Articles, Reviews and Measurements of Audio Products
D&A Alpha DAC & HP Amp Review
This is a review and detailed measurements of the D&A Alpha balanced DAC and headphone amplifier. It was sent to me by Shenzhen Audio and costs US $399.
No, you are not seeing double. What I tested before was the Alpha Pro. The non-pro version has the same distinct white LED and clear front panel with labels that are kind of hard to read. Otherwise, it is a very simple unit to use. I especially like the brightness of LED ring around the volume control changing proportionally to its setting.
I upgraded it before testing it. In the interest of digging my way our of mountain of gear...
No, you are not seeing double. What I tested before was the Alpha Pro. The non-pro version has the same distinct white LED and clear front panel with labels that are kind of hard to read. Otherwise, it is a very simple unit to use. I especially like the brightness of LED ring around the volume control changing proportionally to its setting.
I upgraded it before testing it. In the interest of digging my way our of mountain of gear...
Fosi CA30 Four Channel Car Audio Amp Review
This is a review and detailed measurements of Fosi CA30 four (4) channel car audio amplifier. It was sent to me by the company and sells for US $140.
Construction is very solid with the unit feeling much heavier and denser than it should at this price. The usual options are provided for gain and crossover. Power and speaker connectors are good quality but lack in usuability:
As you can probably tell, the screws go in at an angle. This makes it easier to see them if you are looking from the back. The problem is the screw engagement. Only the edge of it makes contact and worse yet, at the far end of the hole. With finer speaker wires, I had a heck of a time getting the screws to engage them. I must have spend 15 minutes messing with them. The edge of the screw can also saw off some the wire strands. Power connectors were not as bad but still have the same issue...
Construction is very solid with the unit feeling much heavier and denser than it should at this price. The usual options are provided for gain and crossover. Power and speaker connectors are good quality but lack in usuability:
As you can probably tell, the screws go in at an angle. This makes it easier to see them if you are looking from the back. The problem is the screw engagement. Only the edge of it makes contact and worse yet, at the far end of the hole. With finer speaker wires, I had a heck of a time getting the screws to engage them. I must have spend 15 minutes messing with them. The edge of the screw can also saw off some the wire strands. Power connectors were not as bad but still have the same issue...
Interspace PCBB3 Hum Eliminator/Converter
This is a review and detailed measurements of the Interspace/Hive PCBB3 3.5mm unbalanced to XLR balanced converter/"hum eliminator." It was kindly drop shipped to me. This model is superseded by PCBB4 which costs US $151.
I was impressed by the very nice feel of the silicone cable bringing out the 3.5mm jack, ready to plug into a computer in live scenarios. Usually we see RCA jacks. There are options to lower level (pad), convert to mono and lift ground.
Interspace PCBB3 Converter Measurements
I start with my usual 1 kHz tone at 2 Volts:
The unit is passive which I assume it means it has a transformer. As such, the worst performance is at lower frequencies, not 1 kHz:
It saturates at just 0.15 volt and logarithmically gets worse as frequencies get lower. But need not be this bad as we see from measurements of the...
I was impressed by the very nice feel of the silicone cable bringing out the 3.5mm jack, ready to plug into a computer in live scenarios. Usually we see RCA jacks. There are options to lower level (pad), convert to mono and lift ground.
Interspace PCBB3 Converter Measurements
I start with my usual 1 kHz tone at 2 Volts:
The unit is passive which I assume it means it has a transformer. As such, the worst performance is at lower frequencies, not 1 kHz:
It saturates at just 0.15 volt and logarithmically gets worse as frequencies get lower. But need not be this bad as we see from measurements of the...
Interspace USB to Balanced Box (DAC)
This is a review and measurements of the Hive Interspace USB Balbox adapter. It is built in UK and was kindly drop shipped to me by a member. The version I have is no longer on their site but they do have a version 3. No specs are provided to know if there are improvements in issues I have found.
The version 3 costs US $183. If mine is anything like it, it only exposed 16 bits at sampling rates of 44.1/48 KHz. It must be one obsolete, old PC targeted DAC silicon.
Measurements, after setting Windows Volume to max, was super disappointing on multiple fronts:
For a professional product, I expect minimum of 4 volts output. Here, we don't even have 1 volt! And yes, this is with the pad disabled. Enabling the pad gives you candle light levels of output!
Moving on, we see massive distortion as one would expect from super vintage DAC IC. I realize this is a "solution box" but...
The version 3 costs US $183. If mine is anything like it, it only exposed 16 bits at sampling rates of 44.1/48 KHz. It must be one obsolete, old PC targeted DAC silicon.
Measurements, after setting Windows Volume to max, was super disappointing on multiple fronts:
For a professional product, I expect minimum of 4 volts output. Here, we don't even have 1 volt! And yes, this is with the pad disabled. Enabling the pad gives you candle light levels of output!
Moving on, we see massive distortion as one would expect from super vintage DAC IC. I realize this is a "solution box" but...
German Maestro GMP 8.35 D Headphone Review
This is a review, listening test, EQ and detailed measurements of the German Maestro GMP 8.35 D Headphone. It was sent to me by the company and sells for US $245.
As you see the headphone looks somewhat industrial and seems to be built to be durable. It came with another set of pads but I chose to test the defaults as you see. The cups are a bit small for me so the fit was not very comfortable. A detachable 3.5mm connector/cable carries the signal to it and two different lengths are provided.
I had not heard for the company before when they reached out to me. But they explained their long history including at some point being MB Quart.
German Maestro GMP 8.35 D Headphone Measurements
The ribbed section of the headphone covers an adjustment for the headphone band. Alas, no matter what I did, I could not improve the bass frequency response:
I checked and found one other...
As you see the headphone looks somewhat industrial and seems to be built to be durable. It came with another set of pads but I chose to test the defaults as you see. The cups are a bit small for me so the fit was not very comfortable. A detachable 3.5mm connector/cable carries the signal to it and two different lengths are provided.
I had not heard for the company before when they reached out to me. But they explained their long history including at some point being MB Quart.
German Maestro GMP 8.35 D Headphone Measurements
The ribbed section of the headphone covers an adjustment for the headphone band. Alas, no matter what I did, I could not improve the bass frequency response:
I checked and found one other...
SMSL SU-2 DAC Review (NTTY)
Hello Everyone, this is a revie and measurements of the SMSL SU-2 DAC
I bought it from the Ali store, and paid roughly $120 shipping included.
SMSL SU-2 – Presentation
The SU-2 replaces the SU-1, drops the USB input and adds an AES SPDIF (Balanced) connector. It hosts the ESS ES9039Q2M, just like the SMSL PS200 Pro that I recently reviewed.
As you can see from the photo, there’s only one button to power it on/off and switch between the three digital inputs. It can’t be simpler. The chassis is full aluminium and the device is heavy enough not to be dragged by standard XLR cables.
This is the back of the device:
As opposed to the SMSL PS200 Pro, we get XLR outputs with this one, which should allow us to chase few more dBs of SINAD and/or DR here...
I bought it from the Ali store, and paid roughly $120 shipping included.
SMSL SU-2 – Presentation
The SU-2 replaces the SU-1, drops the USB input and adds an AES SPDIF (Balanced) connector. It hosts the ESS ES9039Q2M, just like the SMSL PS200 Pro that I recently reviewed.
As you can see from the photo, there’s only one button to power it on/off and switch between the three digital inputs. It can’t be simpler. The chassis is full aluminium and the device is heavy enough not to be dragged by standard XLR cables.
This is the back of the device:
As opposed to the SMSL PS200 Pro, we get XLR outputs with this one, which should allow us to chase few more dBs of SINAD and/or DR here...
Ascilab C6B Speaker Review
This is a review, listening tests and detailed measurements of the Ascilab C6B bookshelf speaker. It costs USD $1,357 per pair inclusive of import fees. Pricing varies in other parts of the world:
Important note: my other company, TestedAudio, is the sole distributor for all of Ascilab products. Indeed, C6B is by far our most popular speaker. So feel free to read my subjective comments with extreme skepticism.
The C6B shares the same everything with F6B but with an upgraded woofer. I like the white look which reminds of the iconic Yamaha studio monitors (there is a grill if you want to hide it).
This is surprisingly compact speaker yet feels quite heavy and dense. You can better see its compact dimensions from this side profile:
[ATTACH type="full" alt="Ascilab...
Important note: my other company, TestedAudio, is the sole distributor for all of Ascilab products. Indeed, C6B is by far our most popular speaker. So feel free to read my subjective comments with extreme skepticism.
The C6B shares the same everything with F6B but with an upgraded woofer. I like the white look which reminds of the iconic Yamaha studio monitors (there is a grill if you want to hide it).
This is surprisingly compact speaker yet feels quite heavy and dense. You can better see its compact dimensions from this side profile:
[ATTACH type="full" alt="Ascilab...
Cubilux Budget 7.1 USB Sound Card Review
This is a review and detailed measurements of the Cubilux 7.1 USB Surround DAC and line/microphone input. It was kindly drop shipped to me and only costs USD $32.
From the pictures I assumed it was desktop sized but as you see, it is tiny. Fortunately it is made of metal and feels great in hand. You can see the connectivity better from company stock picture:
The other side has a USB-C connection used for both power and data.
Company doesn't state what DAC IC they use but likely is an ultra low cost USB interface usually used in motherboard.
Cubilux DAC Measurements
I was disappointed that even at max volume, we are short of nominal 2 volt output:
Performance is surprisingly good though. Distortion products are near -100 dB which is good enough to more or less resolve 16 bit data. Dynamic range is just as good:
[ATTACH...
From the pictures I assumed it was desktop sized but as you see, it is tiny. Fortunately it is made of metal and feels great in hand. You can see the connectivity better from company stock picture:
The other side has a USB-C connection used for both power and data.
Company doesn't state what DAC IC they use but likely is an ultra low cost USB interface usually used in motherboard.
Cubilux DAC Measurements
I was disappointed that even at max volume, we are short of nominal 2 volt output:
Performance is surprisingly good though. Distortion products are near -100 dB which is good enough to more or less resolve 16 bit data. Dynamic range is just as good:
[ATTACH...
Ascend CBM-170SE2 Speaker Review
This is a review, listening tests and detailed measurements of the Ascend Acoustics CBM-170SE2. It was sent to me by the company and costs USD $248 each. $468 a pair.
There is a grill which I removed, making the speaker look utilitarian. Pick it up though and you realize it weighs more than you expect.
Love the mention of NFS Optimized text on the label:
Ascend CBM-170SE2 Speaker Measurement
As noted, I stripped the speaker off its grill and measured it with Klippel NFS using the tweeter center as the reference:
As noted, the general on-axis response is flat as we like. There are however some variations including a...
There is a grill which I removed, making the speaker look utilitarian. Pick it up though and you realize it weighs more than you expect.
Love the mention of NFS Optimized text on the label:
Ascend CBM-170SE2 Speaker Measurement
As noted, I stripped the speaker off its grill and measured it with Klippel NFS using the tweeter center as the reference:
As noted, the general on-axis response is flat as we like. There are however some variations including a...
Shanling EC Play Review (Portable CD Player, DAC & HP Amp)
Hello everyone,
This is a review and measurements of the Shanling EC Play portable CD player, transport, DAC and HP Amp.
I bought it for roughly $200, and went for the green version which I find very nice as the color is really light and metallic.
Shanling EC play - Presentation
This one shares a lot of similarities with the Fiio DM13 that I already reviewed: 3.5 se and 4.4mm balanced outputs, SPDIF coax output, including the same DAC (CS43198), and dual SGM8262 headphones amplifiers.
The claimed output power is the same at roughly 180mW (se) at 32ohms, and 700mW (balanced).
The biggest difference is that, if the Shanling has one DAC in lieu of two with the Fiio, it can serve as a DAC too when connected to a computer, where the Fiio only offered to rip a CD to a USB-C compatible storage.
The battery...
This is a review and measurements of the Shanling EC Play portable CD player, transport, DAC and HP Amp.
I bought it for roughly $200, and went for the green version which I find very nice as the color is really light and metallic.
Shanling EC play - Presentation
This one shares a lot of similarities with the Fiio DM13 that I already reviewed: 3.5 se and 4.4mm balanced outputs, SPDIF coax output, including the same DAC (CS43198), and dual SGM8262 headphones amplifiers.
The claimed output power is the same at roughly 180mW (se) at 32ohms, and 700mW (balanced).
The biggest difference is that, if the Shanling has one DAC in lieu of two with the Fiio, it can serve as a DAC too when connected to a computer, where the Fiio only offered to rip a CD to a USB-C compatible storage.
The battery...