T.amp tech question

Discussion in 'Amps and Cabs [BG]' started by miccheck1516, Oct 25, 2003.

  1. miccheck1516

    miccheck1516 Guest

    Feb 15, 2003
    So, ive found an amp that seems kinda ok at a great price, and ill probobly buy it.


    Now, there is alot of info there, What i need help with is this,
    I know what ' 2 x 300 Watt 4Ohm, works on 2 ohms, 19", and '2HE, depth: 44cm, In: Jack+XLR, Out: Speakon+Binding Post,' means, however im kinda lost with athh the other things with number.
    Could anyone mabye explain what each of teh other things means and mabye tell me how this effects my sound if at all, thanks.
  2. pbd

    pbd Commercial User

    Jul 17, 2003
    Metro Detroit
    owner Procables N Sound
    Here's some info from the Yamaha, Sound Reinforcement Handbook
    Slew rate is a measure of the ability of an amplifier to respond to very fast chanes in signal voltage...can affect its ability t render musical transients and complex waveforms. I'll get to the others if someone else doesn't in a bit.
  3. miccheck1516

    miccheck1516 Guest

    Feb 15, 2003
    so, if the amp had a big slew rate would that mean it would be fast or slow at responding? Im assuming it is was slow and i was playing parhaps some amazingly fast slap thing it would perhaps cause a slight delay (not one that ears would notice) or perhaps miss some parts of notes or something?
  4. miccheck1516

    miccheck1516 Guest

    Feb 15, 2003
    also, thanks, please post back if no one else does.... i would really appreciate it
  5. THD = Total Harmonic Distortion (or something, questioning the H). Its a measure of how different the signal entering the amp is different to the one coming out, so how much the signals distorts. I think thats a pretty standard rating, don't quote me on it though. My soundguy is slowly building a kit amp quoted at like .002%, I intend to follow his footsteps.

    Input sensitivity, well...how sensitive the inputs are, basically. It'd be measuring the smallest voltage that can be picked up at the input stage.

    I'm pretty sure a bigger number for Slew Rate would be better. 40V/µs, I take this as meaning it'll change by 40V in one µs, µ=micro which is 10^-6, so its a pretty short period of time. I dunno how that compares to others though. You wouldn't be able to notice any real difference in timing in the signal (a delay), its more inclined to just drop out the bit its trying to amplify quickly.

    Hope it helps, I hope its actually all true.
    Josh D
  6. Maybe this is a decent amp, but the specs they give just don't tell us all that much. To really judge an amp on the basis of specs, IMHO a lot more info should be available. I'm not claiming to be an expert at interpreting amp specs, I'm just saying that really well known amp brands make lots more data available.

    The THD figure, for example, seems decent enough--but they tell you it's at 1 Khz, which is prety much a standard test signal. They don't tell you what the THD is over the frequency range of the amp, in fact the spec quoted doesn't even tell what the frequency range is. (Again, this may info may be available elsewher, so I'm not claiming this is a lousy amp). I'm saying that this info by itself is kind of meaningless. A cheap amp could use lots of global negative feedback to obtain a really good THD number at this one frequency, for example, while the rest of the frequency response curve looks lousy.

    Try this site, read all of his articles:

  7. Although it's a very good idea to inform yourself of what all those specs mean, it's never a good idea to buy an amplifier based on those specs. The ONLY way to decide to buy any type of equipment is to LISTEN to it very closely. If you like the sound, buy it. If you don't have anything (or don't have enough experience) to compare it to, but still like the sound, buy it.

    Don't get too hung up on numbers, pay attention to what an amp is supposed to do: produce sound.

    I, myself, know what all those specs mean, but I also know they don't say anything about the sound, because test conditions are far from real life situations.
  8. miccheck1516

    miccheck1516 Guest

    Feb 15, 2003
    alright guys thanks a million for all that info, i wasnt really wanting to buy the amp based on numbers, just wanting to expand my knowledge of what all the numbers meant and be able to relate it to something i am most likely going to have. Thanks again.