In posting #398 http://www.diyaudio.com/forums/showthread.php?postid=1812547#post1812547 I showed you my small 707 DAC with Digitecs trannies in a small enclosure.
I lent this DAC to a friend to compare it to TDA based CD players.
His first feedback is this (translated freely by me from german language):
He will be surprized, when he can listen to the better solution, the upsampling DAC we are talking about here...
So for me this is the best prove, we are on the very good way:
With this DAC's and output trannies, we are able to reach the good sound of the best "old" 16 bit DAC solutions.
But we are also open for higher sample rates up to 24 bits.
Isn't this nice?
Recently, I downloaded some Beethoven recordings from lynnaudio, 96kHz/24 bit.
Mmmmh, very very nice!
And I am also changing my nearfield setup, as I converted my desk into a subwoofer baffle:
This picture is shot during construction, not finished. I am using an active lowpass filter and a bridged LM3886 amp to drive the sub.
Franz
I lent this DAC to a friend to compare it to TDA based CD players.
His first feedback is this (translated freely by me from german language):
He will be surprized, when he can listen to the better solution, the upsampling DAC we are talking about here...
So for me this is the best prove, we are on the very good way:
With this DAC's and output trannies, we are able to reach the good sound of the best "old" 16 bit DAC solutions.
But we are also open for higher sample rates up to 24 bits.
Isn't this nice?
Recently, I downloaded some Beethoven recordings from lynnaudio, 96kHz/24 bit.
Mmmmh, very very nice!
And I am also changing my nearfield setup, as I converted my desk into a subwoofer baffle:
An externally hosted image should be here but it was not working when we last tested it.
This picture is shot during construction, not finished. I am using an active lowpass filter and a bridged LM3886 amp to drive the sub.
Franz
Exactly this is the clue!
I cannot answer why (a layout question of the PCB), but it is like this!
Just download a phase testfile (for example http://persiconi.com/wrx/downloads/empegsound/sound5.htm) and listen to it, then you know the truth.
Franz
12ohm resistors added and phase inverted on left channel. Argh! 😱
It is not good at all Franz! Peter Gabriel is disappeared with the phase inverted! Before to switch phase on left channel the wall was singing and not the lodspeakers. With the phase inverted are the loadspeakers to singing. No, it's not good for me, so I'm gonna switch back the left channel. 🙂
It is not good at all Franz! Peter Gabriel is disappeared with the phase inverted! Before to switch phase on left channel the wall was singing and not the lodspeakers. With the phase inverted are the loadspeakers to singing. No, it's not good for me, so I'm gonna switch back the left channel. 🙂
Piero
Use the testfile and burn it on a CD. Easy to test: "My voice is now in phase positioned in the center between the speakers. My voice is now out of phase...".
I am sure, you have another phase error in your audio chain! If not, your DAC PCB must have a different layout.
Franz
Use the testfile and burn it on a CD. Easy to test: "My voice is now in phase positioned in the center between the speakers. My voice is now out of phase...".
I am sure, you have another phase error in your audio chain! If not, your DAC PCB must have a different layout.
Franz
Franz Gysi said:
Why this DAC with trannies sounded so damn weak? I borrowed from my friend Marantz CD10 and CD16, and later CD14. My DAC with Sowters mopped the floor with all of them. I'm very, very surprised that someone can't hear any difference between old and mediocre CD880 and this DAC.
Marantz CD10 is far better than Philips CD880, and why he heard no difference? Very, very strange
Burned the phase test and played: my dac probably have a different layout, becouse it's in phase. No need to invert phase on left channel as Franz's suggestion
Regarding phase there should be markings on the board: L+/L-/R+/R-.
On my DAC it's a 'mirror image' layout so the two +'s are together in the middle, with the -'s on the outside.
Cheers,
- John
On my DAC it's a 'mirror image' layout so the two +'s are together in the middle, with the -'s on the outside.
Cheers,
- John
Something I don't think that's been discussed yet - and apologies if it has - is 24/192 operation.
Has anyone managed to actually get this function to work yet? It's advertised as being a 24/192 DAC. Is it a 24/192 capable board / design though?
I've had success with 24/96 files, but haven't as-yet got a source capable of putting out a 24/192 signal - was wondering if anybody had done this?
Cheers,
- John
Has anyone managed to actually get this function to work yet? It's advertised as being a 24/192 DAC. Is it a 24/192 capable board / design though?
I've had success with 24/96 files, but haven't as-yet got a source capable of putting out a 24/192 signal - was wondering if anybody had done this?
Cheers,
- John
It seems there are 3 versions of this dac.
1. smd version
2. no usb/upsampling add-on
3. with usb/upsampling add-on.
Which is the recommended one?
Thank you for the reply
1. smd version
2. no usb/upsampling add-on
3. with usb/upsampling add-on.
Which is the recommended one?
Thank you for the reply
LL1690 diagram and capacitor
Same "0" missing in the LL1690 diagram I guess (or ajust with 100R)?
Maybe that's why Franz Gysi didn't like the sound with the wrong resistor/capacitor combination at the primary...
And for the capacitors:
I always choose carefully what I put in the signal path. But I'm not familiar with polystyrene and polypropylene of such small value. The RELCAP RTE caps are the only ones I heard from in that area.
Do someone have something to suggest? I'll probably get my LL1690 next week!
🙂
legarem said:
Same "0" missing in the LL1690 diagram I guess (or ajust with 100R)?
Maybe that's why Franz Gysi didn't like the sound with the wrong resistor/capacitor combination at the primary...
And for the capacitors:
I always choose carefully what I put in the signal path. But I'm not familiar with polystyrene and polypropylene of such small value. The RELCAP RTE caps are the only ones I heard from in that area.
Do someone have something to suggest? I'll probably get my LL1690 next week!
🙂
Hello
For my calculations, twice 1k in series with the trannie and 470pF (0.00047) is resulting in a LP corner frequency of about 680kHz.
I just calculated a simple low pass filter (1k/235pF), without the influence of the following impedance, the trannie itself. Does it shift the corner frequency?
Franz
For my calculations, twice 1k in series with the trannie and 470pF (0.00047) is resulting in a LP corner frequency of about 680kHz.
I just calculated a simple low pass filter (1k/235pF), without the influence of the following impedance, the trannie itself. Does it shift the corner frequency?
Franz
has anyone used the USB input? I searched AA and according to gordon (spelling?) rankin, the pcm2902 aren't the best of usb receivers.
thank you 🙂
thank you 🙂
piero7 said:
but no.2 (the one with upsampling add-on and no usb input) does upsampling as well (the ebay thread is title 24bits/192KHz)?
thanks again
With the complete one you have a chance more to decide if you like the oversampling sound or not.
Re: LL1690 diagram and capacitor
Cirrus use a 50 khz low pass filter on their own evaluation board so I tried this low pass filter with my dac and loved it. The tonal balance is better with the 50khz low pass frequency
Simply use two 100 ohms and a .015 uF cap and it gives a 53 khz low pass frequency.
crazyfrog said:
Cirrus use a 50 khz low pass filter on their own evaluation board so I tried this low pass filter with my dac and loved it. The tonal balance is better with the 50khz low pass frequency
Simply use two 100 ohms and a .015 uF cap and it gives a 53 khz low pass frequency.