Ampeg SVP Pro Bass Preamp

I hooked this thing up with a BBE sonic maximizer and into a Mackie 1400i stereo amp, and was able to dial in some awesome bass tones.
I was playing through a Hartke 3500, which sounded good with the maximizer, but "boxy" without it. This Ampeg preamp blew it out of the water.
The manual is fairly basic. There's not much to know excpept to dial in your favorite tone. It's there!!

I can dial in any tone I want, as well as clean and distortion.
I don't use any stomp boxes, so I rely totally on my amps for my sound.
I play a Warwick Streamer Stage II 5 string inot this rig, and then into a Hartke VX115 and a Hartke VX410 on top. I am planning on purchasing an Ampeg 600 watt 410 cabinet, because I don't think the Hartke's can keep up with my rig.
The rig is virtually noise free when I'm not playing. I've heard people write about the noisy tubes, but I haven't heard it at all.

I've had it for a week, so I can't say how reliable it is yet, but I trust it wi9ll be fine. I always carry a back-up head to a gig, but I'll probably not have to pull it out.

I haven't had to call Ampeg, but have used the website to download information and manuals for Ampeg products. The website is easy to use.

I play modern rock and funk music, with a little classic rock mixed in. This rig has something for everything I play. I've been playing bass for 28 years, and guitar for 38. Besides my Warwick Streamer, I have a Schecter Studio 5, and a 1980 Ibanez Roadster fretless. I also have a Carvin C-850 acoustic guitar. My back-up bass rig is a Hartke 3500 amp head and a Behringer Ultra Bass 3000.
If this SVP-PRO were stolen or lost, I would replace it as soon as possible.
I wish it had a standby mode to keep the tubes cool during breaks.

I have a 72 J-Bass with active EMG's that is my funk machine. I have a 72 P-Bass with a 90's fretless neck that I use for some jazz stuff. I have a late 80's PRS 4-String that I use mor most electric stuff.

I use it for Jazz/Jam Rock/BLues/Funk/Reggae it is an all aroung great sounding head.

it can be very noisy if you do not match the tubes in it, play with various combinations of the AU7 tube till you find a quiet one.

Built in the mid 90's, they have a newer version now.
Very versital pre-amp.
5 tubes (1xAU7 & 4xAX-7's)

A built in Cross-over would be nice for bi-amp

see above, it is a tube amp so make sure you have them checked at least once a year and make sure you swap out the AU7 tube till you find one that makes it quiet.

I have called them only to find the order of the tubes and they are very helpful.

I love this pre-amp for electric stuff, I think for the weight of it compaired to a full tube head it is amazing.

I have been playing sice 1986 or so. I have tons of gear so I will stick with the bass stuff. I have a 76 Musicmaster bass (my first bass) that never gets played. I have a 72 J-Bass with active EMG's that is my funk machine. I have a 72 P-Bass with a 90's fretless neck that I use for some jazz stuff. I have a late 80's PRS 4-String that I use mor most electric stuff. I have a late 90's Knilling Upright with ebony fingerboard and a Davig Gage Pickup that I use for most everything.

Amps etc, I have used lots and lots of various combo's of pre-amps & pawer amps currently I am running an ampeg SVP-Pro > SWR 4004 for electric & Presonus Acoustic-Q > SWR 4004 for the upright. I keep a very old Music Man 120 Tube head around for backup.

Other reviews I have read have said that this unit is noisy. I find it to be absolutely quiet. The tone and depth and grind that it imparts is wonderful. It is easy to get TOO much love when you start to dig in. I am very impressed. It makes our little trio sound a whole lot bigger! I use this amp in conjuction with an SWR 750 X. I run my bass guitar lead into a channel switcher (actually a Loopmaster true by-pass effects loop). One output of the switchmaster goes to the SVP-Pro, which then goes into the effects input of the SWR. Another output of the Loopmaster goes into the regular input of the SWR (through the pre-map section). The SWR has an "effects blend" knob so that I can switch back and forth between the sterile sound of the SWR and the warm sound of the Ampeg. For bouncy, "Beatle" type sounds I use an Epiphone Allen Woody Rumblecat strung with flatwounds. It sounds great through the SWR pre-amp. For harder stuff, I use either a Pedulla Thunderbolt or Gibson SG Reissue through the SVP-Pro and I by-pass the SWR pre-amp altogether. I get the best of both worlds!

Made in 2005. See the Ampeg website for details. I play bass and and sing in a classic rock power trio and Ampeg is THE sound for the harder stuff. It has a nice array of features, although being able to control the amount of distortion remotely (switch or pedal) would be a welcome addition. It has a footswitchable EQ that I use as a volume boost during guitar solos.

I'm gonna give an N/A on this one. I just got it and hope that it is good for the long haul.

See above. I have not dealt with them.

This is a great unit. If it had some sort of remote distortion control, it would be a 10. It is pricey for sure, but it is actually less than the other pre-amps in it's class. If you crave THAT sound but don't want to carry around a huge all tube monster. Or, you're like me and you need 2 distinct sounds. This is the answer.

Fairly simple to use and eq to desired music styles. the slap eq was great.

very good when it was new

Can't depend on it solder joints on power supply broke down several times. This preamp stayed in the shop for repairs. Would cut out on gigs. It won't take the road beating. Maybe best used as a practice preamp for home use only. Will definately have a backup or an amp with it's own preamp section.

Don't have time between gigs to send it back to factory. It only was good thru the warranty period.

was a good match for jazz and R&B when new.

I've read the reviews, tried this unit out for a day, and I can't say I'm impressed at all!

While it is easy to use (if you can't set a graphic EQ and iput output levels, take up tuba), I had nothing but problems with this unit (see sound quality).

The unit right at the store had horrible buzz and microphonic tubes. After some serious grief from the sales guy (I've since been back and he was just having a bad day), got new tubes installed and checked it out.

I brought the unit home (with the assurance of a 30 day money back policy), and hooked it up to my SWR Stereo 800 power amp, SWR 4 x 10 and Cerwin Vega 1 x18 speakers. It buzzed like "mad hornets" as one previous poster said, and no remedy (tube placement, ground lifting, etc...) would rid the pre of this horrible buzzing.

Since I first tried the unit (microphonic tubes) and trying it at home (buzzing and noise), I wouldn't even try it on a gig where you are certain to have a higher noise floor (neon lights, etc...).

Gee, here's where I get a SERIOUS piss-off!

Ampeg's technician, after being explained the problem told me two things-

1. the tubes I was using "weren't good enough!" I needed low noise tubes for this. Now I've tried Teslas, Sovteks, EH's, even Old JAN GEs, and NONE of them "reduced" the noise.

2. I was also told that they couldn't help me with repairs (I do my own, having worked in the industry for over 15 years), as it wasn't bought from a "official" Ampeg dealer.

Well, Mr. Ampeg technician, if you are reading this- you've just cost your compnay a potential customer for life! If I can't repair something (even OUT of warrranty), on my own, or at least get some serious support, the company is NOT WORTH MY TIME OF DAY!

Wouldn't use it, and if it were stolen, the thief can HAVE the damn thing!!! His problem not mine!

I bought a Trace Elliot instead...

Getting a good sound is relatively easy, when it works.....
Manual is readily downloadable from www.ampeg.com

Might sound fine if the hornets moved out.
Buzzes like mad. Unacceptable for a piece of kit of this calibre.

No.
wouldn't gig it, it's going back in exchange for my money, thankyou.

Haven't had the chance. All I know is that the Ampeg site is quite useful.
Check it out before you buy one of these. The forum has a myriad of complaints about this unit humming/buzzing....

Try this with YOUR OWN GEAR before you buy one.
Mine sounded fine in the showroom, then turned into a dog when I hooked it up to my gear, which is equally good.
WHEN it works, it is capable of great results. Shame the reliability isn't there. What a waste of time and money. What a disappointment.
One bad experience has tarnished both my opinion of Ampeg products and of Valves forever. I don't expect perfection, but this is unacceptable.

This is an SVT in a one space rack package - preamp only, no power amp. Very easy to get any good sound from it. When you tweak the knobs the change is very musical and predictable. The tone controls and switches are tailored for bass guitar - you can get a world of tones from this preamp.

The beauty of the SVP Pro is that the tone controls are based around 12AX7 tubes, like the original SVT.

One really good feature is the MUTE button. This mutes the signal from all outputs except the TUNER output. You can use it to switch basses without messing with the volume settings and you can plug a tuner into the TUNER output so you can tune with no sound to the stage or the PA. The MUTE function is also available on the footswitch.

The graphic EQ is good - I plan on using it to EQ different rooms when I play out. The slidepots are real short but manageable with +8/-10dB of control - if they were +/-12dB or higher then they would have been too sensitive.

I got the manual from Ampeg's website and it is well written. It explains each knob/switch and the effect on your sound, and includes sample settings for different styles. The sample settings depend a lot on the bass guitar you are using of course.

The first you MUST do when you buy one of these is to replace the stock Sovtek/Chinese tubes with better ones. I chose a Groove Tubes 12AU7, while the four 12AX7s were replaced with Ruby 12AX7EHs. The immediate difference with the Ruby tubes is that they produced a hotter signal and they were much quieter. The Sovtek 12AX7 would really hiss when the TREBLE tone control was all the way up - not anymore with the Rubys. I swapped back and forth between the stock chinese 12AU7 and the Groove Tube and the GT had a better controllable overdrive. The overdrive from the chinese tube was too brittle, the GT is warmer.

I am using the SVP Pro as a front end bass processor for stage or for studio. When I am on stage I use a PA quality power amp to push a 2x15 cabinet. I tried a 6x10 cabinet but I liked the 2x15 better, especially for six string bass. In the studio I use only the SVP Pro and go direct to the console. That way all the tone comes from the preamp, no matter where I am. I also use a JBL/UREI 7110 compressor in the effects loop to even out the volume - I have the attack set slow so that the punches get through, which is a big part of the Ampeg sound.

The tone controls are three band with mid having five fixed positions for center frequencies (original SVT only had three position mids). The mid tone control is a bandpass filter and is very effective for fine-tuning your sound. The bass control has some serious thunder to it. The treble control is optimized for bass, something that a lot of preamps miss out on - I used to use a Tubeworks Blue Tube and its treble control was not optimized for bass, and with it all the way off that Blue Tube was STILL too bright. Also the Bluetube one has a single tube for its front end; the SVP has five total for front end, tone control, and overdrive.

The manual claims the EQ are active in that they are +/- 12dB but when you turn them all counterclockwise there is no sound - it acts like passive EQs on standard amps. However there is a nice big tube quality to the tone controls - especially on transients when popping/slapping or playing with a pick.

There are three EQ switches - Ultra Low, Bright, and Ultra Hi. Ultra Low does two things - it boosts +3dB at 40hz while it cuts -12dB at 500hz. I really like this setting. This is the AMPEG sound. The BRIGHT switch will boost +8dB at 2Khz - I don't use it all the time. The Ultra Hi switch will boost +7dB at 8Khz - this only seems to be effective when playing with a pick, because it highlights the sound of the pick on the strings.

The SVP Pro adds a DRIVE control that the SVT did not have. It is an overdrive circuit using a 12AU7, chosen for its lower gain. A 12AX7 is way too much gain; great for guitar but not bass. The 12AU7 doesn't distort as easy, the reason it is used for bass overdrive is because 1) it adds harmonics on loud transients while keeping a clean signal (think slapping/popping) and 2) the gain/bandwidth is controllable. In laymen's terms on the latter, when you push a tube too far into overdrive you can hear the bass response drop off, especially on those low B notes on 5/6 string basses. The hot 12AX7 would do this way too easily, hence the 12AU7. The DRIVE control works real good when your playing alternates between fingering and slapping.

Here's how I set up the GAIN and DRIVE: with DRIVE all the way off and 15dB PAD switch off, play fingerpicking style and set GAIN so that the clip LED lights only on peaks. If you have a really hot signal and the GAIN is less than 10 o'clock, then turn on the 15dB PAD and set the GAIN higher - the GAIN setting isn't very effective at low positions.

Then slap that mother while tweaking the DRIVE control. You loud pops will overdrive the 12AU7 which adds harmonics and makes that bass cut through. It also evens out the volume, because an overdriven tube has a natural compression effect. Tweak DRIVE to taste and remember if you go too far you will lose the bass freq

I bought this one used and it had some crackling in the sound. I took it to a repair tech and he found some solder joints that were cracked. When he fixed it the sound was much better.

I peeked inside and it looks well built.

I've been playing bass for over twenty years and have played in many styles - rock-n-roll, funk, soul, R&B. I grew up listening to Aerosmith and Lynyrd Skynyrd and have been broadening my repertoire into modern rock, funk, and classic R&B/soul. I worked with a Gibson RD Artist for a long time and as I recently expanded my musical tastes I bought a MIM Jazz Bass and later an Alvarez six string bass.

I heard some good amps, some bad. I heard Hartke amps and they are way too brittle, Peaveys are OK, SWRs sound wonderful, but the Ampeg SVT was king. I really liked that SVT tube sound, but the only thing that did not appeal to me was that massive head and its reputation of being sensitive to calibrate.

I wasn't aware of the SVP Pro until I stumbled across this one (used) in a store, and when I researched the web I decided that this was a good alternative to the classic SVT. I was right. The Ampeg SVT sound is all there, with a few extra bells and whistles thrown in to bring it up to today's world. Although the SVP Pro was not designed by the same company or people that designed the original SVT, it does get that SVT sound. The fact they used four 12AX7s for the tone control circuits shows how faithful it is to the original. Today's Ampeg is owned by St. Louis Music and many of their amps are designed by Lee Jackson of Metaltronix fame.

I had used a Tube Works Bluetube for a long time, but it only seemed good for one sound and it was too bright. The SVP has now taken its place although I reserve the full bandwidth of the Bluetube for vocals or acoustic guitar. The SVP sounds great and can get a wide variety of sounds. Now I'm happy.

Sounds quite good, just uninspiring to me. Reasonably flexible, but it seemed to me all the EQ options produced variations of the basic Ampeg sound, which isn't quite my cup of tea. Suitable for most music styles, warm clean to big mushy fuzztone. The drive control brings in a nice smooth overdrive, but overall the amp isn't very articulate.

Mid 90's Preamp. 3 band eq w/5 position mid frequency selector, 9 band graphic. 4 12AX7 tubes, 1 12AU7. Drive control, ultra lo and high boost switches, input pad switch, effects loop, tuner out, balanced and unbalanced outs.

Owned for about 10 years, no problems or tube changes.

Never had a problem, can't comment.

I liked the SVP, but it's voice wasn't quite mine. If you'd like to approximate the vintage Ampeg tone but want some flexibility, you would love it.

The sound of this tubepreamp is very ready without any hard eq-settings. For serious bottom its possible to use a 9band graphic eq and a ultralow switch, which cut the middle and boost the low end.
As a special feature this preamp does have a drive knob. The drive uses a 12AU7 tube. When not used the preamp sounds like an svt but turn it to 12 o'clock and its like a 70's Hiwatt-stack, but beefier.
The manual is simple, a block diagram,some settings and the usual front and back panel explanations. If the manual got lost its possible to download it from ampeg.com.

I'm using a Rickenbacker 4003s modified with badass2 and seymourduncan rickenbacker pickups. The other one is a 1983 Fender Precision '57 reissue(dakota red). I'm using this preamp through a crestaudio vs-900 poweramp. The poweramp is in bridge-mono mode(1100W) and it feed the ampeg 8*10" cab. I've owned recently a SVT-classic head. The reason I sold it was that I could get an even better sound through this setup, 20kg less weight,no expensive tube replacements, not have to worry about carrying it when its hot. Everything is nicely packed in a 6U rack-case. Just open the front/backpanels, give the D.I. to the house and go for it. A friend of mine said that don't buy any poweramp unless it read FOR BASS ONLY. So I contacted Ampeg themselves and asked if its possible to use this SVP-PRO with a poweramp. They said that any good professional poweramp should do the trick(+1000w). And they were right. The sound is now much faster, even dropped d-tuning was clear and very responsive, when you radically bend the string the amp will follow!. Many don't like transistor poweramp clipping, but with this setup which have more headroom than any "ready" amp on the market don't clip even after your ears bleed! This setup was a bargain. I got the poweramp for 700? and the preamp for 815? and a case for 200?.The footpedal is also nice, its possible to mute the whole system just by pressing the pedal and at the same time its possible to tune quiet. On gigs and in the rehersalroom its convenient to mute the amp and change instrument or effects and don't have to go to the amp and turn the master off. The settings stay the same. The other feature on the pedal is that it turns the 9 band eq on/off. I use it like a second channel. It is possible to shape, for example a deep dub-reggae sound with it.
I've been playing in bands for 15 years now. This is the first time i'm totally happy with my setup. I'm not going to this typical: I've used this and that blablabla. I've got a svt sound or an overdriven 100W Hiwatt stack with a touch of a knob. No worries about tubereplacements,carrying them or warming them up. Everything is packed safely in a rackcase.

A solid rackcase will protect the whole thing. No backup is needed

I've only sent some emails to them (ampeg). They responded quickly.

I play good rockandroll with some early heavymetal influences. The bass is very solid and cuts through two guitars if you so desire. The other reason why I sold the SVT-classic was that why do I carry a fragile, very heavy amp for just my own monitoring on stage. Because the sound to the audience is different. SVP-PRO has the same tubes as the Classic but driveknob is added. The preamp settings goes through D.I. to the board. Next time we have a recording session I'm only bringing this preamp and connect it to the mixer. I hope nobody will steal it from me, because I'm gonna install a gps-transmitter to it, you can run but you can't hide. Excellent job from Ampeg. Maybe some day I'll buy an old farty bassman and play some quiet blues but now I'm rocking with this for a long time.

One more thing: now I can put all my tube money to something else, Thailand, Mexico, 1966 Thunderbirdbass....

it's a preamp, it dosn't get much easier. some people may wonder what soem of the buttons do - you can find this out by pressing them. Sounds great flat which is always a good sign - this is pretty much how I use it. Don't have a manual or a reason to have one.

Excellent, it sounds like an ampeg. Some people may not like this though and I know what they mean, but you can't criticise it for that. I A/B tested it with the pod model and it is noticabley bigger sounding, Bass Pod is quite close though. It's quiet, I use it on top of an SWR Studio 220 which has a much wekaer sound (but more subtle) and an SWR Goliath Junior II cab. I play Sei bass (Flamboyant and an original), these basses have a pretty hot signal (ok the way mine is set up anyway) and the preamp can cope.

Ok I had a little problem with it once - there was a dry joint, but this can happen to anything so it really would be unreasonable to penalise it for this. As I bought it seconed hand I have no idea if the previous guy abused it....

Asked for the schematic - they mailed it to me quickly from the states to the UK. Can't argue with that!

I Love it, would definitely replace it. They're very cheap and I prefer them to most other valve preamps, especially over the single valve ones. Only wish they made the SVT Pro full valve amp this size but that would defy physics so I'll compromise.