R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2  All   Go Down

Author Topic: The Seventy Nine Dollar Converter  (Read 21363 times)

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
The Seventy Nine Dollar Converter
« on: September 19, 2008, 11:24:55 am »

Here's a nice low budget DAC;

MCM Electronics P/N # 50-7774

www.mcmelectronics.com

It's a 24 bit 96k dac with 2 coax and 2 toslink inputs, a fixed and variable output and a headphone amp. It uses a nice BurrBrown PCM1716 dac chip with a crystal CS8414 input reciever chip. The caps are all 105 degree rated. The weak spot is the 4558 opamp, I replaced it with a National LME49722MA, a very nice improvement.

It's on sale until Oct. 18 for $79.95. Use the source code 808A28 for the discount.
Logged
Jim Williams
Audio Upgrades

hargerst

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1458
Re: The Seventy Nine Dollar Converter
« Reply #1 on: September 19, 2008, 11:35:13 am »

Looks nice, Jim.  Do they have a cheap (but good) A to D converter?
Logged
Harvey "Is that the right note?" Gerst
Indian Trail Recording Studio

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: The Seventy Nine Dollar Converter
« Reply #2 on: September 20, 2008, 12:02:11 pm »

No budget A/D from them but another source is available for that.
BurrBrown makes a very nice A/D evaluation pcb for the PCM4222 A/D converter, their top-o-line chip. It's the PCM4222EVM.
Get one direct from TI at:
www.TI.com
Search the PCM4222EVM and it comes up. It costs $149 and requires a power supply with + - 15 volts and a single 5 volt rail. Power One/Condor makes a nice small 3 output power supply that runs around $70. You can get that from digi-key.
This converter has bested some very expensive products in the $5k price zone, so it's a serious contender. It has DSD outputs, dual s/pdif and AES outputs, digital filters, etc. all selectable via dip switches.
Logged
Jim Williams
Audio Upgrades

elie

  • Newbie
  • *
  • Offline Offline
  • Posts: 9
Re: The Seventy Nine Dollar Converter
« Reply #3 on: September 21, 2008, 11:59:42 am »

Hi Jim!  In which context do you use the DAC?  In your point of view, how does it perform compared to more expensive units?  

About the TI ACD: I've been considering getting one of these for a while...  Would you care to explain exactly what kind of work should I expect to have it boxed and running?  How much soldering, wiring, etc?  

Thanks for the good info!

E
Logged

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: The Seventy Nine Dollar Converter
« Reply #4 on: September 21, 2008, 12:48:26 pm »

I have the Seventy Nine Dollar Converter wired up with multiple sources like the soundcard out, the DAT, the CD player. That feeds the 2 track return of the console for monitoring. I have better stuff here for tracking/mixing like BB PCM1704, 1792, etc, but this is convienient as I just pop the switch and listen though the console or headphones. I like this DAC better than the top-o-line Crystal CS4398, their top-o-line part. The imaging is good on this BB part.

The PCM4222EVM needs a power supply, that's it. Everything else is mounted, balanced XLR/TRS inputs, dual s/pdif and AES outputs. Add + and - 15 volts and + 5 volts and it's ready to go. A better value will not be found.
Logged
Jim Williams
Audio Upgrades

elie

  • Newbie
  • *
  • Offline Offline
  • Posts: 9
Re: The Seventy Nine Dollar Converter
« Reply #5 on: September 21, 2008, 01:26:21 pm »

Thanks for the info!

What do you say is your favourite dac for mixing?  Is there a good dac eval kit which you'd recommend?  

It seems like a great value indeed!
Logged

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: The Seventy Nine Dollar Converter
« Reply #6 on: September 22, 2008, 10:59:24 am »

My favorite dac at the moment is the BurrBrown PCM1792. I have a BB lab pcb of that and the PCM1704. They are fitted with direct coupled class A TI THS high speed opamps and some nice resistors, caps. BB doesn't offer these boards anymore, besides they used to cost $900.

Cheapy A/D's are a bit harder to find. The BB PCM4222 EVM is the best value at $149 sans power supply.
www.TI.com
Logged
Jim Williams
Audio Upgrades

marcel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1257
Re: The Seventy Nine Dollar Converter
« Reply #7 on: September 22, 2008, 12:45:11 pm »

Jim:

Is the National op-amp a direct replacement?

Thanks.
Logged
Best, Marcel

Rod Affleck

  • Full Member
  • ***
  • Offline Offline
  • Posts: 246
Re: The Seventy Nine Dollar Converter
« Reply #8 on: September 22, 2008, 02:19:53 pm »

Jim Williams wrote on Sun, 21 September 2008 13:48


The PCM4222EVM needs a power supply, that's it. Everything else is mounted, balanced XLR/TRS inputs, dual s/pdif and AES outputs. Add + and - 15 volts and + 5 volts and it's ready to go. A better value will not be found.


Okay this sounds exactly like what I need right now, except for one concern--if I output the s/pdif from this into the s/pdif input on my Motu 828, am I going to see any gain in a/d conversion quality through this unit, or is everything going to be limited by the Motu? I obviously have no idea how s/pdif works.

Moderators, since this is getting off topic if you want to split this into a separate thread that's fine.
Logged
Rod Affleck

brett

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1114
Re: The Seventy Nine Dollar Converter
« Reply #9 on: September 22, 2008, 07:13:19 pm »

evil robot wrote on Mon, 22 September 2008 19:19

Jim Williams wrote on Sun, 21 September 2008 13:48


The PCM4222EVM needs a power supply, that's it. Everything else is mounted, balanced XLR/TRS inputs, dual s/pdif and AES outputs. Add + and - 15 volts and + 5 volts and it's ready to go. A better value will not be found.


Okay this sounds exactly like what I need right now, except for one concern--if I output the s/pdif from this into the s/pdif input on my Motu 828, am I going to see any gain in a/d conversion quality through this unit, or is everything going to be limited by the Motu? I obviously have no idea how s/pdif works.

Moderators, since this is getting off topic if you want to split this into a separate thread that's fine.



it's $79. do you really beleive this will improve your sound by any measurable amount regardless of what you read on a forum?  
Logged

Tomas Danko

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4733
Re: The Seventy Nine Dollar Converter
« Reply #10 on: September 23, 2008, 03:42:44 am »

brett wrote on Tue, 23 September 2008 00:13

evil robot wrote on Mon, 22 September 2008 19:19

Jim Williams wrote on Sun, 21 September 2008 13:48


The PCM4222EVM needs a power supply, that's it. Everything else is mounted, balanced XLR/TRS inputs, dual s/pdif and AES outputs. Add + and - 15 volts and + 5 volts and it's ready to go. A better value will not be found.


Okay this sounds exactly like what I need right now, except for one concern--if I output the s/pdif from this into the s/pdif input on my Motu 828, am I going to see any gain in a/d conversion quality through this unit, or is everything going to be limited by the Motu? I obviously have no idea how s/pdif works.

Moderators, since this is getting off topic if you want to split this into a separate thread that's fine.



it's $79. do you really beleive this will improve your sound by any measurable amount regardless of what you read on a forum?  



I wonder what the pricetag would be if a known company boxed it up, put their brand name on it and did some marketing... Let alone making an 8-in 8-out interface like that.

That's really the price range one should compare it to. I wouldn't be surprised if it sounded better than the Motu 828. Imagine the cost of that Motu if they had put a bunch of these boards in there (since it's a multi I/O converter). Most definitely the analog back end of the Motu DAC is not as solid as the National opamp Jim uses instead of the 4558. Otherwise companies such as Black Lion Audio wouldn't bother modding Motu's.
Logged
http://www.danko.se/site-design/dankologo4s.gif
"T(Z)= (n1+n2*Z^-1+n2*Z^-2)/(1+d1*z^-1+d2*z^-2)" - Mr. Dan Lavry
"Shaw baa laa raaw, sidle' yaa doot in dee splaa" . Mr Shooby Taylor

Rod Affleck

  • Full Member
  • ***
  • Offline Offline
  • Posts: 246
Re: The Seventy Nine Dollar Converter
« Reply #11 on: September 23, 2008, 07:12:01 am »

That's my thinking precisely. (Also for the record I was inquiring about the Texas Instruments evaluation module a/d converter which is $149.) While I'd love to have a good-to-great 8 or 16 in converter like an Apogee or Lynx or whatever even fancier name you want to insert here, realistically if I can add two good channels to my existing mediocre eight channels for $300 or so (once power supply and case are factored in) then I'd be extremely happy.
Logged
Rod Affleck

Tomas Danko

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4733
Re: The Seventy Nine Dollar Converter
« Reply #12 on: September 23, 2008, 07:23:15 am »

Ah yes, it was the A/D converter you meant. Well, the MOTU interface can be transparent when hooking the TI A/D into S/P DIF no worries.
Logged
http://www.danko.se/site-design/dankologo4s.gif
"T(Z)= (n1+n2*Z^-1+n2*Z^-2)/(1+d1*z^-1+d2*z^-2)" - Mr. Dan Lavry
"Shaw baa laa raaw, sidle' yaa doot in dee splaa" . Mr Shooby Taylor

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: The Seventy Nine Dollar Converter
« Reply #13 on: September 23, 2008, 10:48:17 am »

marcel wrote on Mon, 22 September 2008 09:45

Jim:

Is the National op-amp a direct replacement?

Thanks.


Yes it is. Just snip off the leads of the 4558 with fine tipped cutters and use a solder iron to melt away the remaining pins off the pads. Remove excess solder remaining. Solder on the new part. Other parts also may work well but since it's surface mount I don't have a socket to play with so I selected the best part that wouldn't cause problems.
The LME49722MA is available direct from National, it's too new to be found at Digi Key.
Logged
Jim Williams
Audio Upgrades

hargerst

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1458
Re: The Seventy Nine Dollar Converter
« Reply #14 on: September 23, 2008, 01:27:32 pm »

evil robot wrote on Mon, 22 September 2008 13:19

Moderators, since this is getting off topic, if you want to split this into a separate thread, that's fine.

Since the original topic was basically about a low cost D/A converter, I don't see that this new discussion about a low cost A\D converter is way "off topic".

Kinda like two sides of the same coin.


Logged
Harvey "Is that the right note?" Gerst
Indian Trail Recording Studio
Pages: [1] 2  All   Go Up