1964 Danelectro twin twelve model 300 f

[ngh]

hello wonderful world of knowledgeable people! I am new here and would love to get some help from you guys.

so here is the skinny!

just scored myself a beautiful dano twin twelve model 300 series f on craigslist for $450. and when i say beautiful i mean beautiful! this thing looks like it came right out of the box, not a scratch in the tolex not a spot of rust. all original (and functioning i might add) tubes, original jensons, unmolested (for better or for worse). the guy i got it from told me his brother found it in the basement of a house he moved into (along with a few accordions and accordion amps), he had found it with the original canvas cover (which i received with it, it has "property of the jaywalkers USA" spray painted on it.) and he was selling it because he needed the money. so long story short I get a kick ass dano for cheap! so if it is so wonderful why am I telling you guys about it? well, it has its issues. first off it has a charming buzzing sound all the time, nothing too horrible but i would like to make it stop. secondly the reverb (which yes i know was horrible anyway) does not work. in fact the reverb pot just cuts volume progressively until it goes silent when it is dimed (I suppose i could re label it "attenuator" and call it a day).

So anyway TL/DR:

I was wondering if any of you guys and gals could give me some advice on this old gal, this is my first vintage amp and want to take good care of it. and more importantly if you guys know of any techs near me who could give her a once over and fix any problems, maybe even mod the reverb section so it is better than stock (fyi I live in colombia county in NY state but spend alot of time down in NYC) that would be wonderful!

cheers,

Nico

[Enzo]

Filter capacitors have the job of smoothing hum out of DC voltages. Yours are now 50 years old. Chances are they are not so good at smoothing these days. Fresh filter caps are a likely first step.

Then isolate the problem. Does the hum remain will ALL controls set at zero? Do ANY of the controls have ANY effect on the hum?

[ngh]

Filter capacitors have the job of smoothing hum out of DC voltages. Yours are now 50 years old. Chances are they are not so good at smoothing these days. Fresh filter caps are a likely first step.

Then isolate the problem. Does the hum remain will ALL controls set at zero? Do ANY of the controls have ANY effect on the hum?

hey enzo thanks so much for the reply! i started to test the controls in order to answer your question then got carried away and got a noise complaint... oops... but anyway the hum is present with all the controls set at zero but is not all that bad until the volume comes up, more so on channel 1 then channel 2. the eq pots on both channels bring out their respective bans in the sound of the hum. I think you are probably right, i think this amp could use a recap and that may solve everything noise wise. from the sneak peak i took of the chassis earlier it seems like the fine craftsman at danelectro might have been pretty tired by the time they got to this old girl. lots of sloppy solder points. i can bet some of that might account for the noise. also a bit of compressed air in the pots would do her some good.

thanks again!

[Enzo]

SO one analysis might then be that the filters need changing, that might reduce the hum all at zero. If turning up the volume raises the hum level, then the preamp is also amplifying the hum. COUld be from the same lack of filtration but could also be from another source, such as a preamp tube or lack of solid ground somewhere. If the tone controls affect the tone of the hum, that means what they were aqffecting had hum in it already at their point in the circuit. So for example, if hum got into the first stage, it has to go through every following stage to get to the speaker, yes?

Keep in mind that hum is not generic, it can come from many places, and often more than one. And each hum source has its own cures. For instance, the hum from a poorly grounded input jack and hum from weak filters. Both can enter the amp, and the cures for one have no effect on the other. Can't just double up on the filter caps expecting to cure jack grounding.

Not an absolute, but in general, hum from power supply ripple (what the filter caps smooth away) will be at 120Hz, while hum from grounding issues will be at 60Hz. Assuming you are where the power mains are at 60Hz.

[ngh]

thanks so much enzo!

so i have a status update for whomever is listening.
so this amp has seemed to sweaten up a bit. since i have been playing it non stop for two days. a buddy of mine told me that that is probably due to some carbon build up in the tubes getting cleaned out with playing (i have no idea if that is total hogwash or not). one thing I noticed just a few moments ago was that one of the tubes seems to not be powering up, or mabey just not powering up as much as the others (not sure if this is new or if i did not notice before due to the dust that was all over the chassis which i recently gave a cursory wipe down). the tube is marked 5y3gt and is right next to the two power tubes (6L6's). any idea as to what this tube is doing and more importantly is it bad that I am running the amp while this thing is out. I know that somebody on here reverse engineered a schematic for these dano twin twelves a wile back. any chance someone who can read it could tell me what this does and if it is dangerous? the schematic is in this thread: http://music-electronics-forum.com/t14240/

[52 Bill]

a buddy of mine told me that that is probably due to some carbon build up in the tubes getting cleaned out with playing (i have no idea if that is total hogwash or not).

Maybe you need to take it out on the highway to clean out the carbon.

one of the tubes seems to not be powering up, or mabey just not powering up as much as the others (not sure if this is new or if i did not notice before due to the dust that was all over the chassis which i recently gave a cursory wipe down). the tube is marked 5y3gt and is right next to the two power tubes (6L6's).

The 5Y3 tube is the power supply rectifier. What are you trying to describe as not powering up as much? The orange glow near the center of the tube?

[ngh]

The 5Y3 tube is the power supply rectifier. What are you trying to describe as not powering up as much? The orange glow near the center of the tube?

i actually noticed it while it was on standby and it just seemed like it was not glowing at all. since then i have cleaned the tubes off a little bit more (they were covered with 40 years of crud) and realized that it is in fact glowing. there are two small filliments at the top of the tube that are glowing a much darker and duller orange than all the other tubes. is this normal for 5y3 type tubes?

[Enzo]

If the amp works at all, the 5Y3 is functioning. If it were not working, you would have no high voltage for the other tubes.