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Discussion Starter #1 (Edited)
MSRP: $99.99
Performance: :4stars:
Feature Set: :4stars:
Ergonomics: :4stars:
Value: :4stars:

RAM DAC-AMP 20 Review


About RAM:
RAM Electronics Industries, founded in 1977, answered the demand for high quality wire harnesses and cable assemblies used in the manufacturing and connectivity of electronic equipment and instrumentation. We offer our customers cut and stripped wire, audio and video cables, complex wire harnesses, ribbon cables, molded cables and other state of the art cables used in the amusement, electronic data processing, gaming, medical and telecommunication industries.

Customers are offered a complete line of services from the initial interconnection design to final product packaging and production. Using connectors from many major brands as AMP, Molex, FCI, JST and others supplements RAM's resource capabilities of matching process to program.

RAM has an extensive inventory of semi-automatic and fully automated crimping, wire cutting and cable handling equipment and offers one of the most complete automated IDC/Ribbon Cable termination systems, in the Northeast corridor.


Unboxing and Setup:
The packaging is what you would expect from a company like RAM. No frills, just a plain white box with the unit packed with the proper amount of internal bracing and the unit was in a plastic bag to avoid any dust particles, etc. Two things caught my eye as I took the unit out the box. First, compared to other units I have seen or used such as the NuForce uDAC-2, the RAM DAC-AMP20 is about twice the size. However; the NuForce is also only USB powered and only outputs via headphones/mini-plug as to where the AMP20 has the ability to use external stereo speakers. The second thing I noticed immediately was that the external power supply was fairly large but again; this should be somewhat expected given that the unit can power two 10 watt channels. I should mention that the unit is only dependent on the external power when using the AMP20 to power speakers, it is completely portable via USB power for the headphones similar to the uDAC-2.

As far as aesthetics go, the DAC20 looks pretty nice. My only recommendation would be for RAM to change the red collar for the headphone output to black so it blends better. Other than that I really have no complaints about the look of the unit.

As for the features; I think the connectivity options are about right for the price of the unit. The digital optical input, which is default when both the USB and optical are connected, makes it convenient to connect devices such as Blu-Ray/DVD players, TV’s with digital output and other such components and the USB connects quick and painlessly to your MAC or PC which is where most of us will end up using this unit anyway. All in all, the setup was fairly quick and painless. I had the unit setup on a Mac-Mini in about five minutes and most of that time was spent running the power so it was hidden in order to avoid any confrontations with my better half.


The DAC-AMP20 is a Digital to Analog Converter with Optical and USB Inputs, and an Amplifier with both Headphone and Speaker Outputs. Headphone output or 10 Watts per channel for connecting a pair of Stereo Speakers to your computer or any toslink digital output device. Along with the unit, RAM also includes the a copy of the test results of each unit that shows the THD and response of the unit tied to the serial number in the documentation. I thought that was a very confident thing to do and thought it should be mentioned.

Update: Scans of the test results.

THD

Signal Noise Level

Dynamic Range

Stereo Crosstalk


Update
After working with the AMP-20 and I have found some additional information that will be important to anyone seriously looking for a DAC solution. As pointed out by one of our forum members, RAM doesn't publish their specs in regard to two very important areas, but I have located the information within my Mac-mini setup and have posted directly below.

  • Maximum sampling rate: 48kHz
  • Resolution: 16-bits

DAC-AMP 20 Specs:

  • Supports LPCM Digital Audio, (no Bitstream support)
  • Dynamic Range: 90 dB
  • Sampling Rate: 32Hz~192KHz
  • Signal to noise Ratio: 90 dB Headphone amplifier:
  • THD: 0.03%
  • Signal to noise: 105dB
  • Power: 45mW

Amplifier Specifications:

  • Power: 10W x 2
  • THD: 0.1%
  • Signal noise 80dBAnalog:
  • Frequency range: 20Hz~20KHz
  • THD: 0.042%~1KHz

Inputs:
  • Optical fiber
  • USB
  • Outputs:
  • 32ohm 3.5mm earphone jack
  • 8 ohm Speaker Wire
  • Dimensions: 90 x 65 x 30 mm
  • Weight: 150 g.

Reference System:
  • Apple Mac-Mini
  • Asus
  • Apple TV
  • Audio Technica ATH500
  • Polk TL2

Subjective Listening:

From the PC via USB:
After playing around with the options for a bit it was time to sit back and do some real listening. I started off with Fates Warning's 'The Eleventh Hour'. The song is a great piece for listening through some headphones and really losing yourself in the mood of the song. Jim Matheos' writing ability is absolutely phenomenal, but it is also a bit of an acquired taste. All of the different emotions in the song come across with clarity and authority. From the despondent feeling of the first two versus to the angry transition to the bridge and back again I really felt like the recipient of the songs message.

Ok, so enough of the depressing stuff; time for an upturn. Of course one of my favorite reference pieces is Clint Mansell and the London Music Works ‘Requiem for a Tower’. Blasting through the Audio Technica’s, thanks Dave, I really felt the energy of the song build and then soar only to crash and re-build. It was an awesome to experience the piece alone in my own little world where I really felt like I was detached from everything.

Next on the list was the song ‘Crying’ by Yngwie J. Malmsteen from his 1986 album ‘Trilogy’. This is one of my all-time favorite instrumental songs for several reasons. First and foremost I think it let everyone know that just because you don’t play your guitar slow, doesn’t mean you don’t play with feeling. Second because the song itself has several different textures of guitar that need to be heard to be appreciated.; the slow fingerpicking of the steel string acoustic and the fast staccato finger picking of the nylon string at the beginning of the song progress to a complimentary melodic rhythm before eventually giving way to a blistering electric guitar solo to finish out the song. That one always gives me chills…

From the Apple TV via Toslink:
For the optical input test I used the Apple TV and a combination of speakers attached to the DAC, the Audio Technica ATH-500’s and plugged directly to my receiver via the headphone jack mini-plug. I started with ‘Let Me Go’ by 3 Doors Down. The song is a good contemporary rock song that has plenty going on with the vocal harmonies and melody of the song that I think it offered some great listening. Each part came out very clear and the sound was full and engaging. Luckily I was going through the Polk speakers so I was less embarrassed about singing out loud, of course my bride was embarrassed enough for both of us.

Alright, it was time for something different now. I love the rock and I am all about the heavy metal, but I need to hear how clear this thing really is. I opted to listen to Andres Segovia ‘Sarabanda’ as loud as I could stand it and in the end the DAC won. I the only noise I could detect was a faint hiss of the volume just before the song started. Other than that, the song was as clear and about as perfect as I’ve ever heard. I really expected the result to be less than pleasing but in the end the unit prevailed.

The last song on my list was ‘Throwin’ it All Away’ by Zakk Wylde from the ‘Book of Shadows’ release from the late 90’s. For any of you that haven’t heard the CD, it is a bit of a departure from any of Zakk’s other material whether it be Ozzy, Pride and Glory or his band for the last 10 plus years; Black Label Society. This CD was heavily influenced by the likes of The Allman Brothers and Lynyrd Skynyrd as it has a very definite southern rock flavor and it’s a shame he only put out the one CD in this genre. The song is a great southern rock style ballad with everything from acoustic guitars, piano, violin (fiddle for the purists) and a great guitar solo. There is a lot of emotion in the song and each instrument comes out clear and full of energy.

Conclusion:
I have to say that I was pleasently surprised by the AMP20's performance. I was honestly expecting a half-hearted solution as RAM is not always at the forefront of my mind when I think of audio components however; I will definitely think about them moving forward. Don't get me wrong, the DAC-AMP20 is not for everyone, especially the crowd looking for something in the Benchmark or Music Hall line-up. But we can't all afford to shell out that kind of money and if you are looking for a solid mobile DAC that will perform consistently and give you an option to connect external speakers; then defintitely check out the DAC-AMP20. However; if you are looking for an inexpensive DAC only, then there are some better options out there that have better performance at an equal or lower cost.

Win this review unit!
 

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Dale, as always - Thanks.

I really like how HTS reviews realistic (affordable by mere mortals) as well as different manufactures than many typical audio/video sites.

This one grabbed my attention. I do have some questions (which I will pose to the manuf. as they are in a better position to answer - hopefully).

That would be:
performance/capability of driving:
  • 4 ohm speakers
  • 16 ohm headphones

I did not find any details on Ram's website as to the above so I will post an email to them.
 

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Discussion Starter #3
Hey Scott, I've looked through the documentation and only found 32 ohm headphone and 8 ohm Speaker listed so my knee-jerk reaction is to say that it doesn't support it. They have been pretty quick to respond to questions though so it never hurts to ask.
 

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Unless they are supplying USB Audio Class 2 drivers with the unit or you are using Mac OS X or Linux, you are not getting 192k performance. Also, with a 32Ω output impedance and only 45mW output (into what impedance?) I would not use it with any kind of low-impedance headphones or IEM. You are asking for wildly fluctuating FR. The DAC'less FiiO E5 ($20) offers an output impedance of .7Ω and over 108/23mW into 15/150Ω, the E7 (w/ Wolfson WM8740 DAC) measures .13Ω and offers 113/23mW into the same impedances. The new E10 offers 24/96 resolution via USB using native OS drivers. You're not going to hear the difference between 96K and 192K. BTW, all these are sub-$100 and offer better distortion characteristics. Also, the supplied RMAA curves are as suspect as all RMAA curves are. Any company that cannot test and prove it's designs on proper test equipment will never get my hard earned Dollars.
 

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Discussion Starter #5
Unless they are supplying USB Audio Class 2 drivers with the unit or you are using Mac OS X or Linux, you are not getting 192k performance. Also, with a 32Ω output impedance and only 45mW output (into what impedance?) I would not use it with any kind of low-impedance headphones or IEM. You are asking for wildly fluctuating FR. The DAC'less FiiO E5 ($20) offers an output impedance of .7Ω and over 108/23mW into 15/150Ω, the E7 (w/ Wolfson WM8740 DAC) measures .13Ω and offers 113/23mW into the same impedances. The new E10 offers 24/96 resolution via USB using native OS drivers. You're not going to hear the difference between 96K and 192K. BTW, all these are sub-$100 and offer better distortion characteristics. Also, the supplied RMAA curves are as suspect as all RMAA curves are. Any company that cannot test and prove it's designs on proper test equipment will never get my hard earned Dollars.
Thanks for the input FLAudioGuy, you obviously have a lot of knowledge in the area of headphone amps. We are working on getting some proper test equipment for more accurate results but are currently limited to subjective listening tests and commentary on the functionality. The unit sounded fine to me which is actually what the review was about and not so much a shootout with the other manufacturers. :T

Thanks again for the input!
 

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Nice feedback FLAudioGuy...thank you. Glad to hear HTS is in the process of more test gear. Myself aside from a RS analog SPL meter I have the two most accurate test devices that matter to me...........my ears.:sarcastic:
 

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Nice feedback FLAudioGuy...thank you. Glad to hear HTS is in the process of more test gear. Myself aside from a RS analog SPL meter I have the two most accurate test devices that matter to me...........my ears.:sarcastic:
Exactly! :T
 

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BTW, Dale, I like your Shiva 12" project build :) Though that uncovered vertical port might be an invitation to your kitty to get lost inside it, lol. Not turning the thread into a shoot-out, per se, just making note of other comparable product in the same price range. I hope I didn't give offense, with only 11 posts I don't want to get banned this early in the game! Have you looked at the Hypex plate amps? Software configurable and very good build quality. Cheers, mate! :T
 

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/soapbox-on

Ears are good but easily tricked by our brains. Objective measurements should play a bigger percentage of our decision making process along with functionality, ergonomics, QC and finally with our ears. Choose an audio unit that meets your needs, has good build quality, good styling, documented specs and be happy with it. Rarely does a piece equipment test 'bad' and still sound 'good'. Majority odds are that a piece of gear that tests well will sound good also. A few units may test well but sound 'bad' but overwhelmingly, IMHO, 'good' will sound 'good'. When people start to quibble about .0001 difference in spec, I stop listening. At that point, the discussion seems to be about one persons ego and is no longer intellectually honest.

I am glad to hear that HTS is looking to procure test equipment(s) and not a purely subjectivist forum. This is the main fault I find in Head.Fi is that the threads seem 'guided' by the manufacturing contributors. Say anything about their product in a negative light or call into question their design processes and the result is getting banned. Pure and simple, this is dishonesty and it makes me wonder about the integrity of such places.

/soapbox-off
 

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Discussion Starter #10
BTW, Dale, I like your Shiva 12" project build :) Though that uncovered vertical port might be an invitation to your kitty to get lost inside it, lol. Not turning the thread into a shoot-out, per se, just making note of other comparable product in the same price range. I hope I didn't give offense, with only 11 posts I don't want to get banned this early in the game! Have you looked at the Hypex plate amps? Software configurable and very good build quality. Cheers, mate! :T
No worries, I didn't realize until I read your thread I didn't really put in any type of disclosure in my review which should be a best practice to add a bit of objectivity to a subjective review. Does that make sense? LOL

I haven't looked at the Hypex plate amps yet, but I'll deinitely check them out for the next build! Thanks!
 

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No worries, I didn't realize until I read your thread I didn't really put in any type of disclosure in my review which should be a best practice to add a bit of objectivity to a subjective review. Does that make sense? LOL

I haven't looked at the Hypex plate amps yet, but I'll deinitely check them out for the next build! Thanks!
Dale, for anyone interested in a DIY'er amp, Hypex™ does offer 180, 400 and 700W Class-D modules and power supplies that can be fitted to your own enclosure. They are very competently designed by an excellent engineer and have all specs documented. For those that don't particularly care for the B&O™ ICEpower® amplifiers, these may give them a very welcomed surprise in sound quality. They can be found here along with their software configurable full-range and subwoofer plate amps http://www.hypex.nl/index.php?option...d=60&Itemid=69 Performance and listening tests are readily available on the web, so no real need to post them here. Cheers, mate, and good luck on your next build :T
 

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Does USB support 24/192?
For clarity, the specification for USB Audio Class 2 (not the same as USB 2.0) does indeed support 192kHz/24bit audio in High-Speed mode.

However, the RAM DAC-AMP20 only supports 48kHz/16bit audio (DVD Quality) but unless your computer is set up properly and you have 48kHz/16bit files, your audio will be resampled and that is not a good thing. Most of the quality gain in 48k audio will be lost in the resample process as well as higher noise.

Cheers and good luck! :T
 
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