here LL1592 and Jensen review
http://www.audioxpress.com/reviews/media/hansen2872.pdf
http://www.audioxpress.com/reviews/media/galo2872.pdf
http://www.audioxpress.com/reviews/media/hansen2872.pdf
http://www.audioxpress.com/reviews/media/galo2872.pdf
Bill Fuss
Excellent! Thanks!
I try to pick it up.
I agree 100%
Many of us have now the first balanced device at the beginning of our soundchain. A good start to have all balanced devices and interconnections later...
I agree, but I dont understand KISS. Could you explain please?
As far as I know, there is another difference. Lower Z trannies have less windings, therefore lower self-inductance.
Higher Z trannies, used mostly for tube equipment, have more windings and therefore higher self-inductance.
Regards
Franz
Excellent! Thanks!
I try to pick it up.
I agree 100%
Many of us have now the first balanced device at the beginning of our soundchain. A good start to have all balanced devices and interconnections later...
I agree, but I dont understand KISS. Could you explain please?
As far as I know, there is another difference. Lower Z trannies have less windings, therefore lower self-inductance.
Higher Z trannies, used mostly for tube equipment, have more windings and therefore higher self-inductance.
Regards
Franz
Re: work in progress
With all transformers I tried, the best resullts I got with 600 to 600 ohms transformers is when these transformers are loaded at their secondary with a resistor value near 600 ohms.
600 ohms can be considered as a really low load so i'm surprized that the sound becomes dead with low loads.
About my taste, simple cathode followers are the worst things that can be done to achieve good sound. it adds grunge to the sound. Current source cathode followers is the best way to go if you plan to try it.
McGyver said:
With all transformers I tried, the best resullts I got with 600 to 600 ohms transformers is when these transformers are loaded at their secondary with a resistor value near 600 ohms.
600 ohms can be considered as a really low load so i'm surprized that the sound becomes dead with low loads.
About my taste, simple cathode followers are the worst things that can be done to achieve good sound. it adds grunge to the sound. Current source cathode followers is the best way to go if you plan to try it.
I looked at the Cirrus specs and they recommend a low pass filter of 50 khz with the CS4398. I tried it and found that the tonal balance is better to my ears with this value of low pass filter.
Notably, the little Studers Franz sold me seems to play correctly with this cut off frequency. (They easily go over 100 khz)
These 50 khz low pass filters are probably not only there to filter RF but they also give right tonality to this dac.
Someone mentionned here that the UTC A-20 had a bright sound with the dac. The 50 khz filter could probably tame the sound correctly.
I should receive soon a pair of UTC HA-108 so more on that later.
Notably, the little Studers Franz sold me seems to play correctly with this cut off frequency. (They easily go over 100 khz)
These 50 khz low pass filters are probably not only there to filter RF but they also give right tonality to this dac.
Someone mentionned here that the UTC A-20 had a bright sound with the dac. The 50 khz filter could probably tame the sound correctly.
I should receive soon a pair of UTC HA-108 so more on that later.
Re: Re: work in progress
There is a lot more such players on my homepage. Take a look: http://www.audiosurgery.beepworld.pl/odtwarzaczecd.htm
No, it is ten years old cheapest Onkyo, DX7211.
Look here:
Regards
I don't know why it happens, but it happens. I hear it very clearly.
Thanks, I will try if I will have enough time.
Franz Gysi said:
There is a lot more such players on my homepage. Take a look: http://www.audiosurgery.beepworld.pl/odtwarzaczecd.htm
Franz Gysi said:
No, it is ten years old cheapest Onkyo, DX7211.
Franz Gysi said:
Look here:
Franz Gysi said:
Regards
legarem said:
I don't know why it happens, but it happens. I hear it very clearly.
legarem said:
Thanks, I will try if I will have enough time.
Bill Fuss said:The CS439x dacs are differential output, meaning they have plus and minus out. No ground connections are needed, they do not need a ground reference. Transformers are differential input and output, they also do not need a ground reference.
That explains my good results after snipping the grounds. Thank you for explaining it!
I don't mean to start an argument but the load the chip sees starts at 0 hz, which is DC. At 0hz the chip sees a load of the series resistors plus the DC resistance of the primary winding which is 60 ohms or less, so in my way of thinking you are overloading the chip at very low frequencies. The load presented will at some point regain some value of the rated impedance with increasing signal frequency and decrease the perceived load that the dac chip sees, but it wont be like flipping a switch from DC to AC, it will definately be at least in the bottom octave of the possible signal.
That's my two cents.
Best, Bill
That's my two cents.
Best, Bill
Bill Fuss said:Here is what I have learned from my research and experience.
The CS439x dacs are differential output, meaning they have plus and minus out. No ground connections are needed, they do not need a ground reference.
Transformers are differential input and output, they also do not need a ground reference.
Amplifiers using RCA inputs use the shield lug to reference the signal to the amp circuit ground to provide a return path for the signal.
Amps using balanced XLR inputs do not need a ground reference, the shield is used only for shielding and is not in the signal path.
You can feed a transformer output to either type with the two secondary wires only, RCA- one to center and one to shield lug, XLR- one to pin two and one to pin three- pin one is the shield ground.
The old adage applies, KISS. You do not need or want to connect anything to ground on the dac board or to the chassis ground.
Thanks for the information Bill. Just to clarify one of your points, are you saying that the secondaries can be connected to a RCA outputs that are isolated from the chassis? Or, are you saying that the RCA should be connected to a grounded chassis to allow a return path?
As a side note, I have used the Tamaura transformers with 1K resistors and 470pf caps. Unfortunately, the sound is a bit too harsh for my taste, and the DAC seems to drop out a bit. I have some 680ohm BA resistors. I will try them with a 2200pf cap for a LPF set at 53KHz.
legarem said:
Let's just say that doing so would eliminate the possibility of damage to the chip and allow the chip to supply the bass response that it is capable of.
The trade off is you will sacrifice some signal level. I used the suggested Jensen value of 250 ohms as a compromise. I'm going to increase them to 330 the next time I have it open to see what effect that will have, probably not much.
Best, Bill
fordgtlover said:
The secondary winding will be referenced to ground inside your preamp through your interconnects. The preamp needs this to operate, the transformer doesn't care. It will supply a plus and minus signal at its outputs for any use you can imagine. Do not ground any signal wiring inside the DAC chassis, it is not needed or wanted.
From the research I've done, 95% of audio transformers have a frequency response that rises with frequency up into the ultrasonic range, so using a filter circuit on the secondaries is pretty much mandatory. I could see it easily with my scope and signal generator, and it was not subtle either.
Best, Bill
Power Tranny
I have tried my new 50VA EI power transformer. It seems to make the sound less smooth, with harsher mids and less bass, than the toroidal that came with the DAC. Even when it is warmed up
I did notice that it is giving 10.6V a.c., not the rated 9V, so could this be causing a problem? My mains electricity reads correctly at 240V. I would be grateful if someone could have a quick look at my connections (image attached).
Thanks
legarem said:
I have tried my new 50VA EI power transformer. It seems to make the sound less smooth, with harsher mids and less bass, than the toroidal that came with the DAC. Even when it is warmed up
I did notice that it is giving 10.6V a.c., not the rated 9V, so could this be causing a problem? My mains electricity reads correctly at 240V. I would be grateful if someone could have a quick look at my connections (image attached).
Thanks
