Super Best Audio Friends

The evolution of the original irreverent and irrelevant and non-authoritative site for headphone measurements, i.e. frequency response graphs, CSD waterfall plots, subjective gear reviews. Too objective for subjectivists; too subjective for objectivists

This is going to be a pretty stream of consciousness type thread. also, yes I know all of these pics will have huge r/malelivingspace energy, you're gonna have to get over it.

[​IMG]
[​IMG]
This video covers a lot of stuff asked of me on SBAF, and more. Also, Lindsay got a lot of time with the Sennheiser guys.

[​IMG]
[​IMG]
Not really a review. It's more of use case thing - using gear I had lying around to put together something I am actually very happy with respect to gaming / precise sound localization with headphones.

[​IMG]

I was inspired to do this because I remarked to some friends how YT videos today are just so shilly (is that a word?) and that I wished reviewers out there would discuss the how and why they purchased and put gear together stuff. I questioned how people can truly be passionate about stuff if they just run through gear review after gear review and never talk about context of how they would actually use it themselves. The answer is that it would be up to me to do it.

Don't forgot to subscribe. I want to be able to livestream in the future so I need the subs.
After a change in my WFH setup, I ended up with a pair of Klipsch RP-160Ms that I wasn't using. I've had a Rekkr on my personal computer desk for some time, but it wasn't ever used for very much, and most recently it was driving a pair of Klipsch R-41Ms that I had sitting around for random YouTube duty. I figured that since there's no kill like overkill, I might as well put the RP-160Ms on the desk and set it up for listening in near-field.

I've been using a Soekris dac1421 as preamp, and that's running into a Schiit SYS that I carefully tweaked so that 0dB on the dac1421 was attenuated to 866mV on the output of the SYS, corresponding to 3W into 4Ω. After using this setup for about a week, I can say that the Rekkr just doesn't have enough power for me for listening duty. Hotter genres like electronic music are just fine, but on some classical recordings I found myself itching to turn the dac1421 up past 0dB, or past 3dB for SACD rips. (While SACD "0dBFS" is technically -6dB, the Scarlet Book allows instantaneous peaks of -3.5dB, which is where a 1-bit modulator tends to become unstable.)

While I'd considered getting a Gjallarhorn, this also established pretty well that another 7dB is still going to leave me setting the preamp at the top of its range at times, and I'd prefer to have a few dB left even when listening to quieter recordings at higher volumes. It's a shame as it's a cute little amplifier, and I definitely see how those with different listening tastes or higher impedance speakers could get away with it.

On the plus side, the Rekkr is an extremely clean sounding amplifier in near field. It's very unpicky about cables and it doesn't bring out any of the harshness from the RP-160Ms that I've heard with certain class D amps.
UPDATE 10/13/2024: https://www.superbestaudiofriends.o...ower-amp-quick-impressions.14663/#post-435302

If you like how the Aegir 1 sounds in your setup, I would probably keep it. The Aegir 2 is definitely cleaner and less organic sounding without the Aegir 1's tonal idiosyncrasies which I loved. Aegir 2 seems arguably a bit more detailed, plankton, better microdynamics, with deeper stage. In fact, these aspects of the Aegir 2 betters the both the HH Scott and Fischer vintage PP tube receivers I've got. However, despite slightly lesser technicalities, the vintage receivers stay because they got that tube bloom and better grunt. Aegir 2 is still a low powered amp though, so the lows can still be a bit soft at louder volumes, even on moderate-high efficiency 93db speakers.

[​IMG]
This is currently a work in progress so please be patient. I also have a pretty bad Essential Tremor when working on small precise stuff so I probably isn't going to be too pretty. So far though everything has been going pretty well.

The first thing I did was paint the top plate a dark cherry. I then painted the bell cap, and the 2 PC-5 transformers. They were suppose to be more blue but for some reason the paint I used ended up looking really green. So now my Kaiju is Christmas themed. Then I glued together the wooden frame and stained it dark Walnut.
[​IMG]
[​IMG]
Please learn from my error. Dasacoustic (https://www.dasacoustic.com/en/index/) the once popular plinth maker is no longer functional and I believe taking orders and not delivering as a scam.

I ordered in May and received communication until August. Then I was told her family was ill and the next thing 0 communication.

I ordered through PayPal and paid for buyer protection. Unfortunately when I lodged the dispute I did not escalate in time and apparently that means I forfeit all my rights. f**k Paypal.
So I lost 1200 euro. I've requested a credit card refund with my bank but they said low chance since it's been more than 120 days.

I found a page that when converted to English explains many people have been caught out too.
https://melius.club/topic/21717-das-acoustic-esperienza-molto-negativa/
The company is only taking IBAN bank transfer now and no longer accepting paypal from what I understand. Not a good sign.

please also see 2 recent purchases on ebay where the product was not delivered: https://www.ebay.com/str/dasacoustic?_tab=feedback

It's a shitty situation for me but not the end of the world, others should NOT buy from Dasacoustic as it appears they are now just a scam site.

Have a lovely weekend
So this is a topic I've been sitting on for a while beacuse I've been trying hard not to be too snarky and, at the end of the day, I am genuinely ignorant. Unlike a very many folks on the forum and elsewhere I have no real engineering knowledge and very often get principles backwards or things outright wrong (e.g. "The Studio Jr 300B sounded *significantly* better out of XLR out so it *must* be a balanced topology amp... whoops, nope!).

Now and again I feel that ignorance can be an asset in a sense, mainly in how I pepper folks who actually know things with often silly questions that, hopefully, might generate meaningful and useful discourse down the line. At this point in time I think I'd have hoped that I'd know more concrete things about how amplifier or DAC topologies work or what sort of fine nuance actually goes into developing the analogue output stages on converters, but nah I'm as much an idiot as I've ever been and with an increasingly worsening memory.

I've got vague ideas of how pairing certain DACs and amps and transducers work, but is the ENTIRE reason that the Sennheisers love those big boi tube amps just because they can provide GOBS of voltage? Is all of what can determine how much a headphone can scale just a matter of power handling and impedance matching, accounting for those massive low-frequency humps with dynamic drivers? How about how much sense of SLAM an amp can give a transducer like that one oldish amp I got to borrow that made my HD600s kick like Focals, is it all just a matter of the OI of that amp being REALLY high so the Senns were severely under-dampened? Is headstage really just an artefact from an upper midrange dip? What about image delineation?
I know Apos requested some adjustments. I haven't had the chance to listen to the original R70x, so I can't comment on it. Honestly, I expected my experience to range from "meh" to just pretty good, but I was pleasantly surprised. Over the weekend, after testing it with various setups, I concluded that the ATH-R70x is fantastic. I believe the R70x will perform well with higher-end tube amps, but I'll need to explore that later. It sounded good directly from my laptop, and the same goes for the iFi Gold Bar. From the Magni and other mid-tier amps, it was excellent as well. I also noticed significant differences when using better DACs and uncompressed music from Qobuz, especially in comparison to Spotify. All of this suggests that the R70x has the potential to scale up nicely.

R70x Define.jpg
It’s all about context. I've previously mentioned I liked Tripath Class "T" amplifiers, which are another variation of Class D. The advantages of Class D amplifiers are threefold: they are lightweight, highly efficient, and cheap. They don't require massive power transformers or a dozens of output devices to generate significant power. Class D products being sold at exorbitant prices; there simply isn't enough stuff in these amplifiers to justify such costs. If you're interested, check out this discussion for more insights: Schiit Vidar vs. NC502M

A comparable example from the automotive world would be the Acura Integra Type S, which dealers are selling for around $60,000. Seriously? A front-wheel-drive, four-cylinder Honda variant at that price? That’s outrageous.

Now, let's talk about the Fosi Audio ZA3. It features the latest and greatest TPA3255 monolithic amplifier chip from Texas Instruments. The Fosi Audio ZA3 exemplifies Class D done right. It delivers impressive power (180W at 4 ohms), generates virtually no heat, is light and compact, and is incredibly affordable at $129 from Apos.

IMG_2118.JPEG
Many audio amplifiers have the following gain configuration:
00 20190110 Typical Amp block diagram.png

The potentiometer or stepped attenuator resistance stability can influence the system low level gain accuracy and residual noise.

A selection of four volume controls will be examined for resistance stability and compared to a stable laboratory reference standard resistor:
https://www.ietlabs.com/esi-sr1-calibration-resistor.html

Background information on resistors and measurements:
https://www.vishay.com/docs/28771/basics.pdf

Additional background information may be found in this IEC standard:
IEC 60195 Method of measurement of current noise generated in fixed resistors...