Can this substitute for High wattage pwr amp?

Discussion in 'Amps and Cabs [BG]' started by Svengali Debris, Nov 10, 2005.

  1. Related to the wattage thread but not covered.

    I run an Aphex 207d tube preamp into the loop return of my Ashdown Mag combo. I set the Aphex pre at +4, as a result, I get way more db out of the power section than the Ash alone. I've talked to Ashdown and they say this shouldn't cause any problem. But now I'm considering a 2x10 or 2x12 cab to replace the Ash 4x10's and don't want to buy a more powerful pwr amp. The cabs I'm looking at suggest 400 watts and up.
    Will the higher gain (up to 65db) hitting the power amp compensate for running one of these cabs at 200w RMS & 8ohms?

    I can't seem to get a straight answer from any of my techie friends.

    Just for giggles, here's my current setup:

    NS Stick

    Bass side - EH Black Finger - Ashdown - loop send - Bass Pod XT -
    Aphex Bass Exciter - Aphex 207D ch 1 - loop return - 4x10t

    Melody Side - POD XT Live - Aphex 207D ch 2 - Mosvalve power amp - Ashdown
    2x10t cab.
  2. Passinwind

    Passinwind I Know Nothing Supporting Member

    Huh? :confused: You mean the Ashdown preamp section can't drive the power amp fully? Or just that the rig's louder at some arbitrary setting of the knobs?

    As to rest of your question, there's still no free lunch. The power amp can't magically make more power with a different preamp, unless the original failed to drive it fully. 200 watts is what you'll get when it's driven fully, game over. There are potentially plenty of other factors like compression and voicing at work though, and if it sounds good to you, it is good. So it's possible that the external preamp may "compensate" in your mind, which is all that matters. But buying a cab with fewer drivers may "compensate" negatively, depending on the relative sensitivities of the old and new cabs.

    Just curious: why pony for new cabs and cheap out on the power side?
  3. The pre section of the Ash drives the pwr section fine, it's just that the Aphex slams a lot more volume into the pwr amp @+4 than the Ash pre does alone. Plus the Aphex sounds killer and gives me 2 quality DI outs. I know it's a convoluted signal chain but it sounds great, is dead silent and really brings out the character of the Stick. If I were still playing bass, I'd just run straight thru the Ash and only use the POD for fx.

    I'm doing this because I went from a gig rig to a daw rig and bought the PODs and Aphex (which is great, BTW!!) to facilitate recording. The Aphex rep said the 207 is often used in a rig after a POD rather than just as a DAW front end. So I tried it and love it. Now I'm going to gig again and want a smaller cabinet w/ better low end for the bass side and the 4x10 is a pain to lug around w/ everything else. I'm limited on $ otherwise I'd buy a powerful Stewart or something.

    I have a blind spot in my brain when it comes to electronics/physics. I really don't understand the relationship between db/volume and wattage & how a cabinet reacts to them.
  4. Passinwind

    Passinwind I Know Nothing Supporting Member

    Don't sweat it then! :cool: You friends can't give you a straight answer because there really isn't one.

    I''m a tech, I understand it all too well. There's still a lot of voodoo though. FWIW, I have an AI Focus and I bypass the preamp completely when I play electric bass into it. I go straight into the loop return, like you're talking about doing. Perceived volume and cut is much improved, especially with the new preamp I just built. So I can relate, and say that the Aphex may compensate in some ways. A cood compressor may help too. The POD probably qualifies, I guess, but I've never used one.

    I carry lots of instruments and use a very convoluted live stereo rig with guitar synth, guitar, processed vocals, and now probably electric upright besides my fretless bass guitars. I'm a big believer in a modular system. We're lucky these days to have all these fine compact cab choices. Which ones are you considering?
  5. Cabs for consideration are
    Epifani 212
    Eden 2x10xlt8? (the new ext-low end model)
    Acme low B2
    Aguilar 2x10t

    any suggestions or experience w/ these?
  6. The thing to remember is your 200W amp is like a 200HP car. Its not putting out 200W or 200HP all the time. It is capable of putting out full power only with a hot enough signal going in. With a light touch on the gas or on the bass, you can easily cruise at 25mph in the Ferrarri, or 25w on your 200W amp.

    The +4 switch has the same effect as turning up the power amp gain (if you have one) or the master volume knob by 4dB. Nothing more.

    Say you have a 200W amp, and you're currently playing at 25W on avg. They you dig in, hit some notes hard, and you hit 200W for loud stuff, slapping. Now turn the switch to +4dB. Now your avg is a bit over 50W. You sound louder at low volumes. But when you dig in you still only get 200W out of the amp. The loud parts that max out the amp are no louder with the +4 switch on or off.