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dam1941 - Next Gen Discrete R-2R Sign Magnitude 24 bit 384 Khz DAC module

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What is the recommended impedance of the next element of the chain to connect the dam directly (in balanced), without buffer ?

I want to connect the dam directly to my ncore 400 amp. I guess it's ok because the datasheet of the ncore recommend 1k ohm, and anyway it's input impedance is very high. But i am curious to know what would be the minimum impedance in which a buffer is needed, in the case if one-day i want to connect the dam to something else.

Didn't find much on the internet, something like a 1:100 ratio ?

The direct R-2R resistor network output on all dams are a voltage source with an output impedance of about 625 ohms (double for balanced). So you can connect it to anything, although a minimum 10K load is recommended.
 
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I bought an OEM board from you a few months ago. But I had to cancel the whole project because it turned out to be too complex for me. I lost a lot of money!

Basically I am still interested in a R2R DAC. Especially a new version like your 19x1. But I don't want to spend that much money for a non result again....

As I use a single ended preamplifier the 1921 will be enough, right?
My primary source is a USB connected HTPC with FLAC and DSD files.
Your website says: "The OEM just need to add a Power Supply and Output Buffer, and if needed, an optional small PCB with the user interface."
Do I get these Power Supply, Output Buffer and the user interface PCB from your side? If so, when and at what prices?
Since I am quite inexperienced, it has been shown that I am not capable of more than "Hypex NC400" DIY. Put components together and maybe a little (!) soldering. Is a 1921 then something for me?

greetings

My dam modules are not beginner projects, although the new dam1921/dam1941 don't require more than being able to solder and put the boards in an enclosure somehow....

The dam1921 is single ended, for use with single ended inputs.

I am working on the Power Supply, Output Buffer and User Interface PCBs, don't know pricing and availability yet, but expect them to be ready at, or close to, dam1921 and dam1941 shipping, and the pricing to be pretty low, maybe EUR 30 for a complete set of three bare PCBs, they're not that complicated....
 
I am working on the Power Supply, Output Buffer and User Interface PCBs, don't know pricing and availability yet, but expect them to be ready at, or close to, dam1921 and dam1941 shipping, and the pricing to be pretty low, maybe EUR 30 for a complete set of three bare PCBs, they're not that complicated....
Are these future boards valid for 19x1 only, or could also be used in 1021?
 
What is the recommended impedance of the next element of the chain to connect the dam directly (in balanced), without buffer ?



I want to connect the dam directly to my ncore 400 amp. I guess it's ok because the datasheet of the ncore recommend 1k ohm, and anyway it's input impedance is very high. But i am curious to know what would be the minimum impedance in which a buffer is needed, in the case if one-day i want to connect the dam to something else.



Didn't find much on the internet, something like a 1:100 ratio ?

Simply connect it directly and use the digital volume control, it works absolutely fantastic and adds no additional components in the audio chain.
 
...
I am working on the Power Supply, Output Buffer and User Interface PCBs, don't know pricing and availability yet, but expect them to be ready at, or close to, dam1921 and dam1941 shipping, and the pricing to be pretty low, maybe EUR 30 for a complete set of three bare PCBs, they're not that complicated....


thanks for your answer.
* Will the output Buffer come with a fixed topology? Or will there be interchangeable Op Amps to change the " sound" ( Sparkos Labs SS3602 or Sonic Imagery 994 for example).
* With or without OP amps? Or class A or D?

* Will there be " just a pair of RCA (1921) or XLR (1941) available? Or also Headphone outputs?
 
Simply connect it directly and use the digital volume control, it works absolutely fantastic and adds no additional components in the audio chain.


This is what i plan. I was using a BPBP between my two 1021 in bal and the ncore, but i will build a single unit including the ncore and the dam, as it is what i use 90% of the time. It's one less element in the signal chain, and i am not sure of any benefice of using an analog attenuator, compare to the digital one of the dam.

I will still use the BPBP, but in another case and for another dac and a phono pre. I juste hope AudioZen oled will work with the dam1941, oled looks great. :D
 
This is what i plan. I was using a BPBP between my two 1021 in bal and the ncore, but i will build a single unit including the ncore and the dam, as it is what i use 90% of the time. It's one less element in the signal chain, and i am not sure of any benefice of using an analog attenuator, compare to the digital one of the dam.

I will still use the BPBP, but in another case and for another dac and a phono pre. I juste hope AudioZen oled will work with the dam1941, oled looks great. :D

If the basic serial controls on the 1941 are the same and I see no reason why they won't be then absolutely it should work the same. I've ran the pair of 1021's direct via balanced to nc400's as my main setup for about 3 years now and I can imagine this new board being every bit as good/better straight out of the box with just some basic diyinhk psus.
 
Hi Soren,
Regarding the PSU, you have mentioned +-5V.
- what are the needs in current of each ?
- will it be possible to power it with "UltraCap™ LPS-1" from UpTone (ultracapacitor's PSU) ? which is a single output 5V (1.1A max)
(??? or even use it partially, just for +5V or... ???)*
*It's probably a silly question, but in this way it will be clearer for me :)
 
Last edited:
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Joined 2009
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Hi Soren,
Regarding the PSU, you have mentioned +-5V.
- what are the needs in current of each ?
- will it be possible to power it with "UltraCap™ LPS-1" from UpTone (ultracapacitor's PSU) ? which is a single output 5V (1.1A max)
(??? or even use it partially, just for +5V or... ???)*
*It's probably a silly question, but in this way it will be clearer for me :)

My prototype dam1941 use when playing:

+5VD 0.35A, inclusive display.
+5VA 0.04A
-5VA 0.04A

The two +5V can be from same source, and you do need both + 5V and - 5V to the analog section. The USB interface sources its power from the USB host.
 
Hello soren,
Is it possible to get the reference of the connectors (usb, toslink, bnc etc), so i can get their datasheet.

I will make the back-panel for my project with front panel designer, i will post it here to be sure i don't make mistake. Also i'm sure it will useful to another member of the community.

Regards
 
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An update:

Production of the dam1921/dam1941 was started at the start of October, but the assembly house have been very busy so the mounted boards won't be ready until end of October, taking more time than usual....

The good news is that all the accessory bare PCBs will then be ready when the dam1921/dam1941 are ready. The set consist of:

psu1951, Linear Power Supply Board using PCB mounted toroid, for 115V or 230V, can supply the +-5V for the dam1921/dam1941 itself, plus +-5V to +-15V for a output board.

buf1961, Simple Output Buffer Board using opamps, can be used single ended to single ended, single ended to balanced and balanced to balanced. The board can use opamps in both so8 or dip8 package.

dsp1971, User Interface Board, consists of a long thing PCB with all the LEDs and Switches, and a small Volume Control and Display Board mounted right angled to the User Interface Board. Have all the features like a dac1541....

The set of all the bare PCBs will be sold at EUR 30, but everybody who have placed an order before we ship will receive the set of bare PCBs at no cost.

It should be said that I have not done prototypes of the accessory PCBs, but they are pretty simple, so they should work but might require small modifications. Except for a few IC's in so package, they're using all though hole parts.

I'm now working on the manual with all information needed, will be ready before the dam1921/dam1941 ship.
 
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Søren,

So if i order now i get the pcb’s for free?
Another question i have is whether you will provide a BoM listing all the components i need for those three pcb’s?

Thanks!

Yes, all orders until we ship will include those PCBs for free. After we start shipping the PCBs will be available at EUR 30 for a set. I do not intend to sell the PCBs individually.

And as I just said: I'm now working on the manual with all information needed, will be ready before the dam1921/dam1941 ship.