All of this and a FIVE tube preamp as well. From what I understand the only transistor circuitry is the Graphic EQ.

The only thing I would have like to have would be a built in crossover, but since most people don't biamp, and panel space was at a premium, I can live without it (I use an external crossover for biamping anyway).

I bought the optional footswitch, which is pricey at $29, but it has the classy Ampeg logo on it, and two LED's. The footswitch let's you select the mute function without having to walk back to your rack, and toggle the EQ in and out. One real nice feature about the footswitch is that it takes a stereo TRS 1/4" cable, instead of having the cable built in. That way if you frag the cable, you don't have to pull the box apart to fix it. Also these cables (1/4" TRS Stereo) used to be hard to get, but are now readily available in lengths up to 30', so you are not limited to the 5 or 10' you typically get with a footswitch.

Anyway - how does it sound?

FANTASTIC (with one caveat)

I've had this thing for 6 months now, and the newness of it has worn off, so I feel I can give an unbiased review now (everything sounds good when you first get it home).

According to a number of people I talked to, and the salesman at the store, there are really only two tube preamps worth considering (not counting ultra high end stuff like the Aguilar).

I compared the Ampeg SVP Pro to the Alembic F1-X and chose the Ampeg. The Alembic is a great piece, basically it comes down to:

1. If you want a real clear, deep, uncolored tone that will compliment your bass, go for the Alembic.

2. If you want a sound where the amp is an integral part of the sound, if you want agression and attitude in your tone, the Ampeg has it with a capital A.

This preamp has made the biggest contribution of anything to my sound in 20 years. I wasn't even aware Ampeg was making it until about 2 years ago when I picked up a new catalog of theirs.

I wished I hadn't waited a year and a half to buy it.

I'll put it this way, usually other band members are ambivelant about bass tone, as long as it's not too loud they don't care.

As soon as I plugged in the SVP Pro, they all went WOW, what the hell is that sound?

Another thing that is cool is the DI. Although the output level is pretty low, the DI sounds great, and since it comes off the tube preamp, it imparts a lovely "tubeyness" to a recorded tone. The DI gives you a switch to select PRE or POST EQ, a nice touch.

One day at practice, I set up for a live to tape recording (multitracked, where the bass got it's own track). I set up for my regular live sound, set the DI to PRE out, and we played. The signal chain was the DI into my TASCAM M1516 board (not exactly a high end board), with a direct out to my TASCAM TSR-8 analog reel to reel 8 track. Virtually no EQ on the channel.

When I played the track back, it had a great, fat, warm tone, with a defined midrange that just killed. It was one of the best recorded bass tones I ever got, and I wasn't even trying!

Now normally my direct chain for recording bass consists of running the bass into a Countryman DI (one of the better active DI's out there), then into a RANE FMI-14 mic preamp, with a parametric eq in the insert, then a direct out into the deck.

While this gets a great sound, the Ampeg DI just sounded more "real", like I was standing there playing the bass instead of the sound coming off tape.

If I had a studio (I mean real, not a basement one like mine), I think I would get an SVP-Pro for the DI sound alone...

There are two problems with the SVP Pro, neither of which is insurmountable.

1. There are so many controls, eq etc. and everything really interacts, it can take you a while to dial in the tone you want. In particular, the drive control has MAJOR effect on the sound of the EQ. I was thinking the EQ was just ok, and then I turned the drive control up and all of a sudden, the EQ really came alive.

Basically you set up the gain and pad controls (You will probably have to use the pad, even with a passive bass) to get a good level, then use the drive control to get the amount of "tubeyness" and EQ punch you need.

Unlike a guitar amp, the drive control doesn't really contribute overdrive or distortion until it's up really high (like over 8) and then only in conjunction with the gain being really high (at least over 5).

If you want that old Jack Bruce sound, or the Geddy Lee "Moving Pictures" grrrr, this thing has that in spades.

It can also sound very clear and clean (except for some preamp hiss) if you want it too. It's very flexible, in fact TOO flexible in some respects.

It took me about 4 or 5 practices to really dial in the tone I like, but it was worth it.

Once you get the sound you like, there is a master volume that turns everything up or down. Unlike some preamps, this doesn't really change your sound except for making it louder.

This preamp is very responsive to touch also, it will track your dymanics very well, purring along until you spank your bass, then it will rip your head off.

As I said, the EQ is VERY flexible, there are not really any bad settings, it reminds me of a high end analog recording board (like the vaunted API EQ), you don't twiddle the EQ knobs to find a good sound, it all sounds good. You twiddle the knobs to find the sound that fits the musical context you are in.

2. Now the real downside - There is a considerable amount of preamp hiss, although in the SVP Pro's defense, the Alembic had a bit of hiss too, just not nearly as much.

The problem was excacerbated when I bought a 2 x 10" cab with a horn. I normally biamp, and use a compressor with a gate, so the idle hiss isn't real bad but for some users with low powered power amps, you may have to turn up high and get an objectionable amount of hiss.

The SVP - Pro is known for this problem, and it was suggested to me that replacing the tubes with Ruby STR-7025's (for the 12AX7's) and replacing the 12AU7 tube would reign in the hiss a little.

I think this mod improved the tone and the hiss a little, but then again it might have been the $50 I spent on the tubes!

I guess complaining about this hiss is like complaining you can't hear the stereo over the sound of the engine on your Ferrari - it's there but doesn't really detract from the sound once you start playing.

Compared to a guitar rig, or even some PA's, it's not bad at all.

I realize that I have fawned over this thing a lot, but it really is one of the best pieces of bass gear out there (especially for under $400). When I checked with some bass forums about choices for bass pre's , a lot of people pointed me towards the Alembic.

As a measure of how good the Ampeg is, one of these Alembic owners later bought an SVP Pro, and says now that he likes it better (he also says the Alembic is more appropriate for some situations).

The Ampeg SVP-Pro is billed as - "the sound of an SVT in a single rack space". If you've always lusted after that SVT tone, but didn't want the weight, retubing expense and hassle of the real thing, this is about as close as it gets.

I would recommend this piece to any player who wants a thick, in your face tone...

Construction	90%
The back jacks are mounted directly to the
circuit board instead of to the panel
Clarity	100%
Even when overdriven you can hear everything
Tone	100%
For rock, blues, roots, this is the piece.
Could do jazz, etc. but the Alembic is probably
more appropriate
Size/Bulkiness	100%
All this in one rack space!
Value	100%
Cheaper than the Alembic and Eden, about the
same price as an SWR Grand Prix, which isn't even
in the same league
Overall	95%
I'm a freak about hum and hiss, so I'm taking
off 5% for excessive hiss. If they fixed that
problem, this thing would be absolutely perfect
(at least for the sound/style that I'm doing)