I2S Connection RPI - Najda
@JLOP: Uuups,
still don´t know why the old version of Volumio stayed muted, but:
New SDHC card, newest Volumio Version, same settings, works at once!
O. k., that piece of coding to make shutdown of RPI possible by pressing a hardbutton has to be inserted once more, but I´m glad to have this running!
Thanks JLOP for Your help!
@JLOP: Uuups,
still don´t know why the old version of Volumio stayed muted, but:
New SDHC card, newest Volumio Version, same settings, works at once!
O. k., that piece of coding to make shutdown of RPI possible by pressing a hardbutton has to be inserted once more, but I´m glad to have this running!
Thanks JLOP for Your help!
Good to know it worked for you. Like PCs, two solutions reload / reboot whatever the problem is
BR
Hi,
if somebody is interested in a complete finished Najda?:
Sjöström ultra linear power supplies for +/-12V and 5V!
Exasound USB to i2s converter!!!
All Elkos in signal path changed to Wima MKP!
All Opamps changed to diskrete Sparkos Opamps!
Big display and all funktions from front by chrome buttons!
Apple remote controller!
For interestet people send me a pm and I will send fotos from in- and outside.
best regards Ulf
if somebody is interested in a complete finished Najda?:
Sjöström ultra linear power supplies for +/-12V and 5V!
Exasound USB to i2s converter!!!
All Elkos in signal path changed to Wima MKP!
All Opamps changed to diskrete Sparkos Opamps!
Big display and all funktions from front by chrome buttons!
Apple remote controller!
For interestet people send me a pm and I will send fotos from in- and outside.
best regards Ulf
Najda Boxed
This is Najad Boxed by Waf.
I did order with USB in so this has all options.
The quality and feel good factor of the boxed version is very hi. You feel the quality of the metal enclosure and all buttons and lettering are just right.
The price for the box (compared to just the board) is less than 200€ so I think it is a very good price and you can provably not do it for less.
There is two USB, in one for sound and the other for NUC program interface. I am able to use an USB hub (passive) so I need to run just one USB line from the computer.
This is Najad Boxed by Waf.
I did order with USB in so this has all options.
The quality and feel good factor of the boxed version is very hi. You feel the quality of the metal enclosure and all buttons and lettering are just right.
The price for the box (compared to just the board) is less than 200€ so I think it is a very good price and you can provably not do it for less.
There is two USB, in one for sound and the other for NUC program interface. I am able to use an USB hub (passive) so I need to run just one USB line from the computer.
Attachments
I have not opened the box but I shall attach some pictures when I do.
This is Nics answer that I got about the USB input that is delivered in the box:
"The USB input is based on the Amanero board, coupled to a in-house I2S bus isolation board. The main benefit compared to alternative modules, is that it's all nicely integrated within the chassis thanks to dedicated fitting points in the enclosure. The USB audio input is on a separate connector, fitted onto the rear panel."
That sounds great..
Wiring the WaveIO in with all shorter than 4cm point to point wiring was a pain but once done the result is great.
I've not had any reliability issues what so ever with Najda or WaveIO, touch wood.
I was an early adopter, so several years of use now..
Pics and internal pics would be great
Wiring the WaveIO in with all shorter than 4cm point to point wiring was a pain but once done the result is great.
I've not had any reliability issues what so ever with Najda or WaveIO, touch wood.
I was an early adopter, so several years of use now..
Pics and internal pics would be great
Hi,
I'm glad to hear that, since using two long USB cables that are connected to the back side of the unit is quite painful. Still, I Wonder how 2 different signals that have separate targets, can go through one cable.
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It is one of the features that USB has. There is plenty of info about the USB standard. But you do not need to understand all of that just try and see does it work.
I am trying to match Najda with my diy multichannel amp but need guidance please. I understand the voltage gain of the different Anaview amp boards should be the same, but alas it is not;
AMS0100 20.6db (6vrms max)
ALC0180 22.45db (1.43vrms max)
AMS1000 27.5db (6vrms max)
The Najda manual suggests using the analogue outs configuration to adjust for different speaker sensitivities, but can I use those settings to adjust for voltage gain of my amp boards?
Also, the max input voltages are vastly different as shown in brackets above. The ALC0180 is a problem at only 1.43V? It is possible for me to remove this board and just use the others if need be.
Thank you for any replies!
AMS0100 20.6db (6vrms max)
ALC0180 22.45db (1.43vrms max)
AMS1000 27.5db (6vrms max)
The Najda manual suggests using the analogue outs configuration to adjust for different speaker sensitivities, but can I use those settings to adjust for voltage gain of my amp boards?
Also, the max input voltages are vastly different as shown in brackets above. The ALC0180 is a problem at only 1.43V? It is possible for me to remove this board and just use the others if need be.
Thank you for any replies!
Thanks, I am stuck on the how therefore. The AMS boards are 7db apart in voltage gain, so I set them at 8db and the max of 15db (6V). The ALC0180 however, if set at 10db, is still way above its max input of 1.43vrms max!? The manual says 0db is 1V I see.
AMS0100 set to 15db
ALC0180 set to 10db???
AMS1000 set to 8db
AMS0100 set to 15db
ALC0180 set to 10db???
AMS1000 set to 8db
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I would set the output on the ALC180 to be at about 1.5V that way you would have to turn the overall volume very close to 100 to be able to clip it.
Whatever that level is set the AMS0100 to +2dB of that value and the AMS 1000 to -5dB of that value.
That will even out the voltage sensitivities of the amps to be fairly close. You can use some digital attenuation to get a more exact match if you want or need to.
There is no point in setting the output to the ALC to a higher level or you will just keep having to turn the volume dial down to stop it from clipping.
Whatever that level is set the AMS0100 to +2dB of that value and the AMS 1000 to -5dB of that value.
That will even out the voltage sensitivities of the amps to be fairly close. You can use some digital attenuation to get a more exact match if you want or need to.
There is no point in setting the output to the ALC to a higher level or you will just keep having to turn the volume dial down to stop it from clipping.
Hi Fluid, there is no way around it therefore. I should not have bought the older design ALC amps (I have two of everything to give eight channels). I think I will have to leave them out. It seems too big a mismatch where the newer AMS boards will be limited by the older design. With my open baffle Nao Note II speakers I believe the amps will need to use most of their voltage input at times.
No big deal, but good to know Najda is so flexible where need be. Just need to find a case for it now. Thanks for the help!
No big deal, but good to know Najda is so flexible where need be. Just need to find a case for it now. Thanks for the help!
Your final adjustments (there is no such thing) will be decided when you get your system up and running. As you do your DSP settings there will be nead to adjust and compensate for EQ, speaker sensitivity and also dispersion pattern. Also your room will interfere so if you have the parts use them and get to the next level.
I think you might be reading the spec sheets in a way that is confusing you.
For the smaller ams0100 amps the maximum voltage is either 3V Single ended or 6V balanced. So if you are running single ended out of Najda then 3V is the upper limit anyway.
Then it depends on the load the amplifier is seeing, the amps are rated to 50W (1% distortion) each channel with a 4 ohm load that is a voltage of 14.14V.
The voltage gain of the amplifier is 20.6 dB (10.715 times) which means that you only need to give it 1.319 volts input to reach 50W with a 4 ohm load.
You can use these calculators to work out the other amps
Decibels to Voltage Gain and Loss convert calculation conversion amplification amplifier electronics - sengpielaudio Sengpiel Berlin
Voltage current resistance and electric power general basic electrical formulas mathematical calculations calculator formula for power calculating energy work equation power law watts understandimg general electrical pie chart electricity calculation
I have used 1.0V output on Najda with LX521 speakers and Hypex UcD amps and on music I still had more voltage than I needed. For movies 1.5V was better due to the increased dynamic range.
I would try it out first before giving up I don't think the sensitivity differences are a deal breaker
Fluid, you have a similar set-up to me in principle, very similar speakers and amp requirements. I have to reconsider how I thought the voltage works and study the links you sent. I am surprised how low you have the voltage. I read elsewhere that the AMS1000 needs 6volts to reach its stated output, which got me thinking I need to aim high, and maybe I still do with these Anaview amps.
I am running the amps balanced, by way of pseudo balanced cables (ground and cold connected to the shield at the rca end). I thought then that the Najda would still output 6volts when told to, but that is not possible on Najda SE outputs?
I am running the amps balanced, by way of pseudo balanced cables (ground and cold connected to the shield at the rca end). I thought then that the Najda would still output 6volts when told to, but that is not possible on Najda SE outputs?
Gain structure
Fluid
don't worry about your amps and if you have bought "the wrong amps"... use the gain structure settings in the Najda setup. I use different amps as well and balanced all in the gain structure of the setup when measuring the speaker system. Works pretty good in my 3-way horn system
The trick is setting the volume for all output levels the same - I use the max. 6V output level. It's more comfortable to operate with the gain settings in the channel processing tab.
Last thought: when using the quasi symmetrical drive of the input you have some more headroom.
Fluid
don't worry about your amps and if you have bought "the wrong amps"... use the gain structure settings in the Najda setup. I use different amps as well and balanced all in the gain structure of the setup when measuring the speaker system. Works pretty good in my 3-way horn system
The trick is setting the volume for all output levels the same - I use the max. 6V output level. It's more comfortable to operate with the gain settings in the channel processing tab.
Last thought: when using the quasi symmetrical drive of the input you have some more headroom.
Hi Joao, I think your message was for me rather than Fluid. So set the global output to 6volts (assuming that is possible on the SE outputs - I may email that question to Nick), then use pre-gain/post-gain in the channel processing tab. Actually that is the way I have it now, using the pre-gain settings below, but then I got concerned when I saw the ALC0180 only outputs 1.43vrms max unlike the other boards at 6vrms max.
Pregain settings in channel processing, with global output level at 6vrms.
AMS1000 -6.9db
ALC0180 -1.9db
AMS0100 0db
Pregain settings in channel processing, with global output level at 6vrms.
AMS1000 -6.9db
ALC0180 -1.9db
AMS0100 0db
The Najda will output 6V but the amps will only take 6V when you use a fully differential connection 3V swing each for hot and cold gives you 6V. Pseudo balancing has cold tied to ground which will only allow 3V.
It is better to use the analogue section at the end to account for most of the sensitivity difference in the amps as that will give you the greatest digital level through the DAC's and therefore use the highest resolution.
If you are running a lot of EQ boost for open baffle speakers then you will already need to use a fair amount of gain reduction to avoid clipping the digital signal.
The level of voltage that comes out of the Najda is also set by the volume control. If you have Najda output a nominal 6V but your amp can only take 1.319 before clipping then you will always have the volume dial set to a low value which will not give you much control.
In the AMS 1000 datasheet it lists 2 x 300W for 4 ohms as the maximum long term power output.
300W at 4 ohms is 34.64 volts with a voltage gain of 27.5dB you only need 1.46 volts for that amp to pretty much max it out.
Most amps need around 1 to 1.5V of signal to get them near clipping. Some of the stated power and voltage specs are nothing more that marketing dribble so it pays to look further into the datasheet.
It is better to use the analogue section at the end to account for most of the sensitivity difference in the amps as that will give you the greatest digital level through the DAC's and therefore use the highest resolution.
If you are running a lot of EQ boost for open baffle speakers then you will already need to use a fair amount of gain reduction to avoid clipping the digital signal.
The level of voltage that comes out of the Najda is also set by the volume control. If you have Najda output a nominal 6V but your amp can only take 1.319 before clipping then you will always have the volume dial set to a low value which will not give you much control.
In the AMS 1000 datasheet it lists 2 x 300W for 4 ohms as the maximum long term power output.
300W at 4 ohms is 34.64 volts with a voltage gain of 27.5dB you only need 1.46 volts for that amp to pretty much max it out.
Most amps need around 1 to 1.5V of signal to get them near clipping. Some of the stated power and voltage specs are nothing more that marketing dribble so it pays to look further into the datasheet.