Noob to Tube Amp Heads, I got some weird noise, need advice

[shnizzle]

Sound samples here. I boosted the volume like crazy to make it audible. It´s nowhere near as loud as it seems here:
https://soundcloud.com/jonathan-19-2/amp-noise

I got me the Peavey 6505 Mini Head. After about half an hour of it running it starts to hum. I guess that´s just the 50Hz from the European electrical grid. But why does it slowly come in after such a long time? Does it have something to do with the tubes heating up to their maximum operating temperature? In the second half of the sample you hear the power amp going a bit nuts. What could be the cause?

I already tried a few things. Different power outlet, unplug any pedals and guitar, connect it via the Torpede Captor to a cab as well as directly to a cab, impedances are all matched to 16 Ohm. The amp was connected to a load at all times as I tested things out and the power tube indicator lights are still green, so there doesn´t seem to be any damage.

Thanks in advance for any replies.

 

[Emperoff]

Bad input preamp tube would be my first guess. Bad capacitor my 2nd.

Input tube is usually closest to the input jack. If you have spare tubes, change it. If not, try swapping them one by one for the last one. Last tube is usually the phase inverter, which can easily ignore microphonics in tubes. I've got a NOS Sylvania that makes that exact noise on V1, but works perfectly in any other position.

If any of your gear has a ground lift option, try it as well. Just to rule out a possible ground loop.

EDIT: Didn't listen to the 2nd part before. Consider checking power tubes as well.

 

[efiltsohg]

doesn't sound like a tube problem but if you have spares around it doesn't hurt to swap in some known good ones

2nd part almost sounds like a loose input jack or missing ground or something like that

if the amp is new I'd probably exchange it on warranty for the least headache

 

[shnizzle]

thanks for the input. i decided to go the warranty route. i´ll send it in and get a replacement. hopefully it´s just a faulty unit and not something with the power in my home. otherwise i might also need a propper power conditioner or something.

 

[Emperoff]

thanks for the input. i decided to go the warranty route. i´ll send it in and get a replacement. hopefully it´s just a faulty unit and not something with the power in my home. otherwise i might also need a propper power conditioner or something.

Sorry your first tube amp experience went wrong, dude. Hopefully it works out

 

[Fenriswolf]

Do you have florescent lights in your house? Back when I lived with my dad, the room I would play in had florescent lights, and they just made my Vox hum, but my 6505 went crazy. And, in my experience, Peaveys just seem prone to making weird noises. Back when cell phones started to be a thing, one my dad had picked up a couple of Mexican phone calls.

The hum just sounds like you have the pre gain turned up pretty high, mine did the same thing.

 

[efiltsohg]

Back when cell phones started to be a thing, one my dad had picked up a couple of Mexican phone calls.

my old Mesa Boogie used to make weird noises when I got a text message (before the phone registered it)

 

[Bandersnatch]

my old Mesa Boogie used to make weird noises when I got a text message (before the phone registered it)

That was due to the GSM antennae in the phone. Happened with all GSM phones back in the day whenever they received a signal from the cell towers and were near an electronic that produced any kind of sound. I forget what the actual reason was, but it was something to do with the magnetic pulses in the antennae. If you actually took a metal that would be attracted to magnets and put it against the phone, the metal would magnetize to the phone. The antennas in the older GSM phones were more magnetic than they are today.

 

[shnizzle]

so i got a replacement amp, same modell. and there is definitely something really wrong in general. bare with me here. i set the amp to 16ohm, it´s connected to the Two notes Torpedo Captor 16ohm, a cab is not connected, the line output of the torpedo goes to my interface, i use impulses. no problems so far, everything works just fine also over a long time of things running. today i did hook a cab to the attenuated output of the torpedo, the cab is switched to 16ohm as well, so everything is matched. after half an hour i get that extra hum again. i disconnect the cab, but the hum persists. i turn off the amp, let it cool off for some time, turn it back on and after about half an hour to an hour that extra hum comes back in again. what the heck is going on here? is the cab faulty? is the torpedo faulty? is that Peavey Mini Head just crap in general? i don´t get it. i´m so close to just calling it quites and revert fully to digital.

 

[Emperoff]

If you really got a replacement (can you compare serials to be sure?), you need to isolate the problem. Take something out of the chain and test again. If going direct works fine, try just using amp and cab. If it works fine the culprit might be the Torpedo cab outputs. If it doesn't it might be the cab, etc.

With that being said, why not just run a preamp direct with a poweramp sim? Much less of a hassle, IMHO.

If you're into 5150 sound you can get a Victory Kraken V4, Kartakou Colossus or even a Peavey Rockmaster.

 

[Deadpool_25]

It sounds like you tried it with just the Torpedo and it works fine.

Have you tried it with just amp and cab, with the Torpedo completely out of the chain?

If this problem exists only with both the amp connected to the Torpedo then it sounds like an issue with the Torpedo. Have you tried usind the ground lift button?

 

[shnizzle]

If going direct works fine, try just using amp and cab. If it works fine the culprit might be the Torpedo cab outputs. If it doesn't it might be the cab, etc.

Have you tried it with just amp and cab, with the Torpedo completely out of the chain?

the problem is still there with just the amp and cab. so i´m sure the output section of the amp somehow broke when everything was connected together. could be the amp model is just crap in general, or the torpedo is actually the culprit and messed up the amp. problem is if i get a new load box with the amp already being messed up, it wouldn´t fix it, i guess.

With that being said, why not just run a preamp direct with a poweramp sim? Much less of a hassle, IMHO.

i´ve been working with sims for about 15 years now. kind of getting tired of it. but if analog is this frustrating all the time, it might not be worth it.

 

[Emperoff]

the problem is still there with just the amp and cab. so i´m sure the output section of the amp somehow broke when everything was connected together. could be the amp model is just crap in general, or the torpedo is actually the culprit and messed up the amp. problem is if i get a new load box with the amp already being messed up, it wouldn´t fix it, i guess.



i´ve been working with sims for about 15 years now. kind of getting tired of it. but if analog is this frustrating all the time, it might not be worth it.

You still end up into a static IR impulse anyway. If you're using the Torpedo captor for the IRs they have built in poweramp simulation that you can tweak.

I was like you, got tired of the ampsims thing and started using tube preamps direct. I run them into Mercuriall Reaxis, where I have the poweramp simulation, Ownhammer IRs and FX. The torpedo suite can do the same (besides the FX).

Getting a head, an attenuator and a cab just to use IRs is pretty overkill and a strange trend I've seen grow a lot lately.