Preamp to increase output of combo?

[surfguy13]

18 hours ago, Muppet said:

I had a BA115 HP which was the higher powered version and whilst the tone was great, the output was still quite poor which was a shame. I ended up selling it as if was only good for quiet rehearsal or recording. I'm not sure you're going to be able to increase the output enough to make a big difference. 

This seems to reflect my experience.  Love the tone, always have with Ampegs, but the output is fairly poor.  I think you're right about not being able to increase output so I think that's a decision made!!

 

3 hours ago, The59Sound said:

A more powerful amp is required. No other solution to this I'm afraid. 

Yup, this is now dawning on me!!!!  Great to have the advice and feedback though; didn't want to ditch the amp and realised there was another option.

 

1 hour ago, Bridgehouse said:

The only Ampeg combo that ever really impressed me was one of the “T” models with a tube preamp - but even that was low output. 

I would suggest something with more heft and power as well. If you can stand the weight you can get some seriously powerful Trace watts for buttons these days..

Strangely enough a Trace is what I had decided to go for.  Such a shame about the Ampeg combos as they really do sound great but the lack of power seems to be right across the board and the fact that they've introduced the HP range suggests that they're aware of this!!

 

3 hours ago, skidder652003 said:

Back on topic...

Ive been using an Ashdown five fifteen purchased from this here parish recently and it was way underpowered for my band (100watt marshall 410 stack) heavy drummer, all mic'd up. But I used my DHA pre amp pedal which has a 15db boost switch and its now easily keeps up (I also go through the PA to be fair), the difference in volume is astonishing, Im probably going to move on my Ampeg rig next year as its just not necessary. So yes, you can boost an underpowered combo with a preamp, IMO

That's exactly what I was hoping to do!  I wonder if this works because you are going into a PA?  I have tried an ART valve preamp box that I use for the acoustic and although it makes a difference it just doesn't make enough difference and also it doesn't sound right somehow?

[cattytown]

4 hours ago, Al Krow said:

Steve - that is really interesting and it would be really neat if that worked generally. 

But I've been told that the physics doesn't work like that ie whatever the input the maximum output of a 100W power amp will be 100W? So I'm now a bit confused on the engineering / physics. 

@Phil Starr? 

 

It's kinda simple. A 100W amp can't give more that 100W. Gain comes into it though. To give that 100W you need a combination of an big enough input signal and enough gain to make that input up to 100W.

If the overall gain of the amp isn't enough to take it up to 100W a preamp may help.

[skidder652003]

5 hours ago, Al Krow said:

Steve - that is really interesting and it would be really neat if that worked generally. 

But I've been told that the physics doesn't work like that ie whatever the input the maximum output of a 100W power amp will be 100W? So I'm now a bit confused on the engineering / physics. 

@Phil Starr? 

so there's no point in Dave Hall putting a 15db boost on the pedal then, cos it won't do anything?

Believe me, it makes a huge difference to the volume, possibly to the point where I need to be careful with the output on the amp in case I blow the speaker. I admit I know nothing about the physics but it certainly works, thats to say with this pedal only, perhaps a normal preamp probably wouldn't do this.

Edited December 26, 2018 by skidder652003

[skidder652003]

1 hour ago, surfguy13 said:

This seems to reflect my experience.  Love the tone, always have with Ampegs, but the output is fairly poor.  I think you're right about not being able to increase output so I think that's a decision made!!

 

Yup, this is now dawning on me!!!!  Great to have the advice and feedback though; didn't want to ditch the amp and realised there was another option.

 

Strangely enough a Trace is what I had decided to go for.  Such a shame about the Ampeg combos as they really do sound great but the lack of power seems to be right across the board and the fact that they've introduced the HP range suggests that they're aware of this!!

 

That's exactly what I was hoping to do!  I wonder if this works because you are going into a PA?  I have tried an ART valve preamp box that I use for the acoustic and although it makes a difference it just doesn't make enough difference and also it doesn't sound right somehow?

no its nothing to do with the PA, the combo itself sounds way more loud, but its the 15db boost thats doing this perhaps rather than the preamp per se, i've tried it without the 15db switch and it doesn't make a big diff in volume

[The59Sound]

30 minutes ago, skidder652003 said:

so there's no point in Dave Hall putting a 15db boost on the pedal then, cos it won't do anything?

Believe me, it makes a huge difference to the volume, possibly to the point where I need to be careful with the output on the amp in case I blow the speaker. I admit I know nothing about the physics but it certainly works, thats to say with this pedal only, perhaps a normal preamp probably wouldn't do this.

But can the speaker handle that dB increase?

[surfguy13]

2 hours ago, skidder652003 said:

no its nothing to do with the PA, the combo itself sounds way more loud, but its the 15db boost thats doing this perhaps rather than the preamp per se, i've tried it without the 15db switch and it doesn't make a big diff in volume

First of all that's a hell of a preamp!!!    It sounds like it may be worth a try.  That looks like a custom/home made preamp......is there such a thing off the shelf with that sort of dB boost?  I guess all I have to be careful with is ensuring I don't blow the speaker.  Mind you, I don't want huge amounts more volume, just enough.

[Lozz196]

The Sansamp Para Driver has a - I think - 20db boost. Certainly makes me jump if I hit it by accident, a bit like a Back To The Future moment.

[Phil Starr]

21 hours ago, Al Krow said:

Steve - that is really interesting and it would be really neat if that worked generally. 

But I've been told that the physics doesn't work like that ie whatever the input the maximum output of a 100W power amp will be 100W? So I'm now a bit confused on the engineering / physics. 

@Phil Starr? 

I wasn't going to answer this question because there are probably people who know the gear you are using way better than I do, but as Al mentioned me I'll put in my little bit.

Very roughly your bass puts out a few thousandths of a volt, this is increased inside the amp in stages so after it has gone through the pre-amp it increases roughly a thousand times and at the master volume it will be around a volt, this feeds into the power amp where it is increased to tens of volts (and lots of current but let's keep it simple) This increase in voltage is called gain. If your bass gives out 5/1000V (5mV) on the loudest note and your amp can make 50V (just over 300W into 8ohms) then the gain is 10,000 or 40dB.

Nearly all amps have enough gain to drive the amp flat out plus a little bit more, they don't know which bass you are going to use and gain is cheap so giving you spare gain is normal. Some amps use extra gain to impress/fool you; if the amp had a gain of 100,000 it would be as loud with the volume set to 1 as another amp set to 10 in the music shop. If you don't know you'll be very impressed, 'it's a really loud amp, way better than that other one'. The trouble is that if you turned it up to 10 then you wouldn't get any more power, just distortion as the power amp can only give it's maximum voltage and current and they are fixed.

So what I think is happening here is your Ampeg has a lower gain than a lot of other amps, so you need to turn the volume and gain up to get all 150W. I know Skidder and if he says the pre-amp makes it louder then I absolutely believe him. (Jefferson Archive, his band are so loud it hurts ) It won't hurt to have everything cranked to 11 so long as you aren't getting a load of distortion, that's just the way your amp is set up. If you want a pre amp to get a bit more gain then go for it but the maximum volume will still be the same, just with your controls at a lower level. You don't need a bass pre amp to test this theory, you could use a PA mixer, guitar effects unit or anything with 10dB of gain between the bass and amp and see just how loud your Ampeg will go before spending any money. If you want a cheap pre amp how about  https://www.gear4music.com/Guitar-and-Bass/Behringer-BDI21-V-Tone-Bass-Preamp/6LV

Edited December 27, 2018 by Phil Starr

[paul_c2]

As above, really. What SHOULD happen, and does happen in most amps, is that at some point the gain/volume/whatever is sufficiently turned up on bass guitar, (maybe pedals etc), amp stages and the amp is now at maximum power. Notes played softly are loud but clean; notes played harder are (in reality) no louder (although your perception might be that you hear them as louder) but have some kind of clipping/distortion/overdrive.

If your bass and amp are unable to achieve that then there's something wrong, somewhere. For example a fault with the bass wiring or the lead, or the socket contact is dirty, or maybe one of the pots on the amp is dirty. Any normal amp, on any normal bass, shouldn't need an additional preamp to achieve its full volume.

[dannybuoy]

On 25/12/2018 at 22:04, Newfoundfreedom said:

Thanks. Just read the first couple of posts and still none the wiser. 

In a nutshell, using PA gear instead of traditional bass amps. More power and higher fidelity for less money and less weight (well, sometimes), then use an amp modeller or preamp in front if you need it to sound like an Ampeg SVT for example. Your amp modeller will sound like it's supposed to and you'll get the same sound on stage as through the PA.

Edited December 27, 2018 by dannybuoy

[chris_b]

A new pre amp would change the OP's sound but any increase in volume would probably be marginal.

It's time to upgrade.

[Newfoundfreedom]

26 minutes ago, dannybuoy said:

In a nutshell, using PA gear instead of traditional bass amps. More power and higher fidelity for less money and less weight (well, sometimes), then use an amp modeller or preamp in front if you need it to sound like an Ampeg SVT for example. Your amp modeller will sound like it's supposed to and you'll get the same sound on stage as through the PA.

I think amp modelling must have come a long way in recent years if that's now a viable option. Everything I ever used with amp modellers sounded muddy and naff no matter how much I messed messed with the settings. But that was several years ago using multi effects pedals like pods, zooms and Boss. I think the Helix and such are probably lightyears away from those. 

[cattytown]

2 hours ago, Newfoundfreedom said:

I think amp modelling must have come a long way in recent years if that's now a viable option. Everything I ever used with amp modellers sounded muddy and naff no matter how much I messed messed with the settings. But that was several years ago using multi effects pedals like pods, zooms and Boss. I think the Helix and such are probably lightyears away from those. 

There’s improvement in modellers, but it’s the use of FRFR that’s also important.

you run am amp rig that colours, and maybe has a high end roll off, and then put a modeller in front of that that simulates a coloured rig, with maybe a different high end roll off and you get mud,

[MoonBassAlpha]

I use a small valve amp in my practice room, and find putting a compressor (TC Spectracomp, in my case), does give an appreciable increase in loudness, probably that the average power being heard is higher.

[surfguy13]

16 hours ago, Lozz196 said:

The Sansamp Para Driver has a - I think - 20db boost. Certainly makes me jump if I hit it by accident, a bit like a Back To The Future moment.

Thanks for that, it looks like a pretty decent bit of kit!  Definitely worth considering.

5 hours ago, Phil Starr said:

I wasn't going to answer this question because there are probably people who know the gear you are using way better than I do, but as Al mentioned me I'll put in my little bit.

Very roughly your bass puts out a few thousandths of a volt, this is increased inside the amp in stages so after it has gone through the pre-amp it increases roughly a thousand times and at the master volume it will be around a volt, this feeds into the power amp where it is increased to tens of volts (and lots of current but let's keep it simple) This increase in voltage is called gain. If your bass gives out 5/1000V (5mV) on the loudest note and your amp can make 50V (just over 300W into 8ohms) then the gain is 10,000 or 40dB.

Nearly all amps have enough gain to drive the amp flat out plus a little bit more, they don't know which bass you are going to use and gain is cheap so giving you spare gain is normal. Some amps use extra gain to impress/fool you; if the amp had a gain of 100,000 it would be as loud with the volume set to 1 as another amp set to 10 in the music shop. If you don't know you'll be very impressed, 'it's a really loud amp, way better than that other one'. The trouble is that if you turned it up to 10 then you wouldn't get any more power, just distortion as the power amp can only give it's maximum voltage and current and they are fixed.

So what I think is happening here is your Ampeg has a lower gain than a lot of other amps, so you need to turn the volume and gain up to get all 150W. I know Skidder and if he says the pre-amp makes it louder then I absolutely believe him. (Jefferson Archive, his band are so loud it hurts ) It won't hurt to have everything cranked to 11 so long as you aren't getting a load of distortion, that's just the way your amp is set up. If you want a pre amp to get a bit more gain then go for it but the maximum volume will still be the same, just with your controls at a lower level. You don't need a bass pre amp to test this theory, you could use a PA mixer, guitar effects unit or anything with 10dB of gain between the bass and amp and see just how loud your Ampeg will go before spending any money. If you want a cheap pre amp how about  https://www.gear4music.com/Guitar-and-Bass/Behringer-BDI21-V-Tone-Bass-Preamp/6LV

That is REALLY helpful and really does help me better understand.  For me the most important point is that a preamp will increase gain which in turn can result in distortion, something I just don't want.  I love Ampegs because they give you a really great clean sound.  

I have had another look at the ART tube preamp I use for phantom power with an acoustic (with my glasses on this time!) and I see it has a +20dB gain button.   It also has an input knob with up to +40 and an output knob with up to +10.   This is definitely worth a try before I do anything.  When I initially tried it in front of the amp it didn't really seem to give me that much in the way of an increase in volume and it also definitely seemed to muddy the signal as the input/output was increased.  However, I hadn't depressed the +20dB gain button!

The Behringer looks like amazing value for money and many thanks for the link!

5 hours ago, paul_c2 said:

As above, really. What SHOULD happen, and does happen in most amps, is that at some point the gain/volume/whatever is sufficiently turned up on bass guitar, (maybe pedals etc), amp stages and the amp is now at maximum power. Notes played softly are loud but clean; notes played harder are (in reality) no louder (although your perception might be that you hear them as louder) but have some kind of clipping/distortion/overdrive.

If your bass and amp are unable to achieve that then there's something wrong, somewhere. For example a fault with the bass wiring or the lead, or the socket contact is dirty, or maybe one of the pots on the amp is dirty. Any normal amp, on any normal bass, shouldn't need an additional preamp to achieve its full volume.

Interesting, I didn't consider the possibility that it could be a dirty pot or dirt on the socket.  I will get that checked out now.  Wouldn't it be great if it was as simple as that! 

[Frank Blank]

5 minutes ago, surfguy13 said:

Wouldn't it be great if it was as simple as that! 

Yes, fingers crossed...