Jump to content

VDS

Regulars
 View Profile  See their activity

  • Posts

    305

  • Joined

  • Last visited

 Content Type 

Posts posted by VDS

    Transconductance amplifiers?

    in Solid State

    Posted

    On 11/30/2016 at 10:35 AM, Chris A said:

    Thanks Carl.  This is actually a pretty esoteric subject, apparently.   Many people really don't know what a transconductance amplifier is.  It's a current-source amplifier instead of a voltage-source amplifier. 

     

    What most people don't really realize is that their Klipsch loudspeakers operate off of current--not voltage.  Using higher output impedance amplifiers--such as SETs--is really about pushing their amplification paradigm towards current source rather than voltage source amplification.  The problem is that most people are also not prepared to hear the boost in low frequency output that they will get around the woofers' resonant frequency when using a true transconductance amplifier.  So all they have to do is to EQ their current source amplifiers down in the 40-60 Hz region [EDIT 19 Aug. 2018:...and the upper midrange region (2-7 kHz)], depending on exact loudspeaker model you're using.  A lot of people seem to have trouble understanding how this can be true, and abandon their transconductance amplifier trial without first dealing with this phenomenon.

     

    Chris

    Would the First Watt F8 fall in this category, Current source?

    First Watt

    in Solid State

    Posted

    On 5/2/2021 at 8:26 PM, richieb said:


    As you may have noted I’m a fan of FW, the F3 in particular. I actually sold the XA25 in favor of the F3. For the money invested I enjoyed the F3 over the XA and sold while they were the latest and greatest from Pass. Fast forward to today and I sold a FW J2 after finding a second F3 to run as monoblocks. I did own an M2 for a short time and found it too didn’t live up to the F3. All my opinion of course - 

    Yes I would agree I would take the F3 over the Xa25.  Think that since the 402 horns increase separation and are so dynamic themselves, maybe the f8 would take away the last remaining “edginess” I have.  Nelson talkes about the high dose of 2nd order harmonics in the f8 and the Xa25 being more 3rd order, not sure where F3 lands.

    Using 2 First Watt SIT3

    in Solid State

    Posted

    On 12/14/2019 at 9:49 PM, Jim Gregory said:

    Thanks for the recommendations and advice. 
    Looks like I will be staying with the single SIT3 for the HF. It really does a great job by itself, just enjoy contemplating different ideas. I would love to try a pair of SIT1 but they don’t come up for sell very often. 

    Any perspective on the SIT 3 sound? I have 402’s with HF powered by F3, wondering about the sound signature of other First Watts.

    thanks, Ted

    What I Got Today!

    in Lounge

    Posted

    On 9/11/2021 at 12:05 PM, Westcoastdrums said:

    After all the rave reviews here, I decided to see if this is my cup of tea or not. Hope I love it and it's a keeper for me.  

    Screenshot_20210911-100328_Gallery.jpg

    What were your impressions of the M2? Have you compared to any other  FW?  I think you just sold it, but can you give an assessment of it. I have an F3 but looking to try more FW amps.

    thanks, Ted

    UMIK 1, REW problem

    in Technical/Restorations

    Posted

    Has anybody had problems with Rew connecting to UMIK 1? I just got one to replace my Dayton UMM6.  After one successful sweep Rew tells me it doesn’t recoconize the mic. I have to restart my computer and then it’s fine for one sweep, then I need to restart again.  
    Any ideas appreciated, Ted

    Subconscious Auditory Effects of Quasi-Linear Phase Loudspeakers

    in Technical/Restorations

    Posted

    On 6/5/2019 at 11:30 AM, Chris A said:

    IIR filters only--no "named" crossover filters, i.e., Danley-style. 

     

    Look at the raw response of your drivers/horns.  Without FIR filtering, you can't improve on the response that you see there after they've been EQed flat (individually).  So you need to select drivers and horns that have good phase response characteristics.  It just so happens that the Jub bass bins and TAD 4002/K-402 horns have really good phase response taken individually--after they've been EQed flat by themselves.

     

    So all you have to do is put the HF and LF drivers together without phase shifts:

    1. Don't use the "crossover filters" that come with DSP crossovers--clear any crossover filters if they're set.
    2. Set the HF or LF channel delay to get perfect impulse response in the time domain--as seen in the spectrogram view.
    3. Flatten each driver's SPL response within their pass bands.
    4. Match the channel gains between flattened phase drivers.
    5. Use output channel PEQs to trim off response on each end of the bass and high frequency drivers until you've got overall flat SPL across the crossover interference band and smooth handover of SPL vs. frequency.  The drivers themselves will tell you where that transition/crossover should occur.  [If you're using MEHs, you'll have to use multiple PEQs to attenuate the bass bin peaks in response above the first notch frequency.]
    6. Use the input channel PEQs to further flatten the overall response within the interference band to correct any dips or peaks in response within that band.

    Voila!  Flat phase.  It's really that easy.

     

    Chris

    @Chris A,I’ve been doing this method, with steep drops and rises where drivers meet. Rereading this thread you are advocating shallow drop offs.  When you “trim the ends” do you use PEQ to get both drivers to rise and fall slowly, similar to a 6db/oct ?  Mine have been very steep, following the natural driver drop off/rise.

    Ted

     

     

    Classical recordings

    in 2-Channel Home Audio

    Posted

    5 hours ago, robert_kc said:

     

    Thanks for making me aware of IDAGIO.   Do their classical videos feature hi-res surround-sound?

     

    Are you interested in a Blu-ray player that supports multi-channel (i.e., 5.1), or 2-channel (i.e., stereo) only?

     

    Will you be using an amp with an HMDI input (e.g., AVR), or an amp with traditional RCA line-level analog inputs?

     

    Budget?

     

    FWIW, I recommend getting a "universal player" that will play:

     

    •    CD, 
    •    DVD, 
    •    DVD-Audio, 
    •    SACD, 
    •    Blu-ray, 
    •    Pure Audio Blu-ray, 
    •    Ultra HD Blu-ray, and 
    •    Hi-res downloads (e.g., 24bit/192kHz FLAC, and DSD).
     

    Following are some quick thoughts.

     

    If your amp supports an HDMI input, then consider the Sony UBP-X800M2.  It’s cheap, and supports almost every format    However, the UBP-X800M2 does not provide analog audio outputs (i.e., it’s HDMI only).

     

    If you are adamant that you only want 2-channel analog audio outputs from a disc player, but want the flexibility to support most modern digital audio and video formats, then consider the Sony UBP-X1100ES.   Or, to save a few bucks, consider the earlier Sony UBP-X1000ES.


    For a multi-channel “universal player” with analog audio outputs, consider a used Oppo player:

     

    •    Oppo UDP-205  (I own 2 of these.)
    •    Oppo BDP-105  (I own 1 of these.)
    •    Oppo BDP-95  (I own 1 of these.)
     

    There is a relatively new product on the market, but I have no experience with it:  https://www.reavon.com/reavon-ubr-x200

     

     

    IDAGIO is FLAC 16b 44.1kHz. Primephonic is FLAC 24b 92kHz, but my Bluesound streamer doesn’t support it.

     

    Im strictly 2 ch stereo, no home theater.

    i could plug Blu-ray player into my DAC, MHDT Orchid, (USB, Toslink) or into preamp inputs, (rca)
     

    I have a great DAC, so I feel like bypassing the Blu-ray players Dac would yield better results. 

    Active Bi-Amping/Tri-Amping FAQ

    in Technical/Restorations

    Posted

    Been playing with active crossovers for a few weeks, This morning I tested my right speaker, I always test left, quite a difference in frequency response! 
    For kicks I decided to try to get the same REW response from each speaker.

    So now I have different Xilica settings left and right, but very similar REW frequency curves coming from both.

    Seems like the best sound I’ve ever heard from these speakers.
    Ahh maybe just expectation/ confirmation bias!

    Active Bi-Amping/Tri-Amping FAQ

    in Technical/Restorations

    Posted

    For anybody that is using active crossovers with digital source.  Has anybody heard a difference by upgrading Dacs? (Skipping the “dacs don’t make a difference” argument). I mean since the analog signal from the Dac is transformed to digital and back to analog in Xilica (or other Dsp)?  
    thanks, Ted

×
×
  • Create New...