New Schiit / Preamps and Power Amp (was Putting the Schiit Signal Up)

Discussion in 'Preamps' started by purr1n, Oct 6, 2016.

  1. cizx.6

    cizx.6 Just couldn't stay away...

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    Well they say that they'll probably be fine in at 4ohm as long as the volume doesn't get too high.. same with 2ohm in two channel. Sounds like they're just covering their schiit.
     
  2. Torq

    Torq MOT: Headphone.com

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    Other than both having a USB receiver in them, they're entirely different devices with very different requirements and implementations.

    Based on actually listening to them?

    I've found the SU-1 to be usefully better than the F-1, and the Eitr either beats the SU-1 or is indiscernibly different - depending on the specific configuration. I'd assume, from that, that Eitr will outperform the F-1.
     
  3. trung225

    trung225 Facebook Friend

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    I only suspect that only from reading what they do, because I haven't yet listened to Eitr. If you have a chance to compare Eitr and SU-1 directly, I am very grateful to hear the result.
     
  4. Torq

    Torq MOT: Headphone.com

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    Already done ... since I have an SU-1 for my Spring DAC (to drive it's I2S input), see here.
     
  5. murray

    murray Friend

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    Bridged amplifiers have their outputs in series, so each individual output effectively "sees" half of the load impedance. Bridging doubles the possible voltage, but not the current (because of the series connection). This is why it's not necessarily the best solution in all cases.

    If you need more current, then you could consider bi-amping as an alternative. You can do this if you have 2-way speakers with separate binding posts for woofer and tweeter sections. Drive each with a separate output from the amplifier in normal stereo mode, using 1 stereo amplifier for left and the other for right. Or one for bass and one for treble - like a PA.
     
  6. Aklegal

    Aklegal Friend

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    I have done this before. I had a big pair of Tyler Acoustics Linbrook signature speakers. I was trying to power them with one Marsh A400 amp but the linbrooks were just too much (very low impedance dips - bass was thin, mids recessed). I bought a second a400 to biamp the speakers and things got a little better but it wasn't amazingly better. I finally sold the pair of amps and got one amp that could legitimately drive the speakers and things then got amazingly better. Long story short if you have a somewhat "off" speaker and amp combo, bi-amping could help, but if your speakers beat the shit out of your amps don't bother with bi-amping with a pair of the same amp.
     
  7. zonto

    zonto Friend

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    VIDAR WEEKLY UPDATE
    Pop from Speakers?
    • Comment re: "pop" through speakers with Vidar power-off: "Since the weather is bad here, I've had to cycle the Vidar off a few times. Power up is silent through the speakers, but there is a slight "pop" when it is switched off. It's not too bad, but slightly disconcerting."
    • @schiit response: "[A] small pop is normal as the relay disengages." (source, and couple posts before)

    Transformers: More Than Meets the Eye
    Some older posts from @baldr on EI core vs toroid transformers I thought some might find interesting given Vidar's use of the former (credit to HF user rkw):

    "Toroids for power transformers are like stained glass windows for greenhouses. Aesthetic but expensive and 90% misapplied. The only advantage of toroid geometric cores is a controlled field interfering less than traditional power transformers - oh, and cheaper to mount because they only require one mounting hole. The former is easier to evade with proper case design, the latter for cheapos. Toroids are made of ferrite core material. The ONLY advantage of ferrite cores is for high frequency appication. For 50 and 60Hz power transformers, iron has much higher permeability and power transfer than toroids. If you are a high-ender and care more about art than proper function, you may choose toroids for your audio gear AND stained glass for your greenhouse. This may be helpful when you point out your gear's/greenhouse's useless features to your ever-diminishing group of friends. Oh, and did I say because toroids run out of gas below the power line frequency they sound like hum-free gutless ass, particularly at lower frequencies. Carry on, high-end audio, in spending technically worthless money to raise prices for all.

    Sorry - power toroids are one of my pet peeves." (source)

    "In all fairness to @jimmers - I dug out some toroidal transformers that were built back in the 1970's and eighties as prototypes for Theta tube type and Theta digital D/A converters, all by the same maker in Fort Myers, Florida. The reason I rejected them at the time was simple; they sounded like ass - flat in a dynamic sense, lacking anything close to cajones, and boring. A destructive analysis was run. Aha, I thought, these are perfectly donut shaped ferrite cores. A closer inspection revealed the ferrite was molded over another structure, which was indeed a tire shaped wound core, apparently iron. All of my protos were built in this way.

    I am not a transformer designer. My fundamental conclusions, however remain unchanged:

    1. Toroids are expensive. I would rather spend the 50% difference on an underrated EI transformer, or better yet get a grain aligned C core.
    2. They sound like hemhorroidal ass.
    3. Given 1 and 2 above, I stand by my original point - Toroids are like Stained Glass Windows for Greenhouses. Despite the fact they have a certain cachet, they degrade the performance at far greater cost." (source)


    NON-VIDAR PRODUCTS UPDATE
    Thursday, July 20, 2017 - Moar headphone products and surprises coming

    "Hey all,

    Yep, I've toyed with the idea of a high-power OTL headphone amp, but I've never really gotten anywhere with it. We have a TON of headphone amps, and I'm not really convinced we need to add to the line.

    But stay tuned...we'll have some more headphone-related products hitting before the end of the year, plus a couple of other surprises. As someone said, we're always developing something.

    All the best,
    Jason"
     
    Last edited: Jul 22, 2017
  8. zonto

    zonto Friend

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    Saw this on Schiit's Facebook page today: "SchiitShow Time! Join us on Friday, July 28th at the Schiitr for an introduction to Vidar and Eitr by Jason Stoddard and Mike Moffat. For those of you who can't make it to Newhall, we'll be streaming video here on Facebook as well. Plus, there may be a bonus announcement!"

    See https://www.facebook.com/Schiit/.
     
  9. msommers

    msommers High on Epipens

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  10. Priidik

    Priidik MOT: Estelon

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    Perhaps a little insight will clear some misunderstandings:
    A torroid of similar VA rating made of typical ferrite would be humongous in size vs E-I (ferrite's pre saturation flux density is 5 times less with similar permeability for cheap ferrite, type k). That is not the case in RL, torroids of 600VA are not the size of a microwave oven.
    Most power toroids use wound silicon steel, same material that most E-I ones use, difference is in better magnetic coupling due to less distributed magnetic gap in core (because E and I pieces are difficult to align perfectly, which means bigger core for E-I for the same VA) and the toroidal geometry that inherently has less stray fields. Less core material, better mutual coupling and more capacitive coupling between prim-sec means it has better high frequency response. If anything, toroid should have more 'kick' in the lows because of smaller impedance (less wire length than for E-I). E-I of same VA is probably more robust to overvoltages due to the distributed airgap and stray fields.

    Sometimes people mistake powder metal or metal glass with ferrite (these look very much alike). I've made the same mistake when I have wound coils for my own use. Powder metal is more like silicon steel than ferrite in properties, although it has much less losses in high frequencies, good thing in RF electronics, bad thing for hi-fi.
    ... all that said, I'd take E-I or C-core for powering hi-fi, because of more losses in high frequencies and better decoupling from grid.
    Fwiw, Nelson Pass seems to like toroids, so do many other established amp builders (Accuphase, Hegel).
    These guys probably chose toroid path becayse it is more compact and more usable in cramped enclosure due to less field leakage.
    For end use applications both have cons and pros, even for hi-fi the E-I is not always clear cut better, in my opinion, of course.

    Mass produced toroids around 100VA to 2 kVA are less expensive here in EU.
    edit: good indication of toroid using something other than silicon steel for core is perfectly circular cross section.
    Most often the toroids are rectangular-ish in cross section.
    Not that silicon steel core can't be circular, but it would be more expensive in this case and is seldom used for low power (sub MW).
     
    Last edited: Jul 25, 2017
  11. Priidik

    Priidik MOT: Estelon

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    Still couple of points:
    cheap transformers are operated in the limits of core saturation:
    1. this makes the secondary voltage practically unable to reach over the spec-ed value when primary side receives overvoltage --> safety,
    2. and more importantly it makes the transformer smaller--> less expensive.
    This is the common for practically all types of cheap transformers, especially those intended for decoupling sensitive electronics from power aparatus, E-I or toroid.
    A crucial difference for hi-fi use might be that due to the inherent airgap of E-I the core will not saturate as easily, and thus might have better regulation and less harmonics produced. I have not heard E-I produce loud hum with harmonics or dc on the lines, but half of the toroids do. Even the one in my EC does.
    It's all general, the specific manufacturers and even specific series of transformers differ quite a bit. I have opened toroids, some are very nicely and conservatively built.
    TL DR : a toroid can be very crappy despite not using ferrite, but can also be very good.
     

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