100uF in series).

I like having a bit more at around 80-100uF total there myself.


Is it trebly in both clean and OD?

See if you can pin down where it's happening better.
Do all the tone controls work properly?

EDIT:
It's hard to see the color codes on your cathode resistors but make sure you have the 3K3 cathode with the 220K plate.
That is the first triode should have the 220K/ 3K3 and the second 150K/ 2K2.

That will make it sound like crap if you get those backwards.

[BobW]

I've used the bare 12 AWG ground wire typicaly used for residential wiring as the Ground Bus on all my builds. Knock the glaze off with a scotchbrite pad before soldering, and you won't have any problems.