Why all this speculation ? There is plenty of space in the FPGA, it's just a question of implementing, and not the least, testing.
dam1941 - Bryston
Dear all,
I am long time reader and now happy to be a part of diyaudio community.
So Hello!
After some DAC experiments (listening Chord Mojo, Hugo, HugoTT, Hugo 2, Qutest, Bryston BDA-1) I decide to try R2R technology.
My crazy idea is to use very good analog stage and Power supply part of my Bryston BDA-1. Somehow, I plan to isolate a bit outdated digital part of Brystone and use it to power dan1941 board and also to use Bryston famous fully discrete output analog stage. There is aslo a lot of space to put dam1941 inside. Please take a look my scheme and photos... and tell me if this is crazzy idea and i better go to assembled dac, but obviously less fun there )
I am no an electronic engineer but can solder and like it.
Thank you.
Dear all,
I am long time reader and now happy to be a part of diyaudio community.
So Hello!
After some DAC experiments (listening Chord Mojo, Hugo, HugoTT, Hugo 2, Qutest, Bryston BDA-1) I decide to try R2R technology.
My crazy idea is to use very good analog stage and Power supply part of my Bryston BDA-1. Somehow, I plan to isolate a bit outdated digital part of Brystone and use it to power dan1941 board and also to use Bryston famous fully discrete output analog stage. There is aslo a lot of space to put dam1941 inside. Please take a look my scheme and photos... and tell me if this is crazzy idea and i better go to assembled dac, but obviously less fun there )
I am no an electronic engineer but can solder and like it.
Thank you.
Attachments
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Confirmed. It is a crazy idea 🙂
But no reason why it won't work.
I personally do not see much value in the PS, or the output stage, but the casing is certainly nice. The question is how many additional holes will be needed and how will this reflect upon the cosmetics.
You will need +-5v for the analogue supplies as well, which perhaps means an additional set of regulators.
The DAM does not necessarily need an active output stage. I would expect the Bryston stage to reduce the transparency without adding much value in the case of an active preamp and reasonably short cables. If you intend to go directly to a power amp or headphones and use the digital VC, then the output stage seems like a good idea.
And lastly: would i do it? No way.
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@analog_sa
Thank you for reply and comments.
Yes, I plan to use Brystone BHA-1 balanced connected as an amplifier after DAC. And i know this headphone amp can work well as preamp also. From what you point out, dam1941 in this setup can be used without any problem directly and no need of any additional bufer o analog out stage? is it correct? It will even do pathway more simple and clear. And if is true, then my ides will only benefit for PS section which is not that interesting. And I also forget about analog 5V source for dam1941. Seems what I though is not that sexy anymore (
Thank you for reply and comments.
Yes, I plan to use Brystone BHA-1 balanced connected as an amplifier after DAC. And i know this headphone amp can work well as preamp also. From what you point out, dam1941 in this setup can be used without any problem directly and no need of any additional bufer o analog out stage? is it correct? It will even do pathway more simple and clear. And if is true, then my ides will only benefit for PS section which is not that interesting. And I also forget about analog 5V source for dam1941. Seems what I though is not that sexy anymore (
The Bryston's +15V/-15V PSU almost unusable for 1941 DAC (+5V, +5V, -5V).
BTW 78xx, 79xx regulators are very mediocre ones compared to low noise, low impedance PSU devices (LT304x, shunt regulators, Jung superreg etc.).
1941 output voltage is enough high, no need amplification (and output impedance is enough low to drive anything).
I would (I'm in the implementation phase of my 1941 DAC) use only an isolating device, the high impedance 1:1 transformer (to minimising ICs in signal path) -Cinemag 15/15B, Jensen JT-11-P-1 or similar).
BTW 78xx, 79xx regulators are very mediocre ones compared to low noise, low impedance PSU devices (LT304x, shunt regulators, Jung superreg etc.).
1941 output voltage is enough high, no need amplification (and output impedance is enough low to drive anything).
I would (I'm in the implementation phase of my 1941 DAC) use only an isolating device, the high impedance 1:1 transformer (to minimising ICs in signal path) -Cinemag 15/15B, Jensen JT-11-P-1 or similar).
I would (I'm in the implementation phase of my 1941 DAC) use only an isolating device, the high impedance 1:1 transformer (to minimising ICs in signal path) -Cinemag 15/15B, Jensen JT-11-P-1 or similar).[/QUOTE]
Do you mean transformers after the unbuffered XLR outputs and just before your preamp? If so why?
Thanks.
nash
Do you mean transformers after the unbuffered XLR outputs and just before your preamp? If so why?
Thanks.
nash
Yes.
I'm a "conservative", hate to use any chip pin as output to potentially unknown device without protection. Static charging, spikes etc. from another device can ruin it output pin.
You don't need to worry too much for the dams, the direct output have 10K resistors to each chip output, so it can take a lot of abuse....
If you want to be safe, put a low capacitance TVS across the outputs, you don't need transformers, unless you want the sound colored....
Hi Soren, my questions:
which input is active when I select I2S via the input button? Is this the second, not yet supported by the firmware I2S input on J9? What is about the first I2S input? Sorry,
I 'm a little bit confused with the I2S inputs...
For example, how can I connect a raspberry Pi via I2S to the DAM?
Best regards, Peter
which input is active when I select I2S via the input button? Is this the second, not yet supported by the firmware I2S input on J9? What is about the first I2S input? Sorry,
I 'm a little bit confused with the I2S inputs...
For example, how can I connect a raspberry Pi via I2S to the DAM?
Best regards, Peter
It's simple: there are no inputs at present and you cannot connect anything by i2s. Keep fingers crossed that one day you might.
There are different opinions about that, but you can take the output directly from the resistor networks, that's the least colored option, that was your plan right, you said the transformer was for protection, and you don't really need protection....
My dam1941 is up. I still don’t have a proper controller so rely on the default setting for source selection(Auto) and the AZ OLED from my 1021 for filter switch. Thinking abt using dimdim’s Ardam Lite for the control.
My 1941 sounds significantly better than my 1021 in every aspect. The integrated source input saves a lot of work and is a big plus for sound. I prefer discrete regulators and buffers (to be added later).
Will enjoy listening to some music for now. 😊
My 1941 sounds significantly better than my 1021 in every aspect. The integrated source input saves a lot of work and is a big plus for sound. I prefer discrete regulators and buffers (to be added later).
Will enjoy listening to some music for now. 😊
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Thanks for sharing your opinion. What PSU are you using?
Does the 1941 board come ready soldered with all of the inputs and connectors as shown in the pics on the website?
nash
Yes, the board comes exactly as shown on the website. I added a connector for the direct output.
I use Borbely’s all-FET regulators. One for +5V and another for +/-5V bipolar supply.
Prakit what filter are you using. Your comments would be useful especially since you also had a 1021. How do the filters compare?
I have gone thru all 24 pages of this thread and nobody seems to have made any mention of filters. The 2018-10-08 manual of the 1941 makes mention of four filters in the uManager Commands section but refers to dam1121 in the Updating Firmware section. Can I assume that updating the dam1941 software is identical?
Are the filters on the dam1941 same as the dac1541? What is the default filter setting?
There are some not so flattering comments about filters used in the dac1541 posted around December 2017, but I see mention made on the Soekris website April 6, 2018 that they have been updated. Are these in the dam1941? Any user comments?
Thanks.
nash