Close, so close
I bought mine used from a reputable source because I was looking for a high-powered amp that could drive cabinets on both sides of a stage. The SVT-7 does not lack for power, rest assured. The analog tone-shaping works well enough, with the classic Ampeg deep, bright and 5 way mid switches. The gain section, however, just doesn't have the "oomph" that one expects with the Ampeg name. Now, I realize there's only one little 12AX7 tube in there, but frankly I expected a bit more warmth and growl. I've recently played through the SVT-4 and I think that may be the way I go on my next purchase. The SVT-4 has a much stronger preamp tube section, and well, the extra 600 watts doesn't hurt.
All things considered, though, the amp does have some good tones in it. I can dial in good thump, slap, pick and tapping tones with minor tweaks of the eq section. They just aren't THE Ampeg sound I was looking for.
The DI is clean, quiet and has good level. It does NOT replicate the sound coming from the speaker cabinets I've used (several different 4x10s, 1x15, 1x12 and even a 6x10). Be prepared to do some tweaking at the board to get your sound through the DI.
The mute function is a godsend, especially when changing basses.
The DI is a zero load, so no cabinet required to use the preamp for DI purposes.
As far as reliability, I've read several reviews that point out inferior quality control. I have had no such issues. I've kept mine in a 4-space rack case and it's never given me a moment's trouble. It resides in a studio for the most part now, but it has been a road dog without ever losing it's bite.
I might change the preamp tube to see if I can squeeze any more gain out of the amp, but even as it sits, it's a powerful little bugger that easily crushes 100W guitar amps, drummers and the occasional flute player.
For someone looking to buy a loud, portable, relatively inexpensive amp that DOES have a lot of great sounds inside, the SVT-7 Pro is a good fit. If you want that gnarly 70's SVT tone, the amp comes up just a little short.