Page 1 of 2 1 2 LastLast
Results 1 to 25 of 49
  1. #1
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127

    300+ wpc, brand new: $420

    I've just comlete my first semi-DIY amplifier. It's working great!

    I was/am very a happy with my Monarch Audio SM-70 Pro monoblocks, but I undertook this build with a few objectives in mind:
    1. I wanted a fairly simple, first audio project to amuse me in my recent retirement.
    2. I wanted more in depth exposure to a digital amplier. I want a comparision no only with the high-bias, low feedback Monarchys, above, but also with the Bel Canto eVo2i, Tripath-based I owned a few years ago, (based on my memory 'cause the Bel is long gone).
    3. See if substantially more power would make much of difference in my usage, say 2.5x the 120 wpc @ 4 ohms of the Monarchys.
    What tempted me to this project specifically was the US-made, Class D Audio, (website here), amps. Their amps are based on commecially available "class D" chips, however the boards and circuitry are proprietary. I selected the SDS-258 (here) model, actually the kit that includes a linear power supply, transformer, and gain pots for US$360, (here).

    The biggest challenge wasn't the electronics, which are basically plug-ang-play, but the cabinet construction. This was something new to me and I made a dozen mistakes along the way, but fortunately none were show-stoppers; (first time I've owned or used a "step drill"). Class D Audio can also supply a case, but it was a little rich for me at $190; my own case included some 1/2" MDF, 1x4" pine, and a Hammond aluminum case botton: this stuff cost me about $20. Assorted hardware including Neutrik XLR connectors rounded up the price to about $420 plus shipping.

    The SDS-258, according to CDA, is ingeniously designed for balanced input and that's the way I built it since my preamp has balanced output. (Single-ended is also supported.)

    My first impressions of the sound is very possitive -- more to follow. Here's a pic ...


  2. #2
    Silence of the spam Site Moderator Geoffcin's Avatar
    Join Date
    May 2003
    Location
    NY
    Posts
    3,326
    Sweet!!!
    Audio;
    Ming Da MC34-AB 75wpc
    PS Audio Classic 250. 500wpc into 4 ohms.
    PS Audio 4.5 preamp,
    Marantz 6170 TT Shure M97e cart.
    Arcam Alpha 9 CD.- 24 bit dCS Ring DAC.
    Magnepan 3.6r speakers Oak/black,

  3. #3
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,523
    Nice! Are those new speak cables you have there? Look like Nordost

  4. #4
    Loving This kexodusc's Avatar
    Join Date
    Nov 2003
    Location
    Department of Heuristics and Research on Material Applications
    Posts
    9,025
    Well done, Feanor...and thanks for the link...I'm gonna have to try one of those soon...

  5. #5
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by audio amateur
    Nice! Are those new speak cables you have there? Look like Nordost
    Yes, they're Nordost Flatline Gold. But they're not new, I've had them for years.

  6. #6
    Forum Regular luvtolisten's Avatar
    Join Date
    Feb 2009
    Location
    Rochester, NY
    Posts
    526
    Congratulations and nice job. Wiring looks professional, I can see it was well thought out.

  7. #7
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by luvtolisten
    Congratulations and nice job. Wiring looks professional, I can see it was well thought out.
    Thanks. I did try to keep the cable runs short over all, especially the source inputs and speaker outs. The wiring to the gain pots -- the black things at the back between the speaker outs and XLR ins -- comes with the kit; perhaps I ougth to have shortened them, but things seem fine at this point.

    I'll comment on the sound in a day or two. So far it's really good.

  8. #8
    Vinyl Fundamentalist Forums Moderator poppachubby's Avatar
    Join Date
    Aug 2009
    Location
    Analog Synagogue
    Posts
    4,363
    Looks fantastic. But where do the tubes go?

  9. #9
    Chicago IL
    Join Date
    Jul 2009
    Location
    Chicago ,IL
    Posts
    1,188
    Looks cool, I would love to hear how it sounds but I will never have the chance, Feanor, you gotta tell us

  10. #10
    I put the Gee in Gear.... thekid's Avatar
    Join Date
    May 2005
    Location
    VB VA
    Posts
    2,307
    F
    Congrats on completing a very cool project!!
    Should'nt there be runes on the front or at least a Silmaril embedded on the front?

  11. #11
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by thekid
    F
    Congrats on completing a very cool project!!
    Should'nt there be runes on the front or at least a Silmaril embedded on the front?
    I like that suggestion!

    How about Feanor's device, (as designed by Tolkien)?


  12. #12
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127

    First impressions

    Quote Originally Posted by poppachubby
    Looks fantastic. But where do the tubes go?
    Toobs, eh, Pops? Well there are none in sight nor any prospect of them with this amp.

    I feel it's still early to give a definitive review -- for one thing, I'd like at least one swap back and forrth with my Monarchys. However I offer a few tentative remarks.
    • Class D Audio says ... "Our Super D Series amps provide more life-like imaging and sound stage, along with the beautiful smooth tube-like sound we're known for. These amps are powerful, clean, quiet , and transparent." Mostly true.
    • "Tube-like"? Well, there's a big variety of tube sound but I'd say not so much, especially if you mean "warm". There is some warmth in the 50-100 Hz bass region but the overall balance isn't especially warm. Vs. the Monarchys, there is some prominence at the top of the midrange, but then again the Monarchys are a little reticent in that area.
    • "Smooth"? Yes! The device, at least to my old and feeble ears, is basically free of solid state "nasties": no grain, no etching, no glare, and more generally, no harshness. This I say with the reservation that the CDA won't likey gloss over the shortcomings of up or downstream equipment.
    • "Powerful, clear, quiet"? Definitely.
    • "Transparent"? Yes, big time! Excellent resolution and "air" far exceeding anything I've heard in the price range; (kicks the heck out of Adcoms and NADs I've heard). Furthermore, the equal of the Monarchys and perhaps even my earlier Bel Canto eVo2i.
    In my system a noticeable quality is excellent brass and percussion sound from things like bells and cymbals, including cymbals struck with steel brush -- I believe the best I've heard in this particular regard (-- does that make it "tube-like"?). Bass generally seems a bit more powerful and punchy than the Monarchys (which aren't bad either). Is this the slight additional bass warmth? And/or is it the extra power??

  13. #13
    Charm Thai™
    Join Date
    Feb 2002
    Location
    Cleveland, Ohio
    Posts
    865
    Wow that is so cool Feanor...great job!

    Weird question but does that PS Audio power cable fit snugly in whatever IEC receptacle you used?

  14. #14
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by shodulik
    Wow that is so cool Feanor...great job!

    Weird question but does that PS Audio power cable fit snugly in whatever IEC receptacle you used?
    Not so weird. It's bearly snug enough -- could be tighter or more positive. I don't like the excessive length of the PS Audio plugs either.

  15. #15
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,243
    Clean work Feanor. It looks great! Great review of how it sounds.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  16. #16
    It's just a hobby
    Join Date
    Oct 2004
    Location
    London, UK
    Posts
    808
    Feanor,

    Congrats on completing your first DIY electronics project,
    It's a listening test, you do not need to see it to listen to it!

  17. #17
    Music Junkie E-Stat's Avatar
    Join Date
    Dec 2003
    Posts
    5,462
    Quote Originally Posted by Feanor
    I've just comlete my first semi-DIY amplifier. It's working great!
    Really cool. That brings back fond memories of building Dyna kits when I was a teenager. The attenuator box I use with the main system is also DIY using components from DACT, Cardas, JPS Labs and Par-Metal.

    rw

  18. #18
    I put the Gee in Gear.... thekid's Avatar
    Join Date
    May 2005
    Location
    VB VA
    Posts
    2,307
    Quote Originally Posted by Feanor
    I like that suggestion!

    How about Feanor's device, (as designed by Tolkien)?

    We are probably enter geek territory but I think that device would actually look really cool. If not that device then a silver tree on one end and a gold tree on the other with the green background would look nice on your little "jewel". You could probably find an overlay at a craft store that you could use.

  19. #19
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by thekid
    We are probably enter geek territory but I think that device would actually look really cool. If not that device then a silver tree on one end and a gold tree on the other with the green background would look nice on your little "jewel". You could probably find an overlay at a craft store that you could use.
    By the way, the reason the exterior is green is that that was the only paint I had around and I was too cheap to go buy another color.

  20. #20
    Man of the People Forums Moderator bobsticks's Avatar
    Join Date
    Dec 2005
    Location
    down there
    Posts
    6,852
    Feanor, as a person that has ruined highschool shop projects I gotta tell ya I respect what yer doin'...further you're bringing me back to remembrances of my Grandfather who, in later life, took up model ship-building as hobby. The intricate workings and the detail are all very impressive.

    I hope that the project not only proves itself a worthy investment of time in compare and contrast but gives you a seperate and equal level of joy as those magniificent Monarchys that you have...

    Peace, Cheers, and thanks for sharing...

    M
    So, I broke into the palace
    With a sponge and a rusty spanner
    She said : "Eh, I know you, and you cannot sing"
    I said : "That's nothing - you should hear me play piano"

  21. #21
    Forum Regular harley .guy07's Avatar
    Join Date
    Aug 2009
    Location
    Springfield, Mo
    Posts
    1,594
    I love when a fellow audiophile puts their ability to work and even though its a kit this is an excellent example of the kind of things that can make this hobby fun. And I am glad it sounds good.

    Marantz SR5008(HT)
    Nu Force P8 Preamp (2 channel)
    Pass Labs X150.5(2 channel)
    Adcom 545 mk2 power amp(rear channel amp)
    Spatial Audio M3 Turbo S Mains Speakers
    Dayton 8" HO custom sealed subwoofer(2 channel)
    Yamaha NS-c444 center channel
    Emotiva ERD-1 surround speakers
    JBL e250p subwoofer highly modified
    Samsung 46" LED TV
    OPPO BDP-83 blue ray/multi format player
    ps-audio NuWave dac (2 channel)
    Dell I660 music server running fidelizer windows 8 audio optimizer
    PS Audio Quintet power center



  22. #22
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by bobsticks
    Feanor, as a person that has ruined highschool shop projects I gotta tell ya I respect what yer doin'...further you're bringing me back to remembrances of my Grandfather who, in later life, took up model ship-building as hobby. The intricate workings and the detail are all very impressive.

    I hope that the project not only proves itself a worthy investment of time in compare and contrast but gives you a seperate and equal level of joy as those magniificent Monarchys that you have...

    Peace, Cheers, and thanks for sharing...

    M
    Thanks, 'Sticks!

  23. #23
    Silence of the spam Site Moderator Geoffcin's Avatar
    Join Date
    May 2003
    Location
    NY
    Posts
    3,326
    Quote Originally Posted by harley .guy07
    I love when a fellow audiophile puts their ability to work.
    Say that twice!

    Back in the 'day, kits were nothing to sneeze at. From DYNACO to HeathKit, guys like Feanor were making quality gear back when the average guy could only get his hands on great gear if they made it themselves or sold their blood for cash. That same homemade gear STILL commands big bucks, and rightly so!
    Audio;
    Ming Da MC34-AB 75wpc
    PS Audio Classic 250. 500wpc into 4 ohms.
    PS Audio 4.5 preamp,
    Marantz 6170 TT Shure M97e cart.
    Arcam Alpha 9 CD.- 24 bit dCS Ring DAC.
    Magnepan 3.6r speakers Oak/black,

  24. #24
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127

    My complete review at AA

    Folks,

    I posted a complete review over at AA; here it is ...

    http://www.audioasylum.com/forums/am...15/157758.html

  25. #25
    I put the Gee in Gear.... thekid's Avatar
    Join Date
    May 2005
    Location
    VB VA
    Posts
    2,307
    Quote Originally Posted by Feanor
    Folks,

    I posted a complete review over at AA; here it is ...

    http://www.audioasylum.com/forums/am...15/157758.html
    Good read!!


Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •