Super Best Audio Friends

The Apollo is a hybrid DD + 2 BA IEM. I don't know if the world has changed much, but typically hybrid IEMs that use two or more different types of drivers have always had integration issues.



Where I will start is that I do expect the band members, or the drivers in this case, to play as a band and not as individuals. I don't expect the timbres of the different drivers to sound the same, as this is impossible, even with multi-way speakers. However, I do expect that the frequency ranges where the drivers overlap and hand the signal off, to sound cohesive and as seamless as possible. This is just one of my pet peeves, whether it comes to multi-driver speakers or IEMs (sometimes I wonder if folks outside of SBAF notice such things concerning overall cohesiveness.) The good news is that California Audio Technology or CAT, manages to pull this off with their Apollo hybrid IEM. The driver integration is on-par with another hybrid IEM that pulls it off decently, the Campfire Audio Solaris. That's two IEMs in my book (there may very well be more today, but I have not gotten my ears on them yet).

I received this unit from @Armaegis a long time ago. Being as it may I only recently opened the box. It's been incredibly busy at work with all this SARS 2.0 issues and so on. However, I'll do my best to review this unit. In many cases I start by listening the unit and then proceed to capture random measurements. This time I did it backwards. I started taking measurements first. I also took pictures. But I'll upload those some other day.

Balanced full scale in this unit seems to correspond to 6.22 Vrms, and so this will be 0 dBFS which in the plots that will follow is dBrA (referenced to 6.22 Vrms).

THD characterization at 4 Vrms are shown below:


We get THD+N of 105 dB (A-weighted) with 3rd harmonic slightly dominating the 2nd harmonic. Note also the delta-sigma modulated noise is effectively suppressed above fs/2 = 48 kHz.

Through a few chance encounters I became very interested in vintage audio and started collecting old audio equipment, manufactured long before I was born. These experiences forever changed my approach to audio in general, and this year I decided to return to playing with headphones, with a focus on vintage and out-of-production models.



This thread will chronicle my experiences with a few select models I have had the chance to own and hopefully serve as an inspiration for others who may find themselves a little bit bored with the state of the modern personal audio market. For members who have been around longer, some of this may be 'been there, done that', but please feel free to contribute your thoughts on any models discussed

Gaudio Labs is a Swiss company new to the IEM scene. You might have read a little about their beginnings and design process here at SBAF on Nico’s thread:
https://www.superbestaudiofriends.o...-journey-from-an-idea-to-a-real-product.8734/

Their first two in-ears, Nair and Clariden are of premium build with ergonomic aluminum alloy bodies. They have a natural silver anodized finish with acrylic logo inserts on the faceplates. The nozzles are polished stainless steel. Everything is machined to look and feel premium, and frankly Gaudio succeeds fantastically. All the kilobuck brands out there need to take notice. This is how it’s done. The look is somewhat reminiscent of Campfire Audio’s industrial build but possibly taken to the next level, particularly in regards to ergonomics and weight. And I can’t say enough about the ergonomics. I was able to give Nico feedback on a very, very early prototype a long while back and a large piece of that feedback was the fit. It was pretty painful. I’m not sure how he went about tackling the fit issues but these housings fit superbly and I have zero complaints. This is an excellent universal housing with custom-like fit. Bravo.

As much as I couldn't imagine to become a grado fanboy, I didn't regard myself as a potential customer of v-moda headphones. .. at least until this year. I know Tyll loved them (during IF's good old days he wrote multiple posts showing his big love). But when I actually heard them, I thought I was too noob basshead to rock with vmoda.



A few years have passed since then. Many things changed. Grado became my top go-to headphones, sennheiser could terminate long love-hatred relationship (in a positive way), ... and I am about to ramble about v-moda headphones, Oh, well...

But later I found some of v-moda's older fans hated m200. That's quite promising green signal as I always believe criticism from fanboys and parise from skeptics are the most sure things in the world.

In short, this is the tube amp that I had wished I had started out with when I was near the beginning of my headphone audio journey many many ago. I instead went in a few other directions from all the HF buzz - all the wrong directions - but this is a solid entry level transformer coupled tube amp. (Note that this is the first version that uses 6DE7 tubes).



Honestly, I don't think there can really be such a thing as a bad sounding output transformer coupled tube amp. What is comes down to to how much performance do we get for the price. At $1300, the Woo Audio WA6 SE is high value. I'm still kicking myself for going off in various random directions early in my journey. I remember reading about the WA6 SE on HF and almost pulled the trigger. (BTW, the construction of the chassis is bonkers solid.)

This is the 3.1 version of the Mysphere, or the "portable" version which is supposed to be easier to drive from modest sources. Depending upon who you talk to, the Mysphere 3.1 is either the less technically strong or the one that is neutral, fast, an detailed. The Zout of the amp I'm using is less than 2-ohms. The 45 custom is transformer coupled and has a little bit of feedback. I also tried it out from the Motu UltraLite's headphone output, which had no problem driving the Mysphere.



I spent some time listening to them for a few hours to get a subjective impression without the "benefit" of measurements. The drivers were oriented fully outward during both subjective and objective testing. (What's the point to keep them closed in like regular headphones!) In my time, I noted the following characteristics:

I learned from @Gazny about a new “startup”, if you could classify it as such, known as Nectar Sound. They were producing electrostatic headphones out of their garage, but touted the experience of an electrostatic, while keeping the redeeming qualities in dynamics that I wanted, primarily impact and bass. I quickly reached out to Sajeev, the owner to inquire about his headphones, and upon talking to him learned that Bottlehead had created a tube energizer to match his headphones. I quickly pulled the trigger since it seemed to be exactly what I wanted, and with a higher end amp from Bottlehead it would be a good investment for other electrostatic headphones in the future. The price of the headphones are $600.

A while back, a few members suggested that we do a review of Audio Science Review. I didn't think it was a good idea back then because I wanted to avoid drama. Now I think it's about time.



One thing I wanted to get out of the way is that I don't have a problem with people who want to use measurements as a yardstick in determining what audio gear to buy. It's extremely confusing out there trying to separate the wheat from the chaff. Heck, I've experienced gear that costs thousands of dollars, recommended by someone at HF, that sounded like poop. I've bought gear based on recommendations from HF randos (or respected HF'ers who I've learned over time not to trust) and had my heart sink after realized the thousands of dollars I just spent had been wasted. And seriously, I wouldn't blame people at all for not understanding what the heck we mean by "microdynamics" or "incisiveness". Utilizing the measurement method for buying gear is a legitimate method. (However, this doesn't mean other methods are not legit - thinking so would be faulty logic).

I know that any mention of Beyer and Tesla (not the car, but Beyer's motor tech) will elicit groans or painful shrieks from most of the members here, but I assure you guys this is not the case with the DT177X. Someone at Drop worked their magic custom tuning on this one for sure. We shouldn't expect Sennheiser type tuning, but we have here is sort of like Beyer trying to be ZMF! The timbre is definitely Beyer, but the tonal balance voluminous in the lows with dip in the 2-5kHz region, with a slight uptick after that. Nothing close to the DT990-250 in the highs - good grief - in fact far from it.



Did I mention that the headphone is gorgeous? I don't think photos do it justice. It's got a nice aluminum cap with the letters DT 177X GO stylishly printed on them. The "Made in Germany" in small print at the bottom is a nice touch! As far as style and layout, it's absolutely perfect.

So what is the Ultra Curve Pro DEQ2496? It's a inline analog and digital EQ. The use case I will cover here is that of a digital equalizer. I'm not interested in the analog EQ function because there is an AD/DA conversion required which I would rather skip (what would be the point of a four or five figure DAC if we are just going to put this in the analog signal path?).



So basically why the heck would I use a hardware EQ instead of software? Well, in the case of pi2AES and Volumio, the EQ plug-ins kind of suck. Also, some people such as myself prefer a physical interface. I've found a small learning curve with Behringer gear - I will go through the basics to get started quickly:

A while back, @zach915m sent me two headphones for review: Verite and Aeolus. The first headphone I opened up and tried out was first was the Aeolus. The reason being is that I loved the Atticus, so I was curious how an open-backed Atticus would sound. The Aeolus uses a biodyna TPE driver, which has a certain timbre, shared with the Fostex dynamics and even the Sony R10. I would have spent a lot more time with the Aeolus, but unfortunately, the Verite sucked most of my time, and as a result, I really didn't spend as much time covering the Aeolus as I would have liked.

ZMF Aeolus
Frequency Response
Top: miniDSP EARS with SBAF compensation
Bottom: Flat Plate (no ear) Coupler (compensated)