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Bubo

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  1.  

    JubeScala II.JPG

     

    Coytee

    • Klipsch Forum Lifer
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    • Coytee
    • Heritage Members
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    Quote

     

    if you're building, you can incorporate the K510 into the top and make it a 2-way (and go active)

    At the same time, you will get a lot better coherence from the 2-way setup and a lot 'larger' (not necessarily louder although it can do that too) sound.

    (not my speaker but they did a nice job)

     

     

    https://community.klipsch.com/index.php?/topic/170006-la-scala-ii-plans-and-drivercrossover-list/

     

    This has a much better aesthetic than the Jube Horn, LaScala bass bin combo IMHO.

    It also puts the horn at ear level

     

    Garage Sale post from 2014
     

    Quote

     

    I have for sale two Klipsch K-510 Horns with K-69 drivers.(Mine are actually P Audio BMD750 drivers however it is exactly the same)

    They have only been used for about 6 weeks.

    These items are a perfect upgrade to take a LaScala to 2-way making it a Jubscala or to scratch build a really nice 2 way "cornscala' with the addition of 2 Crites CW1526c woofers.

    I have a set of Jubscala myself but have got the upgrade bug and i have upgraded my drivers and gone active with the crossover so if anybody is considering it they are ready to go.

    $600 for the lot. (shipped)

     

     

    https://community.klipsch.com/index.php?/topic/150351-k510/

    https://usspeaker.com/paudio bmd750-1.htm

    Recommended cross over at 1khz, looks like 400hz is a stretch

    paudio-bmd750ii-f-fsize475.gif

     

     

    Very cool, now I want one to play with......

     

    EV Dx 38 User Manual

    https://www.electrovoice.com/binary/Dx38_Manual_Rev.5.pdf

     

     

     

    • Like 2
  2. The 2 way crossover quest for the holy grail has been going on at least since the 1950s

    This was Altec's totl home model the 820c with 2 15in woofers

    and a two way crossover 175lbs each

    Lansing had a bullet proof patent on his horn driver and diaphram

    400-17K hz, if memory serves me correctly,

    so everyone else had to stay with 3 way crossover until the patent ran out.....

    811 horn is approximately at ear level if memory serves me correctly

    Klipsch rolled out the K horn either before or after Lansing responded with this.

    The magnets are aligned on the 3 drivers, so phase isn't an issue

    Mahogany veneer with grills.

     

    1446431549759732603.jpg

     

     

    820C_001.jpg

     

    • Like 1
  3. On 10/21/2019 at 7:40 AM, JFHSQT said:

    Quotes are inverted, my comments are in quotes......


    What I would like to improve on the La Scala IIs is a bit smoother midrange with more cohesiveness from the top to bottom end (I am currently supporting the bottom end with dual SVS SB2000 subs). What I absolutely don't want to sacrifice is the scale, dynamics, and speed of the La Scala IIs. There are very few, if any, speakers I can think of that do what the La Scala IIs do so well in those departments. SO the last thing I want to do is spend thousands of dollars then have buyer's remorse because I've sacrificed one of those other areas. 

    Quote

    LaScalas are hard to beat at any price, all designs have trade offs.

    Before you touch the LaScalas I would get your hands on an equalizer and experiment, bumping up 400hz on mine makes a noticeable difference. E bay or something like the dbx listed above. I never run a system without an Eq

    There is some pc software used to measure freqs and you would need a mic, others can suggest cost effective good solutions, Parts Express may have what you need.

     

     

     

    Next option, I guess the most obvious, would be the new AK6 Klipschorns.

    Quote

    K horns have the same midrange horn and driver as LaScala, so no change there.

     

     

    The other most recent option has been looking into Jubilees.

    Quote

    Again they all have engineering trade offs, two drivers is better than 3 etc. the horn on the Jubes will be above your ear which I don't like, ear level is best for me. This is the reason I purchased the LaScalas over the K-horns with slightly better base, and over the very wide belles.

     

     

    I will say I am not a huge fan of the bass bin aesthetic of the Jubes.

    Quote

    They can be dressed up like in the photos, the current production is I believe for theaters. Klipsch may be willing to make you a pair with veneer and grill cloths etc. But I would demo them at someone's home before throwing down the green, it won't be cheap.....Again, how do they sound sitting, not standing.

     

    They do kind of look a little industrial and 1990s to me. Again, size is not a factor, but I don't want an eyesore as the main focal point in the room. However it seems like all of the great things I am reading about the Jubes could potentially be seen by holding on to my La Scala II bass bins and just replacing the tophat with the 402 horn.

     

    Quote

    Probably sounds great, but the only photos I found are not a turn on for me.

     

    In this configuration I could see setting the 402 on top of the La Scala II bass bin, and continuing to use my SB2000 subs (sent out from my preamp). This option could retain all of the great things about the La Scala IIs that I love and improve the midrange and scale of the speakers. 

     

     

     

     

     

     

  4. Another thread on Jubes

    Hello Everyone,

    Quote

    I've owned and love Klipsch speakers. I've kept seeing over the years references to Klipsch Jubilee speakers but I'd get in over my head, get confused and move on. Well, I've got the bug again and am still VERY intrigued in hearing/owning another legendary speaker of very high efficiency.

    https://community.klipsch.com/index.php?/topic/160716-klipsch-jubilee-newbie-seeking-help-please/&page=5

     

    DSC00493.jpg

     

    th?id=OIP.yfPXCr6Nlhha2PaemgO5OwHaE7&pid

     

    304605-klipsch_jubilee_speakers.jpg

  5. On 10/21/2019 at 7:40 AM, JFHSQT said:

    is even possible to just add the 402 to the La Scala IIs and use it in the way I am thinking without a whole lot of tinkering around with crossover settings etc. 

    Lots of people have put different horns on top the LaScala

     

    Your current crossover is a 3 way crossover

    With just two drivers, which is a good idea, you need a two-way crossover

    Your configuration would be Pre amp feeding 1 stereo crossover

     

    Crossovers feeding two, two channel amplifiers. 2 luxmans ?.

    DBX and others have some great options, which are used in pro applications and studios

    Xover will have to support 0-500 hz on the low and 400 to 17k on the high

    How fast one signal drops off and the other takes over is important,

    if you can adjust the roll off and experiment .....better.

     

    Analog vs digital.....once analog I hate to re-encode to digital ...quantization errors

    may be unavoidable, so 96Khz is supposed to be invisible to ear........

     

    For your cross over choices, there are others on the forum that can make better suggestions than I can on specific models.

    Balanced vs RCA, digital vs analog, roll off options, cross over frequencies etc......

    If your pre amp is balanced, I would go all balanced.

     

    You can also think about adding a pro studio Equalizer with a microphone adjustment

    which brings up the same issues as below, lots of choices...... dbx offers parametric

     

    Examples of what is out there

    Crossover $250

    Eq $550 totl digital

     

     

    https://dbxpro.com/en/product_families/crossovers

    https://dbxpro.com/en/products/223xs

    223xs_Front_Large_full_width.jpg

    The dbx 223xs is a dual channel crossover with all the features you would expect from a professional product. It features Linkwitz-Riley 24dB per octave filters, independent output gain controls for level matching, output phase inversion, 40 Hz low cut filter, and optional mono summing of the low frequency (subwoofer) output. Everything in the design exudes great precision from the solid "click" controls to the high quality XLR inputs and outputs.

    Recommended for: Portable.

    Features

    XLR balanced ins and outs

    Mode switch for stereo 2-way or mono 3-way operation

    Low frequency summed (subwoofer) output

    x10 range switch on both channels

    40Hz high pass (low cut) filter both channels

    Phase reverse switch on all outputs

    Individual level controls on all outputs

    24dB per octave Linkwitz-Riley filters (the professional standard)

    Stereo/Mono status LEDs indicate the selected mode

    dbx® 2 year parts and labor as standard

    CSA NRTL/C approved

    CE compliant

     

    234xs_Front_Large_full_width.jpg

     

    The 234xs uses precision filters to separate the audio signal and direct the correct frequencies to your loudspeaker drivers. By directing only the specific frequency bands to each speaker driver the 234xs leaves your amplifiers free to use their full power on the usable signal eliminating distortion and giving your PA system a cleaner and better sound.

    The dbx 234xs is a dual channel crossover with all the features you would expect from a professional product. It features Linkwitz-Riley 24dB per octave filters, independent output gain controls for level matching, output phase inversion, 40 Hz low cut filter, and optional mono summing of the low frequency (subwoofer) output. Everything in the design exudes great precision from the solid "click" controls to the high quality XLR inputs and outputs.

    Recommended for: Portable.

    Features

    • XLR balanced ins and outs
    • Mode switches for mono 4-way or stereo 2-way/3-way operation
    • Low frequency summed (subwoofer) output
    • x10 range switch on both channels
    • 40Hz high pass (low cut) filter both channels
    • Phase reverse switch on all outputs
    • Individual level controls on all outputs
    • 24dB per octave Linkwitz-Riley filters (the professional standard)
    • Stereo/Mono status LEDs indicate the selected mode
    • dbx® 2 year parts and labor as standard
    • CSA NRTL/C approved
    • CE compliant

    iEQ15front_lg_full_width.jpg

     

    iEQ-15 also offers the built-in necessities which include AFS™ feedback Suppression, Type V™ noise reduction and PeakStopPlus® limiting. Besides including two 15-band channels of 2/3-octave equalization, the iEQ-15 also offers +12 dB input gain range; switchable +6 or +15 dB boost/cut range, 40mm faders, XLR, 1/4'' and Euroblock inputs and outputs, nonconductive nylon sliders; and an intuitive user interface with comprehensive output and gain reduction metering. As always, the inevitable result of our meticulous attention to detail and top-quality componentry is exceptional sound, performance, and reliability.

    The iEQ series represents a major step forward in the performance of EQs. The iEQ series is now able to offer state-of-the-art digital EQ performance and specs with an analog look and feel. From its amazing 10Hz to 22kHz frequency response, to its 113dB dynamic range and Advanced Feedback Suppression (AFS™), dbx proprietary Type V™ noise reduction and PeakStopPlus® limiting, the iEQ-15 offers out of this world specifications with a downto- earth price point. Sure to find a home in the studio, on tour and with installed sound venues, the iEQ-15 is destined to take its rightful place in the lineage of great dbx® signal processors that are the professional’s choice in signal processing. With such pristine design and quality, the iEQ-15 offers the maximum sonic flexibility in a straight forward interface and rock-solid construction.

    Recommended for: Portable, Tour.

    Features

    • Advanced Feedback Suppression (AFS™)
    • Type V™ Noise Reduction
    • PeakStopPlus® Limiting
    • 2/3-octave Constant Q frequency bands
    • Switchable boost/cut ranges of +6 or +15dB
    • 18 dB per octave 40Hz low-cut filter
    • +12dB input gain range
    • XLR, TRS and Euroblock Inputs and Outputs
    • Internal Toroidal Transformer
    • Frequency Response of 10Hz to 22kHz
    • Dynamic range of greater than 113dB
    • User Power Up Features
    • Relay Bypass for Power Failure System Protection

     

     

  6. 6 hours ago, Grimtano said:

    Pulled the trigger on the Rotel RA 1572. Couldn't refuse the $1050 price.  It's in god's hands now....

    Rotel has a good reputation for a long time.

    I trust you will enjoy your new purchase.

  7. On 10/19/2019 at 10:37 PM, Grimtano said:

    Have like 800cds, but the 80's in college took a toll on many of them, cracked cases etc.. so they hang out in the attic. So over the years I've built a massive library on iTunes/iPhone + streaming. So what's best way to transfer that music to Forte's via amp.  I'm sure I'll get a CD player next, but picking an amp and not having ability to hear with Forte's has slowed my progress.  I want to do this right.  

     

     

    Get a WiFi router if you don't already have one

    Buy a Network Access Storage Hard Disk connected to the router

    All devices on the network can then access the disk via wifi

    Rip all your CDs lossless onto your PC hard disk, Disk is cheap

    In January I usually rip 300-500 Cds

    Then copy them onto the NAS Disk.

    I use a lap top connected to my DAC for Playback from WiFi Disk and the internet

    There are lots of music file management programs you can run in windows

    I run Media Monkey

     

    • Like 1
  8. YAMAHA LOVE

    StereoPolice on Youtube did 3 parts on the Yamaha AS-1100

    which is a current high end model and his new Forte 3s

    Also did 2 or 3 more on AS-1100 and lots more on the Forte 3s

     

    Very positive on both, very good tech explanation of amps

    he usually opens them up and compares them to spec on the bench

    for the new Yammy he didn't have the test gear for the amp circuit they use.

    https://www.youtube.com/watch?v=xUe3iLa7-as

    https://usa.yamaha.com/products/audio_visual/hifi_components/a-s1100_g/index.html

    47DB3C8469C34B8E845770AC9E7DB75E_12073_3

     

    EE9C72E21500463FBC96B391FFC4C139_12075_3

     

    as1100spregbkls_1372x525_a9893693a8fa742

  9. https://www.newark.com/mcm-audio-select/55-2952/12-woofer-with-paper-conecloth/dp/80R7003

    https://community.klipsch.com/index.php?/topic/186650-heresy-replacement-woofer/

    I would leave the H2s alone

    start looking on this forum and e-bay for used

    H1 or H2 horns, drivers, crossovers etc

    You should be able to score the internals for a pair of Heresys easily

    and then build the cabinets yourself from birch

    and add the veneer you like, or find a friend to help with the veneer.

    Maybe someone could suggest a 12in direct replacement that he could buy new ?

  10. Suggest either completely black or natural stain to bring up the grain.

    I don't like black and did Natural , watco oil  or min wax works well.

    I don't like polyurethane on speakers or fine furnture

    it makes it very difficult if you want to change the look or freshen it up.

    I would do Watco Natural Oil, one application, then wait a few months to see

    if you want to bring the grain up a bit more.

  11. Experiment with the sub moved to the middle

    the Fortes moved close to the corners and slanted in

    experiment with focus on your listening chair

    in front of it and behind at different angles

    sometimes slightly off axis sounds better

    The radiators need room to work

    the question is how much, I would start out a few inches off of the wall and go from there

    I demo'd some that were approx 10ft apart and 3-4ft off of the wall and sounded great

    Area rug between you and the speakers is a good idea.

    Back of the room is a good place for book shelves, curtains or a hanging rug

  12. I would take a hard look at a used Pioneer THX (Ultra 2) Certified Receiver,

     the characteristics are certified in a THX test lab.

     

    These units have high-end built in DACs, Tuners, and excellent performance.

    Just the DAC in these is worth $500.

    Try to find  a unit with Pre outs, Tosslinks and Coax, Remote and Microphone

    A good mic can be scored on Parts express if needed or other

     

    The Amp sections will be either AB or newer units Class D

    - All of the manuals are downloadable from the Pioneer site or HIFi Engine

    - I would connect sources via Tosslink using Glass not plastic for electrical isolation

    - Plug all units into the same power supply to avoid ground loops

    - The Receiver has enough inputs for all of your sources, lots of them

    - Any good aftermarket remote will support the features on the Pioneer Elites

    - Some of the Receivers also have a good Phono input

     

     

    If you want to use the unit as a PreAmp, + DAC,  EQ, Room correction unit in any combination

    You can add a 2 Channel Amp later with world-class specs and performance like the Yamaha MX series

    the MX 600, 630, 800, 830, 1000 units can be had for a few hundred and sound great compared to anything at any price.

    MX-600 sold for $160 ebay, if you like the sound worth replacing the Capacitors, then good for another 20 years.

    MX-600

    https://www.ebay.com/itm/YAMAHA-MX-600U-NATURAL-SOUND-STEREO-POWER-AMPLIFIER/264454799728?hash=item3d92bc0170:g:MsMAAOSwtuRdcVBK

    Power output: 135 watts per channel into 8Ω (stereo)

    Frequency response: 20Hz to 20kHz

    Total harmonic distortion: 0.003%

    Damping factor: 70

    Input sensitivity: 1.14V

    Signal to noise ratio: 123dB

    Speaker load impedance: 4Ω to 16Ω

    Dimensions: 435 x 170 x 425mm

    Weight: 13kg

    Year: 1988

    https://www.hifiengine.com/manual_library/yamaha/mx-600.shtml

     

    HiFi Engnine will allow you to make a short list of Receivers based on Year, certification and specs

     

    Pioneer Elite Receiver VSX-26TX

    This one is Class D, which has become popular lately for the multi channel and 2 channel integrated amps.

    These units allow you to turn off everything and run direct from the DAC into the AMP, or run the signal through the room correction, EQ and THX circuits at the push of a button.

    This one is listed at $250

    https://www.ebay.com/itm/PIONEER-ELITE-SC-27-THX-Ultra2-PLUS-Certified-7-1-Channel-Home-Theater-Receiver/283625274973?epid=97483965&hash=item4209623e5d:g:XQoAAOSwo6hc8zog

     

     

    Pioneer Elite Receiver VSX-26TX 100W/Ch THX Ultra Certified Dolby Digital & DTS  $60.00

    Processing:

    • Dolby Digital and dts Decoding
    • THX Ultra Certified
    • 24-bit Digital Processing Chain for absolute accuracy
      • Crystal 24-bit A/D Converters
      • Motorola 24-bit Digital Signal Processor (DSP56362)
      • Burr Brown 96k / 24-bit D/A Converters
    • Digital Signal processing to re-create different acoustical environments. Modes include: Hall 1, Hall 2, Jazz, Dance, Theater 1, & Theater 2
    • Advanced Theater
    • Midnight Mode
    • Digital Noise Reduction

    Power:

    • Direct Energy MOSFET Amplifier Design
    • Stereo: 100 watts per channel (20 Hz to 20 kHz, @ 8 ohm, 0.09% THD)
    • Surround: 100W x 5 (20 Hz to 20k Hz, @ 8 ohm, .09% THD)
    • 6 ohm load capability guaranteed

    Pioneer Elite VSX-33TX 5.1 Dolby THX $100 Etc etc

     

  13. Rinse the record with warm tap water, try to keep the label dry

    Use some mild dish soap that is already diluted and clean with your fingers

    Wipe dry with a cotton dish towel on the plush side after shaking it out

    Then leave on a dish rack, wooden is best

     

    After that, I use a velvet disk brush with a little diluted alcohol to give the record a quick wipe when I play them

    You could also wipe with a micro fiber towel and distilled water

  14. 32 minutes ago, YK Thom said:

    I would wait until you have a chance to audition a pair. Fortes and Triton 1s are very different animals. You would notice the reduced bass in the Forte right off the bat and will not be happy without a subwoofer to accompany them.

    Just took at look at the Triton 1 web page

     

    Drivers

    GE 6 drivers inc powered subs & 4 side radiators vs.  3 driver Forte with passive 15in rear radiator

     

    Spec out

    Triton Frequency Response:.....................,,.. 14 Hz – 35 kHz. Efficiency:... 92 dB.

    Forte 3 FREQUENCY RESPONSE (+/- 3 dB) 38 Hz – 20kHz, SENSITIVITY 99dB @ 2.83V / 1m

     

    Not totally different design philosophy, but different:

    F3= Simpler crossover, passive (not powered) speaker, horn loaded mid-range & tweeter, much better efficiency

    F2 is the best sleeper I have heard so far, F3 is an updated version of a proven design.

     

    Don't recall GE other than at a show...but too many speakers to remember.

  15. Recommend you play a female voice with a piano through both,

    several tracks, perhaps several different females with zero processing on the voice

    reverb is hard to get away from.

    Freebird Capella on the Duets soundtrack for male vocal good test track

     

    If you can hear this, you have a great stereo

    Ann_Danielewski.jpg

     

    If voice sounds natural the amp and speakers are spot on, especially female

    Piano goes from zero to wide open on the amp and the speakers

    pretty much every frequency you are likely to hear.

     

    Test Tracks

    https://www.youtube.com/watch?v=AEv6NotxuC4

    https://www.youtube.com/watch?v=dzNmG_lpNw8

    https://www.youtube.com/watch?v=gVGCzTlT2hI

     

    Too bad they didn't put this out on CD or DTS

    https://www.youtube.com/watch?v=zRgHgftQY84

     

     

     

    • Like 1
  16. Go on Craigs list or e-bay and score a TOTL surround receiver for less than 200

     

    Someone who wants the latest surround chip sets, can't get much for their used receiver

     

    I like the Class AB Pioneer Elites and Yamahas, 100WPC will blow your head off, 5.1 is perfect

     

    I prefer the THX tested and approved amps, a few examples below, all day long at give away prices

    Burr Brown or other TOTL DAC built in, room eq, eq, ability to roll off high end, or go direct from the DAC to the output with 120db SN

     

    Be sure to get a mint unit, manuals, mic for tuning the room, and remote, box is a bonus

     

    Example research on AV forums and Audio Karma for model reliability etc....

    https://www.ebay.com/itm/Pioneer-VSX-1014TXK-THX-Select-AV-Receiver-Surround-Power-110-W-Massive-sound/183528699479?epid=46571437&hash=item2abb29b657:g:jEYAAOSwY2Jb5uEV:rk:1:pf:0

     

    https://www.ebay.com/itm/PIONEER-ELITE-VSX-81TXV-7-1ch-770w-THX-Certified-Home-Theater-Receiver-HDMI/253959286380?epid=60216615&hash=item3b21272e6c:g:GTEAAOSwb3hb0mY3:rk:3:pf:0

     

    https://www.ebay.com/itm/Pioneer-Elite-VSX-54TX-AV-Receiver-7-1-Channel-THX-Orig-Price-1-500/323514746465?hash=item4b52fb4661:g:caAAAOSwrGlby5h5:rk:5:pf:0

     

    https://www.ebay.com/itm/Yamaha-AVENTAGE-RX-A1000-7-2-Channel-280-Watt-Receiver/173627146519?epid=97513283&hash=item286cfc0117:g:pHgAAOSwolpb4hg8:rk:29:pf:0

     

     

     

    • Like 1
  17. Congratulations on your new LaScalas

    The link below is a collection of my modest improvements

    and lots of other modifications from other owners

    I put them into a collection as a I read them.

    My strong recommendation is one modification at a time, then pause for a while.

     

    If you are having cabinet modifications, new woofer, and 2 way crossover with new horn,

    I strongly recommend you get a quote from a local kitchen cabinet shop

    for a pair of new bass cabinets with the braces, 1 in Baltic birch,

    And depending on the horn and driver, they can make you a two piece cabinet like the LaScala 2s

    Home sales are down from what I read, so a shop might be willing to be reasonable with you.

    If you like your new 2 ways better than the LaScalas, put them in another room or sell to pay for the new ones.

     

     

    https://community.klipsch.com/index.php?/topic/159419-lascala-update-upgrade/

  18. On 11/4/2018 at 6:35 PM, garyrc said:

     

    What is the current status of TIM (Transient Intermodulation Distortion)?  In the late '70s and later, too much negative feedback got the blame.  Some audiophile amplifiers are advertised with "0 feedback."   Otala did a follow up paper in 2013, but I can't find it.  The Google citation for the 2013 paper sends me to the 1977 paper.   When Matti Otala came up with it in 1977, PWK said it should be named Otala distortion, in Matti's honor.  

     

    I think John Curl still gives TIM figures in the spec sheets for his Parasound amplifiers, on the ground that there is little correlation between listening tests and either THD or ordinary intermodulation distortion, but there is between TIM and listening test results?  Yeah, here we go for the Halo jc5:  http://www.parasound.com/jc5.php under Specs (not Features): TIM Unmeasurable

    1977 PDF

    http://www.jockohomo.net/data/7470.pdf

     

     Nice write up by Olin Lathrop

    Transient Intermodulation distortion (TIM) is usually measured by putting a burst of a fixed frequency into a amplifier and then measuring what actually comes out. By Fourier analisys, you can see that changing amplitude of a frequency actually implies additional frequencies. This is why AM radio stations can't be spaced too close together. They don't just radiate at the carrier frequency, but some range on either side of the carrier frequency.

    The additional frequencies of a single-frequency burst cause particular trouble to some types of amplifiers, and the resulting distortion appears more noticable to human listeners than more general distortion. Put another way, audio quality isn't just about total distortion level, but the type of distortion too. Different types of distortion are more objectionable than others, and TIM is of the more objectionable type. This is why there is sometimes a separate spec for TIM in addition to the overall distortion spec.

    TIM seems to be exacerbated by amplifiers that don't have much frequency headroom above the highest desired frequency, and a high global feedback ratio. Design techniques to minimize TIM include:

     

    1. Making the internal signal path of the amplifier still have gain well above the highest frequency of interest. For example, for a "HiFi" audio amp that must work up to 20 kHz, you may want individual stages to be reasonably flat to 100 kHz.
    2. A simple passive low pass filter in front of the amp that limits incoming signals above the specified operating range. This together with point 1 means that the active part of the amp will only see frequencies for which it's gain is relatively flat. This can be as simple as a one or two stage R-C filter.
    3. The gain of each stage should be stable and well-defined. Do not rely on global feedback to deal with high and unrestrained gain of individual stages.
    4. Keep the global feedback fairly low, which is the same as saying keep the open-loop gain of the overall amp only somewhat above the final desired gain of the whole amp. 10-15 dB seems to be a reasonable range. If all the stages individually have reasonably flat gain, then not much feedback will be needed to guarantee overall flat and predictable gain anyway.

    https://electronics.stackexchange.com/questions/156643/what-is-transient-intermodulation-distortion

     

    Decent write up, beat is one of the RF items I could learn more about, Radio the final frontier.

    https://en.wikipedia.org/wiki/Intermodulation

     

    A frequency spectrum plot showing intermodulation between two injected signals at 270 and 275 MHz (the large spikes). Visible intermodulation products are seen as small spurs at 280 MHz and 265 MHz.

     

    576px-RF_Intermodulation_at_280_MHz.jpg

     

  19. Worth reading from the chip set and board level makers, goes over the issues.

    Actually, highly recommended reading........

     

    class_d-fig-07.jpg?la=en

     

    https://www.electronicdesign.com/analog/can-class-d-amplifier-audio-performance-get-any-better

     

    http://www.irf.com/product-info/audio/classdtutorial606.pdf

     

    https://medium.com/@EPC_Corp/egan-fets-in-high-performance-class-d-audio-amplifiers-11e94d78c4d2

     

     

    The differences in power dissipation and efficiency widen at moderate power levels. This is important for audio, because long-term average levels for loud music are much lower (by factors of five to 20, depending on the type of music) than the instantaneous peak levels, which approach PLOAD max. Thus, for audio amplifiers, [PLOAD= 0.1 × PLOAD max] is a reasonable average power level at which to evaluate PDISS. At this level, the Class D output-stage dissipation is nine times less than Class B, and 107 times less than Class A.

    For an audio amplifier with 10-W PLOAD max, an average PLOAD of 1 W can be considered a realistic listening level. Under this condition, 282 mW is dissipated inside the Class D output stage, vs. 2.53 W for Class B and 30.2 W for Class A. In this case, the Class D efficiency is reduced to 78%—from 90% at higher power. But even 78% is much better than the Class B and Class A efficiencies—28% and 3%, respectively.

    These differences have important consequences for system design. For power levels above 1 W, the excessive dissipation of linear output stages requires significant cooling measures to avoid unacceptable heating—typically by using large slabs of metal as heat sinks, or fans to blow air over the amplifier. If the amplifier is implemented as an integrated circuit, a bulky and expensive thermally enhanced package may be needed to facilitate heat transfer. These considerations are onerous in consumer products such as flat-screen TVs, where space is at a premium—or automotive audio, where the trend is toward cramming higher channel counts into a fixed space.

     

    https://www.analog.com/en/analog-dialogue/articles/class-d-audio-amplifiers.html

  20. Class D pluses:

    High effiency

    Switching power supplies, no giant transformers

    Low Heat

    Allow for greater channel density in surround amps where heat and power become big issues

     

    Minus

    Don't spec out against AB and A amps and sound quality has been an issue

     

    "The power supply voltage directly amplitude-modulates the output voltage, dead time errors make the output impedance non-linear and the output filter has a strongly load-dependent frequency response. An effective way to combat errors, regardless of their source, is negative feedback. A feedback loop including the output stage can be made using a simple integrator. To include the output filter, a PID controller is used, sometimes with additional integrating terms. The need to feed the actual output signal back into the modulator makes the direct generation of PWM from a SPDIF source unattractive.[6] Mitigating the same issues in an amplifier without feedback requires addressing each separately at the source. Power supply modulation can be partially canceled by measuring the supply voltage to adjust signal gain before calculating the PWM[7] and distortion can be reduced by switching faster. The output impedance cannot be controlled other than through feedback. "

     

    https://en.wikipedia.org/wiki/Class-D_amplifier

     

     

    Class A is what all amps are compared to as the Reference

    Can you have good and bad designs in each, sure.

    Class A can be used to heat the room

     

    Excellent write up on Amp Types, I can't read it too many times

    https://en.wikipedia.org/wiki/Power_amplifier_classes

     

     

     

  21. You can probably get an excellent used TOTL surround Receiver Yamaha or Pioneer or other for $200

    Once the don't have the latest decoders, their value drops like a rock

    Don't buy one that is Class D, stick with the Class ABs

    100 WPC should do just fine

    turn off all of the digital features, and try running in direct stereo aka bypass

    The built in DAC will probably have TOTL chip sets like Burr Brown or other and a SN of 120db

    You can add a sub later, since the system already supports it

    Later if you go with 5 Heresies, you can run it in Surround 5.1 or 5.2 which would rock,

    then turn off all of the processors and go direct to listen to music in stereo

    The receiver will allow you to EQ both the room and the speakers if you wish.

     

    I like the THX rated Pioneers with remote in excellent condition, you have to check for the HDMI interfaces, the new chip set is what Dolby Atmos ? The SC was the TOTL but you have to check for the reviews on line, some units are more lovable than others and reliable too.

    https://www.ebay.com/itm/PIONEER-ELITE-VSX-33TX-THX-5-1-Receiver-EXCELLENT/202489839818?hash=item2f2555c0ca:g:wxwAAOSw3Zhbor0M:rk:2:pf:0

    https://www.ebay.com/itm/Pioneer-Elite-VSX-54TX-AV-Receiver-7-1-Channel-THX-Orig-Price-1-500/323514746465?hash=item4b52fb4661:g:caAAAOSwrGlby5h5:rk:4:pf:0

    https://www.ebay.com/itm/Pioneer-SC25-Elite-7-1-Channel-Digital-Home-Theater-THX-Receiver/332837602257?epid=97526440&hash=item4d7eaac3d1:g:0CsAAOSwNWhbtqcm:rk:6:pf:0

  22. Text from the AD

     

    "klipsch k horns in a light cherry finish. I bought these unfinished and had a furniture shop stain and spray 3 coats of clear. Also added Crites crossovers and tweeters. Ex/Con. 4500 OBO no trades please and NO I do not need help selling. The only reason for sale is I had a 20K$$ UV Mimaki printer die and I need to replace by Nov. 1

    The dark photos are my I-Phone the lite my Ipad actual color is between the two. No rips, stains, nicks or gouges
    Nonsmoking home."

     

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