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    Akitika GT-108 Stereo Amplifier Kit Review

    Aah... so that blue-wire L1 inductor is connected to the L1A and L1B pads, but not shown right there on @Doodski 's schematic diagram. Thanks for the explanation. Anyway, the speaker cap could explain the power drop to 35 Watts at 20 Hz which @amirm found.
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    Akitika GT-108 Stereo Amplifier Kit Review

    This amp appears to have a unipolar PS, hence the need for the large C13 coupling to the speaker to remove the DC offset of about half VCC. To avoid a loud "thump" and speaker overload upon power up, K1 is likely in the O position so that C13 can charge through R35 and R38 to about half VCC...
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    VMV D2R Stereo DAC Review

    Still, there are some who apparently have so much better ears than everyone else that they write along those lines: "That sense of ease it [AudioQuest Cobalt portable USB DAC] offers with long-term listening is something I don’t want to do without." That keeps new models coming in for review, I...
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    Low volume produced by Amazon Music App on Amazon Fire TV Stick

    IMO, one of the key benefits of Amazon Music Unlimited is to be able to stream tracks in Dolby Atmos to experience the spatial format as it was originally mixed (as opposed to the spatial effects an AVR may artificially add). When you turn Spatial Audio off in the app, then you are downgrading...
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    ROLLS HV6 Headphone Volume Control

    If this is a 520-Ohm "pot-in-the-box," then what else electrically could be expected?
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    AV123 / GR Research X-Voce Speaker Review

    Some low-frequency speaker measurements are made out in the open air, i.e. away from any walls objects that could acoustically interfere. For example, this sub measurement by AH. Is such a ground-plane evaluation a valid approach?
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    AV123 / GR Research X-Voce Speaker Review

    Danny does not seem to use any sophisticated measurement tools like Klippel to evaluate non GR Research speakers that he aims to "improve" by redesigning their crossovers, "upgrading" the caps (from the "dismal" electrolytic ones), inductors (from "awful" iron core ones for midranges and...
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    Low volume produced by Amazon Music App on Amazon Fire TV Stick

    On the Fire TV Stick 4k Max, in the latest firmware version 3.4.1311.0 there is a mismatch between the graphical representation of settings and what the actual processing is. For example, you can set Loudness Normalization to OFF (so that the slider control is in the left position and the...
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    RSL C34E MKII In-Ceiling Speaker Review

    I do not get the idea of all those in-wall speakers. Basically, you are supposed to mount them on the drywall, but you have no control over what is behind them (joists or trusses for the floor or attic above, or studs for sidewalls, with insulation of some type, wires, plumbing, vents, etc.)...
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    Schiit KARA Preamp and Headphone Amp Review

    The volume control does not need to be an actual pot. It could simply be a rotary pulse generator: Turn it clockwise and it generates pulse(s) incrementing a 7-bit counter (with a limit of 0..127) that drives the relays that control a discrete resistive attenuator. Turn it counterclockwise, and...
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    Schiit KARA Preamp and Headphone Amp Review

    Linear in terms of dB, which is a logarithmic measure (see formulas). Let me try another explanation: Consider, for example, a fixed angular change of the pot, say by 10 degrees out of the total possible 270 degrees. As you turn a truly linear pot, for every such angular change the signal...
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    Schiit KARA Preamp and Headphone Amp Review

    This article provides a pretty good description: "The dashed lines in the graph below show the "real" logarithmic and inverse log curves. In practice, logarithmic types which are used for audio applications do not provide a true exponential response, but follow the curve stepwise. The blue line...
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    Schiit KARA Preamp and Headphone Amp Review

    Our hearing is "log": "The ear was constructed to hear both very quiet and very loud sounds of very small and very large frequencies. This is why the ear hears logarithmically." For further proof, consider that: "In order to double the perceived volume, you’ll need a tenfold increase in power."...
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    Schiit KARA Preamp and Headphone Amp Review

    You are still dodging the question by spinning stories. The question is: why employ an expensive and noisy electromechanical attenuator if an electronic one (IC-based) would be cheaper, noiseless, more reliable and more accurate? And no, volume pots are not "log" (or "semi-log") but "exp,"...
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    Schiit KARA Preamp and Headphone Amp Review

    Please quantify this "good," "better" and "perfect" channel balance. The relay-less (IC-based) attenuator I showed as an example has a max. +/-0.2 dB channel imbalance. Tests show anything less than +/-1 dB is generally imperceptible (+/- 0.3 dB only in rare cases at some frequencies).
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    Schiit KARA Preamp and Headphone Amp Review

    What is this "stepped relay" control really supposed to accomplish apart from hype? If the goal is to claim a "fully discrete" implementation that features a "128-step relay-switched attenuator, rather than a traditional potentiometer. This means essentially perfect channel matching and...
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    TempoTec Sonata BHD Pro Portable DAC & Amp Review

    The Meizu MBLU Lifeme is based on the Conexant CX31993 and Maxim MAX97220. See the ASR discussion and the product webpage. The Shanling UA2 is based on the ESS ES9038Q2M DAC & Ricore RT6863 amplifier. See the product webpage. So neither is based on the Cirrus Logic CS43131. Hence the graphs you...
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    TempoTec Sonata BHD Pro Portable DAC & Amp Review

    In those type of devices, the credit for performance should really go to IC designers (in this case, Cirrus Logic). The OEM only adds a PCB (usually, following a reference design from the chip vendor) and a nice metal enclosure. Assuming a proper design following vendor's guidelines, performance...
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    EAR Yoshino 834L Deluxe Preamp Review

    What is the point of this device? If it is to generate a "pleasant" valve distortion at a level of -59 dB = 0.11%, then it is largely useless. For the most part, we cannot detect less than 1% (maybe 0.3% with higher harmonics but only at certain frequencies). With loudspeaker-based playback, the...
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    Apollon NCx500ST Stereo Amplifier Review

    Hypex NCx500 ST NCoreX Stereo Amplifier - Components: "Aluminium enclosure with anti-vibration rubber feet"
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