Let's build an amp! Greg's journey to electrocution

[Greg_L]

Fair enough. Was just thinking it's one of the 5 classic amp flavours! Probably one of the trickier ones too. You're right though, it's not like you'd get anything out of it other than the challenge.

I don't know. If someone asked me to name five classic amps, the Mesa Dual Rec would not be one of them.

I've never even looked at a schematic of a Dual Rec. I don't know how complicated they are.

[JD01]

By 5 classic flavours I just mean fender, Marshall, vox, orange and mesa, not specific amp models.

[WhiskeyJack]

I think the obvious decision here is to build an 800 kit clone or what have you, jam a muttpups logo on it, do a shoot out with your favorite JCM800 and then sell the clone to me.

I mean duh guys. It's so painfully obvious it is nauseating.

[muttley]

I really think we should do a MuttPup amp... You know some that just drips teh awesomeness..

But what could it be? All the best stuff has been done and no one's really improved on the classics. I've built one amp. I don't think I'm ready to design one.

Nonsense. Pick the amp you want and build in the mods you like and omit the bits you dont. Thats how I build guitars.... Cut out the crap build in the cool...

[Greg_L]

Nonsense. Pick the amp you want and build in the mods you like and omit the bits you dont. Thats how I build guitars.... Cut out the crap build in the cool...

So we could build a Blackface Plexi. Lol. Two channel amp, Fender on one side, Marshall on the other.

[Greg_L]

I think the obvious decision here is to build an 800 kit clone or what have you, jam a muttpups logo on it, do a shoot out with your favorite JCM800 and then sell the clone to me.

I mean duh guys. It's so painfully obvious it is nauseating.

Ha, this 50W Plexi reissue I have here that I modded into 1/2 JCM800 and 1/2 Plexi is pretty much the perfect Marshall amp. It's friggin awesome.

[muttley]

Nonsense. Pick the amp you want and build in the mods you like and omit the bits you dont. Thats how I build guitars.... Cut out the crap build in the cool...

So we could build a Blackface Plexi. Lol. Two channel amp, Fender on one side, Marshall on the other.

That sounds good but you know me... I'd have Fender on one side and Fender on the other...

[Greg_L]

That sounds good but you know me... I'd have Fender on one side and Fender on the other...

So what you need is the very amp I built in this thread.

[rayc]

Druthers!
The only amps I've wanted are a Plexi & an AC30.
I almost have the former and have no real use for the latter.

[Greg_L]

Druthers!
The only amps I've wanted are a Plexi & an AC30.
I almost have the former and have no real use for the latter.

Send me your Marshall and I'll fix it up for you!

[WhiskeyJack]

That shipping bill would be interesting.

[muttley]

That sounds good but you know me... I'd have Fender on one side and Fender on the other...

So what you need is the very amp I built in this thread.

Maybe, not so loud though. I always like a smaller backline amp and mic it... I dont play at the amplitude you do.

[Greg_L]

Maybe, not so loud though. I always like a smaller backline amp and mic it... I dont play at the amplitude you do.

This thing's only 22 watts!

[muttley]

Thats about what I need...

Now make me one...

[Greg_L]

Thats about what I need...

Now make me one...

Buy the kit and have it shipped straight to me. And while you're at it, send me a white LP Jr double cut with a dogear G90 in it please.

[Minerman]

Druthers!
The only amps I've wanted are a Plexi & an AC30.
I almost have the former and have no real use for the latter.

Send me your Marshall and I'll fix it up for you!

I'd imagine shipping would be quite expensive, but that would probably turn out great...Gerg could reverse-engineer a Chupacabra & turn your amp into a fire-breather Ray...
You could put the master on about 3-4, & it would push just the right amount of air for a great tone dude (or for me anyway )...
No window-rattling required unless you want it, that is...

[liv_rong]

This afternoon's project. First full recording with the homebuilt Deluxe Retard.

The Witch.mp3

Sounds good man!

Been waiting to listen to this since you posted it. Nice!

[Greg_L]

Sounds good man!

Been waiting to listen to this since you posted it. Nice!

Thanks man.

[Greg_L]

Okay you ballbags. If you're sick of this thing, don't worry, we are reaching the end of the journey.

Today I switched the entire amp to HIGH VOLTAGE!!!!!

My power transformer has two sets of secondary windings. I can only characterize them as "soft" and "hard". Lol.
Here's the PT schematic:

w025130sch - Copy.JPG

I labeled the secondary windings in colored boxes. We'll focus on the red box. Look at the red/wht wires. Together they provide 540 VAC to the rectifier plates. This AC voltage is then rectified to DC and sent out to the amp. With my 122v wall voltage, I was actually getting 553 VAC at the rectifier. Seems like a lot, but it isn't. The DC output after rectification was only 380 VDC. That's what the entire amp has to draw from. How does this affect the amp? It doesn't, really. Everything runs at a proportionately lower voltage than what Fender specified back in 1963. How does it affect the sound? It does somewhat. The breakup is softer and sooner and there is reduced clean headroom - not unlike using a Variac to cut power to an amp. But mainly my amp works great and that obviously was the plan all along. So with it passing the lower power test, time to go big.

Original Fenders used PTs that pumped out about 660 VAC, which is right in range with the other wires on my PT. Look at the red wires in the red box. They kick out 680 VAC! And mine, unloaded, checked and verified, actually puts out 700 VAC. Earlier we talked about getting hit with high voltage in a live amp, try 700 volts on for size. Anyway, I unhooked my other wires and hooked into the red high voltage wires. I also, again, beefed up the first node filter caps. They're 500v handling now. Plenty safe. I haven't jotted down my readings yet, but I've gained abut 100 volts on the B+ power rail and everything falls pretty much right in spec with the original Fender design. My plate voltages, filter cap node voltages, etc are all pretty much spot on. And nothing exploded. So we're good to go. Full power. It does sound a lot cleaner and punchier. Better clarity and headroom for sure. The tremolo works better. So I'd say it's a win. I like it a lot.

I'll try to make a little video of the amp on my new scope so you can see wtf that shit looks like.

[rayc]

AND sounds like I hope. Excellent journey.