Help me troubleshoot.

[B Bent]

It has been a long, long time since I have had to troubleshoot an amp and could use some help. I have been rocking my new 1482 for a while now with no issues whatsoever. I dropped a new Greenback in it the other day and it sounds even sweeter. I took it to church today to play and right before rehearsal when I was about to fire it up and show it off a little I made the comment: "you are about to hear the best sounding $200 amp ever made."

That's when I played the first note and the sound you hear in the video came out. It started out only making the fizzy, sputtery noise on low notes, but now seems to do it no matter what. I can't tell if it is the speaker or something else. Any ideas?

 

[Gearjoneser]

Re: Help me troubleshoot.

No, that's just the sound of them. :chairfall

Since it's an intermittent crackle and still has signal, I'd check all the tube sockets for looseness or arcing. Sometimes, they're not holding onto the tube pins tight enough and need to be retensioned or replaced.
Or a wire is barely dangling from it's connection, creating little sparks.

It's either that, or it needs to be recapped, which is very likely.

 

[everdrone]

Re: Help me troubleshoot.

since you dont troubleshoot amps really, if I were you I would either just sell it as is, or take it to a good repair amp dude. thats the reason I dont like old amps, cause if I got one I would prolly end up buying a dud that works intermittently.

 

[glassman]

Re: Help me troubleshoot.

That sounds like a carbon composition resistor in the act of failing. Since a low level signal is still clean, it would have to be in an area of the circuit that carries an increasing current as the signal increases; this would limit it to either a plate resistor, cathode resistor or a dropping resistor in the power supply. You might be able to provoke it with the chopstick method.

You might want to question the speaker too if you have a spare one to A/B. A speaker issue is less likely since the crackling appears to be present with no signal but it would probably be wise to rule it out if you can. A bad speaker is usually crackly at really low signals and clear up as the volume increases.

 

[Jeff Seal]

Re: Help me troubleshoot.

Ya know, you could just send it to me and I will be more than happy to fix it for free...(I only do one per year..) I love the old Silvertones... PM me if you're interested

Jeff Seal
HoustonAmpRepair

 

[everdrone]

Re: Help me troubleshoot.

this forum is awesome lol

 

[B Bent]

Re: Help me troubleshoot.

I spent a few minutes with the amp this AM. Luckily it is not the speaker. I realized that before I swapped speakers and even a while after swapping I had the channels jumped and was playing in the second "Instrument" input.

I played it yesterday for the first time in the Instrument input without the channels being jumped and THIS is where the gremlin lies. For kicks I played it in the solitary "Mic" input today and it sounds GREAT. In the 1st Instrument input, it sounds like crap.


Is this like old Fender amps where each input side is connected back to a 12AX7 on the input side? I wonder if a tube is bad in V1 or something?

 

[Bludave]

Re: Help me troubleshoot.

B Bent..... did you NOT see the post by Jeff? send him a message & your amp? This place IS awesome!

 

[misterwhizzy]

Re: Help me troubleshoot.

How am I the only person to throw a like Jeff's way?

 

[LesStrat]

Re: Help me troubleshoot.

Jeff is a magician.

Greg has some electronics skills, though. Maybe some more guidance would be easier and faster.

I'd offer some, but I DON'T have e-skills.

 

[B Bent]

Re: Help me troubleshoot.

Ya know, you could just send it to me and I will be more than happy to fix it for free...(I only do one per year..) I love the old Silvertones... PM me if you're interested

Jeff Seal
HoustonAmpRepair

Holy Crap! I barely skimmed over this and somehow missed this. YOu have a PM incoming.

B Bent..... did you NOT see the post by Jeff? send him a message & your amp? This place IS awesome!

I had to go back and reread it. Way cool!!!!

Jeff is a magician.

Greg has some electronics skills, though. Maybe some more guidance would be easier and faster.

I'd offer some, but I DON'T have e-skills.

I don't have the skills Jeff has!!!!! Wow! Very grateful.

 

[Lewguitar]

Re: Help me troubleshoot.

since you dont troubleshoot amps really, if I were you I would either just sell it as is, or take it to a good repair amp dude. thats the reason I dont like old amps, cause if I got one I would prolly end up buying a dud that works intermittently.

I agree. Sell it.........to me!

I spent a few minutes with the amp this AM. Luckily it is not the speaker. I realized that before I swapped speakers and even a while after swapping I had the channels jumped and was playing in the second "Instrument" input.

I played it yesterday for the first time in the Instrument input without the channels being jumped and THIS is where the gremlin lies. For kicks I played it in the solitary "Mic" input today and it sounds GREAT. In the 1st Instrument input, it sounds like crap.


Is this like old Fender amps where each input side is connected back to a 12AX7 on the input side? I wonder if a tube is bad in V1 or something?

Most probably just a bad tube. Usually is.

Is the solder connection to the speaker solid?

BTW, the Microphone input on my old Gibson GA20 is the hottest input of the amp. It's the input I use.