Zobel Filter in Peavey Windsor(Modded)

[byacey]

As Andy pointed out, there's all kinds of misinformation and kooky ideas on the net posted by people who clearly have no understanding of what they are doing. Mindless tinkering with electronics will only lead to wrecking your amp, and a very real potential for injury or death.

Funny that advocates of these crazy modifications don't stop to think why the design engineers wouldn't include such a thing in their designs. Do they think they know something beyond what the electronic design engineer that spent four to six years in post secondary school, doesn't?

I'm guessing that the person that presented that video has no clue, otherwise you wouldn't even consider asking a question about hanging an RC network with the resistor equal to the speaker impedance on the primary of the output transformer.

 

[Aule7045]

As Andy pointed out, there's all kinds of misinformation and kooky ideas on the net posted by people who clearly have no understanding of what they are doing. Mindless tinkering with electronics will only lead to wrecking your amp, and a very real potential for injury or death.

Funny that advocates of these crazy modifications don't stop to think why the design engineers wouldn't include such a thing in their designs. Do they think they know something beyond what the electronic design engineer that spent four to six years in post secondary school, doesn't?

I'm guessing that the person that presented that video has no clue, otherwise you wouldn't even consider asking a question about hanging an RC network with the resistor equal to the speaker impedance on the primary of the output transformer.

The guy playing guitar and who modified the amp is Daniel Forsberg,you know Forsberg amps?
Also Zobel is used in the Dr. Z's carmen ghia amp,I wouldn't think that he doesn't know what he's doing.
Don't want to start a big "this is dumb,don't do it"debate.
When there is much wrong information then help putting the right out there.

 

[agedhorse]

The guy playing guitar and who modified the amp is Daniel Forsberg,you know Forsberg amps?
Also Zobel is used in the Dr. Z's carmen ghia amp,I wouldn't think that he doesn't know what he's doing.
Don't want to start a big "this is dumb,don't do it"debate.
When there is much wrong information then help putting the right out there.

If you know it all already, they why do you come here asking questions and then arguing about the answers you get.

I gave you accurate information, either you don't understand it or you don't like the answer because it's not what you want to hear.

No way is a Zobel resistor the same value as the nominal impedance used on the primary of the output transformer. That would slug the plates, even at the highest frequencies.

I looked at the amp you mentioned, and the resistor is 1000 times larger than the nominal speaker impedance. It looks lovely is it's used to reduce or dissipate some ringing energy under clipping conditions (in theory), the values would be determined by transient analysis, using instrumentation (or by using some heavy duty math to get close first).

 

[byacey]

The guy playing guitar and who modified the amp is Daniel Forsberg,you know Forsberg amps?
Also Zobel is used in the Dr. Z's carmen ghia amp,I wouldn't think that he doesn't know what he's doing.
Don't want to start a big "this is dumb,don't do it"debate.
When there is much wrong information then help putting the right out there.

Never heard of him; You don't need any credentials to have a webpage. Judging from the text on his webpage, he sounds like a tinkerer to me. However, it's your amp to do with as you please.

 

[Aule7045]

I'm ok with the answer,I think was a bit too interested in my own opinion,but I think it can be done,I probably won't do that to the amp,at least now,will have to think it through.
Thank you for your opinion.

 

[okcrum]

You may want to take a look at the amplifier output at clipping, given the odd line voltage you're using. Suppressing burst oscillations is the only reason I know of to use a Zobel network on the OT primary. Typical values for these can be found on some older amps' schematics. In this case, the network is designed to work well above the audio passband.

 

[byacey]

I'm ok with the answer,I think was a bit too interested in my own opinion,but I think it can be done,I probably won't do that to the amp,at least now,will have to think it through.
Thank you for your opinion.

How is the amp performing as it is from the factory? Is it lacking something? I can't help thinking that this suppression network idea is a solution looking for a problem.

 

[Aule7045]

Just wanted to experiment with this,I liked the mod,or what they did in the clip,what it does to the sound,wanted to implement it to be switchable,as a addition.
Now that you mention it,in the practice room it oftentimes has some soundartifacts,which it doesnt have when its under normal usage,seems to be coming from the lights,we have fluoarescent lighting in the room,this occurs sometimes during play and most often when nobody plays

 

[byacey]

This isn't anything to do with that modification, just garden variety electrostatic noise getting into the preamp stages, probably from the pickup.