Hello,
Since the availability of the new boards it has been stated here that the standard 12 volt power supply can be used up to 4 boards.
I think it is even in the manual.
Anyway dont use more than 4 without beefing up the supply.
There are not many people who are using more than 4.
My idea is that for the price of an extra board ( which will also mean changing the 4 expensive resistors). So going from 4 to 5 it will be better to improve the 12 volt supply by using a 100....500 mH choke or change the transformer and use the LL2771.
Greetings, eduard
Since the availability of the new boards it has been stated here that the standard 12 volt power supply can be used up to 4 boards.
I think it is even in the manual.
Anyway dont use more than 4 without beefing up the supply.
There are not many people who are using more than 4.
My idea is that for the price of an extra board ( which will also mean changing the 4 expensive resistors). So going from 4 to 5 it will be better to improve the 12 volt supply by using a 100....500 mH choke or change the transformer and use the LL2771.
Greetings, eduard
Output options to new amp
Hi all, Ive been enjoying my 4-board DDDAC since 2017. Its time for me to do some tweaking (naturally 😉 by implementing quite a few updates to my system like adding a Rpi for streaming and using the FIFOpi reclocker.
However, my question is specifically on the analog output of the DDDAC. My original implementation was with the Cinemag 15/15 in to balanced XLR connections, driving my Hypex NC400 Power amp (volume controlled digitally before the DDDAC). Nice sound, but I tried removing the Cinemags all together and go direct to the amp (ie. pos and neg DDDAC terminals wired direct to the XLR connectors)..... wow it was much more dynamic and that is the implementation I have used for at least 2 years (the NC400 have a DC offset protection circuit). I am now looking to start using headphones more and so looking for the DDDAC to feed an amp specifically for headphones. My concern is whether running the DDDAC directly coupled to a new amp would kill the amp or my headphones. I have no idea how to identify whether an amp is DC coupled or what the various input impedances would mean in this implementation.
Do I need to go back to using transformers? Like the 600/600 or audio creative OPT? Just to be on the safe side? How would I know if a new amp would be ok running direct? Is there actually any sound benefit to use transformers rather than direct with no transformers or caps to my amp? Im not an expert in this so really dont know! Any help would be absolutely awesome!
Hi all, Ive been enjoying my 4-board DDDAC since 2017. Its time for me to do some tweaking (naturally 😉 by implementing quite a few updates to my system like adding a Rpi for streaming and using the FIFOpi reclocker.
However, my question is specifically on the analog output of the DDDAC. My original implementation was with the Cinemag 15/15 in to balanced XLR connections, driving my Hypex NC400 Power amp (volume controlled digitally before the DDDAC). Nice sound, but I tried removing the Cinemags all together and go direct to the amp (ie. pos and neg DDDAC terminals wired direct to the XLR connectors)..... wow it was much more dynamic and that is the implementation I have used for at least 2 years (the NC400 have a DC offset protection circuit). I am now looking to start using headphones more and so looking for the DDDAC to feed an amp specifically for headphones. My concern is whether running the DDDAC directly coupled to a new amp would kill the amp or my headphones. I have no idea how to identify whether an amp is DC coupled or what the various input impedances would mean in this implementation.
Do I need to go back to using transformers? Like the 600/600 or audio creative OPT? Just to be on the safe side? How would I know if a new amp would be ok running direct? Is there actually any sound benefit to use transformers rather than direct with no transformers or caps to my amp? Im not an expert in this so really dont know! Any help would be absolutely awesome!
I had a similar experience with the Cinemag CMLI-600 / 600C. The picture is from the test Cinemag VS Jantzen Silver Z 4.7uF 800VDC. Cinamag lost the battle, Jantzen stayed in DDDAC. Put some good capacitors (4 pcs.) so you don't have to think about whether there will be problems with the preamplifier, balanced or single ended all the same. One capacitor on each output (L+ L- R+ R-). You can put 150k or 220k resistor paralell to signal GND behind each capacitor (usually not necessary).
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Thanks Nixie, and nice lay out by the way 🙂 Im looking for a specific answer on whether I NEED to have caps or transformers when looking to buy a headphone amp (and the theory of why I need them). I would rather go direct and have none like I have been doing if possible. Also, it looks like you have a single board which is perhaps why the Cinemags dont sound great (I have 4 boards so transformers are still an option for me).
It depends on the headphone amp...
Most commercial ones should come with an input capacitor anyways to keep it save. How much DC do you have on the outputs of the DAC?
Most commercial ones should come with an input capacitor anyways to keep it save. How much DC do you have on the outputs of the DAC?
@alexanderbax
There are 2 boards in this DDDAC. This is not my DAC, but from a friend. I completely re-wired it with VDH SCS and other quality cables and now it plays phenomenally. Cinemag should work nicely with 2 decks but that was not the case. If you want to be 100% sure, install a Jantzen Silver Z or similar not less than 4.7uF.
My DAC is much older, with 4 boards, but still with Jantzens on the output.
For quick RC calculations use: RC High-pass Filter Design Tool
-3dB point to be les then 2Hz (lower is better).
For R enter the input impedance of the next stage (amplifier, preamplifier or passive attenuator).
There are 2 boards in this DDDAC. This is not my DAC, but from a friend. I completely re-wired it with VDH SCS and other quality cables and now it plays phenomenally. Cinemag should work nicely with 2 decks but that was not the case. If you want to be 100% sure, install a Jantzen Silver Z or similar not less than 4.7uF.
My DAC is much older, with 4 boards, but still with Jantzens on the output.
For quick RC calculations use: RC High-pass Filter Design Tool
-3dB point to be les then 2Hz (lower is better).
For R enter the input impedance of the next stage (amplifier, preamplifier or passive attenuator).
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Ahhh my eyesight clearly going down hill, Nixie haha Looks a lovely set up and thanks for the info on the caps. Certainly a cheaper option than transformers.
Schiirn, I will measure my DC offset tonight. From memory its not high, hence why I felt safe going to direct output for the last couple of years, but will double check it.
Just Im confused as to whether transformers can offer BETTER sound than direct. I mean, the special Sowters are say between €500 and €600 do they actually change the sound in a good way or is it a case of having to spend more and more and more (I mean whats the limit?) just to get a transformer that operates as close to direct as possible? Does a transformer or cap offer a more stable load to the DDDAC to make it sound better, or is direct truly the best way to get the best sound?
Schiirn, I will measure my DC offset tonight. From memory its not high, hence why I felt safe going to direct output for the last couple of years, but will double check it.
Just Im confused as to whether transformers can offer BETTER sound than direct. I mean, the special Sowters are say between €500 and €600 do they actually change the sound in a good way or is it a case of having to spend more and more and more (I mean whats the limit?) just to get a transformer that operates as close to direct as possible? Does a transformer or cap offer a more stable load to the DDDAC to make it sound better, or is direct truly the best way to get the best sound?
A series connected capacitor is not a load for the DAC. You will find out if it sounds better when you buy transformers. I was lucky that someone else bought the transformers, so I had the opportunity to try them without that cost. Personally, I'm not a fan of transformers, I don't like the price, distortion and narrowing of the frequency range. I also had some bad experiences with transformers in tube preamplifier before this DAC. I apologize to everyone who has the opposite experience. My bad experience is certainly not universally applicable.
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Hi Nixie, just to clarify I originally did have the Cinemag 15/15 in my set up. I liked the sound, but when I removed them I was sold on having a direct output. So I know I prefer direct than Cinemag 15/15, but that doesnt mean that say the special Sowters arent better than direct..... if that makes sense?
This is a very valid reoccurring theme... I would say no Transformer and no capacitor, balanced out (between NEG and POS) are the best.
For that you need an amplifier which can handle some mVolts DC bias. So it is a matter of looking at the next stage what you will do.
If capacitors or transformers are "better" is more difficult. It can heavily depend on the rest of the setup and they all sound somewhat different.
What actually is true, is that high quality transformers or capacitors are not cheap - So you should not compare in price ranges. But that logic is a known factor to all of us....
For that you need an amplifier which can handle some mVolts DC bias. So it is a matter of looking at the next stage what you will do.
If capacitors or transformers are "better" is more difficult. It can heavily depend on the rest of the setup and they all sound somewhat different.
What actually is true, is that high quality transformers or capacitors are not cheap - So you should not compare in price ranges. But that logic is a known factor to all of us....
Thank you, Doede. I figured it might be a recurring theme! That truly answers my question and I will take a look at some amplifiers and figure out their suitability after re-measuring my offset. I think I would like to stick to direct if I can!
I have no idea, I haven’t had a chance to try Sowter.
As Doede said, nothing is the best option at the balanced output, if possible. On SE you need something, cap or transformer.
PS
If I buy some cheap Chinese transformers wound with LC-OFC wire on permalloy core, I'll let you know how they sound.
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Direct is direct. Putting in a transformer or capacitor will always limit bandwidth, add distortion, .... . If DC on the input of the following device screws things up you might destroy the appliance or before that add distortion, limit bandwidth, ...
When I make or repair something, I never leave the possibility for my device to do damage to the next device in any variant. I don't even want to think about such a possibility.
This is no criticism of anyone, just my working principle.
This is no criticism of anyone, just my working principle.
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Not shure this is mentioned before but someone ever tried an opamp I/V? Those latest TI opa’s are pretty good. Downside can be an extra power supply. That said, is a passive I/V better than an active one?
I say, a resistor is always better than a complete amplifier stage with 100db open loop gain, tampered back to a handful of dB including power supply etc etc.
I tried this a few times and always came back to a resistor...
Otherwise I probably would have implemented an opamp in my design 😀
I tried this a few times and always came back to a resistor...
Otherwise I probably would have implemented an opamp in my design 😀
The active version may be interesting, but I haven't seen anyone try for DDDAC. I am very pleased with the sound of the OPA1612 in the SE line preamp and CD player, and for balanced outputs it is worth considering the OPA1632. For balancet to SE there is for example Broskie cathode follower for lamp lovers. The passive version should be better, maybe not? Both active and passive versions affect the sound, more or less.
I personally chose DDDAC precisely because it is a passive I / O conversion, NOS and filterless DAC.
I personally chose DDDAC precisely because it is a passive I / O conversion, NOS and filterless DAC.
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IAN CANADA IVSTD Output stage module for DAC ES9038Q2M - ES9028Q2M - Audiophonics
I have this board in my Ian Canada 9028 dac. I could give it a try. But I agree with Doede, if this would be a good option he would integrated it in his design.
I have this board in my Ian Canada 9028 dac. I could give it a try. But I agree with Doede, if this would be a good option he would integrated it in his design.
NJM2114D is a supercharged NE5532. I would definitely look for something better. There are no modern OPA in the DIP8 case, only SOIC8, so you have to use an adapter (BrownDog), which again affects the sound a bit.
Or design as an SMD PCB from scratch.
Single-to-Dual Op Amp Adapter - BrownDog Adapters - 031101A
Or design as an SMD PCB from scratch.
Single-to-Dual Op Amp Adapter - BrownDog Adapters - 031101A
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