True. I was thinking that an analogue volume control in a chip (like the one in the Najda) would be as transparent as a fixed attenuator. Certainly more flexible. Changing the amp gain seems to me the best solution altogether, as it makes little sense in attenuating something just to amplify it again.
Is there any data on the effects of these volume control chips? And how does the DACs in the Najda compare to say a Buffalo DAC? (note: A Buffalo DAC has different performance if used in stereo and 8-channel mode as you probably know)
Data? hmmmm...
Lots of opinions - yes
Personally I've not done side by side comparisons on the range of attenuators available to comment based on my experience. But I've personally heard differences in interconnects when there should be none, and I've heard and seen enough comments from ears that I trust (cynical engineers' ears) that I believe that different attenuating devices can sound different. What, to what effect and how important it is as a part of the overall system performance is always open to question.
I think najda raises the stakes in comparison to what else is available and value for money. Try it as it is and see if you like it
Cheap PSU for Najda
I've got my Najda board today
. So for now I'm collecting the peripherals to make a test run. I've ordered an interesting PSU in the bay. I hope it will do for the first tests.
I've got my Najda board today
. So for now I'm collecting the peripherals to make a test run. I've ordered an interesting PSU in the bay. I hope it will do for the first tests.
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PSU for Najda
I've got my Najda board today. So for now I'm collecting the peripherals to make a test run. I've ordered an interesting PSU in the bay. I hope it will do for the first tests. Did anybody make some progress with OLED displays like this one?
I've got my Najda board today
. So for now I'm collecting the peripherals to make a test run. I've ordered an interesting PSU in the bay. I hope it will do for the first tests. Did anybody make some progress with OLED displays like this one?Hi Travelbug,
we have tried a digital Power supply, as yours, to a very high upgradet ( sjöström) analog supply. The analog supply ist really much better! There ist a lot of air in the music much more dynamic and silence is silence! Everything sounds open. The differences between the Opamps are much less. Give your NAJDA a good analog power supply, you will never miss it again.
Regards
F2a11
we have tried a digital Power supply, as yours, to a very high upgradet ( sjöström) analog supply. The analog supply ist really much better! There ist a lot of air in the music much more dynamic and silence is silence! Everything sounds open. The differences between the Opamps are much less. Give your NAJDA a good analog power supply, you will never miss it again.
Regards
F2a11
It's just for the first tests. I also consider getting a trafo supply but you'll need 3 coils or 2 trafos for +-12V and 5V. I just wonder if the +-12V is only for the analogue opamps and the 5V is for the digital stuff. So maybe the +-12V stage is the more sensitive part and the 5V can be a switched PSU.
We compared switched PSU and a linear one. Yes, 2 transformers are needed, one for 5 Volt and one for +-12 Volt. The regulators we used are from Sjöström, they are not cheap, but the results obtained with regard to sound quality justified the price we payed. Najda played in another class with the linear PSU!
Also if the 5 Volt are only used for the digital part I would use a linear PSU. I had a similar experience with a BigBen for reclocking the SPDIF signal and when I changed the switching PSU against a linear one, i noticed an increase in SQ. The Original BigBen has only a 5Volt PSU and is full digital. It seems that also digital stuff can be influenced by a clean power supply.
I'm afraid not. There's a upper view from the board as well as a rear panel template available for download on the website.
I've got my Najda board today
I had a quick look at this PSU - well that's really cheap! Seems OK, but there might be one problem, which is the minimum load. According to the specs, the 5V line must deliver 0.5A and the 12V line must deliver 0.1A. In either case you should check the voltage on each line when there's nothing connected, because Najda draws very little in StandBy - and actually less than 0.5A from the 5V line in normal operation. So what you must make sure is that voltages don't drift too far away from the nominal values when there's no current drawn (and otherwise add a dummy load).
Your link doesn't seem to work (?) but I don't think this display is really compatible. Some users and myself gave a try with a model that claimed to be compatible, alas without success. I'll have a new look at it again and will post here my progress.
Since my amps have balanced inputs, it would be nice to have balanced outputs on the Najda. I know Nick won´t change the boards just because it´s nice to have for a couple of people, so I was wondering if anybody here has thought about using the THAT Corp 1646 chip or similar.
Here´s a supplier of a kit that does the conversion - insert the chip of choice it seems, incl. the THAT1646: Balanced I/O Building Block Kits
Here´s a supplier of a kit that does the conversion - insert the chip of choice it seems, incl. the THAT1646: Balanced I/O Building Block Kits
An externally hosted image should be here but it was not working when we last tested it.
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Jcga made himself a fully balanced najda
Start reading here http://www.diyaudio.com/forums/digital-line-level/215379-dsp-xover-project-part-2-a-136.html#post3545662
Really you don't want to convert from single ended to balanced. Instead IIRC the outputs of najda's DACs are balanced, before they go into the opamps, so you want to pick up from there
Start reading here http://www.diyaudio.com/forums/digital-line-level/215379-dsp-xover-project-part-2-a-136.html#post3545662
Really you don't want to convert from single ended to balanced. Instead IIRC the outputs of najda's DACs are balanced, before they go into the opamps, so you want to pick up from there
It's a massive thread. I wouldn't be too embarrassed.
I just happen to be one of those who's been following the thread from the start. I should be embarrassed that I haven't bought one yet, but life's been too busy for me with other priorities over the last couple of years. (It took me 6 months to plug in my UMIK-1 and fire up REW)
I just happen to be one of those who's been following the thread from the start. I should be embarrassed that I haven't bought one yet, but life's been too busy for me with other priorities over the last couple of years. (It took me 6 months to plug in my UMIK-1 and fire up REW)
Hi,
The transformers come from Reichelt.de , one 9 Volt 25VA, the other 15Volt 25VA, both with 2 coils. For the 5V I used the coils in parallel. Sjöström regulators are the super regulators: SSR 01 for positive Voltage (+ 5 and + 12) and the SSR02 for -12 Volt. Here the link
Sjstrm Super Regulator - Sjstrm Audio
Best regards
Hi Carlo, I don't recommend that. From the +/-12V rails are generated a clean 5V analogue and the +/- 8.5V pair for the volume chip. If you feed the board with +/- 15V, that would probably over-stress the regulators.
Hi Nick
Just finished building the Najda, got the board last week, it works, only very often one of the analog outputs clips, although signal is normal , there are sudden red (clipping) moments, and they are very audible, never had that with the CDX2496, I already adjusted the gain, does not seem to do the trick, what to do?
Just finished building the Najda, got the board last week, it works, only very often one of the analog outputs clips, although signal is normal , there are sudden red (clipping) moments, and they are very audible, never had that with the CDX2496, I already adjusted the gain, does not seem to do the trick, what to do?
I had this and was very frustrated with it for a while. (Nick, correct me if I'm wrong here, but: ) When the DSP clips digitally this is VERY audible because it seems to drop back to 0 instead of just hard clipping with all bits high. Make absolutely sure that the gain is low enough to provide headroom for the total of gain and EQ boosts that you are doing in the digital domain. For example, two +3dB additive filters, if close enough to eachother in the frequency domain, might sum to a +4/+5dB bump. Use the output graphs to analyse where your biggest bump is and make sure you secure headroom for that on the input/pre gain.
Hey Nick, would it be possible to implement some sort of a soft clipping / brickwall limiting in the digital domain to prevent the horrible sound/drops that appear if you accidentally make the DSP clip?