Amp Buzzing

[Sugartune]

I’ve got a little 6 watt single 6V6 Valvetrain combo that recently has started to buzz loudly as soon as it warms up enough for a signal to pass. 

Does this if a cable is plugged in or not, doesn’t matter the cable.

Tried different outlets/circuits. Tried other people’s houses, etc. No dice. I have another amp plugged into the same outlet/circuit. No issues with that amp.

Tried replacing all tubes. No dice. 

Tried swapping speakers and also running the external tap. Still not a die in the house. 

Output transformer hurting? Other suggestions?

much appreciated:)

[Dave Scepter]

Ground/ground loop?

[fasteddie]

7 hours ago, Sugartune said:

I’ve got a little 6 watt single 6V6 Valvetrain combo that recently has started to buzz loudly as soon as it warms up enough for a signal to pass. 

Does this if a cable is plugged in or not, doesn’t matter the cable.

Tried different outlets/circuits. Tried other people’s houses, etc. No dice. I have another amp plugged into the same outlet/circuit. No issues with that amp.

Tried replacing all tubes. No dice. 

Tried swapping speakers and also running the external tap. Still not a die in the house. 

Output transformer hurting? Other suggestions?

much appreciated:)

Sometimes with valve amps when you hear a buzzing, pick up the amp and slam it onto the floor as heavily as you dare to do, this shocks and jolts the unit. This is not a joke. You won't do any harm to it.

[Dutchman]

Get a can of deoxit. Clean all the input and output jacks, tubes and sockets, switches... anything that moves or is movable. Not familiar with Valvetrain if they’re PCB or PTP. But if it continues after cleaning wiggle the tubes a little to see if it gets worse or not. I’ve seen issues like your having from the tube socket breaking away from the PCB. Just a hairline crack in the circuit makes noise.

[Sugartune]

4 hours ago, fasteddie said:

Sometimes with valve amps when you hear a buzzing, pick up the amp and slam it onto the floor as heavily as you dare to do, this shocks and jolts the unit. This is not a joke. You won't do any harm to it.

Interesting theory. Even if that worked, I’d rather solve the actual issue. I don’t think the issue is that it needs a good floor slamming, but you never know. 

[Sugartune]

1 hour ago, Dutchman said:

Get a can of deoxit. Clean all the input and output jacks, tubes and sockets, switches... anything that moves or is movable. Not familiar with Valvetrain if they’re PCB or PTP. But if it continues after cleaning wiggle the tubes a little to see if it gets worse or not. I’ve seen issues like your having from the tube socket breaking away from the PCB. Just a hairline crack in the circuit makes noise.

I’ll give the deoxit a go. The issue doesn’t seem to be affected by anything - plugging in or out, turning knobs, etc. But it wouldn’t hurt and probably could use a cleaning. 

PTP. I’ll take a look at the tube socket too. 

Mucho gracias

[Sugartune]

9 hours ago, gtrdaddy said:

Could be filter cap leakage.

This is something I’d see if I opened it up?

[Dutchman]

You can see bad filter caps, look for bubbles on the ends. The other caps need to be tested. 

[Sugartune]

15 hours ago, Dutchman said:

You can see bad filter caps, look for bubbles on the ends. The other caps need to be tested. 

Thanks! I’ll take a peak when I get a chance over the weekend. 

[HamerDave]

This can be caused by cold solder joints too. If you're going to open it up, carefully probe each of the component connections with a non conductive item. I use a cheap Chinese takeout chopstick so anything like that. Don't use a pencil though, graphite is conductive. Start closer to the input end of the circuit as any small amount of noise at the input gets amplified as it passes down the signal path. As you tickle each joint listen for the buzz to stop, get worse or for crackling. Be very careful. Tube amps have voltages present that can kill you. Keep your chubby little meat sticks (fingers) outside of the box. Usually when I'm presented with this problem it ends up being a bad ground at the input, or a screen resistor on one of the preamp tubes bleeding. Power section problems, like transformers, tend to be loud, brief, and a bit smokey. Fuses prevent the worst of the Damage. If you're not blowing fuses or looking for a fire extinguisher you're probably not looking at a high voltage issue. I'm not familiar with Valve train or their amps but, so long as they don't use any digital modeling components this might get you started in the right direction. Most of my work is on traditional tube amps up to current models like the Blues Jrs and Deluxes. Good luck and let's know what you find. 

[Sugartune]

Thank you! 

Nothin digital in this guy. Pretty simple, straightforward Champ variant. 

I’ll finally get to it today. Will let you know.

For the record, I have long slender, girly fingers

[Hbom]

/\ /\ /\ /\

If you keep one hand in your pocket while your other had is poking around in that amp your long slender fingers shouldn't get burned on the ends.

[HamerDave]

2 hours ago, Hbom said:

/\ /\ /\ /\

If you keep one hand in your pocket while your other had is poking around in that amp your long slender fingers shouldn't get burned on the ends.

Good advice that.  

[Sugartune]

2 hours ago, Hbom said:

/\ /\ /\ /\

If you keep one hand in your pocket while your other had is poking around in that amp your long slender fingers shouldn't get burned on the ends.

Oh, so I’m Alanis Morrisette now?  

[Sugartune]

Just opened it. Haven’t done anything else yet but, I immediately noticed what you see in the first pic. Is that a sign?

[HamerDave]

Yeah. That capacitor is leaking or corroding. Even if that wasn't the source of the noise I'd probably swap it out. The soldering looks a bit rough but not terrible. That's a nicely put together Champ clone. I'm going to have to check those out. 

[Sugartune]

16 hours ago, HamerDave said:

Yeah. That capacitor is leaking or corroding. Even if that wasn't the source of the noise I'd probably swap it out. The soldering looks a bit rough but not terrible. That's a nicely put together Champ clone. I'm going to have to check those out. 

Gonna take it to an amp doctor  

It’s a great amp. I’ve had it for a couple of years. Sat new in a local shop for 10+ years. Just didn’t move because it was unknown, especially in Canada and the shop mostly appealed to vintage nerds

. They’re from Florida and build them there. I traded my large and stupid heavy Peavey Classic 50 for it and don’t regret it for a minute. 

They disappeared for a few years, or at least scaled back their profile. Started reappearing on the radar a year or two ago. 

This is a 1x10, the newer versions are 1x12 and much larger cabinet. But they make a number of other cool amps, American made, using as many American made and sourced parts as possible, if you’re into that sort of thing   

[texwest]

On 10/20/2018 at 1:29 PM, Sugartune said:

Just opened it. Haven’t done anything else yet but, I immediately noticed what you see in the first pic. Is that a sign?

That capacitor could definitely be the problem.  I recently had a new hum on my old princeton reverb.  Opened it up and there was a filter capacitor  that looked very similar to this.  Replaced it and it was super quiet again.

[Sugartune]

16 hours ago, texwest said:

That capacitor could definitely be the problem.  I recently had a new hum on my old princeton reverb.  Opened it up and there was a filter capacitor  that looked very similar to this.  Replaced it and it was super quiet again.

It has been diagnosed as such and should be repaired soon, I hope. Not many amp techs in town or surrounding area. They take a while to sort through the back log

[DaveH]

Those electrolytic caps have a shelf life of 10-12 years, after which they will have drifted and are no longer of the advertised value. They can be 'reformed' in a controlled manner, but just turning the amp on and using it can reform them too, but in an uncontrolled manner. Looks like the one cap didn't take to the reforming too well... I'd replace all three with new if'n it were mine. Not necessary, but I'm a little over the top with a lot of things.

Next time do it yourself and save some money. Just be sure to discharge the caps to ground first.

[HamerDave]

^ what he said. The all have about the same number of hours use on them. They’re not expensive at all and easily replaced. I’d also recommend replacing all of them as DaveH suggests unless you’re the sort that replaces the tires on your car one at a time as the go flat.

[Sugartune]

Update: All caps replaced and we are back where we should be. Sweet ass little amp, no noise

Thanks to all for your input and assistance.