recommendations for a cheap guitar preamp / DI box please

[EdnaBucket]

I've got a DMP3 which I put through and RME to record vocals, and I was wondering if there would be any real advantage in getting a purpose built guitar pre-amp instead of one that's intended for mics?

The DMP3 has a purpose-built instrument high-impedance (that's guitar etc) preamp. So I see no benefit at all.

If you're not satisfied about the sound, just swapping the preamp doesn't make that much difference. The used amp sims etc however do!

Is there a huge improvement using active pickups such as EMGs for this type of recording (i.e. guitar - pre - amp. sim.)?

All pickups sound different. You can't make any general statement on actives or passives, since too many other factors contibute to the final sound.

Some people are used to a specific tone of a real amp, and are on the quest for the Holy Grail to get that exact sound out of an amp sim. Not going to happen... Better concentrate on getting the best possible sound you like from the sim instead of a weak copy of what it is not in the first place.

So for this reason (amp sims aren't really there yet) many people prefer to use a real amp and record that with a mic. Better guarantee for satisfaction...

Thanks for the quick and informative reply Cookie! The Amp Sim I'm using ATM is Amplitube Duo - the one that came with RealStrat. I'm not really a guitarist yet - I decided to learn because I want to be able to play in the phrases rather than rely on the preset pattern based approach given by RealStrat/RealGuitar. I guess that in terms of sound RealStrat provides the benchmark for me - if my playing/sound is not in the same class then I'll revert to the VSTi method until I get to the required level.

I'm using a stock Yamaha Pacifica 112. I don't know enough about the other factors involved with the sound to make a judgement on whether it would be worth swapping out the pickups for this type of direct recording. When my playing is no longer ahem.. the constraining factor that it is currently, I want to know that the kit I'm playing is capable of a "pro" sound.
Hence the pickup question is really about using something of a high enough objective quality to be able to gain a better understanding of the exact sound I'll eventually want.

Edna

[GreyLion]

+1 on the VTB-1 if you end up buying instead of building. Mine pleases me a lot. Gives you room to grow, since many consider it the best preamp in its price range.

[vonRed]

The Studio Projects VTB-1 is less than $100, and has been favorably compared to high-end preamps costing substantially more. I've even tracked vocals for commercial releases using it, it's that good. It might be $20 or $30 more than what you could get away with for electric guitar, but once you start recording acoustic or vocals, you'll already be prepared.

That's when it's used as a mic preamp though. For guitar, it's not that good, for bass it's basically an unmitigated disaster.