Ampeg SVT II Pro Needs More Headroom

[ryankself]

I've got a '90s Ampeg SVT II Pro (Red / Blue, Speakon) that I keep trying to love, but I'm having a hard time. I hope you can shed some light on the matter.

About the amp: It's just recently gone into a reputable shop for a checkup, and they said it's fine. It's got relatively new JJ preamp / driver tubes and EH 6550s in the power section. I play it through a 4ohm 410 cabinet using the speakon. I keep the master all the way up and use the gain as the volume knob. At lower volumes, it sounds great (I tend to turn the highs down to about 10 o'clock and leave the rest flat, bump the mid knob to 2 o'clock on the second mid selecter notch for more low-mids, no eq sliders). Anything approaching loud band levels gets pretty distorted and loses all bass response. I have an Ashdown ABM 500 Evo II that I also use, and it just completely kicks the Ampeg's behind at higher volumes, keeping it's tone all the way up past noon on the master volume. At lower volume, I honestly prefer the Ampeg tone, but I need more volume for it to be useful.

Like I said, I want to like the amp. I keep hearing I should like the amp. And maybe that's the problem, maybe I'm listening to other people too much... But I'm ready to listen to you!

Is this just how the SVT II is? How can I get more bass (as opposed to distorted guitar sound) out of this thing?

[Alex1984]

Did you check the Ultra Hi/Ultra Lo switch to make sure they're off? Also, I do hear folks say how they use the EQ as an extra boost: everything flat with the level bumped up. Also, is there a pad switch on the 2 pro for active/passive basses? Might want to check that.

If all of these things fail, well, time to get another 410. Honestly, I don't think I've ever had problems with the SVT volume-wise, and it should handle any indoor gig very well.

[Jazz Ad]

A 2-Pro should be somewhere between freaking loud and unbearably loud.

[ryankself]

Ultra High and Low are off, the Active / Passive switch is set to Passive, etc. They all work, too, because I've messed with them. I just don't use them.

I picked up the Ampeg after hearing so much about it being freaking loud and unbearably loud, but that's just not what I'm hearing.

Also, if the 410 is to blame, why is the Ashdown so much thicker and meatier through it?

Not trying to argue, just trying to problem-solve.

[Alex1984]

I'm assuming impedance is properly set too? I practice on my II non-pro at 9 o'clock, rehearsal volume at about 10, and 11 is already plenty for gigging, never tried going past that. How high is your gain?

[rockstarbassist]

That sucks and is wild.
My 400+ is at about 5 on Chan 2 preamp volume and the master on about 1.5.
And that's with the EQ on my bass flat. I boost the bass and treble, the Master has to come down.
So yeah, at those settings you should be overpowering the drums, guitars AND PA- kinda like I do in rehearsal!

[anderbass]

Maybe your Ashdown ABM 500 Evo II is just a much better high volume match for your Avatar B410 Neo cab. That Ashdown is rated at nearly twice the clean output of your SVT so I"d expect it to produce cleaner lows at high volumes. Most of us that play SVT's really loud end up with large 8x10, 6x10 or 2x15 cabs for a reason. 4x10 neo's rated at 1000 watt are cool but I dont remember running across many guys here recommending them for high volume use with SVT's. But even with a big cab, dont expect an SVT to give super clean/tight low-bass response at loud volumes like a higher powered solid state amp would. When you push a tube amp to its limits the lows are always the first to distort.

I wasn't able to find any sensitivity ratings on the Avatar site for the B410 Neo cab so I'm guessing it must be fairly low.

[ryankself]

Yeah, if I the master is full on, the Gain can go to 9:00 and still be okay. Anything past that turns into distorted guitar clankiness.

I understand the point about the power and the low end being the first to go and all that. I guess I was just expecting a little more, y'know?

[Ronny49]

Better off buying a Carvin BRX410 cab. Sensitivity is very strong for a 410 and the bass frequency is very low for more of that luscious sub bass. AND, they're reasonably priced! =)

But I personally prefer the sound of the Ashdown as I am now a happy new owner of an ABM EVO!

[jastacey]

I'd would try to borrow another cabinet, just to see if the it's really the amp, I'm assuming you tried it with different speaker & input cables, too rule them out, did you check the amp to see if the bias is set, using the LED lites?

[anderbass]

Yeah I think you should take your bass, SVT and Avatar cab to a music store (that has an SVT-2pro or CL and a Ampeg 8x10 in stock) so you could try out your SVT with an 8x10, plus compare their SVT to yours with each cab so you could rule out the possibility of your SVT having some type of problem your tech didn't find. (just tell-em your interested in buying a cab or amp and wanna try each out with your gear)

[jellymax]

if a 500w ashdown kicks it ass by a significant amount, then there is something
wrong with your SVT.

compare it side by side with another svt & see. do it with your technician if possible
so he can see for himself--its important.

[KramerBassFan]

Get more speakers matey!

[Gearhead17]

I had nearly the exact same problem with my 2 PRO. I was using the head with the Ampeg 410hlf and I was boosting the low end 40-150hz and boosting the bass knob, very dumb on my part. Plus I was using a 5 string. I ran out of headroom quickly. Are you boosting the low end on your bass guitar?

I suggest getting another identical speaker and running both of them with the 2 PRO.

You mentioned that you don't like that "clunky" tube growl the 2 PRO creates - that is the cool factor of the 2 PRO. If you don't dig that, I suggest you sell it off and stick to the Ashdown. It sounds like you want more clean power over dirtier power.

[JimmyM]

i don't know...i'm thinking you would be better off going the other way around. frankly i don't like the sound of svt's with the master cranked and the gain low. been a while since i did it, but the last time i did it i seem to recall getting similar results. have you tried running with the gain set just below noticeable distortion using your ears and adjusting with the master? i may be wrong, but i would think that your master section would have to work harder doing it your way. someone can (and will) correct me if i'm wrong, but it's worth a try anyway.

if that doesn't help, then i agree you should take it to a music store and ab it. maybe pick up a small item while you're there so they don't bust your balls

[ryankself]

Good info, guys. I will have to do some A/B action with the head. I think the cab is fine, what with it pushing out some serious bass from the Ashdown (same cables, same place, same bass, etc.). It's really annoying hearing this after having it ok'd by a tech, but something just isn't right.

I have tried it using the Gain and Master as they are "supposed" to be used, and I actually get a bit louder doing it with the Master all the way up and the Gain as the volume knob. I start getting preamp distortion around 10:00 or so on the Gain (passive PJ w/ a pick and chromes).

Or maybe it's me, and maybe I do expect too much clean power out of my bass. But for it to be acting like this doesn't feel right.

[JimmyM]

unless you've just got extremely sensitive hearing, you should be able to crank that gain really high without getting noticeable distortion. ya, maybe there is something screwy going on. got a spare 12ax7 you can throw in the v1 slot?

[rbbrchkn]

I don't know if this is the case with the SVT II Pros, but many common tube amps will clip the phase inverter before the power section starts to overdrive. The master volume should be right before the phase inverter, and bringing the level down there should give you the possibility for more clean headroom.

Of course there's no substitute for more clean power if that's what the situation calls for.

[jmercer91]

maybe the tubes are high gain tubes.

[ryankself]

Cool. Once again, thanks to everyone for the ideas. I'll try swapping around some tubes to see if there's a bad one somewhere, and I'll try different combinations of Gain / Master to see what I can get out of it.