5150's

**pancho** · 05.22.07, 11:20 AM

I have a technical question for those gearheads out there that can answer this.. years ago I used to talk to James Brown who designed the 5150 with Ed.. James was an awesome person, sent several pics of him and Ed with the prototype head/cabinet signed by him and Ed.. anyway.... I asked him and he always sideshooted the answer.. OK.. in a Marshall or typical old style amp, the distortion/overdrive/gain is gotten by overdriving both the preamp and power amp sections causing the distorted or even harmonic distortion... but in the 5150 its' obvious that the overdrive is actually happening in the preamp and the power amp is volume distribution... is this done solid state style of clipping or did James and company find a way to actually clip the 12AX7's in the preamp which is why there were 5 when normal amps at the time had 3... I know that EL34's usually dont sound good in a 5150 cause they only sound good overdriven in the poweramp section and the 5150 doesnt need to overdrive that section... anyone explain this?

**Jape Man** · 05.22.07, 01:21 PM

The overdrive is definitely coming from the 12ax7s. But, the 5150 is like pretty much any other tube amp, in the fact that it's the power tube distortion that really gives it it's singing tone. Just because it has a lot of preamp tubes doesn't mean you aren't supposed to get power tube overdrive out of it.

Old marshalls had 3 preamp tubes, the 5150 has 5, but both kinds of amps sound best with power tube distortion as well.

**pancho** · 05.22.07, 01:31 PM

Originally Posted by Jape Man

The overdrive is definitely coming from the 12ax7s. But, the 5150 is like pretty much any other tube amp, in the fact that it's the power tube distortion that really gives it it's singing tone. Just because it has a lot of preamp tubes doesn't mean you aren't supposed to get power tube overdrive out of it.

Old marshalls had 3 preamp tubes, the 5150 has 5, but both kinds of amps sound best with power tube distortion as well.

Welll not really... I know the best answer James gave me was that Ed wanted sustain not distortion.. so they went after a clean power section on purpose not to distort. He was vague about the sustain in the preamp.. LOL like I was a spy for a company or something.. My assumption has always been that they went after a solid state "style" of clipping method and used tubes to warm it up and push it over the edge.. I dunno though really I'm not a tech so I'm guessing on this. Cause I know that marshalls used BOTH pre and power to acheive it's signal clip hence the variac that people use. But the 5150 does not relay on power signal clip. So I was wondering what Peavey used to clip the signal.

**smme5150** · 05.22.07, 01:55 PM

I know he was Ed's tech during development of the amp. It's my understanding that he would have an answer for you, not to mention he has the column in a guitar mag about this shit.

**gproud5150** · 05.22.07, 04:17 PM

Originally Posted by Jape Man

The overdrive is definitely coming from the 12ax7s. But, the 5150 is like pretty much any other tube amp, in the fact that it's the power tube distortion that really gives it it's singing tone. Just because it has a lot of preamp tubes doesn't mean you aren't supposed to get power tube overdrive out of it.

Old marshalls had 3 preamp tubes, the 5150 has 5, but both kinds of amps sound best with power tube distortion as well.

I have to respectively disagree with that. 6L6 based amps don't get the singing distortion that EL34's get. The 5150 was 'designed' after the Soldano SLO, which gets it's mojo from the preamp, not the power tubes. They rely on the power tubes for a nice, clean translation of the preamp distortion, rather than distorting themselves. That's why Ed's new EVH amp has 8 preamp tubes. Same design scenario as the 5150 and 5150 II, only the third channel requires the extra tubes.

**Majestic** · 05.22.07, 06:55 PM

Yeah, the 5150 "borrows heavily" from Mike Soldano's creations. The resonance knob was a nice touch, though. I think the 5150 is a BETTER option if you're trying to sound like "Balance", or "3".

Soldanos are amazing. Not my "style", but they're amazing.

**Jape Man** · 05.22.07, 07:29 PM

You guys are missing my point. All I was saying is that both the preamp and poweramp have much to do with the sound. Yeah, the 5150s generate more distortion up front, before the power tubes -- but you still need the power section to complete the tone. It's more than simply a means of amplifying the signal. If that were the case, they could have used a mosfet power section.

Yes, I agree that EL34s sound better when pushed, but 6l6s, 5881s, and the like still play a role in the overall tone.

And, yes the 12ax7s are the primary source of the preamp distortion. . .as they are in Soldanos, Bogners, Mesas, and the like. The Marshall Silver Jubilee used diode clipping to enhance the preamp overdrive, but I do not think that's the case in the 5150. It sounds like the straight tubes to me.

**HipCat5** · 05.23.07, 04:29 AM

I own the 5150 combo and I've been over the schematic many times (simply out of curiosity and looking for ways to improve it). There are no clipping diodes in the 5150. There are solid state components but its all in the channel switching and not in the signal path.

I've always wondered why the amp has that brittle solid state-ish sound to it myself, especially at lower volumes. While going over the schematic I noticed Peavey put the master volume before the effects loop. This means one could put an active preamp/buffer on the effects loop to control the volume but not color the tone of the amp and yet open the master volume to "7", for example. I've done this a few times and it does give the amp a little more tone. Anyone know why? Maybe it comes down to that whole idea of the power amp being designed to be 'clean'? I dunno.

food for thought

**Jape Man** · 05.23.07, 05:27 AM

Your getting a little more tone because you have the power tubes contributing to the tone. With the power section at a very low volume, you're not getting any of the output tube sound.

**pancho** · 05.23.07, 01:12 PM

Yeah I agree with you guys,, the distortion or "sustain" as Ed and James called it,, defunately comes from pushing the pre amp.. I asked James a couple times and he sidestepped the issue,, it's ok I mean I"m just more curious for myself cause those old Marshalls in my day you pretty much had to have everything cranked up to 10 to get a distorted sound, then Soldano came along and you didnt have to crank it. Granted the power amp does have to hit a sweet spot for it all to get it's mojo to work good, but it defunately does not relay on power amp distortion for it's tone.

I've looked over schematics as well and I just can't figure out how the clipping could be done without some type of solid state configuration telling the tubes to "heat up" if you will.. ya know?

**pancho** · 05.23.07, 01:16 PM

oh by the way,, that was a good suggestion of Matt Bruck and I tried that also,, Ed and his people keep secrets well guarded is all I can say.. But for those that know Peavey and all,,, James Brown no longer works for them last I heard,, he was an awesome person to talk to,, believe it or not he called me!!! I just wrote a letter saying how much I loved the 5150 and wanted an autograph and like a year later he called me.. I was like WOW,, he was a wonderful guy and plays guitar in a band himself in his spare time.. but when he left peavey I lost contact with him....

AT · 05.23.07, 07:42 PM

Did James Brown have a hand in the 5150 II at all, or had he left Peavey by that time ('97/'98)? I've never heard...

There was a Peavey up-and-coming products catalog that came out in early 2004 showing some new lines. In it was a 5150 II combo and 5150 mini stack. After seeing that I wondered why Peavey didn't issue those under the new 6505 moniker.

**pancho** · 05.24.07, 12:28 PM

Originally Posted by AndrewThomas.net

Did James Brown have a hand in the 5150 II at all, or had he left Peavey by that time ('97/'98)? I've never heard...

There was a Peavey up-and-coming products catalog that came out in early 2004 showing some new lines. In it was a 5150 II combo and 5150 mini stack. After seeing that I wondered why Peavey didn't issue those under the new 6505 moniker.

Yes he did have a lot to do with the II model.. but he told me and this was in may of 2000.. that he and Ed were working on a 1x12 model!! Obviously this never happened cause james left peavey.. half way wonder if when james left ed lost his inventor...could be one of many reasons ed left?