tubee said:
I don't know.
My CD players never have been stable.
While the pots get adjusted there is no cover on the CD player and everything gets less warm.
Room temperature also is not always the same.
So IMHO everything should have as small drift as possible.
My DAC now seems to be stable but I have the pot only on one side because I fiddle canceling MSB error with combinations of chips.
But for the moment I try to figure what is the best sounding filter:
Passive LC, active GIC or transformer + RC.
tubee said:
yep, i've got a few of them (and seen the lot).
And to anyone reading this: all gone, none availalble.
Plan is to use it with four pcm63's and the pass i/v stage i have lying around. Got all the stuff, only a powersupply, clock and gluelogic required. And a nice pcb. Had enough of the 1541 for now, going to be busy with this for a while.
http://www.diyaudio.com/forums/showthread.php?threadid=69663
Post 17 & 21 has a bessel filter. No Gic btw
Bernard, you are experimenting with a 300//600 ohm transformer, where did you get it from?
And i must unfortunately admit here: I had TWO Philips line stepup transformers, sitting in a Mu metal housing with tube-like pins from a tube amp. I have demolisched 1 of them as study object, the other i still have. But what to do with one when i want stereo.....
Post 17 & 21 has a bessel filter. No Gic btw
Bernard, you are experimenting with a 300//600 ohm transformer, where did you get it from?
And i must unfortunately admit here: I had TWO Philips line stepup transformers, sitting in a Mu metal housing with tube-like pins from a tube amp. I have demolisched 1 of them as study object, the other i still have. But what to do with one when i want stereo.....
My friend did record a squarewave into a redbook CD on CD-ROM.QSerraTico_Tico said:
Much to my surprise the sqaurewave after playing on NON-OS DAC came out without any ringing.
So I don't understand how's it possible as one need a low-pass filter before the ADC.
He used an Onyx400 mixer and firewire cable to the PC.
I've placed the pcm56's next to the 8 logic chips. This time the R channel is completely silent and easy to adjust in MSB alignment on ear with headphones, with crickets noise on the first track of Roger waters, Amused to Death. Used a simple 100K pot, it is set around middle now, the previous 15 turn pot was at the end. So there was a small error in the PS of the R dac in previous circuit. Now the soundstage can be fully tested at last.
Wil swap some clocks now.
Wil swap some clocks now.
1 and a half year silent.
It plays:
It plays:
An externally hosted image should be here but it was not working when we last tested it.
Yes good observation Bernard.
It sounds rather good, some treble rol-off. It plays for a few days now
Filter:
It sounds rather good, some treble rol-off. It plays for a few days now
Filter:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Bernhard said:
Thanks Bernard for filter values.
I have listened to the bunch of pcb's yesterday all evening.
I am sure the better dampened cabinet is sounding some better as the plastic CD660 base, but little bit dull sometimes. (leaded MDF and acryllic sheet base, and leaded cdm2)
The first used AD844 stage had a lift in treble, wich annoyed me after some time. Now the treble has a rather obvious roll-off, and i miss some treble. Soundstage is not deep but wide. Each instrument can completely followed as isolated instrument, bass is some coloured but deep. Sound is some mellow or something, never sharp or harsch.
Treble @20k is about 3dB down i guess. I want to compensate the treble roll-off, have mailed to Pedja Rogic (thnx Pedja
)He advised me to re align my used filter to get a notch response. I will try your suggested steeper filter Bernard it sounds good to me.I have bought a simple C/L meter, nice tool for selecting caps and winding L's.
And yes Tico the ripple is coming back with steep filtering, see also:
http://www.pedjarogic.com/non_os/lpf.htm
http://www.pedjarogic.com/1541a/L-sinc.htm
tubee said:
Those values are not what I use ( my filter is much steeper ), just a quick and dirty modification of your schematic that compensates the treble roll-off and has the corner frequency @ 20 kHz.
The two 200 ohm resistors give the same 100 ohm for the I/V resistor as in your schematic.
Their values can not be changed as they are part of the filter.
You may use a switch to bypass the 3.3 mH to compare between compensated and uncompensated treble rolloff.
The 33 ohm need to be adjusted.
I will tell you how when you have built the filter.
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