Wolfeman and other amp tech guys...

[MetalJonesy]

Right on, yeah I don't want to redo anything, just take the existing circuit/layout/pcb and get rid of the tube power section and OT. Leaving me with the preamp and some outputs and all the other goodies so I can fabricate a 1U chassis for it and use it as a preamp like an Engl e530 et al. To utilize the power section and transformer that would take some time because I would have to have a new board and wire it all up, as well as fabricate the chassis. The main goal is to make a preamp unit that is the Krank sound

Without a schematic of the Rev Jr., there isn't much to go by. I'm working on getting a schem right now though, been e-mailing Tony Krank back and forth about Krank making a Rev preamp as well as me getting the schem to try a DIY one...no response on the schem yet though.

~006

let me know if you get anything back!!! would like to see em!!

 

[iekobrid]

if tubes are soldered vertically on the main preamp board, then you can easily forget to make a 1U rack preamp using that same pcb, simply because that would be higher than 4cm...

Yeah, that was the first thing that occurred to me. Are there right-angle sockets he could solder in to replace the current connections? (assuming that wouldn't cause the tubes to invade the airspace of other components on the board)

I'd be interested to see pictures of a disassembled Jr, see what it's got under the hood. Wouldn't have a clue what I was looking at most of the time, but it'd still be interesting.

 

[006]

Are there right-angle sockets he could solder in to replace the current connections?

I think so

~006

 

[Wild Hades]

Pictures would help a bit, but figuring the whole circuit out of an industrial made pcb is not easy, expecially if you have components on both sides...
Anyway, you should check the connection on the master volume pot. That's where the preamp section really ends, and you should see 2 paths, one goes to the fx send jack through a switch and an impedance adapter (solid state opamp probably). You should get rid of everything after the master volume pot (apart from the Fx send if you want to use it with impulses).

 

[MetalJonesy]

Krank Rev Jr Documents

 

[TheDude]

PM Wolfeman. It's a really interesting idea. Keep us updated, please.

 

[iekobrid]

The main goal is to make a preamp unit that is the Krank sound

It there's a chance you might find a way to make it function as an Egnater / Randall MTS module, I might be willing to help fund your project, Nebula impulse thread style.

 

[006]

Haha, right on! Baby steps first though, if it can be made into a rack preamp, then it only takes some design adjustments to make a MTS module version I would think. I have looked into those, they are pretty cool.

~006

 

[iekobrid]

The first thing I did when my first MTS module arrived in the mail was to bust out the ol' multimeter and check which of those twelve contact points on the back formed a circuit. I have no use for that knowledge yet, but I just had ta know. I suspect they put so many seemingly unnecessary contacts on there specifically to intimidate people out of trying to engineer their own MTS compatible products.

 

[006]

Looks pretty simple though

~006

 

[iekobrid]

The board, sure. But all them extra contacts put a voice in the back of my head that says, "Surely they must do SOMEthing. Maybe the design isn't as straightforward as it seems. And lose some fucking weight, tubbo!" I'm gonna murdalize that voice one day.

 

[006]

Fo sho. So I'm still waiting on the first e-mail of the day from the guys at Krank, I've been talking with Tony and a tech named Patrick which I originally made a post on the Krank forums addressed to him. This has to go one of two ways, either I will somehow get ahold of the schematic for the Rev Jr. or they will make a Rev1 preamp. Simple. Got a little preoccupied last night, but tonight will be dismantling the Rev Jr. and taking pics Even if I have to get someone to basically reverse engineer the little bastard, I will figure this out.

~006

 

[Metaltastic]

Fucking awesome man, good luck to ya! I would LOVE a Rev preamp, and since they can get it in the Rev Jr for like $550, I would hope maybe they could sell it by itself for like $350... (wishful thinking, I'm sure, but I can hope! )

 

[MetalJonesy]

yer would be wicked if they could make one for no more than half the price of the rev jr! id deffo be interested, looking forward to seeing the pix of the rev too!! i just cant be bothered to open mine up yet, its usually the first thing i do when i get an amp!!

 

[006]

Well, the price point being hinted at is closer to $600 (Engl e530's retail), which would be fair IMO. The used market will be close to half the price indeed though.

~006

 

[Metaltastic]

Correct me if I'm wrong, but isn't it just a matter of taking out the 4 bolts on the bottom and pulling out the chassis? That's how it was on my JSX and Dual Rec, come on you lazy bitches! (though you did scan the documents Mark, so thanks for that )

Also, does the Rev Jr. have a phase inverter tube?

 

[006]

Lol Marcus, yeah it's easy to take it apart, I just haven't had time is all - unless you are talking about Mark! Chicks take up a lot of time, plus I have a 60-hour work week so it's kind of hard to make time to take apart an amp and snap good pics of the chassis and everything, especially when your gf is like "do you know what you are doing? do you have money to fix it? I don't think you know how to take that apart"...

~006

 

[iekobrid]

it's kind of hard to make time to take apart an amp and snap good pics of the chassis and everything, especially when your gf is like "do you know what you are doing? do you have money to fix it? I don't think you know how to take that apart"...

One of my earliest memories is of ignoring a female voice (my mother) warning me not to take a screwdriver to the Tie Fighter toy I got for Christmas '77 or '78. And she was right -- the damn thing never did make its flashy laser light noises quite right ever again!

 

[MetalJonesy]

Lol Marcus, yeah it's easy to take it apart, I just haven't had time is all - unless you are talking about Mark! Chicks take up a lot of time, plus I have a 60-hour work week so it's kind of hard to make time to take apart an amp and snap good pics of the chassis and everything, especially when your gf is like "do you know what you are doing? do you have money to fix it? I don't think you know how to take that apart"...

~006

haha i only see my gf every other weekend, of for when she has her school holidays as shes a teacher. (so its great i can get on with my music) i only work a 20 hour week too, so i really have no excuses to pick the amp up fom beside me and open her up, but i really cant be arsed

 

[Wolfeman]

Hey I haven't read the rest of the thread other than the first post, but it is very possible. All you really need to do is get voltages from the amp now, and then find a torridal power supply that will fit in a 1u rack along with a power supply and pre board.

You also need to take into consideration that you will need to modify the power supply section of the amp currently... I mean without the power tubes there you can leave it as is, but it would kinda be a waste...

But this is totally doable, no schematic needed.

And your FX send should be good enough level as the output.