My new favorite SansAmp
In the late 70's and early 80's my favorite bass rig was a '70s SVT head and cab. For awhile I switched to modern gear, but eventually realized I wanted the classic SVT tone. I didn't want to deal with the weight and bulk of a 90 pound SVT head, so I tried various amps and rack rigs to try to duplicate that tone without all the weight. My favorite SVT-style preamps were the SVP-Pro, SWR Interstellar Overdrive, and also SansAmps: the BDDI, RBI, and RPM. No imitator can give the full glory of a vintage SVT rig but to my ears the BDDI/RBI could come closest.
Then came the VT pedal, and now the rackmount version, the VTRM. I recently jumped on the VTRM, and after numerous gigs it's become my favorite SansAmp overall, and my favorite device for getting SVT style tones. The Ampeg SVP-Pro preamp has a more SVT-like EQ section, but despite being a mostly tube preamp, it doesn't give the overdrive characteristics of warm 6550 power tubes. The solid state SansAmps are designed to do that, and to me they do it better than genuine tube preamps.
The VT/VTRM emulation does vintage SVT best of all, and the magic is in the Character control. Panned over to the left, you get some mid scoop (think Ultra-Lo switch on the SVT). With Character closer to noon you get a flatter EQ curve. Then as Character moves to the right of noon it provides thick, chunky overdrive. Turning both Drive and Character to the right results in outrageous amounts of distortion and fuzz, especially with an active bass, but to emulate a V4B or SVT stack run really loud to the point of overdrive you can get there by being more gentle with the Drive. The Blend control is also useful: by dialing it back from full, you add more of the natural tone of your bass to the mix. Combined, these controls give you a nice range of SVT style tones, from clean to warm to dirty. You can also get a broad array of non-SVT distortion too.
The VTRM doesn't have the EQ capabilities of a true SVT, which has Vari-mid, Ultra-Hi, and Ultra-Lo settings, but again, it covers a wide range of SVT tones, and the most important benefit is the sound of warm power tubes. My favorite environment for my vintage SVT rig was a big stage in a big venue (or outdoors) where I could run it really loud, just to the point of overdrive or sometimes beyond. The VTRM does this beautifully, and unlike a real SVT it gives you power tube overdrive/distortion at any volume.
Note that the VTRM controls are powerful: a small turn of a knob can result in a significant change in tone or overdrive. However once familiar with the device it's easy to dial in your desired tone, and even change from cleaner to dirtier tones with only a few tweaks.
I would not recommend the VTRM to someone looking for modern clean/flat bass tone. That said, like all SansAmps it's beautifully designed and has a true bypass. So, if you want to run clean/flat and use the VTRM for occasional overdrive, the VTRM will not change your clean tone when it's switched out.
Extra credit to Sweetwater for offering the best possible price, free shipping with quick turnaround, and free extended warranty.