Great River MP-2 , info, schematics & discussions

[clintrubber]

[quote author="matta"]I expect it to have a different tone/character from both the Greens and the SSL9K, though I've not done A/B test... heck I've not even heard the MP-2, I'm just up for a new, interesting project!

Cheers

Matt[/quote]

Hi Matt,

Thanks for adding & for the link to the MP-2 review.
Quite different topologies indeed, but different methods towards the same goal (assuming it was 'absence of influence') could still result in comparable preamps of course (roughly speaking; there'll always be differences of course).

But hey, there's only one way to find out, so... :thumb: :wink:

I myself should finish those Greens first, but I'll sure keep an eye on this thread.

Cheers,

Peter

 

[Gustav]

Well, Ill make some PCBs then, although itll take a little while. Itll probably be a month and a half or so, depending on how long Ill have to wait on the prepping of the files for fabrication.

Gustav

 

[matta]

[quote author="Gustav"]Well, Ill make some PCBs then, although itll take a little while. Itll probably be a month and a half or so, depending on how long Ill have to wait on the prepping of the files for fabrication.

Gustav[/quote]

Great :thumb:

That gives us time to thresh out the other details, like matching the transistor, or rather which ones need to be matched etc.

I also noticed in the BOM the Inductor says 'Factory', does that mean we need to order them from Dan?

I guess more questions will follow...

Plus there is no way I'm starting any new DIY projects for the next 2 months, LOL!!!

Cheers

Matt

 

[okgb]

Not sure if It was intentional not to send the psu gerber i sent all i had, but the pre can use a basic version , Great Rivers include a surface mount comparitor for overload indication that , while nice is not critical .

The pre does need a higher than normal psu voltage [ 36v iirc ]
It is a clean nuetral pre , but with a smooth solid midrange [ depending
on input xfmr ] compared to a milenia i felt it was a little less airy , but
also not as thin [ this on more distant orchestral miking ] and thats
listening hard , i never found fault with it in anyway . and removed the
zobal net work because i used the Lundahls

Now what we don't need is for bogus copies to show up like all the
ssl comps these days

 

[clintrubber]

[quote author="okgb"]Now what we don't need is for bogus copies to show up like all the
ssl comps these days[/quote]
How about modifying the Gerbers for some note on the PCB (silkscreen and/or copper) that would give CFP's (Cloners-For-Profit) something to explain when selling ?

It'd hurt the 'good cloners' as well though, in case they need to sell for other reasons than making an intended profit, so I'm not too sure about this. But if I had to choose then I'd say add that note.

It could always be removed of course by some PCB-mutilation. And then better hurt the internal cosmetics of 'CFP'-boxes, be it at the expense of 'good sellers'.

 

[rafafredd]

Audio Card Parts Overlay 2 – 14Kb

Can´t download this one...

 

[bernbrue]

hi peter,
thanks for pointing out the differences between the MP2 and the MP2NV version. Nevertheless, interesting stuff to read and an interesting Mic Pre anyway, that's for shure. It wasn't my intention to mess things up. :wink:
regards
bernd

 

[SALSA]

rafafredd : link has 1 f too much at the end (pdff for pdf).

Just remove the f and the link will work (looks the same however as the previous pdf ?)

Cheers,

Mike

 

[Dan Kennedy]

Hi Guys,

Have fun with the stuff, I'll pop in now and then, or Greg knows how to find me, give me a list of questions, or screw-ups and I'll sort it out.

The output inductor is just an 18uH cored inductor, like the little axial ones J.W. Miller puts out. But I have a thousand or so in the back room, as scrap now, so I can send a pile to somebody if they want to spread the wealth to anybody doing the project.

I'll try to post a set of gerbers for the supply, but I need to modify the last production board, it didn't include the voltage doubler that we wound up using in the last run rather than a custom transformer with a phantom winding. An off the shelf 30va 22 + 22 transformer will power this up just fine. I did the doubler with a simple cut and jumper, but I want to lay it out right for y'all.

I've still got a pretty good pile of the FET's too, we'll figure out a way to get them out as well.

There isn't anything exotic, so feel free to substitute stuff.

Have fun!

 

[Guest]

Isn't that sweet - and a Happy New year to you sir..
All the best and ...
thanks

 

[clintrubber]

[quote author="Dan Kennedy"]The output inductor is just an 18uH cored inductor, like the little axial ones J.W. Miller puts out. But I have a thousand or so in the back room, as scrap now, so I can send a pile to somebody if they want to spread the wealth to anybody doing the project.

I've still got a pretty good pile of the FET's too, we'll figure out a way to get them out as well.

There isn't anything exotic, so feel free to substitute stuff.

Have fun![/quote]

Thanks for passing by :thumb:
And those coils, that's generous!

How about sending these goodies to Gustav ? (as he's most likely making PCBs) - and covering your component & shippings costs of course.

A PCB set from Gustav could then have the coil & FET's with them right away.
Just an idea.

Regards,

Peter

 

[okgb]

A great gift indeed , Thanks Dan

To the earlier poster , I have 4 of the G.R. pres , and the great thing about them is that you turn the gain to where you need it , and if you don't like the sound , it ain't the preamp !

That said , i may built a green , without the xfmr it's going to be cheaper,
perhaps easier , but i'm glad i have the G.R.s and would never get rid of them [ Scott Dorsey mentions using them for remotes where the input
xfmr gives better rejection ]

We should also start a very modest beer fund for Dan , hah !
[ don't want the preamps turning out crooked ]

And i like the idea of marking the pcb NOT FOR PROFIT somehow if possible

 

[chrissugar]

Many thanks Dan, a very nice gift.
A happy and successful new year to you. :thumb:
By coincidence today I received from a friend your EQ for testing. An excellent tool. :thumb:

chrissugar

 

[Flatpicker]

What a nice guy!

Thanks, Dan! :thumb:

 

[Ptownkid]

I'd get em made

 

[CJ]

weird editor bugs lately.

Funny how some projects get done in a hurry, and others are slow.
This one was "boom, wham, slam, see ya!" as far as turnaround. Heck, most cpmpanies do not work this well together.
Thanks to the Great Boboski, freezing his white ass off in the frozen, caribou infested tundra.
Don't forget the block heater.

 

[louder]

Hi
i`m out of words.
thank you so much Dan.
and Greg.
and Matt.
and Gustav.
where`s my soldering gun?.
best regards
pedro

 

[okgb]

Before ya get too excited , you still have to build it
and it doesn't cash cheques but..................
you'll be well rewarded .

then again , everytime i want another marshall amp
i just go practice and either i'm too shitty & don't deserve
one or have such a great time , i don't need one
[ doesn't work with pro audio though ! ]

In the freakin -30s C here [ -40 is where it meets F ]
But No eskimos

Happy New year everyone , regards Greg

 

[pstamler]

I second everybody's remarks: thank you, Dan, for your generosity.

Gustav, or someone...how about putting on the Gerber something like "©2007 Dan Kennedy; non-commercial use only"?

Peace,
Paul

 

[Samuel Groner]

I can provide a mirror for the files: mp2mhpcb.zip

Hope we won't see to many ugly soldered clones selling for $3000 on evilbay...

Samuel