Articles, Reviews and Measurements of Audio Products
Review and Measurements of Ayre CODEX DAC & Amp
This is a review and detailed measurements of the Ayre CODEX balanced DAC and headphone amplifier. It is on kind loan from a member. The CODEX is a current product but seems like it was released 3 or so years ago. It costs USD $1,795.
I am puzzled by the look of the CODEX as it doesn't match the rest of the Ayre products:
If you are not familiar with Ayre, it is a US company and is probably best known by its late founder, Charles Hansen. He has been active on forums for years. The company is in high-end audio business so my expectations were high on this DAC and headphone amplifier.
I was pleased to see a set of balanced XLR connectors on the unit and inclusion of mains power supply despite its rather diminutive size:
Then again, closeness of the mains input gives me some pause regarding its noise immunity for the RCA outputs.
In use the CODEX runs very warm. The marketing material...
I am puzzled by the look of the CODEX as it doesn't match the rest of the Ayre products:
If you are not familiar with Ayre, it is a US company and is probably best known by its late founder, Charles Hansen. He has been active on forums for years. The company is in high-end audio business so my expectations were high on this DAC and headphone amplifier.
I was pleased to see a set of balanced XLR connectors on the unit and inclusion of mains power supply despite its rather diminutive size:
Then again, closeness of the mains input gives me some pause regarding its noise immunity for the RCA outputs.
In use the CODEX runs very warm. The marketing material...
Review and Measurements of Acoustic Power APL1 DSP
This is a review and detailed measurements of the Acoustic Power Labs APL1 digital audio signal processor. It is on kind loan from a member. The APL1 comes in a number of formats. The one under review is the automotive version and costs 510€ or USD $570. This is for the bare hardware. Software that let you program its internal "FIR" filters costs 262€ or USD $295. I am surprised that given the cost of the hardware, the software is not bundled in for free. For this testing, I only focused on the measurements of the hardware as the software seems non-trivial to use.
The automatic configuration of APL1 is nice and slim with phoenix connectors for power:
The LEDs change color depending on where you leave the slider switch. In my case I set the switch to bypass.
Here are the back connectors:
We have analog RCA input and output. In addition there is also S/PDIF and Toslink for input and...
The automatic configuration of APL1 is nice and slim with phoenix connectors for power:
The LEDs change color depending on where you leave the slider switch. In my case I set the switch to bypass.
Here are the back connectors:
We have analog RCA input and output. In addition there is also S/PDIF and Toslink for input and...
Review and Measurements of Cyrus soundKey DAC
This is a review and detailed measurements of the Cyrus soundKey portable USB DAC and headphone amplifier. It is on kind loan from a member. It costs USD $98.99 from Amazon with prime shipping. It comes in a few colors.
I like the flat form factor with detachable USB cord:
I received two short USB cables, one of which you see in the picture above. I don't know if that is how Cyrus ships it or the owner sent it me as such.
There are no volume controls so you would be relying on your software player for that.
One of the differentiators for the soundKey is low power consumption according to the company. I will be measuring and reporting on that later in the testing. For now, there was no rise in the temperature that I could feel on the unit.
Audio Measurements
As usual, we start with our dashboard view of 1 kHz tone:
Typical of these small dongles, there output is too low to use the soundKey...
I like the flat form factor with detachable USB cord:
I received two short USB cables, one of which you see in the picture above. I don't know if that is how Cyrus ships it or the owner sent it me as such.
There are no volume controls so you would be relying on your software player for that.
One of the differentiators for the soundKey is low power consumption according to the company. I will be measuring and reporting on that later in the testing. For now, there was no rise in the temperature that I could feel on the unit.
Audio Measurements
As usual, we start with our dashboard view of 1 kHz tone:
Typical of these small dongles, there output is too low to use the soundKey...
Review and Measurements of Lounge LCR MKIII Phono Amp
This is a review and detailed measurements of the Lounge Audio LCR MKIII Phono stage (amplifier). It is on kind loan from a member. The LCR MKIII costs $300 from the manufacturer direct.
The LCR MKIII is a very simple, typical DIY box:
A touch of class is intended to be provided by that lexan sheet with blue LED. It doesn't do much for me especially since the lighting is not uniform.
The back panel is simple too:
Since this is a moving magnet only phono amplifier there are no switches or controls. We have our simple RCA in and out plus a ground lug. Power is provided through an external AC adapter which is not a bad idea to keep mains inductance from the transformer leaking into sensitive amplifier stage.
As the name technically implies, this phono amplifier sets itself apart from others by using an inductor ("L") to implement RIAA equalization instead of just using capacitors. In...
The LCR MKIII is a very simple, typical DIY box:
A touch of class is intended to be provided by that lexan sheet with blue LED. It doesn't do much for me especially since the lighting is not uniform.
The back panel is simple too:
As the name technically implies, this phono amplifier sets itself apart from others by using an inductor ("L") to implement RIAA equalization instead of just using capacitors. In...
Review and Measurements of Lake People G109-S Amp
This is a review and detailed measurements of the Lake People G109-S headphone amplifier. It is on kind loan from a member. It costs USD $520 as of this writing but I see it has been offered on Massdrop for lower price.
Lake People is located in Germany and designs and builds its products there. Alas, the industrial design is ordinary and doesn't impart what I associate with German engineering:
I saw the anniversary edition (?) with gold letter and larger feet and that looked better. I know enclosures are expensive but over $500, I like to see a more professionally designed writing, logos, etc.
The volume control is analog but has notches in it. There are two headphone out jacks but they are identical (unlike some others where one is lower gain). I would have wished one was 3.5mm to accommodate IEMs without adapters.
Missing from the unit is any kind of external gain control. If you open the unit which requires removing...
Lake People is located in Germany and designs and builds its products there. Alas, the industrial design is ordinary and doesn't impart what I associate with German engineering:
I saw the anniversary edition (?) with gold letter and larger feet and that looked better. I know enclosures are expensive but over $500, I like to see a more professionally designed writing, logos, etc.
The volume control is analog but has notches in it. There are two headphone out jacks but they are identical (unlike some others where one is lower gain). I would have wished one was 3.5mm to accommodate IEMs without adapters.
Missing from the unit is any kind of external gain control. If you open the unit which requires removing...
Review and Measurements of Dynaco ST 70
This is a review and detailed measurements of the vintage Dynakit Dynaco Stereo 70. It is on kind loan from a member who bought it used online and repaired it. Previous owner hand upgraded it but could not get it working.
Given that it is 60 years old, one can forgive the rust and dust:
Some of the online samples I have seen are a lot more crusty.
The unit I received came from matched pairs of tubes from Apex. While each pair had the same parameters, the ones for each channel varied quite a bit. As you will see, this is reflected in the measurements.
This unit has an upgraded driver board:
There is a single bias control for each pair of tubes which is not optimal. I went ahead and adjusted both for 1.56 volts as stated in the manual.
I am not sure what output transformer tap is used. I tested it as is with my 4 ohm load. Hopefully the owner will advise what it is wired for...
Given that it is 60 years old, one can forgive the rust and dust:
Some of the online samples I have seen are a lot more crusty.
The unit I received came from matched pairs of tubes from Apex. While each pair had the same parameters, the ones for each channel varied quite a bit. As you will see, this is reflected in the measurements.
This unit has an upgraded driver board:
There is a single bias control for each pair of tubes which is not optimal. I went ahead and adjusted both for 1.56 volts as stated in the manual.
I am not sure what output transformer tap is used. I tested it as is with my 4 ohm load. Hopefully the owner will advise what it is wired for...
Review and Measurements of Audioengine D3 DAC & Amp
This is a review and detailed measurements of the Audioengine D3 portable DAC and headphone amplifier. I bought this refurbished from the company direct a year ago. I think I paid USD $99 for it but now see it new for the same price from Amazon including shipping. A member wrote to me asking if my version was 2 or the original. His has v2 after it, mine does not. I contacted the company and just heard back that the new versions have lower output impedance than what I measured. They do not note any other changes.
The D3 is one of the more substantial thumb drive DACs with chunky and solid metal enclosure:
On the back side there is full set of regulatory certifications including CE and FCC which I was pleased to see. And yes, the CE logo conforms with the EU graphics standard.
Audioengine is big enough company that likely did go through proper testing. The metal enclosure definitely helps with any radiated emissions standards.
As soon as...
The D3 is one of the more substantial thumb drive DACs with chunky and solid metal enclosure:
On the back side there is full set of regulatory certifications including CE and FCC which I was pleased to see. And yes, the CE logo conforms with the EU graphics standard.
Audioengine is big enough company that likely did go through proper testing. The metal enclosure definitely helps with any radiated emissions standards.As soon as...
Review and Measurements of Schiit BiFrost DAC
This is a review and detailed measurements of the Schiit BiFrost audio DAC. The unit is on kind loan from a member. The one I have doesn't have USB input so not sure if that is an older version or current??? Schiit website shows USB input as standard but then again there is some wording regarding optional USB module. Regardless, as best as I can figure out, the cost for BiFrost is USD $399 plus shipping.
Note that I had previously measured the Schiit BiFrost Multibit. This is the non-multibit version which is based on AKM DAC chip.
Not sure what is to say about the look of Schiit other than if you have seen one, you have seen them all:
Since there is no USB input, the momentary switch toggles between Toslink and S/PDIF. I used the latter for all of my testing.
The back panel has nothing exciting...
Note that I had previously measured the Schiit BiFrost Multibit. This is the non-multibit version which is based on AKM DAC chip.
Not sure what is to say about the look of Schiit other than if you have seen one, you have seen them all:
Since there is no USB input, the momentary switch toggles between Toslink and S/PDIF. I used the latter for all of my testing.
The back panel has nothing exciting...
Review and Measurements of Meier Corda Jazz Amp
This is a review and detailed measurements of the Meier Audio Corda Jazz headphone amplifier. It is on kind loan from a member. The Corda Jazz costs USD $355 from the company direct.
Given the inclusion of an AC mains power supply, the Corda Jazz feels quite hefty for its size:
No, you are not seeing double. I actually received two identical units for testing!
I find the graphics preminative and unattractive.
Other than the usual low and high gain, there is a cross-feed button which I did not play with.
The headphone socket is a Neutrik and mates nicely with 1/4 inch headphone jacks.
The back panel is as simple as you can get with AC IEC connector and a pair of RCA jacks:
II am not one for detail as you can tell from my posts but come on: why is "designed" not capitalized?
Measurements
I started with my unity gain test of 2 volt in and 2 volt out...
Given the inclusion of an AC mains power supply, the Corda Jazz feels quite hefty for its size:
No, you are not seeing double. I actually received two identical units for testing!
I find the graphics preminative and unattractive.
Other than the usual low and high gain, there is a cross-feed button which I did not play with.
The headphone socket is a Neutrik and mates nicely with 1/4 inch headphone jacks.
The back panel is as simple as you can get with AC IEC connector and a pair of RCA jacks:
Measurements
I started with my unity gain test of 2 volt in and 2 volt out...