AAW Black Amp impressions thread

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Erroneous, Feb 2, 2021.

  1. Erroneous

    Erroneous Friend

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    Someone sign Barry up for the BHA-1 loaner that's brewing. That'll easily show him what slam is.

    I think @loadexfa said it well. I can say it more crudely and try to explain that when the music has balls, cojones, WEIGHT, heft to it, when it just kicks you square in the nuts, that's slam. Slam is nice, it's a great quality in an amp.
     
  2. penguins

    penguins Friend, formerly known as fp627

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    These are my approximate definitions of both slam and heft as the two are different aspects of sound to me. My definitions may not be 100% correct or the same as definitions used by other members, etc. :

    slam: The impact, kick, hit, initial and sustaining boom, or the general feeling of power in the bass. Not to be confused with slappy bass or as only an initial (or sloppy) overshoot coming off of a "flat".

    heft: sustained or continued fullness, presence, weight, the feeling of "there-ness" in the bass. Not to be confused with a slow or unnatural decay, adding some kind of delay, etc.

    -----
    Although heft and slam are not explicitly defined here, the SBAF glossary (and maybe one on HF) may also be useful for providing common definitions:
    https://www.superbestaudiofriends.o...ology-subjective-terms-used-on-superbaf.3400/
     
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  3. BarryT

    BarryT MOT: Austin Audio Works

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    Thank you, my education continues.
     
  4. tommytakis

    tommytakis MOT: E.T.A Headphones

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    blackamp.jpg
    AAW Black Amp Impressions:
    pi2aes > Sonic Frontiers SFD2 > Black Amp > HD600 | GenP

    - All in all, I think this is a pretty good sounding, versatile amp but with tons of features 3 input (2 single ended, 1 balanced) and adjustable impedance(?) knob in the back.
    - slam and macrodynamic contrast feels a bit lacking for my taste compared to something like Black Widow, BHA-1, 3F. I was hoping for some explosive dynamics.
    - I do hear fair amount of nuance in micordynamics and plankton, but I don't think it's quite up there with the big boi amps, solid state or tube.
    - clarity is good, but not great. Maybe part of it is bad pairing with SFD2 since it doesn't have the best clarity.
    - staging and imaging is quite good for a solid state. I actually feel like bha1 staged better but it's definitely better than the black widow from memory.
    - I think the pricing would be a lot more attractive at $1k new.
    - I like the small form factor and the overall aesthetics.
    - To be perfectly honest, I'm not sure if I would purchase one for myself, but I think it can be a solid all rounder amp for folks. Thank you @BarryT and @k4rstar for introducing us to this amp.
     
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  5. BarryT

    BarryT MOT: Austin Audio Works

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    Hello my friends. Our last interchanges were about the words 'slam' and 'heft' as I had not been familiar with them. While these are terms derived from the passion of the music I am helpless to use them until I understand their physics, that is the 'what' property or aspect of a physical event that causes them and thus possibly to quantify and measure them. I subsequently spent almost three weeks with a medical issue whose meds rendered me non compos metis. That is behind me now and I have been crystallizing thoughts of these words. This has lead building models in simulations to reveal the dynamics of an audio signal that could account for the use of the words.

    Let me offer some thoughts that I would ask you to consider, reflect on, and comment upon.

    I think that it is safe to say that Slam and Heft are not steady-state terms. Bandwidth and frequency response are not really frames of reference that are definitive of them. I see them as relativistic and transient sensory impressions.

    This suggests to me that they are 'second derivative' effects of an audio signal, that are more related to the rates of change of a signal's envelope than the pure signal itself. A quick example would be a plucked bass note that is asymmetric in its production (as are all plucked or struck notes,sounds generated) suggesting that a second time constant is key to the overall sonic signal.

    In all amplifiers there is such a second time constant, it is the DC gain path of the amplifier. While we want AC gain in the amp (the purpose of the amplifier in the first place) we don't want DC gain as if can toast the voice coils of the transducer over time. So there is a filter in all amplifiers separating the AC from the DC. Some amps us a simple blocking capacitor as a high pass filter, some use an integrator such as a DC Servo to do the same thing. The Black AMP uses a servo, this may be were the possible 'slam' question resides, I am experimenting with the amp now to that effects.
     
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  6. roshambo123

    roshambo123 Friend

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    I tend not to be too excited about solid state amps and originally declined to demo The Black Amp because it didn't seem my speed. @Erroneous and @Phantaminum talked me back into it because it was a said to be tubier solid state that "leaves Jot in the dust." My evaluation therefore focused mostly on how it performed vs. Jotunheim 2, but also if the price tag was warranted. I've added The Black Amp to my impressions table for more context.

    [​IMG]

    Headphones: HD6XX, HD800SDR, HD600, LCD-2.1
    Amps: The Black Amp (BAL), Jot 2 (BAL), Mjolnir 2 (BAL)
    MJ2 Tubes: EH 6922
    DAC: Yggdrasil GS (BAL) Lynx AES16.
    Notes: Black Amp sensitivity knob turned to provide good headroom, keeping the volume pot around 10 o'clock but never past noon. I heard no hum on any input or output combination. Balanced output seemed slightly better sonically than the SE output, although it's reasonably close.

    General comments
    The Black Amp run in balanced mode is resolving, slightly warm, and features excellent cohesion and strong consistency across genres. I think it falls short on some technicals and the overall build quality is not commensurate with a $1500 price. I think it solidly beats Jot 2's treble in terms of naturalness and wetness but the macrodynamics and excitement in the presentation are not there for me.

    The Black Amp has a neutral house sound that doesn't assert itself. It's an easy going listen, and for those looking to avoid aggressive presentations it might be a great choice. I don't think it's fair putting it against a big sounding amp like Starlett, which has wider headstage, blacker blackground, and lots of macrodynamic fireworks. Mjolnir 2 has macro in the same ballpark of Starlett and jumping from MJ2 to The Black Amp there's a big delta in this category. Cohesion is better on The Black Amp, but an amp like Jot 2 is also cohesive, but it does so while being nearly as slammy as MJ2. My sonic preferences lean rich and exciting, but I can also appreciate laidback when it's been a long day.

    One area that I can't let go is build quality. A spray painted project box with a wall wart is not acceptable for something near the top of mid-fi pricing. The loaner amp has traveled, but the paint has scratches all over, the finish is flaking off around connectors, and it just has a workbench prototype feel. Maybe production builds are better, but with The Black Amp's modest appearance I'd be rushing to justify the price tag to a naïve onlooker with statements like "Honestly, it sounds good!" For improvement, I'd like to see a proper C14 power connector and the power transformer moved inside the chassis housing, even if the amp has to be a little larger. It's really quite compact, and a larger footprint wouldn't be fatal. After that, I'd like to see a better finish and maybe better fonts or branding that doesn't seem cookie cutter.

    I do like the sound of The Black Amp. I found it engaging on all headphones with no fatigue factors, but I'm not sure I'm as excited about it as some of our other members, but I can understand it could be a winner for some.
     
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    Last edited: Jun 10, 2021
  7. E_Schaaf

    E_Schaaf MOT: E.T.A Headphones

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    Impressions from the loaner (late to the party here since I had it before roshambo above) -

    My experience with this amp was a highly mixed bag and I know some potential changes may be in the future so I don't want to belabor what I felt to be the negatives (or compare with other amplifiers) without hearing a revision first. If the weaknesses could be improved while retaining the strengths, I think it could be a winner. Both the strengths and weaknesses of this amp felt rather pronounced in my listening at all times regardless of the source or headphone. As-is, I don't think it's an exceptional value at the price. I cycled through my Naks, SPL Phonos, Burl B2 Bomber, and Monarchy M22B DAC as sources. Bunch of Senns and ETA selection for headphones.

    Likes:
    buttery smooth highs with good HF extension, completely fatigue free even at higher SPL or with harsh tracks, nice I/O flexibility, mellow timbre and cohesive tone, good spatial rendering, compact size, would probably allow me to listen to any HD800 without crying tears of blood.

    Dislikes:
    poor channel matching even at around 10:00 on the pot, soft/gutless dynamics, homogenized bass, doesn't scale changes of source very well, felt like the sonic equivalent of corn starch.

    In general, I trust @BarryT to make great products and I welcome his enlightening / refreshing posts here. I know how much a simple tweak can lock everything into place, product development can be a roller coaster :confused: I have a feeling a nudge in the right direction is all this amp needs, something to bring a sharper edge to the sound of transients across the spectrum. All of the dislikes kind of orbit around that one weakness for me. I look forward to revisiting this amp if such a revision is in the pipeline. Cheers to sending your creations out into the wild regardless! Thanks Barry.
     
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    Last edited: Jun 14, 2021
  8. BarryT

    BarryT MOT: Austin Audio Works

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    Hello Folks -

    Over the last few months I have been taking in your comments and trying to put good physics to the aural feeling associated with 'heft' and most of all "SLAM". How do they occur, what makes the phenomena singular to the ear, and of great import, why now (2000+ and not 1970's)?

    Protracted thought left me with some ideas to pursue and a theory to test, thus an experiment.

    The image below is my Concept AMP, my idea testing physical platform. It is exactly the same circuit as the Black AMP, just more and bigger parts to operate at 50 Watts into 8 Ohms (I should say the Black AMP is a smaller version this amp, I have a 100 W version about half assembled) This has speaker and headphone outputs letting me evaluate a change in the circuit on both.

    Front panel.JPG
    DSCF0481.JPG
    DSCF0480.JPG
    Last week I added two controls to the C-AMP-50 platform and on Sunday delivered it to a friend/critiquer who will be doing a group listening tomorrow. I don't attend such sessions, you never have the mother around when you are discussing how ugly the kid is.

    My challenge to them is to evaluate the effects of these two independent controls in the light of the comments you have provided me with.

    #1 - A control is called BASS. It does not boost the base, that would require the use of negative feedback, and as I always say, feedback sucks the life out of your music.

    What this control does is to passively reduce signals above a certain frequency with minimal phase shift and no phase shift in the audio above the cutoff. It is very important that nothing changes in the resolution and detail of everything, the timbre is transparent, one of the strongest characteristics of the Current-Mode design.

    My question to them is about how much if any such change is of value to the listener, would a control of this characteristic be a good addition to the Black AMP?

    #2 - A control called SLAM, which suggests that I think I know enough about the anthropomorphizing of this word to take a damn good guess what physical events generally cause it to happen in the mind. This insight allows me to make an electronic circuit that will cause the effect on demand in an audio playback system given content with the proper energies.

    This control sets characteristics of what I call a 'third-order amplification' (see below).


    In my world a First-order amp has no feedback ('faire naturellement' (a little French always makes this sound so classic, but we both know it really just means nothing today)), and a second-order amplifier employs negative feedback to control all aspects of the gain process insulating it from the effects of real world (with positive feedback the amp just becomes an oscillator totally spewing power out into the real world). Funny, when you think about it they are one in the same when relating to the outside world. Negative feedback makes the output node a 'zero' point that will source or sink current to stay at a zero-voltage-point, positive feedback turns this output node into a source only limited by the power supply. Both in a way ignore the outside world while interacting with it. Oh, that got pretty philosophical, I'll watch out for that.

    So what's a third-order amplifier? Well if I'm on the right path I have to write a patent before it can explain it publicly, If I am wrong then who cares, I will be glad to tell you of the thinking that caused.

    Again my listener friends will seek the truth to this.

    I have held up building Black AMPs to see what changes I need to make. I can build some new amps within 30 days once I decide to add a control. I have already made some changes, there will be a 3-position Sensitivity switch on the front (+18,+12,+6 dB), remove the LED dimmer, new choice of output impedance, improved DC Servo on each amp, improved safety control sensitivity. Then I can get back to the BlackDAC.
     
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  9. dasman66

    dasman66 Self proclaimed lazy ass - friend

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    I am delinquent in posting my impressions - I had the amp after Roshambo123 and it's been on to MisterRogers for over a week at this point. I directly compared this to my 3F, and indirectly to the loaner BHA-1 that had left my desk only days before.

    Rig
    Pi2AES -> AES -> SESCOM -> BNC -> SFD-1 Mkii SE+ -> XLR -> 3F | Black Amp -> Bal -> ZMF Auteur (Cocobolo/Eikon Lamb)

    Anner Bylsma Prélude to Bach’s Suite for solo cello No. 1 in G major
    The 5 Browns Malagueña from Andalucia Suite
    Pamela Frank/Zurich Tonhalle Orchestra Mozart’s Serenade No. 7 for orchestra in D major
    John Williams/John Etheridge Extra Time for 2 Guitars
    Duplessy & The Violins of the World Kung Fu
    Kaki King Ingots
    The Beatles Norwegian Wood
    Carl Anderson Heaven on their Minds
    James Brown It’s a New Day, Pts. 1-2
    Earth Wind & Fire Shining Star
    Los Lonely Boys I Don’t Wanna Lose Your Love (Live at Blue Cat Blues)
    Led Zeppelin Moby Dick (from How the West was Won)
    Daft Punk Giorgio by Moroder
    Cream Badge
    Ben Harper & The Blind Boys of Alabama Take My Hand
    Horace Silver Quintet Finger Poppin’
    Maynard Ferguson Birdland
    Phil Woods Rain Dance (Live from the Showboat)
    Bill Evans Trio Detour Ahead [Take 2]
    Ray Charles/Count Basie Orchestra Oh, What a Beautiful Morning
    Macy Gray Redemption Song
    Joni Mitchell California

    The Black Amp came to me set at 300 on the rear of the amp (thank you to whoever labeled the gain control on the back) and that's where I ended up as the preferred sweet spot for my listening with the Auteur. Like others, I found the Black Amp to be laid back... not as aggressive with the treble as the 3F, but it wasn't really lacking air either. IMO, the Black Amp nails my treble preference... easy to listen to all day at work... no fatigue, no matter what the music or the quality of the recording6.

    The mids on the Black Amp sounded a touch wet to me, sounding more like a neutral tube amp than a SS amp in this area. Spot on with acoustic instruments... piano, guitar, sax... just perfect.

    The bass... for a SS amp I thought it was slightly lacking in extension.... not getting as far down on the Daft Punk track, which I followed up with some Beastie Boys Brass Monkey just to confirm. Definitely doesn't reach the depths that the 3F (or the BHA-1) can get, and doesn't have the slam of those amps either. That said, I didn't find it as objectionable as others here (which could be more indicative of my headphones... if I was driving slamming orthos then I might feel differently).

    Headstage - the 3F probably isn't a fair fight in this regard as I found it both wider and deeper, but I could easily place instruments on the stage with the Black Amp... no blobs of sound, good definition and spacing... just with everything a little closer together than the 3F.

    For the genres I tend to listen to most at work (classical - piano/guitar/chamber/not orchestral, jazz, folk, some classic rock), I prefer the Black Amp to the BHA-1, and maybe even my 3F. The laid back sound with the Auteurs is just perfect for a work system where I don't want the music to necessarily pull my concentration away from what I'm doing, but still present most everything I'm looking for if I choose to go look for it. The 3F can reach out and grab me sometimes, which isn't a great thing if I'm trying to get work done.

    Finally, since others have commented on the build quality, I might as well chime in.
    1. While I appreciate the quality of the paint job, I don't care for a painted surface on audio equipment. Maybe its me, but once I hit a certain price point I'm expecting a step up (maybe anodized aluminum?). I tend to agree with others that the paint cheapens the appearance (looks like plastic).
    2. I love the feel of the volume pot, but I don't care for the knob. Whenever I see that style of knob my mind thinks of a switch and am expecting to clunk between a few different settings (ie., like the input selection). If I purchased, then I'd definitely be swapping the knob out.
    3. From a form factor standpoint, the Black Amp does a great job conserving real estate and would work great on a crowded desk. Although as I type this I'm not sure how it would stack on something like a Bitfrost (I neglected to measure the Black Amp and can't find dimensions on the website). You're definitely not going to put anything on top of the Black Amp...
    It will be interesting to see how this amp evolves. Hopefully the tweaks being worked on can improve the bass while leaving everything else on this amp untouched. I can definitely see picking one of these up for work at some point, allowing me to take the 3F home where I don't mind getting grabbed by the music.

    I really appreciate @k4rstar finding this for us and a big thank you to @BarryT for putting a work in progress on public tour.
     
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  10. MisterRogers

    MisterRogers Ethernet Nervosa

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    First off, thank you @BarryT for making this amp available to our community to evaluate and enjoy. I enjoyed the week I spent with the Black Amp, so I want to say overall - that it's a good amp value wise for it's (current) price. While the build quality is a bit on the rough side, those of us who value the work of our 'small-batch' engineers will not likely be put off.

    I dropped the Black amp in my chain (Amber->Pavane via I2S) with DAC output(s) going to both my ZDS (super) and the Black amp. My primary (testing) headphone was a ZDS Blackwood Auteur.

    Right off the bat, I'll say that ZDS excels with:
    • Wider and deeper sounds stage (well of course).
    • More slam.
    • A more richer, organic tone.
    But truthfully, I think expecting the Black amp to keep pace with these ZDS attributes is unfair. What it does, it does well:
    • Precise imaging.
    • Clean separation of instruments.
    • Fairly neutral.
    • Good tonality (not tubey, but a bit 'wetter' vs. most SS amps I've heard).
    • Clean bass.
    Where is fell a bit short, as has been already noted, is lacking bass extension and slam / impact. As has also been noted, this is more or less an issue depending on personal taste or genre. For my part, I look forward to Barry's tweaks to address these issues, as with these areas addressed - this good amp will likely have much broader appeal.

    Thanks again for this opportunity Barry!
     
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  11. BarryT

    BarryT MOT: Austin Audio Works

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    It is my hope that this entry finds you all well and life good. I would like to report on my experiment with the Black Amp and the results of the listening session. I would like to also note that I was not a participant, as I pointed out earlier, one cannot be objective when discussing how ugly a baby is in front of the mother. I am told that an extensive conversation was had about SLAM among the 4 members basically affirming the definitions that SBAF have adopted about this subject. In summary:

    1 - The BASS control was just that, a bass control. What was unique about it was that it was passive. Typically bass boost is done with feedback. As the Black AMP employs no audio feedback and gain is established by the programmed current flow of the circuitry, there is no way to ‘make’ more bass. The way I created bass, the perception that is of increased bass was to passively subtract some of everything that was not bass from the signal. As this could be done with a simple first order filter, the issues of resolution, detail, and ‘fidelity’ in general were not comprised but only the relative levels were changed. In the end, the relative bass was higher, thus bass boost appeared. But it was simply bass boost and had no effect on the SLAM.

    2 – The SLAM control was an interesting idea that in the end sounded just like bass boost. What I did was take the output of an amp, run it through a low-pass passive 4-pole 200-300 Hz and level control, feed it as Positive Feedback to the input, This re-amplified the bass information. The trick here was that the output of the amplifier is high impedance - when the speaker’s impedance went up at the low end (the hump), there was less load and more voltage at the speaker. This meant that more signals were fed back into the input of the amplifier with a slight delay due to phasing, a greater bass was passed through the system. This enhanced the bass signal and exaggerated the envelope of the bass data somewhat but more delay is needed. My thought was that the temporal nature of SLAM was signal envelope in nature (kind of like Ed Long and Ron Wichersham’s speaker low-end extension patent (US 4481662) idea from the 1970s. This idea turned out just to be a different kind of bass when I tried it last week.

    BUT I DID INCREASE THE SLAM OF THE BLACK AMP!

    Since I was into an ‘envelope waveform state of mind’, on a hunch a mod I made was to change the coupling of the input into each current mode amplifier with a rather refined but simple circuit. Originally the AMP was DC coupled so this radically changed the nature of the input. It takes advantage of the new family of Aluminum Organic Polymer Capacitors combined with classic Mylar capacitors and Voila’ - out jumped the SLAM we were all looking for. It was an envelope issue but one a bit more metaphysical in nature – a very big change in the transfer function and its associated derivatives as well as the invocation of the Fletcher-Manson work of Bell Labs in the 1930s when we learned all about audio.

    At some point in time, after a few Brandies, I will muse on why I think that old whitehead hi-fi never really ran across this issue of SLAM.

    I thank you for your comments for they have changed the course of my amplifier and my reflections on the real world interfacing of circuits.

    All this has made me realize that there is a control of great value. That is a Loudness Control. I feel that this drives to the heart of the SLAM issue, as basic to the issue is the difference between Level and Loudness. More on this latter

    Thank you. Barry
     
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  12. bilboda

    bilboda Florida boomer

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    An update to my previous thoughts. Pairing this amp with ETA Genesis G puts to rest in my mind, any thoughts of slam lacking in the amp.
    Listening to Mira by Melody Gardot on Qobuz. This is a fun, playful buoyant recording, lots going on. Early on, the background singers are not spaced together nut randomly sounding real happy, with a light rhythm guitar and percussion. A flute comes in upper left for just a few notes but is announced by it's clarity, the rhythm guitar then comes in strongly for a bit with a major announcement, slam in the mid range. Background voices move together and the instruments come and go as they please. Amp and phones go real low on other recordings, acoustic bass grinding and expressing with clarity, nothing missing. Just a top end audio experience for me.
     
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  13. BarryT

    BarryT MOT: Austin Audio Works

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    Hi Campers,

    A remark - SLAM has been brought up several times in the SBAF forum. Most recordings don't have much SLAM, it is not typically present in the original music and as recording has been all about faithful reproduction of a musical event, one would not expect to find it in recordings. Good electronics would not be expected to add it as SLAM in that case would actually be a form of distortion which I believe is a low-end envelope modulation .

    I will admit that I am biased from over 60 years of 'hi-fi' as well a 50 years of live recording, both studio and live venue, and having designed and built consumer, recording, and broadcast hardware as well as associated physical sites. It was not until last year that I ran cross SLAM. In all my years of hi-fi listening I never heard the term SLAM which is why I asked what is was when you first mentioned it.

    What I have discovered since is that SLAM seem to be a component of Hip-Hop music and is generally synthesized in such recordings. As Hip-Hop has strived to be sonicaly unique, SLAM became one of the effects developed to help the music style accomplish that, it is in effect a new (the last 20 years or so) and culturally acquired taste issue. Us 'white-head' hi-fi guys are generally not familiar with it because it did not exist in the music we enjoyed.

    It is neither good or bad, it is simply a learned style preference and part of the continuing human experience of growth. I can certainly see how it's desirable just like more bass , but if it is not originally in the program material it is to be considered an 'effect' and technically a distortion albeit of a desirable nature. As I worked on creating more SLAM I began to recognize that I was not being faithful to the original design tenet of true fidelity.

    Now that I have pushed as far as I have into SLAM I see that I can produce a circuit that will synthesize the effect on a consistent basis based on the work of Long and Wikersham in the 1970s. I think that when I have the time I will build a small stand-alone box to generate as much of the effect/artifact as one would want. But that is then and this is now and now I want the Black AMP and all my products to be as faithful to the original musical data as possible meaning not to add to the music, just faithfully reproduce it.
     
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    Last edited: Aug 17, 2021
  14. BarryT

    BarryT MOT: Austin Audio Works

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    Hello,

    I have been digesting comments from these SBAF tour and made changes to the Black AMP and Black Swan accordingly. Referring to the Black AMP specifically I did the following:

    Modified the incoming front end to pass greater low-end program material and thus altered the sub-sonic and low-end energy/time envelope of the amplifier. This is in the direction of SLAM but done without altering the AMP's extreme low-end resolution.

    Lowered the output impedance of the current cell to 5 ohms from 20 increasing available instantaneous current flow at lower frequencies

    Increased the current flows in several of the constant-current sources and current-gain cells in the AMP's infrastructure.

    Added a 3-position Sensitivity switch offering +6, +12, or +18 dB levels.

    Things to make testing and assembly easier.

    This is now good to go and I have started a production cycle of 30 days personally building a limited number of Black AMPs and Black Swans with a unique serial number protocol to easily identify the units.
    Please contact me at [email protected] if you would like to pre-order to get one of the special first few or have questions or comments.

    Thank you all for your suggestions and guidance. You have graciously offered me a wonderful growing path to further knowledge through your thoughts and perceptions.

    Thank you,
    Barry Thornton
    [email protected]
    512.912.6820
     
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  15. Azimuth

    Azimuth FKA rtaylor76, Friend

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    I will just mention some things from my experience:

    Good
    • Lack of congestion. Drives with ease.
    • Warm for an SS amp and not peaky. Very non-fatiguing. Not aggressive amp at all (which may be good or bad based on preferences)
    • Has balanced and unbalanced inputs and sound does not change from either In use. Unbalanced actually has higher output, but this has more to do with the amp's overall topology and design.
    • The adjustable impedance is interesting - although it just sounded to change gain.
    Not so good
    • Very kind of hazy. Not only was it non-fatiguing, I also did not feel there was a good solid black background or space between instruments.
    • Lack of dynamics, but this might be attributed more to the transients not coming through on the top end as well. It can just sound soft at times and I can see why tube amp lovers like this, but I have also heard much livelier tube amps.
    • Width slightly more centered as some other amps and sometimes seemed monophonic.
    • Channel imbalance at bottom of the pot. I think MTCH had similar issues, so I know it happens with these small pots.
    Overall the softer sound and the haziness did not seem to be to my preferences.

    Gear: Theta DS Pro Basic II, HD650, JAR600, ETA Genesis-G, Mjolnir 1, Gilmore MK2 clone, ZDT Jr.
     
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  16. Beefy

    Beefy Almost "Made"

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    This seems to be a very consistent finding amongst auditioners. And I'm really not convinced that a lack of 'slam' is an absence of bass, or that 'slam' is a construct of any particular type of music. It is just a symptom of an amp's performance.

    Did anybody manage to get this on a scope or tester? I'd be interested to see what the slew rate and settling behaviour looks like on square waves. I've always hypothesised (with zero supporting evidence mind you) that amps perceived as having weak dynamics undershoot on square waves, versus harsh/aggressive amps that overshoot. And I'm never convinced that this would be visible on a high frequency sweep even if the amp is being asked to slew at equivalent rates.
     
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    Last edited: Aug 19, 2021
  17. bilboda

    bilboda Florida boomer

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    I'm a little lost on slam. How do you define it? Dynamics?
     
  18. Beefy

    Beefy Almost "Made"

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    When describing the overall presentation of an amp, I've always considered each of...
    No slam
    Polite
    Laid back
    Slow
    Weak dynamics
    ... as being fairly synonymous for the same thing, but to differing degrees.

    I'm honestly not sure what the designer believes slam is. Audio needs a more definitive reference dictionary.
     
  19. Azimuth

    Azimuth FKA rtaylor76, Friend

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    Yes. Macrodynamics. Not micro.
     
  20. bilboda

    bilboda Florida boomer

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    I suppose synergy comes into play, source and phones, wires and electrical power can also make a difference, In the end we can only compare it to what we have and evaluate the differences and judge based on our values.. Weak doesn't suit this amp. Polite in terms of distortion, yes, but also dynamic throughout the frequency range, as high as I can hear anyway. I have heard polite and laid back, mcth, aaa789, HP1, even the crack and slamming excessively, Jot 2.
     

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