Preamps that maximize power amp's potential?

Discussion in 'Amps and Cabs [BG]' started by Planet Boulder, Apr 14, 2004.

  1. Planet Boulder

    Planet Boulder Hey, this is a private Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    I've had a few preamps in the past that simply did not maximize the potential of the power amps through which they were running, leaving me disappointed, to say the least.

    I have a couple of different rack setups right now, one of which being a Rocktron bassMAXE into a Trace Elliot 500 watt power amp and it is loud as HELL!!!!!! That Rocktron REALLY pushes the power amp unlike any I've owned or tried.

    So, basically, I'm wary of trying a different preamp (which I might like to do for a different tone, trough this Rocktron's tone is quite nice) because I fear finding one that won't push my power amp like this Rocktron.

    Can anyone suggest other models/makes that really push the power amp, based upon actual experience? Oh, and though I would love to have a Demeter, I can't spend that kind of bread. ;)
  2. Arthur U. Poon

    Arthur U. Poon

    Jan 30, 2004
    SLC, Utah -USA-
    Endorsing Artist: Mike Lull Custom Basses
    I have an old Ashley BP-41 solid state preamp that will drive any power amp I've tried. I've also had problems getting the most out of my amp(QSC PLX-2402) with many different tube preamps. If you pm Bob Lee/QSC he'll give you info on some units that connect between your pre and power amp that will increase your pre's output.

    Best Wishes, A.P.
  3. K-Frog


    Feb 6, 2002
    Camden, AR, USA
    Yamaha PB-1 is a hot one
  4. my RBI and Carvin DCM1500 go really well together (if only the Carvin didn't weigh 35lbs)
  5. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    My Pearce BC-1 has a weak output compared to modern preamps. As a result, it couldn't drive most off-the-shelf poweramps to full output. So...when I ordered my QSC PLX-2402 from Mark at Life Effects Pro Audio in OK, he customer ordered it from QSC with increased input sensitivity.

    QSC didn't charge extra for this service (at the time anyway) and I had my new amp within a week of ordering it. Great customer service!!!

    Anyway, you just need to know what the preamp's output level and the power amp's input sensitivity are to make sure that you have a match.
  6. HannibalSpector


    Mar 27, 2002
    I tested different models of preamps not long ago. I was looking for something to replace my old Intersound IVP. As I was after something more modern.
    About 12 different preamps were tested alongside my existing preamp: Peavey , ADA , Line 6 , Sansamp(Tech 21) , Labsystems , SWR , Yamaha PB 1, Trace , Marshall , Alembic and a few others both used and new.
    As far as output goes the IVP faired best. Others had alot of gain but were quite noisey. They stopped making IVPs about 20 years ago.
    I decided not to get another preamp.
    To 'modernise' my sound I use an outboard EQ.
  7. Matt Morgan

    Matt Morgan Fellow Conspirator Supporting Member

    Oct 21, 2001
    Plano, TX
    I think BillyB hit the nail on the head. I think getting the most out of your pre-power combo is based on two things...
    1. Having a pre that puts out good signal strength and
    2. Having a power amp that has a sensitivity rating that allows it to be driven to full power properly by your pre.
    I think that a lot of power amp buyers (myself included when I went the pre/power route) don't initially realize that this is a significant issue.
    You may love the tone of your pre but if you're using a power amp that has a really low sensitivity rate, you're never going to get the power and sound that you expect.
    When shopping for either of these components REALLY read the fine print and specs to make sure of what you're getting and if the manuafacturer doesn't publicly post these specs write them and get the real answers!
  8. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    The power amp has to work with what the preamp can put out.

    The preamp has to work with what the bass can put out.

    Gain controls are there to make different things capable of working together.

    Most combinations can work out if you just adjust the gain controls appropriately. Most power amps have an input sensitivity (the input signal voltage at which the amp puts out full power at full gain) in the range of 1 to 2 volts, which isn't much. Most can do that, but some can't.

    After that, the next question is whether the bass's output is strong enough to make the preamp put out that much signal.