Articles, Reviews and Measurements of Audio Products

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Sonic Frontiers SFS-80 Tube Amplifier: A "new" benchmark to beat from 1992

Up next on testing gear that would be impossible to ship safely... the Sonic Frontiers SFS-80 tube amplifier. 70 lbs, all concentrated in the transformers.



Believe it or not, Sonic Frontiers is a company we all know very well... today, they're known as Anthem AV. In the late 80's or early 90's, a Canadian part distributor began to ship DIY kits for tube amplifiers. They began to sell their finished products under the Sonic Frontiers brand and rapidly grew. As home theater and the DVD era was introduced, Sonic Frontiers established a "budget line" known as Anthem. Generally, Sonic Frontiers focused on tube-based products while Anthem focused on solid-state. Fast forward to 1998 and Sonic Frontiers/Anthem were purchased by Jerry VanderMarel and Scott Bagby...

Three Generations of Marantz flagship integrated amps measured (updated PM-10 test!)

One of the biggest challenges with amplifier testing is shipping the gear without damage. We've already seen how the JBL SA600 from 1965 pretty much has an amplifier section that performs similarly to the JBL SDR-35 with processing in 2022. But what about Marantz? Have they improved their technology over time?

On deck for today's review?

Marantz PM-90
1991 - all analog flagship, second only to the PM-95. Last Marantz product BEFORE the introduction of HDAMs. Exact model tested...

This is a review and detailed measurements of the HifiBerry AMP60 made for RPi form factor. It costs US $44.90 and was kindly dropped shipped to me by a member.


While the unit looks like a typical RPi "HAT," it is actually a stand-alone amplifier with no dependency on the RPi computer. It does however have headers for input which mate with company's own DAC (output). For testing, I just wired up a set of RCA cables to the header.

You are responsible for supplying a power supply with a voltage of up to 20 volts. No current specifications are provided. Strangely, the spec sheet goes up to 24 volts. I powered it using my Keysight lab power supply, set to 20 volts with maximum current of 3 amps.

The core of AMP60 is the TI class-D TPA3128D2. In use it barely got warm so perhaps it could run at higher voltage than 20 (rated to 26 volts).

HifiBerry AMP60 Measurements
As usual...

This is a review and detailed measurements of the second sample of Emotiva XMC-2 AV Processor. It costs and US $3,199 and was kindly supplied by a member.


Please see my sample 1 review of XMC-2 for details. Here, I am going to focus on measurements only. For simplicity and giving the maximum benefit of doubt to the unit, I am using Toslink input for all the measurements. Unit was reset to factory (was new anyway) and firmware is the latest 2.5.

Emotiva XMC-2 Measurements
Let's start with our dashboard:


The channel offset issue I found in the first sample is gone. Sadly, the high noise floor remains at low frequencies as does harmonic distortion. So ranking stays the same as...

This is a review, listening tests and measurements of the Truthear Crinacle Zero IEM review. It was sent to me by @crinacle as he has been a consultant on the project. It costs US $50.


I like that it has a bit of "bling" but not too much. The cord is just the right length for me (many IEMs are too short for my use). It is super flexible with very little microphonics. You get two sets of silicone pads in three different sizes which suites me fine. I wear the largest one and it stays nicely put.

The claim to fame of this IEM is that it complies with the Harman target. Let's see if that is the case.

EDIT: These are the included tips and the ones used for measurement and listening tests:


Truthear Crinnacle Zero IEM Measurements
Let's start with our frequency response measurement:
[ATTACH type="full" alt="TRUTHEAR x Crinacle Zero IEM...

I worked for a consumer audio business for several years, from 2012-2015 and 2017-2020. It was a tiny company and we aimed directly for the middle of the market, say $100-300, which for our target customer, was expensive. Mainstream. (I won't say which one but you can probably figure it out if you're good with Google.) So much of what I say won't apply to bigger companies, or higher-end ones.

However, it might be good to know a little bit of what goes on behind the scenes. I see some assumptions about the biz that are not quite on the mark here and there, so maybe my experience can "lift some veils".

None of this is actually secret (it would be common knowledge for anyone employed in the industry) but isn't well-known outside of it. This audience has a lot of professionals in it so a lot of this might not be news to you. Also, I only worked at small volumes. Our company was a startup and about 10 people. My view of the industry would pale in comparison to someone who worked for...

This is a review, listening tests and measurements of the Dan Clark Expanse open-back planar magnetic headphone. It was loaned to me by the company and costs US $3999.

The design takes that of Stealth headphone to another level with nicely done grill on the outside. It is very comfortable to wear, nicely molding to my head. You have a choice of cable connectors (I received the balanced XLR one). The cable itself is quite thick and sturdy but nicely drapes so no complaints there.

Dan Clark Expanse Measurements
Let's start with our frequency response and comparison to target:

Prior to measurement company had told me that it...

This is a review and detailed measurements of the AudioQuest GO-4 speaker cable. It is on kind loan from a member and costs about US $599.


The attached dongle is a 72 volt battery supply that feeds an unterminated wire the length of the cable. Different terminations can be ordered. Here are the company advertisement about the cable:



And this interesting note about terminations:


They are certainly dull looking but in addition, they have already tarnished/oxidized:


I slid my meter over the terminations and whenever it hit an oxidized spot, it would add about 0.1 ohm of resistance! Both...

After massive failure with my previous review(https://audiosciencereview.com/foru...dio-p422-stereo-power-amplifier-review.35969/), I got great technical supports from ASR, Speaker gallery of DC inside, E1DA Discord Channel(@IVX, @staticV3 ) and Marchaudio.
(Detail for the appearance, see previous review post.)

Disclaimer
This is a review and undetailed measurements of the Marchaudio P422 stereo class D power amplifier. It is on kind loan from myself and costs US $1,988.68(P422 $1,675.21 + shipping to South Korea $132.68 + import tax $180.79) as previous

But this time, Marchaudio sent one low power reference load for free.
As 3rd party reviewer, I absolutely guarantee that there was no ask of change direction of review, and the supports has no influence on the review.

P422 is Purifi 1ET400A based amp with custom designed Power supply and buffer board.

Conditions
[ATTACH type="full"...