Ampeg SVT3 Pro questions

[AM1]

Hoping someone can help with my stupid questions!

Am still getting my head round the "brains" of the SVT3 amp before I use it live.

A few questions:

OK - for a live situation - if I use the Ampeg head and whatever cab I can pikey, and go through the PA...there's 2 XLR outputs on the amp (balanced and unbalanced) - can I go from one of these direct into the PA or do I need to go through a DI box? What's the advantage/disadvantage of not going through a DI box? On the Ampeg amp, you can take the signal into the PA with EQ off on the amp..presumably then the PA would do the EQ or a DI box....or you can take the signal into the PA "post EQ" so the EQ is all done from the amp onstage. Is it better to use the PA for EQ? Or this completely dependent on the venue size?

The amp itself - I notice it appears to be clipping a bit, even with the gain turned down - but in the manual it says there is an attenuation switch, which when activated, attenuates input signal by 15dB, allowing gain to be used over a larger portion of it's range. But the manual also suggests adjusting the gain until a strong signal from the bass causes the LED to flicker (indicating clipping)!! A bit confusing!

The EQ - technically I could play with EQ off, then use a footswitch to activate the EQ (if I wanted a different sound)... but how would that work if the amp was DI'd into a PA?? Is this dependent on pre or post EQ settings?

There is a line output level control at the back of the amp, separate from the main master "volume" control. The manual says this control adjusts the output level at the XLR jacks (at the back of the amp). What does it mean by output level? Volume? Or actual output?

The Speakon socket - apparently when working at full output you should use speakon cable rather than normal 1/4" jack. This head can handle 8 ohm load and output 275 watts and can handle 4 ohm load and output 450 atts. So, I am taking "full output" to mean in the ohms sense, so if you were running a single cab of 8 ohms, the normal 1/4" jack is fine, but if you run 2 x 8ohms cabs, you get 4ohms and need to use the speakon? Or if you were using a single 4ohm cab, you should use the speakon?

What does it do to the amp if only a single 8ohm cab is used all the time, does this not mean the amp is not working at full capacity? Or what if you run at 4ohms but don't use the speakon jack, is the amp then working too hard? Technically, when I plug in 2 cabs, if those 2 cabs equal 4ohms, I should ALWAYS be using that speakon jack, otherwise the amp is going to be working too hard? Even without everything cranked up? Because the actual output is 4ohms?

Sorry for the stupid questions but I don't really know much about impedance etc!

Cheers
AM

[chris_b]

You shouldn't need a DI box, even if the engineer says you do!! A DI box will bypass the amp altogether, which is not what [i]I[/i] want. I use the Balanced DI, post EQ and have the DI level at 3 o'clock. The line level is independent of the volume controls.

If the amp is clipping even with the gain turned down, your bass is too loud, turn your bass down. I’ve never used the buttons and have them all in the out position.

Use either output socket. They really make no difference to the sound. The number of cabs will have no bearing on how "hard" the amp works. I don't use the graphic, I have all the buttons out, I have the master volume on 3 o'clock, the gain on about 11 o'clock and I control the overall volume from my bass. Most of the other controls are flat-ish at about 1 o'clock. You might have to make changes to this if your cab(s) are less sensitive.

An SVT3 is pretty bomb proof and you really will be hard pressed to damage it and it always gets a good sound.

[steve]

I'll have a go, since I have one of these heads

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']OK - for a live situation - if I use the Ampeg head and whatever cab I can pikey, and go through the PA...there's 2 XLR outputs on the amp (balanced and unbalanced) - can I go from one of these direct into the PA or do I need to go through a DI box? What's the advantage/disadvantage of not going through a DI box? On the Ampeg amp, you can take the signal into the PA with EQ off on the amp..presumably then the PA would do the EQ or a DI box....or you can take the signal into the PA "post EQ" so the EQ is all done from the amp onstage. Is it better to use the PA for EQ? Or this completely dependent on the venue size?[/quote]

Will you need to go through the PA? The gigs I played through mine were loud enough without it - using 2 x 8ohm cabs (omni10.5s)

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']The amp itself - I notice it appears to be clipping a bit, even with the gain turned down - but in the manual it says there is an attenuation switch, which when activated, attenuates input signal by 15dB, allowing gain to be used over a larger portion of it's range. But the manual also suggests adjusting the gain until a strong signal from the bass causes the LED to flicker (indicating clipping)!! A bit confusing![/quote]

If the LED is just flickering, this represents the point just before the pre starts to clip, and you're getting the maximum signal without any distortion

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']The EQ - technically I could play with EQ off, then use a footswitch to activate the EQ (if I wanted a different sound)... but how would that work if the amp was DI'd into a PA?? Is this dependent on pre or post EQ settings?[/quote]

I think so, but I never needed to use the graphic to get a sound I was happy with, and never bothered switching channels

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']There is a line output level control at the back of the amp, separate from the main master "volume" control. The manual says this control adjusts the output level at the XLR jacks (at the back of the amp). What does it mean by output level? Volume? Or actual output?[/quote]

not sure, never needed it

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']The Speakon socket - apparently when working at full output you should use speakon cable rather than normal 1/

4" jack. This head can handle 8 ohm load and output 275 watts and can handle 4 ohm load and output 450 atts. So, I am taking "full output" to mean in the ohms sense, so if you were running a single cab of 8 ohms, the normal 1/4" jack is fine, but if you run 2 x 8ohms cabs, you get 4ohms and need to use the speakon? Or if you were using a single 4ohm cab, you should use the speakon?

What does it do to the amp if only a single 8ohm cab is used all the time, does this not mean the amp is not working at full capacity? Or what if you run at 4ohms but don't use the speakon jack, is the amp then working too hard? Technically, when I plug in 2 cabs, if those 2 cabs equal 4ohms, I should ALWAYS be using that speakon jack, otherwise the amp is going to be working too hard? Even without everything cranked up? Because the actual output is 4ohms?[/quote]

best way to resolve this would be to just use a speakon jack, whatever the cab configuration.

I agree with chris_b tho, they are bomb-proof - just plug it in and make it sound good to your ears

[chris_b]

[quote name='AM1' post='449322' date='Mar 30 2009, 11:40 AM']....I don't really know much about impedance....[/quote]
The only cab combinations you cab use are: 1 8 ohm cab or 2 8 ohm cabs (which make 4 ohms) or 1 4 ohm cab. That's it, but that should be enough for anyone!

[cetera]

The other two secrets of great tone from this amp are:

1) The 'drive' (edit - I mean 'tube gain') control works in reverse i.e. with the 'tube gain' control at 7 o'clock (off) it is driving harder than at 5 o'clock (full on)...

2) Run the Master Volume on FULL and adjust the volume via your gain control...

Seriously, try it...

Edited April 1, 2009 by cetera

[chris_b]

Master on full might be a little noisy. I can get mine to 3 o'clock before excessive hissing starts. But the Master should be as high as you can get it.

Which one is "drive"??

Edited March 31, 2009 by chris_b

[Clockworkwar]

Buy a product where the company that makes it knows how to write proper instructions.

[steve]

[quote name='Clockworkwar' post='450704' date='Mar 31 2009, 05:38 PM']Buy a product where the company that makes it knows how to write proper instructions.[/quote]

[cetera]

[quote name='chris_b' post='450690' date='Mar 31 2009, 05:26 PM']Master on full might be a little noisy. I can get mine to 3 o'clock before excessive hissing starts. But the Master should be as high as you can get it.

Which one is "drive"??[/quote]

Sorry, I meant 'tube gain'...

[andy67]

master and tube gain (drive by me too) full on and gain at three works fantastically well for me.