I think it would be god if you declared your signal chain used?
I do agree on one of your observations and that is the one about left/rigth focus. However, for me this was on multi-mic recording. On live acoustical events I didn't notice this but rather a deep stage with a lot of air - quite opposite of your findings - interesting.
I made an early declaration about my findings which I still stand by. I did not adress all aspects in that one and I'm still exploring/evaluating the product.
//
just curious to how you powered the dac?
i found ac powered to be a complete flop if were to match it against real high end dacs
thats exactly how to describe it
also glad that its not just me thinking this way
i strongly suspect some power supply upgrades and cap changes could turn it inside out
there seems to be very well detailed and i think its got a lot of potential with modding
curious to see what effect different filters will have
still lovin the project though
i found ac powered to be a complete flop if were to match it against real high end dacs
i read this this morning and thought
thats exactly how to describe it
also glad that its not just me thinking this way
i strongly suspect some power supply upgrades and cap changes could turn it inside out
there seems to be very well detailed and i think its got a lot of potential with modding
curious to see what effect different filters will have
still lovin the project though
The more honest opinions, the better! We all want to see the DAC become even better if possible. I hope more people will chime in with their impressions.
I power the dac with AC. It's a Gerth Trafo 4815-2 which was suggested by someone earlier in this thread. One of the cheapest ones I could find, just to sort of get the project started. I too am keen on a battery solution.
I still say thanks for your opinion, I welcome all opinions as long as they're well funded.... It's not like I expect everyone to just love the dam1021, it is quite demanding on the rest of the signal chain and people have different personal tastes.
And one place where there are plenty of space for improvements are the digital filters. Right now there are:
FIR1, upsampling from incoming sample rate to 352/384 Ksps in one step, with different filter lenght based on incoming sample rate. All FIR1 filters are basic Parks-McClellan "brickwall" types, designed with http://t-filter.appspot.com/fir/index.html, but still shorter than your regular DAC.
IIR, bank of 15 biquads operating at 352/384 Ksps, with one used for the CD de-emphasis filter, none otherwise used for the basic DAC.
FIR2, upsampling from 352/384 Ksps to 2.8/3.1 Msps, reasonable short and soft but still using same design as FIR1.
All filters are using 32 bit coefficients, with up to 67 bit MAC accumulator.
I'm not a believer in no filters (non oversampling), but also don't like the sharp "brickwall" filter types with the pre-ringing. The goal is to work towards filter types that remove just enough to not cause problems with aliasing. It's pretty easy with higher sampling rates, but is long and hard work and listening tests with 44.1 Ksps, which still are the sample rate mostly used....
I intend to procure some commercial filter design tools, but are also very interested in people with more experience in filter design, the filter work with dam1021 is a first for me.... I do have the filters tools and will release them soon, just need to make the docs.
Hello Søren,
You can try rePhase to generate the FIR.
It will let you specify any sampling rate (the drop down menu only shows common values, but it can be manually edited) and configure any type of filter (brickwall, LR or arbitrary slope, linear or minimum phase to avoid preringing, etc.) and let you see what you can get at the end for a given number of taps and windowing algorithm.
There is no manual (yet
) but I would be glad to help if something is unclear or if you need specific functionalities.I used lifepo4 power last night 8 0 -8 v
it was a very good improvement over ac which I had in previous
but still lacking the depth, calm, acoustic positioning a sense of time and space that can be achieved with excellent power supplies
sebastian how does it compare to other r2r dacs in regards detail ?
my impression is that it very well could be better than any sigma delta I've heard detail wise
Can someone draw a rapid shematic on how to get +/- 12 VDC from a 9V/30VA RCore please . I have one on hands ! (measured 10 V unloaded on the two secondary windings !
I can testimonie as my DAM1021 is running with a 7W/15VA torroid and I share some of the conlusions with Sebastian ! IHMO there is a hole in the mids but it doesn't lake of bass : just a subjective lacke of mid-bass and life whic can be resolved with EQ. I didn't try the SE Buffer side (just the unbuffered SE) but plan to do it today with the input of Spzzzzkt member above ! My Pre is 47 k ohms at the input and the amp is 100 k ohms input (and believe me : don't lacke of life and bass : Chord SPM 1000 B, modulatios links are Oyaide Across 750)
I will testimonie after using the R-core if someone helps me with a shematic !
I have some 16V 2200 Panasonic FM & FR and some Schottky diodes ! From almost the beginning I was in for vias to swap the mains caps to test some alternatives, I would like to see how a serie diodes bridge can mix with the existing one ! Because the single 860 uF negative rail : does a DC Pi filter have to go not further than this value for the first cap after the rectifier diodes ? So something like : 860 uF -> resistor for Pi filter and to get a lower VDC -> 860 uF to 2200 uF then connecting to the DAC PS plug ?
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You can never please everybody. Unless you sell 3 boards to people who like it already.
What you can do is let people know what they can tweak on your board, a manual with full description of which is which will let a million experiments begin and that is a good thing, that way everybody can play their favorite card - PSUs, batteries, filters, tubes, transformers, moon dust, this is DIY audio and everybody knows where good sound comes from.
I bought the board, it is a very exciting and promising product, I did not expect to have a TotalDAC for cheap(would not mind though), I bought it because it still has a lot of features that are important for me as a test tool.
You opened a can of worms with this DAC, now help us teach them dance and sing
What you can do is let people know what they can tweak on your board, a manual with full description of which is which will let a million experiments begin and that is a good thing, that way everybody can play their favorite card - PSUs, batteries, filters, tubes, transformers, moon dust, this is DIY audio and everybody knows where good sound comes from.
I bought the board, it is a very exciting and promising product, I did not expect to have a TotalDAC for cheap(would not mind though), I bought it because it still has a lot of features that are important for me as a test tool.
You opened a can of worms with this DAC, now help us teach them dance and sing
A positive thinking.
Stock it worth its price, no problem and as many things can be improved (EQ, FIR, etc...) : it is a positive product. I appreciate some member like FOR want to help to improve a commercial product on the Datas side for the communauty !
A two cents question of a non technician please for the experienced diyers and designers : do the ceramic caps on the buffer output can affect the sound on a bad way ? Can I expect to have better subjective results with the buffered SE ? As far I understand 1.4 V and few hundred ohms of the non buffered SE output is enough for a 47k ohms input pre ?!
Stock it worth its price, no problem and as many things can be improved (EQ, FIR, etc...) : it is a positive product. I appreciate some member like FOR want to help to improve a commercial product on the Datas side for the communauty !
A two cents question of a non technician please for the experienced diyers and designers : do the ceramic caps on the buffer output can affect the sound on a bad way ? Can I expect to have better subjective results with the buffered SE ? As far I understand 1.4 V and few hundred ohms of the non buffered SE output is enough for a 47k ohms input pre ?!
I have a suitable transformer 'in bound' to compare AC / DC performance. I'm very curious to see. While I understand and accept the logic that the onboard PS's are more than adequate, running with the S03 DC 12V and a Reflektor-D powering the ISO 3.3 - my impressions are much stronger than yours. It's very much in focus, dynamic and for the most part neutral.
Of course, given the differences in our hearing / preferences - this doesn't mean much.
Source -
Synology NAS WiFi->Lan repeater ethernet out via MeiCord Opal patch cable (as recommended by Klaus ‘Soundcheck’)->Squeezebox Touch w. EDO applet and BTWS psu, USB out via modded USB cable->Amanero I2S->DAM1021-01 onboard *xlr out via Artisan Silver cable->
1. headfi system -
Questyle CMA800R solid state headphone amp via Aphrodite Cu29 Zeus pure copper cable->LCD-3
2. headfi system -
Stax SR-006t-> Sennheiser HE60 electrostats
* alternatively rca out via Nordost Blue Heaven->
Note that I’m very familiar with the sound and performance of these systems as I have been using them both quite intensively.
If that all documents then I have problem
, I do not have enough electric and audio DIY experience to start with that!OK let start ... pull hair first!
If you and everyone could help me some hint to start, I like to find a fast way to make it sound now and go higher level later! May be connect with my AE/AppleTV ?
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All along it has been my intention of looking into the impedance match, but for some reason never got to it, assuming that the impedance would more or less match. Thought I had a pair of XLR adaptors lying around that takes care of that, but now I can't seem to find them. It's definitely a thing that's on my list.
I must point out, that with all the dacs I've used so far I've never done anything to accomodate the impedance. Always just connected them 'as is' them straight out of the box.
How are you powering the ISO 3.3V?
Misterrogers mentioned he is using a reflektor which I imagine would be about as good as you could get.
Also wondering what the source is for your totaldac? The touch?
And thanks for your review, I agree to get all opinions out there.
Randy