Negative Feedback Circut??

[Tubebender]

I originally started a thread about opinions about the Peavey Classic 50 410 before purchasing one. So all the responses sounded great, so I bought it, and could NOT be more impressed with it.

My question is referring to one response I recieved from NFB that
stated :
"My goto 50 watt head ..........has never let me down.........

Great amp.......disconnect the negative feedback circuit and the amp comes alive.....!:dude"

Yet, he didn't post any explanation, and made me PM and call him to get the scoop, but doesn't leave me with any confidence in opening an already great amp.....

Before I trust one person even considering this, does anyone know about disconneting this? On the Peavey classic 50 410, he clamis it's a "white wire off the speaker jack that you remove from the PCB"

Anyone????:dunno

[FrankieSixxxgun]

Sounds about right. Most NFB connections are to the speaker jack. If you remove the NFB you will get a lot more power section grunt in your signal, but it might be too noisy. Sometimes just lowering the amount of NFB is enough.

[SatelliteAmps]

Most amps have the NFB connected to a tap on the output transformer NOT the jack itself. Some amps have the taps directly wired to individual jacks, but the NFB would be connected to only one tap on the transformer.

The Peavey Classic 50 has it attached to the 8Ω tap of the output transformer, which is directly wired to the 8Ω jack. It should not be attached to the 16Ω jack at all.

If you want to try it and see how it works, it is very easy to remove the wire to test this out. It's more personal opinion than anything else. Some people like it, some don't. I don't think it makes the amp better, just different.

[mark norwine]

so I bought it, and could NOT be more impressed with it.


Devil's advocate: So why mess with it? Why not just play your guitar through it & make music?

Seriously!

[Tubebender]

Devil's advocate: So why mess with it? Why not just play your guitar through it & make music?

Seriously!

Yahhh, I dont' plan on unplugging anything! (at least for now) I like the amp, but still curious about tech info. Others had inquired too, and the answers were vague or nill.
Maybe If there's enoungh info on the topic, down the road if the amp is open, may test it....

as long as it's safe for the amp, and the person holding the guitar.

[donnyjaguar]

It will make the amplifier louder for the given volume settings. It will however reduce maximum output power if you consider the harmonic distortion of the signal. It will also reduce damping factor of the amp, which means a much looser sound, and generally speaking will make the amplifier more peakie in the frequency response. Its a safe modification though.

Many vintage amplifiers didn't run any negative feedback and that's part of their charm.

[dazco]

Don't believe everything you hear. removing NFB isn't better, it's simply different. I can easily see how one might think it's better upon forst hearing it. But i have a marshall style amp i built, and i have a switch to remove NFC completely. It sets the circuit back to exactl;y how it is w/o NFB, which by the way isn't the same as just removing the wire from the OT tap. Anyways, i thought it sounded great with no NFB, but after a long while with this amp i rarely cut NFB out any more because i think it sounds better with it. There are advantages to both, but without NFB it can sound a bit to raw and farty compared to using NFB. It sounds nice, but it;'s just not as versitile IMO. But like i said, the important thing to note is that it's not better, just different.

[Tubebender]

Don't believe everything you hear. removing NFB isn't better, it's simply different. I can easily see how one might think it's better upon forst hearing it. But i have a marshall style amp i built, and i have a switch to remove NFC completely. It sets the circuit back to exactl;y how it is w/o NFB, which by the way isn't the same as just removing the wire from the OT tap. Anyways, i thought it sounded great with no NFB, but after a long while with this amp i rarely cut NFB out any more because i think it sounds better with it. There are advantages to both, but without NFB it can sound a bit to raw and farty compared to using NFB. It sounds nice, but it;'s just not as versitile IMO. But like i said, the important thing to note is that it's not better, just different.

Thanks man. I like the amp, so prob won't be pullin no white wire.....(Id rather pull a green one, or cut a blue one anyway) Maybe just experiment with tubes when these don't sound good. Peace
TB

[tweeks5]

very interesting thread. this leaves me with a few quesitons
1. with the presence control all the way up on 12, does that effectively mean theres no negative feedback?
2.do you have to cut the wire at the jack, or can you unplug it from the output transformer?
cheers