I was mostly pointing out that I would rather have an active IV, which may or may not include a filter in its design and use this filter/buffer to provide that function vs the option of using this filter/buffer directly on the output pins of the DAC. I agree the complexity is unnecessary in many cases and that modifying the filter in the IV makes more sense. But, it is still a valid option that could be tried.
I was mostly pointing out that the additional THD/Noise/complexity of the extra filter/buffer IMO is still a better option that trying to drive this filter/buffer with current out DAC...
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Do you have any idea what the THD or noise is for this passive filter and the cascode source follower circuit in the audio band ?
We don't.
We cannot measure anything with a HP339, so we have to send one to the States to measure down to -120dB.
And those who actually built the circuit seemed to agree it is worth the additional THD & noise, whatever it is :
http://www.diyaudio.com/forums/grou...rhard-filter-buffer-es9022-7.html#post3297584
Patrick
We don't.
We cannot measure anything with a HP339, so we have to send one to the States to measure down to -120dB.
And those who actually built the circuit seemed to agree it is worth the additional THD & noise, whatever it is :
http://www.diyaudio.com/forums/grou...rhard-filter-buffer-es9022-7.html#post3297584
Patrick
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Patrick, its not a miracle filter, it adds THD, no matter how little.
There is no need to get defensive, I did not at any point criticize the circuit, I think for its purpose its very good indeed, but its IMO superfluous to add after an IV, which should already include a filter. it also adds expense, another set of power supplies etc etc, which are all IMO a waste and add complexity to what should be a pretty simple and for my taste minimal circuit. In fact it would seem against your very own ethos to add complexity where its not called for.
There is no need to get defensive, I did not at any point criticize the circuit, I think for its purpose its very good indeed, but its IMO superfluous to add after an IV, which should already include a filter. it also adds expense, another set of power supplies etc etc, which are all IMO a waste and add complexity to what should be a pretty simple and for my taste minimal circuit. In fact it would seem against your very own ethos to add complexity where its not called for.
Quite agree, best to keep things passive
...and if you are driving a high impedance stage like headphone amps or short interconnect cables to other buffer/amps you can do away with the on-board FET buffer.
i'm quite amazed at the lack of understanding here, I thought I was pretty clear I was not talking about the es9023, we never have been. we have been talking about adding or modifying an existing filter as part of an IV stage, instead of adding an entire second board and more power supplies just to add a passive filter.
My assertion was simply that any decent IV stage worth its salt should optionally include the filter, which you can populate or not. that filter could if you so desire, be exactly as the passive filter here... adding an entire second board with its own power supplies and a further buffer WILL add noise and distortion in the pass-band, it may/will attenuate that outside of the pass-band if there is anything there, thats its job, but its no different to what can be done as part of the basic IV design.
myself I leave it unpopulated on mine now, but the option is there if I wish to play with it again; perhaps when I can reliably measure less than -115dB THD+N.
it was shown, with the type of measurement gear you dont have yourself Patrick, to be of no real (worthwhile) benefit in the case of the NTD1, as performance was already at the boundaries of the audio precision system 2 (well not quite, but you know what I mean).
adding a further buffer and filter after such a design, no matter how good it is (and as ive said, this is obviously VERY good) will lower performance, perhaps you may tune it subjectively to taste, but adding negative noise and negative distortion in the pass band is impossible, by adding active and passive parts in series with the output
My assertion was simply that any decent IV stage worth its salt should optionally include the filter, which you can populate or not. that filter could if you so desire, be exactly as the passive filter here... adding an entire second board with its own power supplies and a further buffer WILL add noise and distortion in the pass-band, it may/will attenuate that outside of the pass-band if there is anything there, thats its job, but its no different to what can be done as part of the basic IV design.
myself I leave it unpopulated on mine now, but the option is there if I wish to play with it again; perhaps when I can reliably measure less than -115dB THD+N.
it was shown, with the type of measurement gear you dont have yourself Patrick, to be of no real (worthwhile) benefit in the case of the NTD1, as performance was already at the boundaries of the audio precision system 2 (well not quite, but you know what I mean).
adding a further buffer and filter after such a design, no matter how good it is (and as ive said, this is obviously VERY good) will lower performance, perhaps you may tune it subjectively to taste, but adding negative noise and negative distortion in the pass band is impossible, by adding active and passive parts in series with the output
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And of course you also know what equipment the xen team has.
And you have listened to Joachim's buffer or a similar circuit and concluded that it is not worth the trouble.
If so, I have no problems.
You are of course entitled to your opinion. This is an open forum.
I am also entitled to mine.
And I think Joachim has given us a worthwhile addition which I also use for the likes of PCM5102 and AK4430.
Cheers,
Patrick
And you have listened to Joachim's buffer or a similar circuit and concluded that it is not worth the trouble.
If so, I have no problems.
You are of course entitled to your opinion. This is an open forum.
I am also entitled to mine.
And I think Joachim has given us a worthwhile addition which I also use for the likes of PCM5102 and AK4430.
Cheers,
Patrick
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''And I think Joachim has given us a worthwhile addition which I also use for the likes of PCM5102 and AK4430.''
And that's exactly what I have in mind for my second filter buffer.
In my opinion the 9023 and PCM5102 struggle a little driving high capacitive loads (yes I’ve found them both to be very cable sensitive).
That’s why I’ve used other buffers in the past with both of these DACs.
The buffer seems to sort that out quite nicely along with the other benefits I’ve mentioned in previous posts that the filter brings.
Others may have a different take but that’s DIY.
With my 9023 Joachim's filter buffer sounds great
in my system and to my ears.
I’m looking forward to trying the filter buffer with my DIY PCM5102.
And that's exactly what I have in mind for my second filter buffer.
In my opinion the 9023 and PCM5102 struggle a little driving high capacitive loads (yes I’ve found them both to be very cable sensitive).
That’s why I’ve used other buffers in the past with both of these DACs.
The buffer seems to sort that out quite nicely along with the other benefits I’ve mentioned in previous posts that the filter brings.
Others may have a different take but that’s DIY.
With my 9023 Joachim's filter buffer sounds great
in my system and to my ears. I’m looking forward to trying the filter buffer with my DIY PCM5102.
Yeap, once you get the hang of it you can work really really fast.
E.g.:
SMD löten lernen (0805+0603) - YouTube
As I've said before, I actually find it faster (and more fun) than working with through hole components.
Also, in tight layouts and if temperature is too high (or you don't move fast enough) you'll have solder re-flowing in neighboring pads; which is never a good idea because parts near the one you're working on will start moving!
The only thing you can never really practice enough is trying to find an 0402 or 0603 component that you drop on the floor...
I actually lost one of the caps (or was it a resistor?) when I was soldering this filter board! Good idea to include a spare one in the kits..!
E.g.:
SMD löten lernen (0805+0603) - YouTube
As I've said before, I actually find it faster (and more fun) than working with through hole components.
Also, in tight layouts and if temperature is too high (or you don't move fast enough) you'll have solder re-flowing in neighboring pads; which is never a good idea because parts near the one you're working on will start moving!
The only thing you can never really practice enough is trying to find an 0402 or 0603 component that you drop on the floor...
I actually lost one of the caps (or was it a resistor?) when I was soldering this filter board! Good idea to include a spare one in the kits..!
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I have to agree - I find I prefer SMD work these days. I'm 55 and requires a good 5x viewing glass, but I find it more enjoyable. I think part of it is seeing my technique improve as I do it. I added a reflow oven to my bench awhile back, but I still prefer to lay components down by hand. I find it relaxing.
Hi All
OK I know that most of you guys here are old hands at SMD work but I’m still pretty new to it all.
Others may be also
Here is what I usually do.
Tools
Adjustable temp soldering iron. (Set for around 300deg C)
Good quality low melt solder (I use Cardas as it’s nice to work with)
10x magnifying loop
A pair of fine pointed nose tweezers
A flux pen
An old aerosol lid in white preferably. (Stops SMD’s disappearing into thin air)
A sheet of white paper.
I use a board clamp but I’m sure that a couple of blobs of blue tack or such like will stop the board from skidding around.
1) Select the SMD component to be soldered and drop it into the aerosol lid.
2) Solder one of the pads for the SMD on the board
3) Take out the SMD from the lid and put it onto the white paper with the tweezers.
4) Apply flux to the end of the SMD to be soldered to the pre soldered pad.
5) Grab the SMD with the tweezers and place it flux side to the pre soldered pad
6) Quickly apply heat to the pre soldered pad and device once you have it correctly aligned.
7) Check the joint with the loop
8) If happy solder the other end of the SMD and check both joints with the loop.
With resistors I usually check for continuity with a Multimeter from the pad before to the pad after.
Remember to take as much time as needed
The only thing that should be quick is your work with the iron.
I’m new to all of this stuff but I was lucky enough to have help getting started but if I’ve got it wrong or missed something please chip in as your experiences may help others.
Good luck
OK I know that most of you guys here are old hands at SMD work but I’m still pretty new to it all.
Others may be also
Here is what I usually do.
Tools
Adjustable temp soldering iron. (Set for around 300deg C)
Good quality low melt solder (I use Cardas as it’s nice to work with)
10x magnifying loop
A pair of fine pointed nose tweezers
A flux pen
An old aerosol lid in white preferably. (Stops SMD’s disappearing into thin air)
A sheet of white paper.
I use a board clamp but I’m sure that a couple of blobs of blue tack or such like will stop the board from skidding around.
1) Select the SMD component to be soldered and drop it into the aerosol lid.
2) Solder one of the pads for the SMD on the board
3) Take out the SMD from the lid and put it onto the white paper with the tweezers.
4) Apply flux to the end of the SMD to be soldered to the pre soldered pad.
5) Grab the SMD with the tweezers and place it flux side to the pre soldered pad
6) Quickly apply heat to the pre soldered pad and device once you have it correctly aligned.
7) Check the joint with the loop
8) If happy solder the other end of the SMD and check both joints with the loop.
With resistors I usually check for continuity with a Multimeter from the pad before to the pad after.
Remember to take as much time as needed
The only thing that should be quick is your work with the iron.
I’m new to all of this stuff but I was lucky enough to have help getting started but if I’ve got it wrong or missed something please chip in as your experiences may help others.
Good luck
mmm. I soldered up my boards, fried one of the 150pF caps in the process. That was replaced, and it measures OK. But there is something wrong, I get distorted sound on one channel and almost nothing on the other. If I plug out the distorted channel, I get sound on the silent one.
I made a boo-boo somewhere....
EUVL - I am using your dac. Ground and signals are going from the outputs on your dac straight to the JG filter (what would have gone to the rca jacks). Power is +/-12V supply from a Salas shunt. Dac on its own is perfect, so its deinfitely something in how I have assembled/wired the filter.
Fran
I made a boo-boo somewhere....
EUVL - I am using your dac. Ground and signals are going from the outputs on your dac straight to the JG filter (what would have gone to the rca jacks). Power is +/-12V supply from a Salas shunt. Dac on its own is perfect, so its deinfitely something in how I have assembled/wired the filter.
Fran
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Sounds like you swapped the Gnd and the input signal wires to the filter, or shorted them somehow on the PCB.
Suggest you do the following :
Use a functions generator (or sound card output) to supply a 1kHz Sine wave to the filter, one channel at a time.
Use an oscilloscope to see the waveform.
This will at least tell you which channel has gone wrong, and why.
So simple circuit !!!!!!!!!
Patrick
Suggest you do the following :
Use a functions generator (or sound card output) to supply a 1kHz Sine wave to the filter, one channel at a time.
Use an oscilloscope to see the waveform.
This will at least tell you which channel has gone wrong, and why.
So simple circuit !!!!!!!!!
Patrick
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Err, em. Fess up time. I had gnd and + output wrong way round on one channel. That was the reason for sound on one side only. Distortion was because I had set the shunt incorrectly and Vs was low. Easy to make such silly mistakes late at night under pressure.
Sound: more 3d soundstage, more detail and reality to the sound of each instrument. It doesn't jump out at you, but when you switch back and forth its apparent.
+1 for the design team!
Fran
Sound: more 3d soundstage, more detail and reality to the sound of each instrument. It doesn't jump out at you, but when you switch back and forth its apparent.
+1 for the design team!
Fran
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