Because I already have SLFs binned in various inductances I was able to simplify the prototype not to need the 22uHs. Next step is modifying the I/V resistor of the DAC and then.... listening
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I get no satisfaction using a ready made product (call me a masochist)
When ferrite cores arrive, I will try the intentional air gap
George
PS. The aspirin trick works, thanks (an outdoors activity)
Thanks for a feedback. I picked up some resources, I think it will also help @abraxalito, if not now, then in the later stage.
This one is for EI core, but interesting, as I thought that it would be sufficient to remove material layer from the centre: Building Your Own Audio Frequency Choke Coils, October 1932 Radio-Craft - RF Cafe
This one is focusing on the optimum air gap (from a Brooks perspective): Air gapped magnetic cores
Forum discussion on air gaps. I also picked up a screenshot from the John Birckhead post: design - Why do we want gap in the core material while designing inductor? - Electrical Engineering Stack Exchange
A Google link to the most recent publication, there is a lot on air gaps:
https://www.ieee.li/pdf/viewgraphs/fundamentals_magnetics_design.pdf
The most of resources focus on tubes (of course), like this part on filters, but it is very comprehensive guide when looking form the index page: audiofilterchokes
A link to the TDK catalogue you posted before is also nice. It seems that distributed airgap is the best from a leakage perspective, but I didn't check prices.
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Thanks for the links.
Well, I can’t diy distributed air gaps
https://www.tdk-electronics.tdk.com...7082863776922b6e0d52/ferrites-air-gaps-pb.pdf
I will experiment with the single one (after finishing the painting of my house walls. I can't escape from my wife's choke arm wrap).
George
Well, I can’t diy distributed air gaps
https://www.tdk-electronics.tdk.com...7082863776922b6e0d52/ferrites-air-gaps-pb.pdf
I will experiment with the single one (after finishing the painting of my house walls. I can't escape from my wife's choke arm wrap).
George
Whether the filter can be used will depend on the output impedance of the 'noDAC'. Its designed to be used with current source output DACs (high output impedance). It can work without much degradation down to 1kohm (the output impedance of PCM1704). Below that I've not explored. Aren't most 'noDAC's based on logic chips? Their output impedance is likely going to be low - below 100ohm.
@abraxalito
What about these inductors: Finest Audio Inductors
Could be custom: Custom Audio Inductors
The RM8 core seems the more interesting, custom:
Max-Pins: 8 (incl. Pin0)
Max-Values: 7 custom windings/values are possible. Pin0 is always 0mH.
Max-mH: max 2000mH
Inductor Tolerance: < 3%.
Tolerance deviation for multitaps with low self resistance: Measured 100mH=2% and 20mH=5% depending on requirements.
Within an order of more than 10pcs we do a measuring in between and optimize the tolerance to < 2%.
Also possible add copper shielding-set for +4,90€
What about these inductors: Finest Audio Inductors
Could be custom: Custom Audio Inductors
The RM8 core seems the more interesting, custom:
Max-Pins: 8 (incl. Pin0)
Max-Values: 7 custom windings/values are possible. Pin0 is always 0mH.
Max-mH: max 2000mH
Inductor Tolerance: < 3%.
Tolerance deviation for multitaps with low self resistance: Measured 100mH=2% and 20mH=5% depending on requirements.
Within an order of more than 10pcs we do a measuring in between and optimize the tolerance to < 2%.
Also possible add copper shielding-set for +4,90€
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They look good for those who need a European source - over here I can get all that capability at a significantly lower price - though probably I'd need to order larger volumes than at Don Audio. My filter inductors are considerably lower values than their standard ones which are for EQ sections in mixing consoles.
Phidac pdf
Hello, Is it possible to get a pdf copy of this dac to make own pcb.
Regards
Hello, Is it possible to get a pdf copy of this dac to make own pcb.
Regards
PhiDAC SE gerber files
Here you go - data for the main DAC PCB plus the capacitor 'pants'.
For the sake of completeness, the PhiDAC SE BOM and schematic are here : lingDAC - cost effective RBCD multibit DAC design
Here you go - data for the main DAC PCB plus the capacitor 'pants'.
For the sake of completeness, the PhiDAC SE BOM and schematic are here : lingDAC - cost effective RBCD multibit DAC design
XO freq for the Ling
As far as the "ideal" XO freq for the Ling, what might that be? I recall some info at diyparadise noting that for the TDA1545-based Monica DAC, the asynch. reclocker was using an 80.000 Mhz. The owner of that website claimed higher XO freqs. were better.
Dunno.... I see many 4x or 8x TDA1387 Chinese DACs using either 12.000 or 50.000 Mhz. Not sure why THOSE two freqs are used.
As far as the "ideal" XO freq for the Ling, what might that be? I recall some info at diyparadise noting that for the TDA1545-based Monica DAC, the asynch. reclocker was using an 80.000 Mhz. The owner of that website claimed higher XO freqs. were better.
Dunno.... I see many 4x or 8x TDA1387 Chinese DACs using either 12.000 or 50.000 Mhz. Not sure why THOSE two freqs are used.
An externally hosted image should be here but it was not working when we last tested it.
Cause that slave the USB to I2S input chip which after send a "reclocked" I2S signal to the dac chip(s)
same here : AUDIOPHONICS I-TDA1387 TCXO DAC Raspberry Pi 3 / A+ B+ / Pi 2 / I2S - Audiophonics
btw this last is a bang for the bucks if you have a Rpi many EC diyers pointed out here.
same here : AUDIOPHONICS I-TDA1387 TCXO DAC Raspberry Pi 3 / A+ B+ / Pi 2 / I2S - Audiophonics
btw this last is a bang for the bucks if you have a Rpi many EC diyers pointed out here.
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I'm not a fan of asynchronous reclocking so I don't recommend anyone use it with any of my DACs. I really can't see the point - it introduces the chance of meta-stability in the reclocking FFs, something that's best avoided.
Here's one of my early prototypes of the 5th order filter - its not on general sale yet as I'm not sure I can make them in sufficient volume. But by all means ask if I have any available
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Confusion
Frankly, I don't know a PhiDAC from a LingDAC. As far as I can tell, the "PhiDAC" is not a DAC at all; it's a reconstruction filter for a TDA1387-based DAC. Correct?
How many of the projects in this thread are offered in "Buy" or "Kit" threads?
Amending POST #1 with a Quick Guide or FAQ would be helpful.
Otherwise, the el cheapo TDA1387 Chinese offerings on ebay or Ali seem much more attractive. Not unless abraxalito projects are on Ali/eBay ... are they?
This is long, dense thread with many "sub-projects".Here's one of my early prototypes of the 5th order filter - its not on general sale yet as I'm not sure I can make them in sufficient volume. But by all means ask if I have any available
Frankly, I don't know a PhiDAC from a LingDAC. As far as I can tell, the "PhiDAC" is not a DAC at all; it's a reconstruction filter for a TDA1387-based DAC. Correct?
How many of the projects in this thread are offered in "Buy" or "Kit" threads?
Amending POST #1 with a Quick Guide or FAQ would be helpful.
Otherwise, the el cheapo TDA1387 Chinese offerings on ebay or Ali seem much more attractive. Not unless abraxalito projects are on Ali/eBay ... are they?