RAAL requisite audio SR1a Review: HOLY MOLY! Buy this now!

Discussion in 'Headphones' started by purr1n, Jul 12, 2019.

  1. Ringingears

    Ringingears Honorary BFF

    Friend
    Joined:
    Sep 26, 2015
    Likes Received:
    3,713
    Dislikes Received:
    3
    Trophy Points:
    113
    Location:
    Northern Californium Valley
    Nice dick waving Marv. I felt the breeze from it all the way up here. It moved the flag over the State Capitol. :D

    Since I’m a believer that at a certain point transducers make a bigger difference than amps I have a question. With my previous statement in mind, how do you think the SR1a would pair with the Black Widow ver1 ? Not sound like shit?

    Edit: guessing BW doesn’t have enough power. I have several power amps sitting around 150-250W range. Is that’s what we are looking at for best performance?
     
    Last edited: Jul 23, 2019
    EagleWings likes this.
  2. Lyander

    Lyander Too sensitive for SBAF

    Friend
    Joined:
    Feb 25, 2017
    Likes Received:
    6,012
    Dislikes Received:
    25
    Trophy Points:
    113
    Location:
    Pasig, Philippines
    Poor humour incoming: I rather doubt your wife would be very happy that you went to brencho's house just to wave his Richard around.

    On a serious note, more than loads of other products in recent memory this one excites me, and it's not quite as ridiculously priced as the Utopia to boot. Still complete unobtanium for myself, but fingers still crossed for cheaper ribbon cans in maybe the next decade— lack of low end heft aside measurements and subjectives make me think I might really, really take to their sound profile.

    Just based on your impressions it seems the SR1A is a bit of a chameleon depending on upstream (provided gear can drive it "well") but doesn't change major characteristics nearly as much as other cans might with the same changes? Seems like profile remains consistent save for speed, texture, resolution and all that jazz. Might be due to amps passing through the magic RAAL box, really wondering what a third party one might do.
     
  3. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    60,701
    Dislikes Received:
    106
    Trophy Points:
    113
    Location:
    Antarctica
    I think a BW kind of sound (organic) would be great. Note the personality of the amps that I have liked with the SR1a: warm (Vidar), mid-centric sweet (Aegir x2), laid-back and sweet (Dartzeel NHB-108). I think ribbons, no matter how good, can be unforgiving and a poor match for sterile and antiseptic (or bad) solid-state.

    Now the problem with the BW? We really need a direct drive version, otherwise, we are talking about 100W into 6 ohms to start. The converter box that RAAL Requisite has a series of resistors that help present a suitable load to the power amplifier. The reason this is needed is because of the 0.02-ohm impedance of the ribbon. This is essentially a short-circuit. The downside to this approach is that A LOT of power is wasted in the impedance matching resistors.

    I've heard someone say that the SR1a is horribly inefficient. This is not true at its core. What's really needed here are special direct-drive amps that are low voltage, but that can provide several amps of current! I think I heard that RAAL Requisite is already working on such an amp. And Jason @schiit already mentioned that he is too. To me, this is as close to an endorsement from Schiit, as they have traditionally kept away from niche stuff like stat amps. (Then again, making stat amps is fraught with political risks as well). I wouldn't expect bargain prices for such an amp from Schiit though because of the lower volume higher-end niche of the SR1a.

    I have no doubt more affordable products will follow. If not from RAAL Requisite, then from others. RAAL Requisite has got a head start, and they do have the best ribbons in the business. A headphone (circumaural) version of this would certainly have plenty of bass. Could, in theory, be cheaper too as the ribbon doesn't have to be as large as with the open baffle approach of the SR1a.

    "Speed" seems to change more than I expected, but honestly, I need to try out more amps, sources, preamps, to say for certain. Tonal response too, as I couldn't imagine myself using one of those ADCOMs or an AHB2. The highs would kill me on the former and the thinness on the latter. It's textural capabilities have seemed pretty consistent. Same with dynamic impact, but none of the amps I have tried so far can be said to be limp sounding.
     
    Psalmanazar, obsiCO, pavi and 4 others like this.
  4. Zhanming057

    Zhanming057 Friend

    Friend
    Joined:
    Dec 13, 2018
    Likes Received:
    892
    Dislikes Received:
    20
    Trophy Points:
    93
    Location:
    Boston
    My impression is the opposite - it reflects strength and weakness of the source more than other cans.

    Fast is fast and there's not a massive amount of variation there aside from running pure tube amps, and aside from the speed and the 33hz rolloff, pretty much everything is amp-dependent and scales upward by a lot when you put these on better amps. @Torq has similar impressions between the Vidars and a Linn 4200. I've tried these on a couple halo amps - the Thrax Spartacus for example - and subjectively they do seem to be scaling up, even at that level.

    The box is nothing fancy, it's a voltage to current drive conversion and there's no doubt that if you want to spend the money, you can get the same box with better components than the stock box. But the box doesn't feel like a limiting factor to me.
     
    kitty995 and Lyander like this.
  5. Lyander

    Lyander Too sensitive for SBAF

    Friend
    Joined:
    Feb 25, 2017
    Likes Received:
    6,012
    Dislikes Received:
    25
    Trophy Points:
    113
    Location:
    Pasig, Philippines
    Sorry, didn't mean to imply I thought it was a limiting factor, only that it might impart enough of its own character to the headphones that the influence of upstream gear isn't as pronounced. Others might beg to differ but I wouldn't necessarily qualify that as a "bad" thing.

    I'm gonna have to trust both of you guys when it comes to TOTL stuff since I'm certain my own listening skills are horrible relative to yours (can't really discern changes between filters on the silver Micro iDSD, for example). I was following the thread over on headphone.com for a bit before the sheer volume of replies made me balk, generally got the same idea from Torq's write-ups that going from Vidars to rarer fare made for a pronounced change, but statements like that are relative IMO; "night and day" for very experienced listeners is "... maybe?" for me.

    What really interests me is how your impressions of changes in speed and texture between upstream components are directly diametric to purr1n's. I'm pretty sure that you're both operating using similar definitions of the terms, curious. You have had them for much longer though, and have had opportunity to experiment with more stuff. Just skimmed through your review again (thanks for the excellent write up!), I don't necessarily see any contradictions because it could be down to specific gear used and how they synergise (ugh, hate that word) with the transducers.

    Eh, I'm shutting up now and hopefully getting ears on these so I can be suitably left disemboweled with awe.
     
  6. Zhanming057

    Zhanming057 Friend

    Friend
    Joined:
    Dec 13, 2018
    Likes Received:
    892
    Dislikes Received:
    20
    Trophy Points:
    93
    Location:
    Boston
    Marv said that it changes more than he expected, and there is definitely a decent amount of variation across solid states. They slow down a lot on tubes - think V110SE or Rogue Cronus Magnum - and that's something I don't like, it takes too much away from what makes the SR1a's special. Otherwise, bass speed suffers on weaker amps. Before I had a chance to try out stage amps I assumed that they would slow down a lot on cheap Class D amps, and it's a good thing that this is mostly not the case, and definitely not an issue for treble response per se.

    My general feeling is that if you're going in blind, a warm-ish solid state will be your best bet because there's definitely more treble energy here than most TOTL cans, and 100wpc+ tube amps are finicky and more often than not pretty noisy until you get to really high end stuff.
     
    Lyander and pavi like this.
  7. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    60,701
    Dislikes Received:
    106
    Trophy Points:
    113
    Location:
    Antarctica
    This is the load of what a power amplifier will see when plugged into the interface box. This load should be easy for any power amplifier to handle. The nominal impedance is about 7-ohms rising with frequency. Note that the load for the actual ribbon driver is listed as 0.2-ohms.
    upload_2019-7-23_22-35-40.png
     
    fp627, Serious, Biodegraded and 2 others like this.
  8. Vtory

    Vtory Illogical Spock

    Friend MZR
    Joined:
    Sep 12, 2016
    Likes Received:
    5,434
    Dislikes Received:
    38
    Trophy Points:
    113
    Location:
    Greater Philadelphia Area, PA
    That sounds just wonderful. Low or no feedback and high biasing point do justice and magic all the time, as I kinda hate the other direction (lots of nfbs resulting in fantastic measurements). I like vidar for that reason, but it seems that dartzeel extended the approach to the brutal extent lol.

    Very excited.. until I googled the price of that amp. oh well. :(

    Chinese people seem to reverse-engineer the circuit and make some copy products. But I doubt the quality somehow.
     
  9. Serious

    Serious Inquisitive Frequency Response Plot

    Friend BWC MZR
    Joined:
    Sep 28, 2015
    Likes Received:
    1,822
    Dislikes Received:
    0
    Trophy Points:
    113
    Location:
    near Munich, Germany
    I thought the 0.2 Ohm was mostly from the cable with the driver being more like 0.02 Ohm, no?
     
  10. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    60,701
    Dislikes Received:
    106
    Trophy Points:
    113
    Location:
    Antarctica
    LOL, I'll measure, with cable and without.

    I was very tempted to buy a clone from AliExpress, until I read a review from one customer in Australia who was initially happy with it, until it failed. Said customer claims the seller hurled insults and ultimately retorted "neener, neener, neener", but not before resorting to saying something to the effect that he was untrustworthy because he was from the land from knaves, hoodlums, and criminals (a common Internet trope used by Chinese mainlanders towards Australians). Hahahahaha. I guess "racism", or perhaps more accurately stereotyping is everywhere.
     
    Last edited: Jul 25, 2019
  11. Zhanming057

    Zhanming057 Friend

    Friend
    Joined:
    Dec 13, 2018
    Likes Received:
    892
    Dislikes Received:
    20
    Trophy Points:
    93
    Location:
    Boston
    The cable used to require a 0.2 ohm rating. Later production moved to around 0.5-1 ohm because the 0.2 ohm requirement made the cables too thick and rigid.

    The drivers are ~0.02 ohms, AFAIK.
     
    Serious likes this.
  12. Thenewerguy009

    Thenewerguy009 Friend

    Friend
    Joined:
    Oct 11, 2015
    Likes Received:
    395
    Dislikes Received:
    32
    Trophy Points:
    63
    Damn.
    I'd bet those marketplace sellers just ship them out & are not involved in the process of building them, so they probably had no clue in repairing it.
    If his broke within the Aliexpress return period, he could have just returned it for a refund.
     
  13. Jozurr

    Jozurr Facebook Friend

    Joined:
    Oct 20, 2015
    Likes Received:
    206
    Dislikes Received:
    15
    Trophy Points:
    43
    Does anyone have an idea if the SR1a will benefit more with higher current (amps) or higher volts on an amplifier?
     
  14. jazglers

    jazglers Rando

    Joined:
    Jun 22, 2019
    Likes Received:
    28
    Dislikes Received:
    0
    Trophy Points:
    13
    Location:
    Los Angeles
    I'm trying to imagine good examples of an instrument, sound, or voice that becomes lifeless without harmonic texture. Would a real life example be like someone with a really resonant voice, close-up? (mids) Or like the tactility of a live concert bass drum? (bass) Or live trumpets? (highs). Those are the closest I can come up with. Like having them play behind a door and then opening the door (kinda).
     
    Lyander likes this.
  15. Lyander

    Lyander Too sensitive for SBAF

    Friend
    Joined:
    Feb 25, 2017
    Likes Received:
    6,012
    Dislikes Received:
    25
    Trophy Points:
    113
    Location:
    Pasig, Philippines
    "Textures" as used in auditory perception is subjective as hell, so I'd not be surprised if my definition of it is different from others'. That said I can kinda see what you mean by your door analogy if I'm not misunderstanding— small nuances like how, when listening to well-recorded guitar, it's extremely satisfying to hear the "air" of loose reverberations and that sharp tzing when someone drags fingertips lightly, quickly, across a string while shifting their hand? That all gets lost without "texture", like you're somehow getting enough of a sonic image to identify what instrument is playing, what note it's playing at any one instance, but not much else to make you feel like you're there, closer than you might actually be listening live.

    Nitpick, it'd be more like listening through varying densities of cloth more than a door in my opinion, since doors are pretty damn effective at bollixing sounds :))

    I basically equate the term to really subtle nuances in recordings, maybe it's a mix of how people here define microdetail and microdynamics.
     
    jazglers and Richgard like this.
  16. Biodegraded

    Biodegraded Friend

    Friend
    Joined:
    May 28, 2017
    Likes Received:
    3,704
    Dislikes Received:
    1
    Trophy Points:
    113
    Location:
    Vancouver BC
    Heh. We NZers like to say the same about them - conveniently ignoring the fact that a large proportion of early white NZ colonists were released Australians or their descendents.

    See the definition under the Changstar spoiler tab in @zonto 's post at the bottom of P1 of the old SuperBAF Audio Glossary thread (which I repeatedly find to be a great reference, even though I'm guilty of not using it consistently myself):

    Texture: The sound of a frequency band in itself. Related to timbre.
    • Example: Gritty, grainy, plasticky, artificial, muddy, etc.
     
    Lyander likes this.
  17. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    60,701
    Dislikes Received:
    106
    Trophy Points:
    113
    Location:
    Antarctica
    On textures, it's that above. But I was also thinking also harmonic textures, e.g. being able to tell with clarity what effects pedals are being used with guitars. The lack of an imposed timbre of its own really helps in this regard.

    And this ^ above. I think it's the combination of transient cleanness and tactility that helps bring out these textures.

    More power is always better. The load is an easy 7-ohm with a rising response. With the interface box, I don't think massive current capable amp that can do X watts into 1-ohm will help because we aren't seeing dips in the impedance curve. I can see higher Class A biased as better, because of the voltage (and wattage) being pushed high.

    Now without an interface box, with a direct drive amp... that would be totally different. Again, it's a fricking metal ribbon (bathed in a magnetic field) with electrodes attached at the ends, i.e. a short circuit!

    As an aside, I am curious about the interface box. Looks like chokes or transformers in there, but also a lot of resistors. Don't know if it's resistors doing all of the jobs, or if the coils are frequency response shaping and/or step-downs.

    The RAAL ribbon speaker drivers employ only a step-down transformer box. Actually, something like a 100:1 OPT would make tube amps viable for driving the RAAL without being all sloppy. A direct drive from a tube amp may be possible; but it may not be so easy if there is some FR shaping.
     
    Last edited: Jul 25, 2019
  18. Zhanming057

    Zhanming057 Friend

    Friend
    Joined:
    Dec 13, 2018
    Likes Received:
    892
    Dislikes Received:
    20
    Trophy Points:
    93
    Location:
    Boston
    Alex showed me some material on the box circuitry when I expressed interest in making my own version of the box. I can't find it at the moment but I'll write to them and post those here (assuming that they give me permission).

    The transformers perform the step-down and the resistors are responsible for the tuning, in fact you can physically get up to +4db of bass by snipping the resistor bank at the right spot. Not sure if there is tuning from the transformer, though.
     
    mscott58, pavi, sacredgates and 2 others like this.
  19. Serious

    Serious Inquisitive Frequency Response Plot

    Friend BWC MZR
    Joined:
    Sep 28, 2015
    Likes Received:
    1,822
    Dislikes Received:
    0
    Trophy Points:
    113
    Location:
    near Munich, Germany
    Shouldn't it be pretty easy? We know the impedance of the driver + cable and you've measured the OI of the black box with the headphones. Should be simple enough to replicate the filter and even then we have FR measurements to guide us if it goes terribly.

    What I'm most curious about with this design is just how nuts it is to waste 90-95% of your efficiency in the cable. I guess with mW required for headphones it doesn't matter so much, but it still feels bonkers to me to pair a 0.02 Ohm driver to a 0.5-1 Ohm (?) cable. Acoustically the headphone probably isn't even that inefficient. The specs say it's 85db/mW (so 115db/W), which could even be with the cable as regular headphones are in the 100db/mW range and the driver has a lot of surface area. At 0.5 Ohm the cable should be a 14db loss with an additional 3db or so from the response shaping in the black box.
     
    E_Schaaf likes this.
  20. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    60,701
    Dislikes Received:
    106
    Trophy Points:
    113
    Location:
    Antarctica
    I think it was about being pragmatic. Nothing much we can do for a driver element that is a strip of wire. I for one am happy that the cable isn't firehosed sized. I prefer thinner flexible cables, having dealt with one too many crusty inflexible heavy specialist cables for HD800, LCD3, etc. at prior meets. Requisite makes stuff for the pro market, not audiophiles who want to show off how thick their hoses are. Pros aren't going to put up with BS.
     
    SeaBupter likes this.

Share This Page