New user hello and Marshall MGP 9004 questions :)

[rackemrack]

Hello all!

I have just registered at ssguitar.com although I have been visiting this site for some time now. I have been eyeing a locally advertised MGP 9004 preamp for some time now and have a few technical questions I hope some of you forum experts and EE's will be able to give me some advice on

1. I have attached what I believe are the schematics of the preamp. I was wondering if the preamp bears any resemblance to another marshall preamp design, and how different is it from the preamp circuit of the 8100 Valvestate mk1 head (I can tell the 9004 lacks the contour control of the 8100)? I have been looking for an 8100 at a good price locally to no avail.

2. In your opinion and from an engineer's perspective, is this a good example of a solid state guitar preamp? Is it worth more than 50 dollars on a rainy day?  :lmao: The example I'm being offered comes with original wall-wart PSU, the rack ears have been removed however by a previous owner in order to cram the poor thing into some combo enclosure Seller is asking 60€ shipped for the unit. Or is this just another stompbox crammed into a rack enclosure to make it more appealing to "professionals"?

Thank you in advance all replies and opinions are appreciated.  :dbtu:

[J M Fahey]

It's actually quite good, excellent distortion , not exactly "Bluesy" but Metal type , it's an "improved"Valvestate type preamp, with the addeed bonus of stereo loop capability (you plug a stereo chorus pedal, add a stereo power amp and 2 speakers and heve an excellent stereo chorus amp).
In fact, the Valvestate 40+40 and 80+80 W rack amps were specifically made to complement it, buy any pawnshop special  stereo power amp will do nicely.
The headphone out is very good too, since it was reasoned that being a preamp only, many would actually *use* it , and it's also compensated for direct recording.
****Much**** better than a distortion pedal, almost for the same price .

*Even*  if you have a bunch of gear, I'd always carry it everywhere as an emergency backup unit, it *can* be sent straight to mixing desk if no amp available and listened to through floor monitors.
In fact it would be perfect if it were housed in a pedal enclosure.
And if you actually *need* rack ears, they can usually can be purchased on their own at rack supply shops.

FWIW ZZTop uses something similar, its big brother the JMP1 preamp driving Valvestate (yes, SS  :dbtu: ) power amps ... and lots of 4x12"of course 

[rackemrack]

Thank you very much Mr. Fahey that is exactly the kind of info I was looking for! I was very impressed with what I saw here and I'm kind of a rack gear fanatic (more so because racks are so very uncool where I live and hence, rack gear tends to go for absurdly low prices );

http://www.youtube.com/watch?v=S14_dZakXQk

There is also a Valvestate 8008 1U power amp for sale locally I may snap up later if the seller agrees to a reasonable price. I do own the EL34 100/100 power-amp from Marshall, but it gets very little use since I can actually go out and buy new SS gear for the price of a re-tube  :duh

[rackemrack]

So I just received the preamp, first impression is I cannot believe how tiny and light this thing is! The seller failed to notify me that the bottom plate is missing, however I ended up getting it for 50€ shipped so I suppose I got my money's worth either way. Gave it a quick run through with my G&L ASAT Special and here's my thoughts:

Clean Channel: Very nice and full-bodied, bright enough for most situations (a little more chime would've went a long way but it is a marshall, not a fender or a vox). Very nice crunch with gain maxed!

Rhythm Channel: Goes from clean to uselessly overgained. A bit honky and boxy but very fat. You can tell this thing was voiced on G12T-75s, and that's where it really shines. Greenbacks and V30s, not so much.

Very satisfied with the purchase, while these are not "to die for" tones, they are completely useable. I like this thing a lot better than my ADA MP-1s already