2.3 TL amplification

Options
riglehart
riglehart Posts: 276
edited December 2006 in Vintage Speakers
I am driving my 2.3TL with a single NAD 2200 (100W continuous, 400/600/800W at 8/4/2ohm dynamic), or an NAD753 AV receiver (150/200/225W).

Obviously, more is better. But, honestly, am I underpowering these things?

If I buy a second amp and biamp high/low, how important is it to get an amp with a gain adjustment? I am considering a 2nd 2200 (they're relatively cheap and easy to find), but there is no gain control on these.

Would biamping the 753 and the 2200 be worth trying? If so, which one would you put on "top"?

I have an AI-1, so getting a 2nd 2200 gives me the option of trying a L/R biamping, too.
Jolida Tube
Polk 11T, 7, 5, 5jr, 4
Standard equip not worth bragging about.
Post edited by riglehart on

Comments

  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited December 2006
    Options
    riglehart wrote:
    I am driving my 2.3TL with a single NAD 2200 (100W continuous,...)

    Obviously, more is better. But, honestly, am I underpowering these things?

    Absolutely. You can consider 200 wpc with high current capability to be the starting point for powering SDA's.
    riglehart wrote:
    If I buy a second amp and biamp high/low, how important is it to get an amp with a gain adjustment?

    Think of it this way: if you were using a single amp, would you want the high frequencies to have one gain and the mid and low frequencies to have another gain? If this were the case, your amp would be acting like an active equalizer.

    Another thing to consider is that, if you biamp and mix and match amps from different manufacturers, the gains and power ratings of the two amps may actually be different, even though they are stated to be the same on their respective spec sheets. This is because there is no industry standard for measuring amplifier power.
    riglehart wrote:
    Would biamping the 753 and the 2200 be worth trying?

    Sure, if it is something you are really interested in. You may like what you hear. Some people believe that it is better to use a higher quality single amp than a bi-amp configuration with two lesser amps. Also, I am of the "minimalist" ideaology that believes in sending the signal through as few components as possible.
    riglehart wrote:
    If so, which one would you put on "top"?

    Since the tweeters require much less power than the mid and bass drivers, the lower power amp should be on top.

    I once explored bi-amping my SDA SRS 1.2TL's. You can read about it here.

    Have fun and let us know how your experiments work out.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • riglehart
    riglehart Posts: 276
    edited December 2006
    Options
    Just got done setting up my 753 and 2200 in a high/low biamp. Wow! That made a huge difference. Everything came alive. I thought it would be a lot louder, but it's not. However, the music was being "thrown" at me before compared to now. I'm hearing details. I'm sold on Biamping.

    I sense I'm not close to what is possible, though.

    Now a couple questions.

    1) When I shut the 2200 off and just drive the highs, my first impressin is that relatively little power is expended on this (the highs). Is that true? I would guess the 2200 is expending pretty much the same amount of effort on the low, even without the top channel. However, the top channel can now really focus on the detailed highs without the low end sucking all the amp resources. Hence the detail.

    2) Would a 2200/2200 setup be better?

    3) Any suggestions of something better than 2200s that would be a good incremental step up? This experience has me pretty excited to up the ante. I've never had one change make this much difference.
    Jolida Tube
    Polk 11T, 7, 5, 5jr, 4
    Standard equip not worth bragging about.
  • westdr1
    westdr1 Posts: 12
    edited December 2006
    Options
    I have recently upgraded from the 2200 to the C 272. The 2200 has a 100wpc and the 272 is 150. I just installed the amp today and will have to wait before I can provide an opinon on the differences.

    I would agree that 200wpc is recommended with the 2.3 albeit Polk recommends a minimum of 50. Since I was only able to achieve half volume on my 1240 w/o clipping I find 50 watt to be unacceptable. The NAD 2200 is really rated very conservative. There is 6 db head gain on the amp.


    The 272 has a gain control for bi-amping.

    I am in the upgrade mode for my system. I am considering the NAD 162.
    My next project is the crossovers on my 2.3's

    schwarcw has been an excellent source of information on the rebuild of these crossovers.
  • riglehart
    riglehart Posts: 276
    edited December 2006
    Options
    WESTDR1

    Let me know what you think of the 272 compared to 2200. I've been thinking the same thing and they come up on ebay every couple weeks. If there is a stark difference, I might sell my 2200 (instead of getting another one) and buy a couple 272.

    Or, maybe you have a 2200 I could take off your hands cheap?
    Jolida Tube
    Polk 11T, 7, 5, 5jr, 4
    Standard equip not worth bragging about.
  • F1nut
    F1nut Posts: 49,855
    edited December 2006
    Options
    Since I was only able to achieve half volume on my 1240 w/o clipping I find 50 watt to be unacceptable.

    Almost every amp will start to clip at 12 noon on a volume dial.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • westdr1
    westdr1 Posts: 12
    edited December 2006
    Options
    F1nut wrote:
    Almost every amp will start to clip at 12 noon on a volume dial.
    I guess it depends to what degree of clipping.

    I could not resist briefly pushing the 272 after a quick warm up, and I can tell you I had it to the 2' oclock, before I turned it down. Since the 272 is the most power I have applied to my 2.3's There is a substanial difference in the levels I can drive these at.

    I am trying to be patient on the burn in. I will report back what I have discovered.

    As noted in a previous post I believe there is a problem in the right speaker. I will know once I rebuild the crossovers.
  • westdr1
    westdr1 Posts: 12
    edited December 2006
    Options
    riglehart wrote:
    WESTDR1

    Let me know what you think of the 272 compared to 2200. I've been thinking the same thing and they come up on ebay every couple weeks. If there is a stark difference, I might sell my 2200 (instead of getting another one) and buy a couple 272.

    Or, maybe you have a 2200 I could take off your hands cheap?

    I will let you know the outcome. I would opt for the 272 over another 2200 though. It may be a while before the 2200 is repaired. I understand there may be a problem with parts availability. I really do not waqnt to give up the 220 though. It was a good amp. I understand there was a systemic problem with the speaker relays though?
  • TroyD
    TroyD Posts: 13,077
    edited December 2006
    Options
    2 O'clock?

    ....all around the mulberry bush RuSsMaN chased Dorko. Dorko thought it was all in fun.....POP GOES THE TWEETER.

    Sooner or later, it will happen.

    BDT
    I plan for the future. - F1Nut
  • westdr1
    westdr1 Posts: 12
    edited December 2006
    Options
    TroyD wrote:
    2 O'clock?

    ....all around the mulberry bush RuSsMaN chased Dorko. Dorko thought it was all in fun.....POP GOES THE TWEETER.

    Sooner or later, it will happen.

    BDT


    If the 2.3's can handle 750w it should be handle a couple spikes from a 150w amp? If the tweeters are that susceptible to over load why is the protective circuit being bypassed?
  • F1nut
    F1nut Posts: 49,855
    edited December 2006
    Options
    If the 2.3's can handle 750w it should be handle a couple spikes from a 150w amp?


    That's not how it works. It's those "spikes" that cause the damage and one gets those spikes much easier from lower powered amps than higher powered amps.
    If the tweeters are that susceptible to over load why is the protective circuit being bypassed?

    If one uses good, clean power and doesn't get stupid with the volume levels, one will not have a problem with cooking the tweeters.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • TroyD
    TroyD Posts: 13,077
    edited December 2006
    Options
    westdr1 wrote:
    If the 2.3's can handle 750w it should be handle a couple spikes from a 150w amp? If the tweeters are that susceptible to over load why is the protective circuit being bypassed?

    Those spikes are pure DC and WILL fry your tweeters....but, hey, it's your gear.

    BDT
    I plan for the future. - F1Nut
  • riglehart
    riglehart Posts: 276
    edited December 2006
    Options
    This brings up a question I have. My NAD753 receiver has an electronic volume control. The readout is in db. -30db is where my wife likes it. -20db is where my wife starts to complain. -10db is getting pretty loud. 0db is rocking. 5db is all the farther I dare go. If I shut the speakers off and crank it, I think it goes up into the 20s somewhere.

    How does this relate to the 12o-clock where most amps crap out. Is the 0db just a random location picked by an engineer, or is there a real significance to it that is common to all amps?

    (This is starting to remind me of a Spinal Tap scene. "No, you see, this volume goes to 12!")
    Jolida Tube
    Polk 11T, 7, 5, 5jr, 4
    Standard equip not worth bragging about.
  • F1nut
    F1nut Posts: 49,855
    edited December 2006
    Options
    0dB is the "reference level." How that is determined I can't tell you. I also can't tell how that scale relates to noon on a dial knob, but you should be able to hear the amp clipping when you get there.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • westdr1
    westdr1 Posts: 12
    edited December 2006
    Options
    TroyD wrote:
    Those spikes are pure DC and WILL fry your tweeters....but, hey, it's your gear.

    BDT

    After getting a nice burn-in on my C 272 I was able to test it again. At 12 o'Clock it was hardly working. I cranked it up to the 1 0'clock and it was about right. I then cranked it up to 2 and was pushing. I believe the 1 position is the sweet spot.

    Although the 2200 has been pretty good, the 272 is a good investment.

    My next project is the crossovers.
  • schwarcw
    schwarcw Posts: 7,328
    edited December 2006
    Options
    Congrats!

    Carl
    Carl