Articles, Reviews and Measurements of Audio Products

This is a review and detailed measurements of the Ladder Schumann "FPGA" (R2R) balanced DAC. It was sent to me by Shenzhenaudio and costs US $1,399.

The box is solid and has fair bit of heft to it, likely due to power supply transformer. The interface is pretty simple with the exception of the "Mode" button which I could not figure out. There is no manual supplied in my sample (which came back in July), nor could I find one online. It seems to select one of a few oversampling modes (2X/4X/8X) but I could not figure out how to get it to do that (seems to do something in setup). There is a dedicated button and turns off oversampling and filtering.

The main notable thing on the back panel is inclusion of XLR balanced out which you don't always see on R2R DACs:



Ladder Schumann DAC...

This is a review and detailed measurements of the Schiit Fulla E DAC, Headphone Amplifier and microphone input. A member kindly drop shipped one to me and costs US $109.

I think the packaging and color are absolutely adorable! And I really like the feel of a volume control on top. Connectivity is rather rich despite the tiny package:



You have Toslink in addition to USB-C input. No power supply is provided but you need one to use Toslink by itself (or use your computer's USB connection). A microphone input is provided to go with the gaming angle:


During the testing I ran into a problem with the clock sync would get lost at times. I could not figure out what was going on. I contacted Schiit and they sent me another one with the same problem. You can see its manifestation here:


Source tone was 1 kHz so we should see a flat line but...

This is a review and detailed measurements of Marantz NR1510 5.2 4K slim Home Theater AV Receiver. It is on kind loan from a member and costs US $799.

I have been wanting to test a slim AVR for a long time as they much better fit under a TV in a living room than the monster that regular AVR line has become with so many channels that never gets used in this application (there is an NR170 with two more channels for Atmos). I also like the more traditional look of this Marantz compared to their regular line with the obscure porthole for the display and such. Here is the back panel:


During my testing, the unit hardly got warm to touch which again, makes it a great fit to stick in a cabinet below the TV.

Marantz NR1510 DAC Measurements
Let's start with our divide and concur test of the DAC subsystem using the pre-out and HDMI input with volume adjusted to get 2 volts out:
[ATTACH...

As requested by a member, here is a video review of the PS Audio Power Plant 3 AC Regenerator:

Hi

here are some measurement of the new RME ADI-2/4 Pro SE in RIAA (phono) mode

The RME ADI-24 Pro SE is RME's last addition to their ADI-2 converters range.

RME explains that SE means "Special Edition", and they advertise it as a Special, Limited edition, on top of the existing ADI-2 serie.

Externally, the family relation with the ADI-2 range can't be denied.



Here-above, from top to bottom,
RME ADI-2 Pro fs BE
RME ADI-2 Pro fs R BE
RME ADI-2/4 Pro SE

The most obvious difference with the ADI-2 Pro fs (R) is the presence of an additional 4.4mm Pentacon connector, to allow direct connection of balanced phones.
On the rear, there is also a Trigger output, to remotely switch on a power amplifier, as an example.

The new ADI-2/4 is also deeper than the ADI-2 pro (160mm vs 130mm) and it includes those large "HiFi look" silver feets instead of the small...

This is a review, listening tests and measurements of the Neumann KH150 DSP 2-way studio monitor (active speaker). It is on loan from the company and costs US $1,750 (each).


The design language is not changed of course. The main woofer is 6.5 inches now powered by 120 watt dedicated amplifier. While it is about 3X larger than the KH 80 DSP, it is still light and quite manageable. Here is the back panel with all the expected connections/controls:


As bad luck would have it, I yet again managed to test a Neumann speaker during colder weather here (around 56 degrees F). I kept the speaker indoor prior to testing with Klippel NFS speaker...

This is a review, listening tests and detailed measurements of the PS Audio Stellar Power Plant 3 AC regenerator. It is on kind loan from a member and costs US $2,499.

There are no front panel controls other than standby/power switch on the left. To activate the MultiWave and ClearWave requires remote control which I did not have. Very bad form to not put a simple switch in the front to cycle that way. Not much to the back panel:

Shame there is no power sequencing/sense for power management.

A heavy AC cord is supplied with the unit but I got a kick out of this statement in the manual:


You buy an AC regenerator and it still is sensitive to what the power cord does...

This is a review and detailed measurements of Topping L70 balanced headphone amplifier. It was sent to me by the company and costs US $349.

The L70 has the beautiful white segmented display. It is the most visible/high contrast display I have seen on an audio product. Volume control is very responsive and is relay based to provide perfect channel matching. You get both unbalanced and balanced output with the latter providing substantially more power. A remote control is provided. Back panel shows some nice extra features:

You have 12 volt trigger to power it on or have its power switch power other gear. A ground lift is provided as well to help with ground loops. And my favorite feature which is an included power supply.

A microprocessor controls the...

(Photo from Marchaudio)

I saw some of ASR members request about review this Amp.
And for my personal curiosity I asked to Company to lend one for review. After I finished measurement, I asked company how to return. But the Company gave me right to dispose of it.

Disclaimer
This is a review and undetailed measurements of the Marchaudio P501 Mono Block Class D power amplifier. It was sent to me by the company, free of charge.
Otherwise, the company has no influence over the review, and I myself have consistently maintained my credibility as a third-party reviewer.

let's look at the data of the makers.

P501 Amp is based on Purifi 1ET7040SA
70 Means 70 V of rail power, 40 Means 40 A of Max output current.





Through the datasheet, we can...

This is a review and detailed measurements of the Monolith by Monoprice USB DAC (29512) portable DAC and headphone amplifier. It was kindly sent to me by a member and is on sale for US $60.

I like the volume control on the right. Other than that, there is not much else to it.

Monolith by Monoprice USB DAC Measurements
Let's start with our usual dashboard:

I must say, that is one odd looking noise floor! Company specifies output voltage of 2 volts but we are shy of that at 1.85. This is critical for headphone amps as that also sets the max power into high impedance loads. I don't know where their 117 dB spec comes from (datasheet for ES9018K2M chip???). We are nowhere in the same universe with SINAD of 82 dB.

Another major deviation is in dynamic range:


96 dB is OK for the application but why spec 122 dB that requires state of the art desktop DACs to achieve...