Since this got bumped.....
any prognosis on Volumite firmware for the 8740 Opus boards? I'm slowly building initiative to try an arduino control system, but since I already have an empty volumite, firmware delivery would be easier 🙂
any prognosis on Volumite firmware for the 8740 Opus boards? I'm slowly building initiative to try an arduino control system, but since I already have an empty volumite, firmware delivery would be easier 🙂
dwk123 said:
I have the rough cut WM8740 code done. Brian and I are working to get it tested. 🙂 I finally have had some time to work on it now.
The WM8741 versions(Mono and Stereo) of the Volumite code are complete and tested.
I am very sorry for the delay with the Opus Volumite code.
Cheers!
Russ
Russ White said:
Cool - looking forward to it. This hasn't really been a delay yet, but it's getting close. I'm happy to go through some beta versions if you need testers for a single 8740 stereo setup.
Will the S/PDIF Receiver Module becoming available again sometime within the next few months? If not i'll just go ahead and buy the 4:1 receiver. Thanks
My OPUS project, and need of some advise
Some details here: http://hifiduino.blogspot.com/
Now that the DAC connects directly to Hypex ucd180 amps, the volume is plenty loud. Normal listening is in the ~ -50 dB. digital volume starts loosing data at below -48 dB for 16 bit content.
So I have a couple of choices: Use a TPA Ivy balanced output stage and reduce the gain or use a 50K-50K resistor divider (after the Ivy) to cut the gain in half (or more). Any advise as to which is "better"?
For higher volume listening, I can use the microcontroller to remove the voltage divider out of the signal path and can even change the gain resistors in the opamps. however, is it advisable to have relays control the gain resistors in an opamp?
Thanks in advance.
Some details here: http://hifiduino.blogspot.com/
Now that the DAC connects directly to Hypex ucd180 amps, the volume is plenty loud. Normal listening is in the ~ -50 dB. digital volume starts loosing data at below -48 dB for 16 bit content.
So I have a couple of choices: Use a TPA Ivy balanced output stage and reduce the gain or use a 50K-50K resistor divider (after the Ivy) to cut the gain in half (or more). Any advise as to which is "better"?
For higher volume listening, I can use the microcontroller to remove the voltage divider out of the signal path and can even change the gain resistors in the opamps. however, is it advisable to have relays control the gain resistors in an opamp?
Thanks in advance.
Re: My OPUS project, and need of some advise
Why is this? The 8741 is a 32-bit DAC... it's not clear how wide the datapath is, but it has to be at least 32-bits, no? So you'd have 32-16=16 bits of digital volume adjustment before you started to lose data. That gives you 96dB of clean volume adjustment.
How did you calculate the 48dB?
glt said:
Why is this? The 8741 is a 32-bit DAC... it's not clear how wide the datapath is, but it has to be at least 32-bits, no? So you'd have 32-16=16 bits of digital volume adjustment before you started to lose data. That gives you 96dB of clean volume adjustment.
How did you calculate the 48dB?
Re: Re: My OPUS project, and need of some advise
From reading off the discussion at PSAudio on the new Perfect Wave DAC which also has the same Wolfson DAC
Wodgy said:
From reading off the discussion at PSAudio on the new Perfect Wave DAC which also has the same Wolfson DAC
BrianDonegan said:
Thanks Brian, but want to keep the signal balanced all the way to the amp.
glt said:
I would suggest (again) 🙂 the IVY configured for a loss.
I would use something like 1K at the inputs and 392R at the feedback Rs. That should get you close you what you want. Adjust the feedback resistors if you want more or less gain. Increasing them will get you more, decreasing them less. You can go down to about 187R without fear.
That will be a nice low noise low distortion solution. Much better than a resistor divider.
Cheers!
Russ
Re: Re: Re: My OPUS project, and need of some advise
Thanks, I'll check it out. Though they must be referring to 24-bit input data (where you would only have 48dB of clean volume control). On Redbook you should have 96dB.
glt said:
Thanks, I'll check it out. Though they must be referring to 24-bit input data (where you would only have 48dB of clean volume control). On Redbook you should have 96dB.
Russ White said:
Russ, thanks (again) 🙂. Just reading the specs of the OPA and notice that best THD are at higher signal levels (not sure if input or output). Thus trying to explore the merits of lower gain in opamp or higher gain in opamp and resistor divider. OK, so one additional question: can I change the gain on the fly? by changing the resistor with a switch/relay?
Thanks.
glt said:
Not without compromising feedback loop with long routes. 🙂
Amplifiers in general will show better DNR with larger signals. 🙂
This why if I were you I would reduce the gain of your power amplifier. Leave the rest alone. 🙂
Russ White said:
Well, according to Hypex, the amps PSRR is proportional to the gain... and I'm using unregulated linear PS...
I think I'll stick to the gain of IVY, no surgery required...
Too bad modern recordings are so loud. The old CDs I have the "right" volume.
Thanks for all your help.
Using Headphone with IVY
Hi,
My Opus is setup as follow:
Opus dual mono --> IVY dual mono --> Ballsie for SE conversion
Question:
I would like to get a headphone output from the Ballsie, so I am going to tap the SE output from the Ballsie, going to a volume pot, then out to the headphone jack.
Do you think this arrangement would work fine to drive a headphone? If not, what is your suggestions for optimum setup?
Any recommendations to what value for the volume pot?
Thanks!
Hi,
My Opus is setup as follow:
Opus dual mono --> IVY dual mono --> Ballsie for SE conversion
Question:
I would like to get a headphone output from the Ballsie, so I am going to tap the SE output from the Ballsie, going to a volume pot, then out to the headphone jack.
Do you think this arrangement would work fine to drive a headphone? If not, what is your suggestions for optimum setup?
Any recommendations to what value for the volume pot?
Thanks!