I think I have the mod bug pretty bad.

[karpathion]

I Finally got a good bite on one of my 1x12 cabs I was trying to move. The guy wanted to buy it from the get go, but you know how us gear heads are. We ended talking about gear and mods for half an hour. 

Turns out he is a bit of a tech and mod junkie too. He was telling me about 2 Valve Jr's he had modded. One of them had the upgraded Classic Tone OT, and was modded to be clean platform for pedals. Very Fenderish as he called it. I believe it is a version 2.

Well, he has something wrong with the mod that causes a tremolo effect oscillation. The more you crank it, the louder the oscillation becomes. 

I asked if he would be willing to trade that one for the cabinet. He had no problem with it. Now, I have another one to tear apart molest. I'm thinking this one is a prime candidate for a Gibson GA-5, Gretsch 6150, or 5f1. I'm just going to pull the pcb, and put in a turret board for ease of build, mods, and service.


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[karpathion]

The oscillation is gone now. I just moved some wires around and pushed a few long legged components away from what I saw as problem areas. It's working just fine now.

It doesn't sound bad like it is, but I'm going to molest it anyways. I was thinking about changing it to an EL34 power tube and Marshalizing it.

[Snake Aces]

That's awesome man! A guy I used to play in a band with went on a Valve Jr modding spree back in 2007 and he had a sick sounding little setup and he was just running it through a 12" Celestion mounted into a subwoofer box at the time!

I like where you're taking the project though

[karpathion]

I'm still brainstorming and doing the research right now. Any tube amp I can get my hands on at the moment is going to get a conversion of sorts. Just have to figure out if the transformers can handle what I want to do.

The Classic Tone OT in this one can do 15W. I'm looking around now to see what the stock PT can handle. I'd like to do a 2203/2204 preamp into a single EL34, or a duel el84 push/pull power section. I just don't know how much current draw this PT can take. 

I'm looking at powering 3x ecc83/12ax7, and 2x EL84s. Everytime you parralel off of the power supply, the current goes up. I may have to put a little change in the PT to do what I want.

[LesStrat]

I saw the thread title and thought you were campaigning to be the next SDUGF moderator.

[karpathion]

I saw the thread title and thought you were campaigning to be the next SDUGF moderator.

I'll leave all that professional mumbo jumbo to the pros. I just want to make some noise...

[GoldenVulture]

I'll leave all that professional mumbo jumbo to the pros. I just want to make lots of noise...

fixed :evil:

[karpathion]

Alight, I'm not going to be able to do a push/pull 2xel84 power section. This PT will only to a single ended set up. But, from looking around, I can add a Preamp tube or 2. Looks like I can parralel off the 6.3v filament line a few times and be ok, and the 260V tap can go a  couple more too. It's probably going to give the PT a good work out, but I'm told it can take it. It can even the handle the jump to a single el34.

This one is getting a Plexi style preamp, PI will be added too, into a single ended el34. At least that's the plan right now. I'm sure someone will step in tell me I can't do that before I get too far. 

The scary yet cool part about this is, I'm pretty much on my own now. There are no mod schematics like this, and no one is going to hold my hand and walk me through it. 

Luckily, I spent so much time studying and laying out the Plexi/2203 preamp, I can probably build that part from memory with no problems. That's the easy part.

Getting the right setup on the el34 is where it gets interesting for me. It'll be my first cathode biased project, as well as single ended power section. Seems easy enough though. What could possibly go wrong?  :toast:

I'm batting 1000 so far on tube amps I've worked on, "like 10." If I'm going to stretch my legs a little risk a fuck up, I'd rather be on a little cheap ass Valve Jr, than something nice. I'm bound to fuck up eventually.

[Oinkus]

Shit happens. That is universal , don't worry about it. Not like you have a bunch of money tied up in it so far. When you ruin a brand new $1000 guitar give me a call and we can compare notes.

[GoldenVulture]

Alight, I'm not going to be able to do a push/pull 2xel84 power section. This PT will only to a single ended set up. But, from looking around, I can add a Preamp tube or 2. Looks like I can parralel off the 6.3v filament line a few times and be ok, and the 260V tap can go a  couple more too. It's probably going to give the PT a good work out, but I'm told it can take it. It can even the handle the jump to a single el34.

This one is getting a Plexi style preamp, PI will be added too, into a single ended el34. At least that's the plan right now. I'm sure someone will step in tell me I can't do that before I get too far. 

The scary yet cool part about this is, I'm pretty much on my own now. There are no mod schematics like this, and no one is going to hold my hand and walk me through it. 

Luckily, I spent so much time studying and laying out the Plexi/2203 preamp, I can probably build that part from memory with no problems. That's the easy part.

Getting the right setup on the el34 is where it gets interesting for me. It'll be my first cathode biased project, as well as single ended power section. Seems easy enough though. What could possibly go wrong?  :toast:

I'm batting 1000 so far on tube amps I've worked on, "like 10." If I'm going to stretch my legs a little risk a fuck up, I'd rather be on a little cheap ass Valve Jr, than something nice. I'm bound to fuck up eventually.

Well you won't need a Phase Inverter. :toast: