sldbone - Posted - 02/04/2024:  13:38:58

can anyone help me to price this reso-amp correctly? it is a 1936 National Dobro 15w with the original Chicago Radio Company speaker. has been Modified tof 3-prong and the tubes sound bad.

amp in the sun

sldbone - Posted - 02/04/2024:  13:45:45

I think i am prohibited from sharing a link: youtu.be/7FhcmVhKNA0

sldbone - Posted - 02/04/2024:  13:53:00

Nope, ok well that is a video of me trying it out. you can hear the poor little dobro try to squeeze out some sub 400hz tone, but it just farts out. I think that is bad tubes, but to be honest as a child of musical privilege, I have never played on a bad tube in my life, and I don't even know what one would actually sound like. I read also that these amps were made when the average household in the USA was wired for 110-115 volts and to get the correct sound, you need a variac. I'm not too sure about any of this Reso-related stuff and I will appreciate any advice.

lap dog - Posted - 02/05/2024:  04:28:08

You should have a qualified tube amp shop look at this. I could not tell from the video, but if it has the power cord incorrectly wired with unpolarized plug (or the ground conductor not terminated properly), this could be a shock hazard. Early amps had what was called a death capacitor on the input power that actually grounded one side of the 120 VAC power to the chassis. If the cap goes bad (they all do) and you plug in an unpolarized plug in an outlet the wrong way, you'll have 120 VAC hot on the chassis and, by the shield connection of the guitar cable, the metal parts of the guitar and strings will now be HOT. Touch those parts with one hand and then something correctly grounded like a mic stand with your other hand and you will complete the circuit through your body. Back when I was a stupid kid, I had such an experience and it was spectacular to say the least. And like the dope I was, I was outdoors with wet shoes!



The sound you're getting does sound like a bad preamp tube. All capacitors, especially the electrolytics in the amp need to be replaced as they have drifted way off their value. An amp shop can get rid of the death cap if present.

Edited by - lap dog on 02/05/2024 04:38:39