Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Twisted Pear Audio Opus DAC
New Posts  All Forums:Forum Nav:

Twisted Pear Audio Opus DAC - Page 3

post #31 of 994
Thread Starter 
I did notice that the dac boards have regulators on board for both digital and analog supplies onboard, I am still curious though. My plan was to build the sigma22 and try it to see if theres a difference, and if there wasn't I would just change a few parts out to use for my future beta22. After reading some more I think I understand how it works a bit better now. I still have so much to learn
post #32 of 994
Quote:
Originally Posted by Nebby View Post
I did notice that the dac boards have regulators on board for both digital and analog supplies onboard, I am still curious though. My plan was to build the sigma22 and try it to see if theres a difference, and if there wasn't I would just change a few parts out to use for my future beta22. After reading some more I think I understand how it works a bit better now. I still have so much to learn
Not all is lost. Get the sigma22 for your future project and use the positive rail to power the analog supply of the dac and see if it makes a difference. If it does then you may want to upgrade to the sigma11's down the road. Just make sure the sigma22 is configured to supply 6-7volts for the dac (calculations are on the AMB website) to keep the onboard LDO regulator(s) from dissipating too much heat.

Renato
post #33 of 994
It's like a whole other language that I don't speak. Thank goodness you guys do!

Datos and dovetails I know!
post #34 of 994
Thread Starter 
No worries, I'm picking up a sigma11 or two for my squeezeboxes, so not all is lost either way
post #35 of 994
Thread Starter 
Quote:
Originally Posted by swt61 View Post
It's like a whole other language that I don't speak. Thank goodness you guys do!

Datos and dovetails I know!
I'm learning that language slowly yet surely too!
post #36 of 994
Quote:
Originally Posted by Nebby View Post
No worries, I'm picking up a sigma11 or two for my squeezeboxes, so not all is lost either way
Nate (n_maher) built some for squeezboxes. If i remember correctly there was a change to the configuration for 5Volts. I think it's in the sigma22 thread on headwize.

~R~
post #37 of 994
Quote:
Originally Posted by swt61 View Post
It's like a whole other language that I don't speak. Thank goodness you guys do!

Datos and dovetails I know!
Steve I feel ya! Ben had been helping me and I really have no idea what I am doing with this stuff. The Opus sounds trully amazing balanced through a speaker rig. I really don't care for it with headphones much but I can't wait to build one for the speakers! Thankfully he left it with me for a couple of weeks to play with.

I emailed Jeff at GlassJar and Ti about the Sigma 22 board. I'll probably use the Twisted Pear power supply to start until you guys perfect the Sigma 11 build and use a shielded transformer and a copper housing for now.

BTW, who else sells shielded transformers other than Avrel? Excuse me as I am a NOOB when it comes to this I have a strong desire to build this and fast
post #38 of 994
This is from Ti in response to the Sigma 11 boards being used for the Opus DAC.

" You can configure the sigma11s to output 7.5VDC by using the 9V configuration, except use BAX55C7V5 zener diodes for D5."
post #39 of 994
Thread Starter 
Quote:
Originally Posted by philodox View Post
The Zapfilter is just a high quality analog output stage.
I just noticed Twisted Pear has a line driver that would fit the bill as a line driver: http://www.twistedpearaudio.com/txd/txd.aspx I wonder how it would compare vs the zapfilter
post #40 of 994
Quote:
Originally Posted by looser101 View Post
Nate (n_maher) built some for squeezboxes. If i remember correctly there was a change to the configuration for 5Volts. I think it's in the sigma22 thread on headwize.

~R~
Yup, I've built 3 or 4 now. There is 5V specific information on amb's site now too.
post #41 of 994
Thread Starter 
Master of the Squeezebox Sigma you are, Nate
post #42 of 994
Ha! I'm sure it won't stay that way for long.

And I had quite the interesting visit with Brian from Twisted Pear yesterday. All I can say is keep your eyes on these guys. They've got some really cool stuff planned in the near future.
post #43 of 994
Just because there's been more than one voltage said to be optimal for the Opus power supply, let me quote directly from the Opus documentation.

"The Opus is designed to utilize separate analog and digital power supplies from 6.5V to 15V. They do not need to be regulated, but a good dual regulated supply like the LCPS is recommended. There are two on-board voltage regulators to provide power to the DAC. If you use the LCPS adjust both output voltages to 7.5 for good results. This will provide more than enough voltage drop for the on-board LDO VREGs while not making them dissipate more power than required."

Just a note about pre-regulators, which is what you guys are planning on using the Sigma 11 for. These things need not be so elaborate to get the DAC to operate well. Depending on what sound you're looking for, an even simpler regulator could give you better results. A less regulated supply using a simple pass transistor without any feedback could give you looser, fuller bass and more overall warmth. I tend to like these more for pre-regulator use, but that's just me.

On that note, I do like the circuit topology of the Sigma series regulators, which feature very good stability into various loads. But man, for the current that the Opus or two Opuses are going to be drawing, TOTALLY overkill But heck, going overkill is one of the advantages of DIY. Have fun guys.
post #44 of 994
Quote:
Originally Posted by n_maher View Post
They've got some really cool stuff planned in the near future.
Can you hint at all in what direction they're going? More amps, more steppers, more DACs?
post #45 of 994
Yeah, that was just evil to drop that hint and run!
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Twisted Pear Audio Opus DAC