Someone may have already posted the link to what I call "Eublet's TH Rosetta Stone post" back in March 2011, but I figured I would just add it in as cut and paste below. Once you "get it" the TH is very versatile and a lot less frustrating. FWIW, Eublet's observation in a later post was IIRC that the AGS on setting is roughly the same as the Drive control on the TH head being at 3 o'clock - given that, it's obvious why AGS on/AGS off is such a dramatic change with Gain up on the TH DI.
From Eublet's March 2011 post:
The Tone Hammer to me is quite simply an outstanding piece of gear. I've used it often, as well as the BDDI, in a variety of settings, both as a preamp/DI, as a recording unit, and as a preamp for a poweramp. I can answer a lot of questions about this if you ask. I'll give some highlights on each though.
The Blend on the Para does work, but in the end, I never cared for how it worked in the end. The wet signal you blend is has a default scooped tone, which you can try to alter with the mid control, but in the end it seems to be blending the mid-boosted natural tone of your bass with the scooped tube emulated tone. Not to my liking at all. This issue isn't as dramatic sounding with the BDDI because there is no mid boost, so it feels more natural. The tube emulation on the Sansamp is VERY fat, and hard to get away from also. Running lower blend settings help control that, but again the catch is that you wind up hearing a lot of your basses tone mixed in with a completely different tone. Doesn't always wind up getting you were you want to be.
The Tone Hammer is a totally different animal. With the AGS off, it's just an uber clean EQ with gain boost. Very high quality, and the sweepable mids are fantastic. You know how everyone raves about the Sadowsky outboard preamp/DI pedal. I had one, until I got my Tone Hammer. The TH covered the Sadowsky thing VERY well. The low control has the same 40 hz setting with the AGS off, as does the 4k treble setting. The sweepable mids on the TH are just wonderful, though I do wish it would go up to about 2k. No big deal.
The EQ on the TH is flat when it is engaged. When you also turn on the AGS, at the lowest setting, there is no hair on the notes at all. Again, NO hair at all unless your bass is just SUPER hot in terms of output. What does happen when you engage the AGS is that highs are immediately rolled off in a way that simulates a vintage tweeterless cabinet. So the tone gets warmer sounding off the bat, even though the lows and mids are still the same. The Treble control now acts more like a Presence knob does on the Sansamp stuff. It dials in grindy mids in the 2.5k region. Very slick. The lows are tightened up a bit as you boost them, so instead of getting really deep and boomy, they get fat and vintage. Again, still no hair on the notes because the AGS gain is fully counter clockwise. The mid control still allows you to cut/boost mids where you want them. Very slick. Vintage tones with no hair.
As you add more AGS gain, the tone gets warmer until you get some hair, and then it starts overdriving. With the EQ flat, the overdrive tone is VERY mid-oriented such that it can sound a bit nasally and harsh. But remember, this is with the EQ flat, and most folks who are used to hearing a classic tube amp (think SVT for example) should note that an SVT is no where near flat. There's a mid scoop. So to get rid of that nasally midrange in the TH, you have to cut mids as you boost the gain. Setting the knob around 2-3 o'clock puts the mid control around the 750 hz mark, where you'll get some classic SVT'ish mid scoop going. Start cutting the mids there to get the tone you want. Cut to anywhere from 10 to 8 o'clock, and you can pretty much close your eyes and thing your running through the BDDI and not the Tone Hammer. The cool thing is that you aren't having to use a Blend knob at all to control that mid scoop. Just scoop the mids as deep as you like to get the tone you're after, and then adjust the Treble (which now more like a Presence, remember?) to get the amount of cut you want. Then, dial up the bass if you want it fat and deep, or cut it back to keep a thinner tone. Very slick, and way cool.
Here's another trick about the TH that I use a good bit. I'll scoop the mids ALL the way out around 750 hz for a rock tone. With the Bass/Treble boosted to around 2 o'clock, this is very similar to the "Fat Tube" setting from the BDDI manual. But the cool trick is instead to cut treble and bass back. I'll set bass to 11 or maybe 10 o'clock, and cut treble all the way back to 8 or 9 o'clock. The result is a very warm, lower-mid dominant tone (because the upper mids and lows are cut back so far), with a subtle, understated top end. It's very B15'ish and sounds awesome with a P bass or jazz with flats. At this point, if you want more depth, rather than boosting the bass, you move the mid frequency knob clockwise, which pools out upper mids and articulation. If you want more of that, then you move the knob counter clockwise to bring those upper mids back into the tone. The highs and lows stay the same, so it's an easy way to adjust your tone on the gig to get more/less articulation in the mix.
These are just a few examples of what the Tone Hammer can do. I'm a huge fan of it obviously, but I came from being a BDDI user for quite a while, and I just never could bond with the new VT pedal. I still love and have a deep respect for the BDDI, and while I don't use one myself much anymore, I know I can always make it work. The Para Driver I wouldn't bother with myself.
A lot of folks around here have slammed the Tone Hammer because you can't use the AGS like a second channel, where you can engage/disengage overdrive at will without causing volume differences. I guess I can understand that, but really that's not the Aguilar's design intent. Instead, think of it more as a single channel tone shaper, that will "hammer" (pardon the pun) your tone into a wide variety of directions. It just takes a little time playing with the controls to figure out what does what. I still learn new things about it all the time. It's not that it's complicated, but rather that the AGS circuit ties in very closely to the mid control, so changing the mids affects the overdrive tone, and the more gain you add, the more the low end tightens up to prevent things from getting muddy.
