Peavey Ultra Plus tubes... Which is which?

[warlok]

Spivonious - I did some more investigating and it's starting to buzz earlier everytime now. Once it gets going, it's directly related to how much gain I have on. It's barely noticeable on the clean channel, pretty noticeable on the crunch (gain on 6, boost switch off), and very noticeable on the ultra (gain on 7, boost switch on). But the weird thing is it is also variable intensity according to where I'm standing or facing. It's definitely a problem with the amp as it does it with every guitar, passives and actives, all exactly the same. I have no other electronic devices anywhere near me so I don't get the interference problem but that's secondary right now. I'm leaning towards a preamp tube as opposed to a power tube now. Sound more likely?

[Spivonious]

Yeah sounds like a bad preamp tube...probably one of the first ones in the circuit since it's on all channels. Try swapping them around and see if you can get the clean channel without buzz.

[Twitch]

Spivonious - I did some more investigating and it's starting to buzz earlier everytime now. Once it gets going, it's directly related to how much gain I have on. It's barely noticeable on the clean channel, pretty noticeable on the crunch (gain on 6, boost switch off), and very noticeable on the ultra (gain on 7, boost switch on). But the weird thing is it is also variable intensity according to where I'm standing or facing. It's definitely a problem with the amp as it does it with every guitar, passives and actives, all exactly the same. I have no other electronic devices anywhere near me so I don't get the interference problem but that's secondary right now. I'm leaning towards a preamp tube as opposed to a power tube now. Sound more likely?

Could be filter caps too....

[warlok]

I'll have the new tubes in a day or 2 so I'll wait and try them. hopefully thats all it is. I was also told a secondary possibility could be the electrolytic caps. Is that the same as the filter caps?

[Trem]

Spivonious - I did some more investigating and it's starting to buzz earlier everytime now. Once it gets going, it's directly related to how much gain I have on. It's barely noticeable on the clean channel, pretty noticeable on the crunch (gain on 6, boost switch off), and very noticeable on the ultra (gain on 7, boost switch on). But the weird thing is it is also variable intensity according to where I'm standing or facing. It's definitely a problem with the amp as it does it with every guitar, passives and actives, all exactly the same. I have no other electronic devices anywhere near me so I don't get the interference problem but that's secondary right now. I'm leaning towards a preamp tube as opposed to a power tube now. Sound more likely?

Yeah mine did that, it turned out to be my furman being too close to the head i guess. All i know is when i got to close to it with my guitar it would buzz and hiss, even with a decimator.
At the time we were practicing in a house, and i had to be 4-5 feet from it no choice.
Before i figured it out i thought it was the house electrical or bad ground or something. I just about spent a bunch of money on a voltage regulator.

I asked around and no one else said that happens to them.
But just for testing, i tried it with my mp1 at home and a totally different furman and it does the same thing (to a lesser extent), but it's not a 120 watt head.
So i am skeptical - two different furmans, a 120 watt head and a preamp all exhibit the same thing.

I tried fully shielding one of my guitars and that killed that totally, Decimator or no and less feedback.

We practice in a giant warehouse now so i'm not standing next to my amp anymore but even when i do i haven't noticed it, i kinda forgot about it, (not playing shielded guitar either)

Curious i'll have to specifically try to make it happen again to see if it still does that.

I'll check this weekend.

[warlok]

It's kinda weird, Now I see that if I stand right in front of the amp, it quiets down. It literally happens in the exact same spots, facing the same directions, with any guitar I play. Guitars are fully shielded, I unplugged everything except the head, plugged head directly into wall (instead of the surge protector it's normally in), still exactly the same. And when it's buzzing the worst (ultra channel), my smart gate has to be on the high trigger and almost all the way up to even have an affect on it. Very strange. I moved the stack to the other side of the room when I got this head. The only thing I haven't tried is moving it back. I'll try that tomorrow. If not I'll swap around preamp tubes and see what happens. Can a tube (bad or good tube) cause interference?

[warlok]

HOLY FUCKING SHIT... That woke it up!! What a difference a new set of tubes makes. The buzz is nowhere near as noticeable as it was. This is how it should be. And the sound changed drastically for the better. Clean tones are not much different except a bit sparklier and doesn't distort anywhere near where it did. Before, it was dirty no matter what, even volume on 1. Now i had it up to about 6 (fucking loud!!) and still pretty clean and sounding good. The gain on both the crunch and the ultra are MUCH better. The crunch is everything from SRV, KWS, Jimi, Zeppelin, AC/DC and all things between. Then the ultra is the "double live brutal" (lol) ultra gain I hoped it could be. The gain on the ultra with the boost switch in is smoother, tighter, and more modern sounding which is exactly what I wanted. This now IS the versatile amp I've wanted. I have permagrin and finally found what I'm looking for....

Until the next GAS of course... lol

[Trem]

grats man,glad you got it sorted.
it is fucking brutal especially cranked up.

i have my eq about: bass-1 mids-12 11 or 1 depending, and edge 4 o'clock.
gain on 6 which is plenty, master 5-6.
i use a parametric eq to fine tune, and cut and boost the desired bass frequencies in straight to the power section, and add a little hump in certain midrange frequencies.
tight yet creamy and punch city

crunch sounds really good, but once on ultra i don't want to use anything else i just roll back my volume knob for those tones.
tone ranging from rock to full on brutal.


hey on your power tubes what were the average bias rating, mine came what i thought was really low between 13-16 but they sound great pushed, warm breakup.

and did you tell them what kind of amp it was when you ordered them?

i just bought another Ultra yesterday mine has a few points missing on the logo piece and i wanted a pristine looking one :think:

so for tubes i was thinking i might ask for some ranging closer to the 20's.

just curious of their "expert" opinion if you told them what amp it was for what they sent you.

[Spivonious]

The buzz is still there? Is it possible it's just 60 cycle hum? Are there any flourescent lights or CRT computer monitors nearby? Does it buzz without the guitar plugged in?

[warlok]

The buzz is still there but way less than it was before. I'm pretty sure it is interference but I just don't know from what. Could be 60 cycle hum but don't know what from. No monitors, flourescent lights, or anything around me where I'm playing in the house. Upstairs, in the corner of the house, not near anything. It completely stops if I unplug or turn the volume down on the guitar. Does it with every guitar and they're all shielded so don't know what the scoop is. Could it be my phone in my pocket? I don't know what else to think now.

[Spivonious]

If it stops when you turn the volume down on the guitar, then it's something in the room that the pickups are transmitting. Very odd.