Qsynth plays soundFont banks (sf2). More often then not, these would contain sound libraries (banks) with sounds ordered following the MIDI standard (Pianos, basses, strings etc ). These sf2 fonts can be either downloaded for free from Internet (http://tinyurl.com/ycnkkal) or purchased (http://tinyurl.com/yaeo4d9). Bad, good and better imitations of real instruments, basically.
ZynAddSubFX generates its own sounds using sophisticated tone-generators.

Thanks.  I need to get a bit more confident with it all.  I need to buy a MIDI to USB cable so I can connect the guitar synthesiser to the computer.  I also need to buy a keyboard such as an M Audio Axiom 49 or an M Audio Keyrig 49 or and M Audio MK-425C or an Edirol PCR 80 to drive these synthesisers or the linuxsampler I want to play with.  I don't know which one of these keyboards makes the most sense to buy at this stage.  I also need to get a monitor like the ESI Near05 experience or whatever it is called.  I assume the computer sound outputs can connect directly to such a monitor. 


 

What is the difference between Jamin and GCDMaster?

Jamin is a Mastering program. Once you have recorded your midis on Rosengarden using either Qsampler for soundfonts or ZynAddSubFX as sound engines, and you have composed your drums in Hydrogen, and recorded your vocals/guitars in Ardour, you want to make a nice balance of the recording, and even it out dynamically and frequency-wise (make a Master recording). So you run all those apps through jamin, and record its output as a track in say, Ardour. You put this track in GCDMaster to get it ready for burning on disk.
Jamin has a compressor and EQ, GCDMaster doesn't.

When you do mastering The write up in the 64studio manual says:

• Start Jack and open Ardour.
• Completely turn down the volume of each monitor and make sure they are off or muted
• Load the 14dBFS-Pink wav file into ardour, and play out to the monitors. Be sure to leave the faders at 0dB positions on ardour and the playback hardware if applicable
• Place the dB SPL meter to measure exactly in the spot where your head would be while seated at the mastering rig.
• Unmute or switch on the first monitor and increase it's volume until the SPL meter reads 83dB. Mute again.
• Complete the previous step on all monitors, one at a time

 
etc......  Do I really need to do all that?  What is an SPL meter?