Hoping someone can help me with my understanding of these knobs. I did search for this topic on TB and found one thread from 2018 about AMPEG amps and I did watch it for the AMPEG approach. I have also read statements on various sites like: "gain should never be higher than master!" and "master should never be higher than gain!" I am using a Markbass CMD 102p (300W 2x10 combo); I assume the concepts apply equally more or less to all amps that have both these knobs. My previous experience has been with amps that only had one "volume" knob. My understanding is that GAIN is the signal going into the amp (pre-EQ) and MASTER is the signal going out of the amp to the speaker (post-EQ). It seems to me you can get an overall comparable output level (volume) with higher gain & lower master and lower gain & higher master. When setting your overall amp volume, what is the correct approach to dialing in these two knobs? Is there a best practice as to how each one is set compared to the other or order in which they should be set? Am I over thinking this and it is as simple as setting it so it sounds good?
Here is the recommended approach from Markbass: "Here's what we suggest: set your bass volume on full, and start with the gain and master controls off. Play your bass at your hardest level, and turn up the gain until the blue clip light starts illuminating. Now back off your gain level so that it's at its highest level without clipping. You've found your optimal gain level. Now use the master control to set your desired output volume." Did I just answer my own question?
I think your confusion comes from the fact that the typical setting varies from amp to amp, depending upon your goals. First, keep in mind that knob settings mean nothing in regards to how much clean power the amp has left. Some amps hit their max clean power with the knobs set relatively low, and some require you to crank the knobs relatively high. The output level of your bass is a significant factor. If your bass has hot pickups, then the amp will hit its limit with the knobs at a lower level, and if you bass has weak pickups you will need to crank the controls higher to get the same volume. Next consider that some amps are designed to make desirable distortion in the preamp. So you crank up the Gain until you get the desire saturation level, and then use the Master to set your volume level. The idea with this type of setup is to allow you to have distortion at a reasonable volume level. But most people who run tube amps into distortion actually prefer pushing the output tubes rather than the preamp. Also, you may find that you prefer the sound with the Gain set relatively low, because as you turn up the Gain the sound may become darker and less articulate. If you like the Gain set relatively low, then you need to crank up the Master to compensate. Other amps are designed primarily for clean sounds so the proper way to set the Gain may be to turn it up until a LED flashes to indicate you are at the optimum level. Something the consider here is the way the signal LED behaves tends to vary from one amp to the next. With some amps you need to hit the LEDs pretty hard or the amp will not get very loud. Ultimately the best advice is read the manual, but then fiddle with the knobs to see what happens. With experience you develop a feel for this.