Help- building my own IIC+ preamp

[petejt]

Hi folks, I tried posting this earlier but my browser crashed, yep and it was Firefox (which is odd).

I'm an amateur/intermediate guitarist, I've outgrown my Roland Cube-30, my SansAmp pedal, and my Line6 Flextone II. I've had it with woofy cabs and modelling, I want to make my own tone. In fact I'll be using a different amp alongside this MarkIIC+.

I cannot afford buying a whole amp head right now or even a Studio preamp and getting that modded by Mike B, it would cost too much. Also I'd like to build my own chassis for it etc., have green LEDs.

It will just be the PREAMP- later on I'll get a Stereo 2:50 poweramp or a 50/50 if I can.

I have some schematics but have a couple of issues with them. I've been advised to follow the Studio preamp schematics, but,

*is this the exact same circuit as the IIC+? It is very essential that I build the IIC+ preamp, not IIC-.

*Do the preamp valves need biasing? (dumb question but I need to get that cleared).

*I don't want reverb in the circuit. How do I omit it without affecting the amp? How will it all connect together?

*Where to the live and neutral wires for the power supply, connect to the actual circuit?

*What transformer will I need to convert from 240Volts AC?

 

[Elpelotero]

you may have problems as far as transformers go because the original ones are discontinued. you may have to "settle" for those used by the mark4, which are similar though. i'm not sure if this affects your plans for a preamp as i'm not a techie, but i saw you mentioned transformers.

 

[Boogiebabies]

You have got to be kidding. Your going to electrocute yourself.

 

[RR]

You have got to be kidding. Your going to electrocute yourself.

Like this?

petejt, do you know what you are doing? Not that I'm questioning it or underestimating your ability but ...

 

[Boogiebabies]

 

[petejt]

you may have problems as far as transformers go because the original ones are discontinued. you may have to "settle" for those used by the mark4, which are similar though. i'm not sure if this affects your plans for a preamp as i'm not a techie, but i saw you mentioned transformers.

Thanks Elpelotero. I want to contruct the same circuit as the MarkIIC+ preamp, but it doesn't matter too much if some parts aren't exactly the same.

What transformer does the Mark IV use?


Alot of the problems I'm having is that the circuit diagrams I have are a bit blurry read. Some of the values written are a bit smudged, or the polarity sign of the electrolytic capacitors.

If anyone who has built their own MarkIIC+ preamp, and has a clear diagram, please post it here, thanks.

 

[ytse_jam]

i think building MKIIC+ or every other preamp on your own will cost more than buying a studio pre and get it modded!

 

[justanotherboogieplayer]

Hi,

the cheapest way to get all the parts you need is to buy a Studio Preamp !

The Studio Pre is very close to the MK IIC+ if you turn down the gain a little bit.
There is a big difference from which company the parts are, even one single resistor can change the sound. I own three loaded MK IIC+s. They all have the same circuit, but sound little different. If you use different (cheaper) parts, you will, for shure, get a different (cheaper) sound.
A Studio Pre will have original Mesa Boogie parts. It is build by experianced people. It sounds great and it is not far away from a C+.
You do have the EQ, which is an important issue and the sound is more like a C+ with "Deep" pulled.
Allso important: if you take care of it, you will not loose money when selling it again, what possibly helps to get the 100% C+ sound some day, when you can afford a real IIC+.

After trying a lot, I finaly found the Studio Preamp to be the cheapest way to get close to a C+ sound.

 

[Elpelotero]

Nobody except Mike bendinelli and randall smith have ever built a 2C+ circuit. so you won't find much help from experienced people. if people knew how to copy that circuit, i personally believe there would exist 50 knockoff versions of it by different companies since it is the best sound. the transformers played a large part in the c+ sound. there were 4 of 'em, no longer in production. the 100, 105, export 101, and the output trans. my suggestion to you would be to forget the idea. it would be difficult to get all the time-era correct parts, you may have to guess a lot, and you may electrocute yourself! i don't even know if some of the more experienced people here with the c+'s are capable of building one.
i trust my electronics to those who know it best. that's why i play guitar!

 

[Shep]

he want's to build a pre amp....it doesn't need a output tranny does it? Or the massive current draw to run the output tubes....but dude....just save up and get a studio pre...Or save up abit more and go a Mkiii red stripe!!!

no matter wat that would be a much better /safer plan...

Tom

 

[RR]

That is the best. Now, if you can only show what 490V does to the testes !!!

What about this?

he want's to build a pre amp....it doesn't need a output tranny does it?

My thoughts too.

I'm admire your ambition petejt.

 

[Elpelotero]

Shep wrote:
he want's to build a pre amp....it doesn't need a output tranny does it?
My thoughts too.

you are correct. i got carried away there.

 

[Boogiebabies]

8)

 

[funk49]

I think it is dangerous for anyone who has to ask if a preamp tube needs biasing to screw around with the 400V taps necessary to the plates.

Quoted for truth. If you need to ask these questions, you really don't want to be tinkering around with building your own circuit. You will seriously kill yourself.