PLX1602 or 1202?

Discussion in 'Amps and Cabs [BG]' started by joeybcdt, May 15, 2004.

  1. joeybcdt


    May 6, 2004
    SE Texas
    I'm currently running a GK 700RB head with the 210RBH and 115RBH. I tried out the Sansamp DI a few weeks ago and decided I really liked the tube sound. I just got an Ampeg SVP Pro (on the way) and need to decide on the amp. I plan to run bridged at 4Ohm. Is 1200W enough? Is 1600W over-kill?

    All the talk on here about Epifani and Bergantino is starting to give me GAS. Do these speakers sound noticeably better than the GK's? Has anyone compared the new GK "Neo"?
  2. cgworkman


    May 14, 2004
    No not really - both cabs are rated 400 watts - peak power would be 800 each - there's you're 1600 watts.

    You just have to use the head on your shoulders when running this one. I plan to get another PLX amp soon - those GK cabs will just suck up their 400 watt rating from the amp and then beg for the headroom the PLX is capable of.

    But like I said - you have to be careful when running anything at peak power. Technically it's alright - but if you get crazy you may regret it. I'd go for the 1600 watts if I were you.....

    Good luck! ;)
  3. Poon


    May 20, 2003
    Los Angeles, CA

    I say go for a 2402 or 3002 :D
  4. I own a 1202 and two 3002. You get the better circuity in the 2402 and larger models.

    The hidden gotcha with QSC is the increasing amount of line voltage required to drive the amp to full power. The 1202 requires 1.0v where the 3402 requires 1.9v. If you have a Demeter, etc, preamp that produces a ton of output, this a non-issue. I have an SWR IOD that only produces 0.7v at full throttle, so this is a huge issue for me. I have crossovers, EQ, and dbx sub-synth between the IOD and QSC, so I avoid the problem with the other devices increasing the final output voltage.
  5. monkfill


    Jan 1, 2003
    Kansas City
    I chose the 1602 because its power ratings through the various configurations (stereo and bridged) were pretty much the same as the Ampeg SVT-4 Pro and the SWR SM-900, and because of the price point. To me it was the best balance between power and price in a lightweight amp.
  6. cgworkman


    May 14, 2004
    Are you satisifed with the performance of the 1602?

    What settings are you playing in? i.e. What style musics, what volume, etc?

    Also what are you using as a preamp?

  7. Tim__x


    Aug 13, 2002
    Alberta, Canada
    I hear you can change the input sensitivity on them fairly easily. Perhaps Bob Lee can can explain further. To paraphrase a fellow TBer, 'Where's that bat signal for Bob Lee'.
  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
    Turning the gain control(s) down will change the input sensitivity (that is, it'll make the input sensitivity voltage higher). ;) Of course, that's not what you want if you have a preamp with a meager output voltage capability.

    But the gain of the amp can be increased by modifying some circuitry. QSC charges $35 labor plus a couple dollars for parts to do this.

    But first, determine whether it is actually necessary to do so. If you need to adjust some preamp master or gain knobs to make it work, go ahead and do so; that's what the knobs are for.

    Be aware that boosting the gain of the power amp may make it less valuable if you decide to sell it. That's because it might then appeal to a much narrower range of potential buyers. Then again, it might not, if that's exactly what a particular buyer is looking for.

    There is an alternative to modifying the power amp, and that's boosting the signal from the preamp before it goes into the power amp. Radio Design Labs, for one, makes a number of inexpensive little audio signal boosters that you can place in an equipment rack and power from a simple wall wart.
  9. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    I would get the 1602. Headroom is a nice thing to have. I just bought a 2402 and for most gigs I bridge it into a Bergantino 210. Although I only turn the gain up half way I like to know that I can take it higher if I need to.

    At one time I was using a Mackie 1400 bridged into an Acme 210. When I ran out of headroom (yes bridged into a 4 ohm speaker) at a somewhat small gig I decided I would never let that happen again.
  10. Tim__x


    Aug 13, 2002
    Alberta, Canada
    If you don't mind me asking, what is the modification? Is it just a single resistor in an op-amp feedback loop? Or something else all-together.
  11. Some time back, Bob Lee posted some test he had done on the various QSC models set to bridge mode at 4ohms. the 1202 was the only one he couldn't cause to thermal out. For that reason I got the 1202. I've used it with a Hartke 4.5XL (8 ohm) and now a pr of Bergi 112HT/EX. (4 ohms)) I've never been anywhere near clipping. I'm satisfied with the 1202.
  12. 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
    It involves changing two surface-mount resistors on each channel's input section.