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djk

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Posts posted by djk

  1. " A 9090DB would be the bomb "

     

    Use one in my shop, no where near as good as a Tandberg, Yamaha CR800, HK730/430, etc.

     

    I was surprised how much better an ebay $100  Hafler DH200 sounded compared to the 9090.

     

    Tandberg Audio went belly up around 1978, Tandberg Data was acquired by Cisco Systems.

    • Like 1
  2. " with 2 port tubes facing the rear tuned to 30 Hz. "

     

    Experience has shown that for the K33E 35hz works better, two 4" ID about 7" long (a bit linger if using flared ports)

     

    I also use 6th order EQ, an EV Interface A (or similar) device. Virtually any EQ device with a low filter (high-pass, subsonic, infra-sonic, etc.) will work, only needing a couple of resistors to be changed.

  3. " (with blown ST-350 which I think uses the same motor as the T-35) "

     

    St350 had a bigger magnet, same diaphragm. What your dealer should have sold you was a pair of the STR tweeter protectors. The ST350B used two stacked square magnets (as used in the K77).

     

    IMG_15041.JPG

     

    Big ring magnet version.

     

    img3380_130924.jpg

     

    Stacked square magnet version.

     

    857585-electrovoice-str-tweeters-protect

     

    The EV drivers with the 1-1/4" coils usually use a 0.5A PTC to protect them in their factory crossovers.

    The Speaker Exchange crossover shows a pair of 211-2 lamps in parallel, way too much current. One 211-2 would be more appropriate. The #1141 looks to be a better choice.

    #211-2  I^2=1 works well with 8Ω drivers with 1" coils
    #1141   I^2=2 works well with 8Ω drivers with 1-1/4" ~ 1-1/2"coils
    #1156   I^2=4 works well with 8Ω drivers with 1-3/4" ~ 2"coils

    Edited by _djk_ - December 22 2011 at 4:02am
    • Like 1
  4. " Why not use a polyfuse ? "

     

    Too slow.

     

    A 561 or 211-2 is about right.

     

    It will have less insertion loss than a Polyswitch, and after a few 10's of milliseconds of overload it will heat up and attenuate the signal in a smooth fashion (instead of cutting out like a Polyswitch).

     

    " In series with the positive wire or negative? "

     

    Either, makes no difference.

     

    Klipsch used to use a 0.9A Polyswitch in the KG4 and I had to replace tons of diaphragms when high-school students played their 50W NAD amps at too-damm-loud volume levels.

     

    Installed lamp, end of problem. It also made them sound much smoother when the amps got harsh during clipping.

     

    I even had students wanting the lamps when they had never blown a tweeter. The KG//2 products originally had clear cones and the lamp would light up the cones when you played them too loud.

     

    I originally noticed the 561in the Boston Acoustics C700 loudspeakers, the 211-2 is easier to solder to (its a 561 with tinned end caps). I've seen these in just about everything in the decades since.

     

    EV had a tweeter protector for the T35/K77 product that was based on a relay, it would cut-out like a Polyswitch, but was much faster. Then later on they had a bulletin showing how to add a lamp in parallel with the relay to make things work smoother.

     

    I've been thinking about duplicating the later EV version with the lamp (for the purest that wants the lamp out-of-circuit completely at low volume levels).

    • Like 2
  5. " I had MC2100 in mind here, 2W rating.  Going to higher power is fine. "

     

    I guess I have had to fix the solder joints when they crystallize (after many years) and stop conducting.

     

    Sometimes I just wick out the old solder and apply new, depends on if the board is baked (badly discolored).

  6. " Miss the chats -- how are you doing man? "

     

    Been better, been worse. Trying to find a primary care quack, they don't like dealing with people that are knowledgeable and that can think (me).

     

    Buried phone line is out, phone co does not want to repair, I have problems trying to use a cell (too small, hard to hear, etc). This also happened to a friend of mine, after a couple of months of the phone co abuse he ended up buying a cell.

  7. " Would suggest bleeders on the 22000uF cans, 1kOhm, 2W. "

     

    Will run too hot.

     

    Most resistor ratings are based on a 250°C rise above ambient.

     

    With  ±35V rails a 1K resistor will be dissipating about 1.225W, a 2W part will thus be about 150°C above ambient (with a 25°C ambient the part will be running neat the melting point of 63/37).

  8. " Either way, if they have been stored face down OR face up, then no rotating of woofers is necessary... "

     

    Your right, the woofer will need to be replaced.

     

    Woofers stored face up or face down for years will have the spiders taking a permanent set.

  9. All food tastes the same(if you have a zinc deficiency), all women kiss the same(if you're a eunuch), VHS and Beta look the same(to Ray Charles and Stevie Wonder), and all amplifiers sound the same(to the deaf old men at Stereo Review).
    WHO?

    Tell the deaf/dumb/blind kid to go play pinball.

     

    ***********************

    Used to meet all those magazine guys at the CES show, but don't want to speak ill of the dead.

    • Haha 1
  10. I would use a single Belle, or stack them vertically (invert the top one).

     

    While the Belle can drop down to 4Ω, the MC2125/2120 can drive it with ease on the 8Ω tap. You can strap the outputs in parallel (if the amp is perfect), use the 8Ω taps though. If you insist on using both of the Belle, I would run one per channel and use a 'Y' cord on the amplifier inputs.

     

    The MC2125/2120 can take massive abuse, I have driven it into 2Ω on the 8Ω tap with the PowerGuard defeated! It will make popping and barking sounds when driven more that 6dB into clipping in this fashion (8 LaScala bass bins in series-parallel on one channel, mids and HF on the other channel).

  11. Yes, the 68µF caps are Mylar.

     

      CBB60      70MFD 250V   60x120mm

     

    The capacitor takes heavy-edge metallized Al/Zn PP film or web-like fuse film as dielectric. Its components are sealed with flame-retardant epoxy resin. It has cylindric outline with high reliability and stability.

     

    https://www.amazon.com/CBB60-250VAC-Cylindrical-Motor-Capacitor/dp/B01E5W5UJ4/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1512087302&sr=1-1-catcorr&keywords=70uf+capacitor#feature-bullets-btf

     

    $13

    • Like 1
  12. " dealers quite often just pulled two Heresys from what they had in their warehouse... "

     

    Unless they were Walnut or Oak.

     

    I did have a customer buying for his bar&grill that was buying Walnut singles and painting them brown (anti-theft deterrent), he ended up with 14 Heresy (birch and Walnut mix), a pair of LaScala, and a pair of K-horn bottoms.

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