Power Amp, Cab and Pre Amp Pedal Setup?

[Linus27]

I was thinking today how each manufacturer of amps, cabs, active basses etc. have their own sound and add colour to some degree and you never quite know what you get until you buy your new gear and either love it or hate it. It then got me thinking about how the old Mission Cyrus HiFi amps never had a bass or treble controls and was one of the best amps I'd heard back in the day along with NAD amps. I then read a post on Facebook about how some bassists are running a power amp with their chosen speaker and using a pre-amp pedal for tweaking their sound but mostly letting the natural sound of their bass come through rather than an amp colouring it. This got me interested and more so when one chap said he was using a GRBass Pure 800 power amp, a Barefaced cab and a Sansamp pre-amp pedal. Another said he does the same but uses the GRBass One 800 amp as you can bypass the EQ completely and just use it like a power amp.

 

Is anyone running a setup like this and does it work? Would be interested on any thoughts or feedback.

[Dan Dare]

I used to run a BBE pre' plus PA power amp. Worked well, but was no better than my current Aguilar head (and a lot heavier/bulkier - a modern class D power amp would get round that issue). If your head has an fx return, you can run a pre' into that and bypass the onboard tone stack/preamp. The only way to find whether it will suit you is to try stuff out. In my experience, running a flat rig is nice at lower volumes, but it can get a bit lost when you need to push some air and compensate for venue acoustics, other instruments/amps, noisy stages, etc. If you want that studio monitor clean sound at high volume, you need to spend quite a bit of money.

[BassmanPaul]

The 'Gotcha' here is signal levels. Most Stereo power amps operate with line level signals. A pedal, typically made to drive the input od a normal amplifier will use Instrument level. It will not be able to push the power amp to serious volumes.

 

In my case I bought a 2KW capable Class D stereo power amp, run in parallel mode, with one or two of my Acme B2 bass cabinets on each channel. To drive the power amp fully I built a tube pre-amp I designed for the job.

 

Using a pedal you might have to add a signal amplifier between the pedal and the power amp.

Edited August 30, 2023 by BassmanPaul

[jrixn1]

It's a good, modular concept: the instrument and pedals provide the tone; the power amp and speaker have just the one job - to amplify it transparently.

 

However, a GR Bass Pure 800 is, what, £680 - if you can find one in stock anywhere.  A Big Baby 3 is £1,149, with a three-month lead time.  That's £1,829.

 

Instead, look into powered speakers (some people call them 'FRFR', so use that as a search term).  An RCF 732-A is about £750 and you can get it on next-day delivery from any number of shops.  The internal 700W RMS power amp benefits from DSP which handles crossover, phase control, and speaker protection.

 

I used mine with various preamp pedals with no problem - just plug them in with a normal jack cable.  The powered speaker has options for input level (mic or line); line level is fine - be careful with mic level as it will very loud.

 

Other RCF powered speaker models to look into: HD 32-A, 932-A, 745-A.  And from other manufacturers you have the QSC K12.2 and Yamaha DXR12/DXR15.

 

Since moving to powered speakers I've had the best and most consistent sound ever - definitely never going back to a traditional bass amp.

[Linus27]

35 minutes ago, jrixn1 said:

It's a good, modular concept: the instrument and pedals provide the tone; the power amp and speaker have just the one job - to amplify it transparently.

 

However, a GR Bass Pure 800 is, what, £680 - if you can find one in stock anywhere.  A Big Baby 3 is £1,149, with a three-month lead time.  That's £1,829.

 

Instead, look into powered speakers (some people call them 'FRFR', so use that as a search term).  An RCF 732-A is about £750 and you can get it on next-day delivery from any number of shops.  The internal 700W RMS power amp benefits from DSP which handles crossover, phase control, and speaker protection.

 

I used mine with various preamp pedals with no problem - just plug them in with a normal jack cable.  The powered speaker has options for input level (mic or line); line level is fine - be careful with mic level as it will very loud.

 

Other RCF powered speaker models to look into: HD 32-A, 932-A, 745-A.  And from other manufacturers you have the QSC K12.2 and Yamaha DXR12/DXR15.

 

Since moving to powered speakers I've had the best and most consistent sound ever - definitely never going back to a traditional bass amp.

 

Thank you. I should of said that I do have a Barefaced Two10 already and a MarkBass Little Bass IV. So I'd keep the cab and just swap out the amp but I do get what you're saying.

[MrDinsdale]

You could probably test the theory by running your preamp of choice into the FX return on your amp if it has one. 
 

I did this a few times with my Model FeT and Capo preamps and it sounded great. Also did it with the Boss GT1000 core quite a bit. That was a GK Fusion S 800 amp.

[Jack]

My first attempt at a bass amp that sounded like a mini-pa system did what you're talking about, although my pedal preamps (mostly an MXR M80 at the time) wouldn't drive the power amp properly and so there was a channel strip too. The Presonus was pretty transparent and I appreciated the compressor and eq too. Actually that was a hell of a rig to be fair. Clean, powerful and so loud. Nowadays I wouldn't bother. In fact I don't. Powered PA cabs are just so much better.

[Downunderwonder]

There's a Quilter 800w amp in the classifieds for you. Beats carrying a 2U power amp, and you can DI off it at the same time. Noon knobs is flat everything just like a power amp but it isn't at all fussy what you feed it from. Originally conceived as a power module for bass players with pedals, they decided it would make a lot more sales as an integrated amp that could also plug a bass in and EQ. Go figure. All things to all bassists so of course sales were slow and it got discontinued in favour of a more EQ model.

[sandy_r]

[not needed on journey]

Edited February 21 by sandy_r
forgot how to write in English

[Steve Browning]

Am I being incredibly dense here? What is the difference between using a power amp and an external pre-amp and using an amp with one built in?

[Linus27]

4 minutes ago, Steve Browning said:

Am I being incredibly dense here? What is the difference between using a power amp and an external pre-amp and using an amp with one built in?

 

My understanding is if you plug your bass direct into a power amp, you get a pure uncoloured tone and just the sound of your bass. You do however lack any controls to modulate the bass, mids and treble. If you plug into a bass amp, you are then restricted to the manufacturers pre-amp and the tone that they bring. So if you have an Ampeg amp, you get the Ampeg pre-amp colour, if you have a MarkBass amp then you get the MarkBass pre-amp colour and so on and so forth. Using a just a power amp, you get an uncoloured sound and then you can use the pre-amp of your choice to colour your sound, for example a MXR pre-amp, an Ampeg pre-amp, a Sansamp pre-amp and you are not limited to the colour of a pre-amp in a bass amp. 

[jrixn1]

12 minutes ago, Steve Browning said:

What is the difference between using a power amp and an external pre-amp and using an amp with one built in?

 

Modularity?  It's a lot easier to swap out an external preamp than a built-in one.

[Phil Starr]

20 minutes ago, Steve Browning said:

Am I being incredibly dense here? What is the difference between using a power amp and an external pre-amp and using an amp with one built in?

Not dense at all that's exactly what you get, except that when you buy a bass amp you are stuck with someone else's choices.

 

By and large if you feed into the effects return in a bass amp then you'll get the same sound going through to the speaker. Not all amps share the same architecture though so don't hold me to this. The tone shaping in a bass amp is in the pre-amp section and so you are stuck with any flavour which may be designed in. There's often different amounts of HPF, smiley faced pre shaping and not all tome controls are flat at 12.00 o/c. I'm guessing the OP wants to control his own pre shaping.

 

Almost exactly a year ago we had hold of the three micro amps Gnome/Elf/ BAM. They all come in almost the same dimensions with the same controls/facilities and so on. We measured the frequency responses and they are all different. With controls flat the Elf is classic smiley face, the Gnome has a raised top end and the BAM in between. All of them had a reduced output at 400Hz and all the mid controls were centred on 400Hz. Interestingly it was almost/totally  impossible to make each of them flat or to make them sound completely identical despite the mid control conveniently lining up with the mid suckout and having the measured frequency response in front of us. The same will be true of pretty much any bass amp.

 

As an analogy I'd say its a bit like using pickled onions in a recipe when you've run out of fresh ones, you'll never quite get rid of the taste of vinegar

[Dan Dare]

38 minutes ago, Steve Browning said:

What is the difference between using a power amp and an external pre-amp and using an amp with one built in?

 Probably not that great in many cases. It depends on the eq/facilities different pre's offer. A channel strip type of pre will probably allow more extensive tone-shaping and have less of a baked-in sound. When I made the switch from pre + power to a head, I found a head that gave me results I liked with my instrument and cabs without my needing to do much with the eq. Of course, if my tastes/instrument/cabs change, I may have to change it to get what I want. As I'm pretty ancient and set in my ways, that's relatively unlikely.

[Phil Starr]

On 30/08/2023 at 18:35, Linus27 said:

 

 

Is anyone running a setup like this and does it work? Would be interested on any thoughts or feedback.

Lot's of us are doing this though it's a only minority, but one that is increasing.

 

I've played through PA amps into PA speakers, bass amps into PA speakers, PA amps into bass speakers and recently regularly straight into active PA cabs. My regular set up is currently Sansamp into active PA monitors or into a Bugera set flat and on to an LFSys Silverstone which is a flat response bass speaker. That's when I don't just use in-ears.

 

The best sound I get is at home putting the bass straight into studio monitors sometimes using the Sansamp or often just into the mixer. You can get pretty close to this on stage but room acoustics can make that difficult at times.

 

Going this way is great if you like the sound of your bass 'au naturel' it also makes eq simpler. If your bass amp has a 'shape' then you can only really control it if your parametric tone controls can be set to the same frequency and  Q and you have an ear educated enough to make that happen. Otherwise your tone controls work like a committee, eventually compromising because they can't actually reach agreement

Edited September 1, 2023 by Phil Starr

[Linus27]

41 minutes ago, Phil Starr said:

Not dense at all that's exactly what you get, except that when you buy a bass amp you are stuck with someone else's choices.

 

By and large if you feed into the effects return in a bass amp then you'll get the same sound going through to the speaker. Not all amps share the same architecture though so don't hold me to this. The tone shaping in a bass amp is in the pre-amp section and so you are stuck with any flavour which may be designed in. There's often different amounts of HPF, smiley faced pre shaping and not all tome controls are flat at 12.00 o/c. I'm guessing the OP wants to control his own pre shaping.

 

Almost exactly a year ago we had hold of the three micro amps Gnome/Elf/ BAM. They all come in almost the same dimensions with the same controls/facilities and so on. We measured the frequency responses and they are all different. With controls flat the Elf is classic smiley face, the Gnome has a raised top end and the BAM in between. All of them had a reduced output at 400Hz and all the mid controls were centred on 400Hz. Interestingly it was almost/totally  impossible to make each of them flat or to make them sound completely identical despite the mid control conveniently lining up with the mid suckout and having the measured frequency response in front of us. The same will be true of pretty much any bass amp.

 

As an analogy I'd say its a bit like using pickled onions in a recipe when you've run out of fresh ones, you'll never quite get rid of the taste of vinegar

 

That is such a great explanation. 

[Linus27]

26 minutes ago, Phil Starr said:

Lot's of us are doing this though it's a only minority, but one that is increasing.

 

I've played through PA amps into PA speakers, bass amps into PA speakers, PA amps into bass speakers and recently regularly straight into active PA cabs. My regular set up is currently Sansamp into active PA monitors or into a Bugera set flat and on to an LFSys Silverstone which is a flat response bass speaker. That's when I don't just use in-ears.

 

The best sound I get is at home putting the bass straight into studio monitors sometimes using the Sansamp or often just into the mixer. You can get pretty close to this on stage but room acoustics can make that difficult at times.

 

Going this way is great if you like the sound of your bass 'au naturel' it also makes eq simpler. If your bass amp has a 'shape' then you can only really control it if your parametric tone controls can be set to the same frequency and  Q and you have an ear educated enough to make that happen. Otherwise your tone controls work like a committee, eventually compromising because they can't actually reach agreement

 

This is super interesting, especially the point about if you like the 'au naturel' sound of your bass and how you have compared the EQ of the Elf, Gnome and Bam. I have the 280w Gnome and what you say the Gnome is flat, I actually find this to be too bass heavy for my liking and need to dial a bit of bass out. So my preference for a natural bass sound to my ears is different to the flat sound and how a coloured amp can complicate things even further.

[asingardenof]

1 hour ago, Phil Starr said:

Not dense at all that's exactly what you get, except that when you buy a bass amp you are stuck with someone else's choices.

 

If you've bought an amp with both preamp and power stages that'll be because you like those choices though. Knowing there's an option that removes the need for a preamp stage is useful, but I still like the choices Ashdown and Trace have made with the amps I use.

[Phil Starr]

6 hours ago, Linus27 said:

 

This is super interesting, especially the point about if you like the 'au naturel' sound of your bass and how you have compared the EQ of the Elf, Gnome and Bam. I have the 280w Gnome and what you say the Gnome is flat, I actually find this to be too bass heavy for my liking and need to dial a bit of bass out. So my preference for a natural bass sound to my ears is different to the flat sound and how a coloured amp can complicate things even further.

Actually my Gnome didn't measure flat at all with everything at 12.00 but your 280W big brother may well be eq'd differently. Mine rolled off quite early, had a bit of an upper bass boost then a huge upper mid/treble boost. That does give it a clean, hi fi sound with the right speakers but it is ultimately not a very accurate sound. I only mention it because it is objective evidence of how manufacturers do flavour their amps, they aren't just wires that have gain as the old Cyrus amp was meant to be but full flavoured additions to your bass sound. The Bugera turned out to be one of the most neutral amps we tried at 12.00.

 

As to the point about dialing bass out I find you need to do that as a matter of course to get a good live sound and to boost the mids. That's even worse with PA speakers that are meant to be flat response when flown and are way too bassy on the floor.

 

The LFSys Monza and Monaco's are designed to take that into account and have an extended but tailored low end.

[Linus27]

2 hours ago, Phil Starr said:

Actually my Gnome didn't measure flat at all with everything at 12.00 but your 280W big brother may well be eq'd differently. Mine rolled off quite early, had a bit of an upper bass boost then a huge upper mid/treble boost. That does give it a clean, hi fi sound with the right speakers but it is ultimately not a very accurate sound. I only mention it because it is objective evidence of how manufacturers do flavour their amps, they aren't just wires that have gain as the old Cyrus amp was meant to be but full flavoured additions to your bass sound. The Bugera turned out to be one of the most neutral amps we tried at 12.00.

 

As to the point about dialing bass out I find you need to do that as a matter of course to get a good live sound and to boost the mids. That's even worse with PA speakers that are meant to be flat response when flown and are way too bassy on the floor.

 

The LFSys Monza and Monaco's are designed to take that into account and have an extended but tailored low end.

 

@Phil StarrI've just been reading your post about the LFSys Speakers that yourself, @stevie and @bussonetthebass were testing earlier in the year. As a fretless bassist who generally likes a very clean, warm and rounded tone, it has certainly got me very interested. I'm currently using a Barefaced Two10 with a Gnome 280w which I do really like or a MarkBass LM IV which has not grabbed me so much. I only use reverb, chorus and octave but its important that the sound stays clean and the octave especially keep the notes defined and doesn't go woolly or mushy. I play in a pretty busy acoustic three piece and we need to keep separation of frequencies between the acoustic guitar, vocals/vocal layers and then my bass. I play a lot of melodic fretless bass and need to maintain a very clear, defined sound whilst maintaining a full bass to fill that bottom end. At times I feel I don't always achieve this, especially with the octave pedal as it loses clarity. By pure chance, I used a Fender Rumble 500 at a festival the other week which I believe uses Celestion speakers and when I kicked my octave in, the sound was incredible. Even our singer mid sentence stopped singing, looked over at me and voiced "wow" at me and then kept doing it every time I used the octave pedal. He even left me and drummer to just groove at the end of one song with the octave pedal on as it sounded so good.

 

So the LFYsys cabs sure look interesting and I'm assuming they are named after F1 circuits which as an F1 fan since 1979 who proposed to my wife on the grid at Monza, honeymoon'd at Monaco and driven Silverstone a few times spurs my interest a bit more 😁

Edited September 1, 2023 by Linus27

[Baloney Balderdash]

On 01/09/2023 at 11:31, Phil Starr said:

Not dense at all that's exactly what you get, except that when you buy a bass amp you are stuck with someone else's choices.

 

By and large if you feed into the effects return in a bass amp then you'll get the same sound going through to the speaker. Not all amps share the same architecture though so don't hold me to this. The tone shaping in a bass amp is in the pre-amp section and so you are stuck with any flavour which may be designed in. There's often different amounts of HPF, smiley faced pre shaping and not all tome controls are flat at 12.00 o/c. I'm guessing the OP wants to control his own pre shaping.

 

Almost exactly a year ago we had hold of the three micro amps Gnome/Elf/ BAM. They all come in almost the same dimensions with the same controls/facilities and so on. We measured the frequency responses and they are all different. With controls flat the Elf is classic smiley face, the Gnome has a raised top end and the BAM in between. All of them had a reduced output at 400Hz and all the mid controls were centred on 400Hz. Interestingly it was almost/totally  impossible to make each of them flat or to make them sound completely identical despite the mid control conveniently lining up with the mid suckout and having the measured frequency response in front of us. The same will be true of pretty much any bass amp.

 

As an analogy I'd say its a bit like using pickled onions in a recipe when you've run out of fresh ones, you'll never quite get rid of the taste of vinegar

 

 

"Bass amps are like pickled onions, you always know it's gonna taste like vinegar"

 

- Woody Lump -

 

Edited September 9, 2023 by Baloney Balderdash

[mattpbass]

I’m just setting off down this path, been running a Jad Freer Capo (pre amp pedal) for almost a year, love the thing and 90% of the time going straight to desk/PA and working on in-ears. For smaller gigs where amp is needed the pedalboard is going into an Aguilar Tonehammer 700 and SL410 cab, which is fine but I really just want the sound of the Capo amplified, not further colouring from the TH. So I’ve recently ordered the Coda head that JF make specifically for use with the Capo (or any other pre-amp), it’s just a 700w power amp which in itself is quite unusual, and it’s also a class G amp rather than D, which I’m really curious about. 
 

Taking a punt being as I can’t find a single review or user anywhere online but the Capo is amazing so I trust their quality, counting down the weeks till it arrives…

[Steve Browning]

18 hours ago, mattpbass said:

I’m just setting off down this path, been running a Jad Freer Capo (pre amp pedal) for almost a year, love the thing and 90% of the time going straight to desk/PA and working on in-ears. For smaller gigs where amp is needed the pedalboard is going into an Aguilar Tonehammer 700 and SL410 cab, which is fine but I really just want the sound of the Capo amplified, not further colouring from the TH. So I’ve recently ordered the Coda head that JF make specifically for use with the Capo (or any other pre-amp), it’s just a 700w power amp which in itself is quite unusual, and it’s also a class G amp rather than D, which I’m really curious about. 
 

Taking a punt being as I can’t find a single review or user anywhere online but the Capo is amazing so I trust their quality, counting down the weeks till it arrives…

Class G? Specially done for ventriloquists, I presume. 

[MrDinsdale]

19 hours ago, mattpbass said:

I’m just setting off down this path, been running a Jad Freer Capo (pre amp pedal) for almost a year, love the thing and 90% of the time going straight to desk/PA and working on in-ears. For smaller gigs where amp is needed the pedalboard is going into an Aguilar Tonehammer 700 and SL410 cab, which is fine but I really just want the sound of the Capo amplified, not further colouring from the TH. So I’ve recently ordered the Coda head that JF make specifically for use with the Capo (or any other pre-amp), it’s just a 700w power amp which in itself is quite unusual, and it’s also a class G amp rather than D, which I’m really curious about. 
 

Taking a punt being as I can’t find a single review or user anywhere online but the Capo is amazing so I trust their quality, counting down the weeks till it arrives…

There was a chap on TB chatting about the Sisma which is essentially a Coda with a B-15 inspired preamp infront. He was raving about it. 

[Hellzero]

As a fretless bass player myself, I love the most natural sounding tone coming out of the speakers, that's why I bought a GR Bass AeroTech Full Carbon Combo 800 coupled to a GR Bass AeroTech Full Carbon Cabinet 112+.

 

I also have two fretless Leduc U-basses (one 4 and one 6) with a Fishman BP-100 twin piezo pickup and magnetic pickup(s) going to an internal Fishman PowerChip, which is a buffer preamp allowing to split (stereo cable with two mono jacks on the other end) or sum both signals (the usual suspect mono lead).

 

As I wanted to have two very distinct tones from the magnetics and piezos, I ended up buying a GR Bass Dual Pre, which is a twin preamp with two separate identical EQ's, a compressor working on both channels and a distortion section working on channel 2 only.

 

I then go out to the GR Bass combo switched in the "Pure" position thus having a non really colouring powered cab with just a gain and a master, both set at noon as I manage the power on the preamp pedal with the two master volumes.

 

And it's working the way I want, with a very rich and deep tone on the piezo nearly emulating a double bass tone and a fretless tone with loads of mwah possibilities (if you want so but it will be linked to the way you play with these U-Basses and their free floating soundboard) on the magnetic pickup(s), so channel 1 is double bass like and channel 2 is typical fretless tone, but I can also have the two channels mixed or bypassed or muted and add distortion (on channel 2) and/or compression.

 

So yes, @Linus27 I'm using something quite close to what you described, but for other reasons than you.

 

And I still have the opportunity to use the combo as a standard combo with its own EQ, when disengaging the "Pure" switch.

 

Furthermore, the whole rig is super lightweight.

 

This GR Bass Dual Pre is also working really well with my other combo: an old original Hevos Midget 10 with everything at noon.

 

Here is the preamp out of the box and it's bloody complete with even 2 D.I.'s (one for each channel), an fx loop, an aux in, a parallel out (non treated signal) and an headphones out with its own bass, treble and volume: