A dual opamp (and associated power supply decoupling caps, but that's a given, right?) and 6 resistors (7, if you want easily adjustable gain). That's all it takes. That's trivial by any standard - the Cmoy is often touted as the ideal beginner project, and this is no harder. Putting it on the board takes a little space and requires more input connectors, and I imagine that's why it was omitted.
You'd just have to take a little care that your inputs weren't too hot - since a balanced reciever typically has a gain of 2, it'd be pretty easy to exceed the 2V input spec of the Rev. B miniDSP.
You'd just have to take a little care that your inputs weren't too hot - since a balanced reciever typically has a gain of 2, it'd be pretty easy to exceed the 2V input spec of the Rev. B miniDSP.
I have lots of those... can't bear to struggle with Windows, it offends my sense of elegance. When i get my Intel Mac i'll bear it long enuff to install VMWare & Parallels and set them so that i only have to deal with the applications.
dave
Alright.. let's try to combine a couple of answers to your good questions! 
No matter how hard we try, there will always be something else... So our answer to your needs (e.g.you need balanced in, but plenty of our users don't need to drive long distances), is to provide a motherboard (i.e. miniDSP kit) + I/O cards (SPDIF/Balanced/Amplifier). It may be a concept a bit hard to wrap your head around at first, but think of the PC market. Did u "ever" find a motherboard that had everything you needed? Most likely not... You had to buy the video card you liked (and was willing to add extra money for the extra RAm you need for your application), the sound card at the price point you were willing to spend... etc... miniDSP kits + I/O cards are exactly the same. Hope that clarifies a bit the concept of why we have a barebone board, shipped at the lowest cost, smallest size, that goes with other I/O cards to fit peoples needs. The more flexible we keep it (and away from trying to add too many features per board), the more freedom we give to our end users.
As "TheSeekerr" points out very well, if you can't wait for our balanced in/out card, building a balanced input is indeed quite simple and this forum is really loaded of information on how to do it. Do a search on balanced preamp/line receiver and have a look at the That recommendations I gave. You'll see that it's indeed just few parts and there are a lot of very easy to get information out there.
Hope this info helps.
We understand your point of view (as a pro audio guy) but as we try our best to explain in the product concept page, the perfect product with the perfect I/O configuration that fits everybody's needs doesn't exist. Period.
No matter how hard we try, there will always be something else... So our answer to your needs (e.g.you need balanced in, but plenty of our users don't need to drive long distances), is to provide a motherboard (i.e. miniDSP kit) + I/O cards (SPDIF/Balanced/Amplifier). It may be a concept a bit hard to wrap your head around at first, but think of the PC market. Did u "ever" find a motherboard that had everything you needed? Most likely not... You had to buy the video card you liked (and was willing to add extra money for the extra RAm you need for your application), the sound card at the price point you were willing to spend... etc... miniDSP kits + I/O cards are exactly the same. Hope that clarifies a bit the concept of why we have a barebone board, shipped at the lowest cost, smallest size, that goes with other I/O cards to fit peoples needs. The more flexible we keep it (and away from trying to add too many features per board), the more freedom we give to our end users.As "TheSeekerr" points out very well, if you can't wait for our balanced in/out card, building a balanced input is indeed quite simple and this forum is really loaded of information on how to do it. Do a search on balanced preamp/line receiver and have a look at the That recommendations I gave. You'll see that it's indeed just few parts and there are a lot of very easy to get information out there.
Mmmmh, I'm guessing that you're trying to build a Left/Right highpassed with satellite speakers + 1 Sub? We're planning to release such version but with the PEQ (6each bands) on outputs, instead of the current graphic EQ on the input. It will be what I think you're looking for. No release date yet but in the pipeline.
Hope this info helps.
Mmmmh, I'm guessing that you're trying to build a Left/Right highpassed with satellite speakers + 1 Sub? We're planning to release such version but with the PEQ (6each bands) on outputs, instead of the current graphic EQ on the input. It will be what I think you're looking for. No release date yet but in the pipeline.
Hope this info helps.
Yes, almost, a Left/right satellite and 2 switchable subs...
If we forget about the equalization for the moment, with the minidsp and the actual pluggins, is this setup possible?
Output1 = highpassed left input
Output2 = highpassed right input
Output3 = lowpassed (left+right input)
Output4 = lowpassed (left+right input)
This configuration is actually a very simple modification to the Stereo Crossover configuration. (i.e. just mixing the post EQ L&R for output 1&3 going to the Sub). So while it's currently not available, I could easily make up a new configuration for that one.
Note that however the EQ will be Pre Xover. Many years ago, in my live sound days, I've never found it to be a problem having a graphic EQ for L&R to make a system sound great. It's only lately with the advance of DSP and PEQ, that people got used to having PEQ on in&outs and now feel that they won't be able to get a system working without them...
Anyway, if you want to get a board with it, let me know and I can always build a new plug-in since it's an easy fix.
Interesting product.
Why don't you support 44.1? It is the most obvious SR which IMO should be supported to stay away from SRC.
Is it possible to run the board without PC , once it is configured? Does it keep the configuration also after power-down/up?
When do you plan to come up with 48db slopes?
Any specs SNR/Jitter?
How about Linux support? Would at least the standard USB driver work for playback? (configuration could be done under Windows - in the beginning as a workaround)
How about power consumption?
THX a lot.
Why don't you support 44.1? It is the most obvious SR which IMO should be supported to stay away from SRC.
Is it possible to run the board without PC , once it is configured? Does it keep the configuration also after power-down/up?
When do you plan to come up with 48db slopes?
Any specs SNR/Jitter?
How about Linux support? Would at least the standard USB driver work for playback? (configuration could be done under Windows - in the beginning as a workaround)
How about power consumption?
THX a lot.
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Hello Soundcheck,
Let me try to answer your questions, some which could be answered by having a look at our FAQ's.
Also bear in mind that the USB is for control only. miniDSP kits are not a USB audio streaming device, so playback isn't going to happen.
Hope this information helps,
Let me try to answer your questions, some which could be answered by having a look at our FAQ's.
Sampling rate of 44.1 is indeed typical for digital CD audio sources, but not so typical when it comes to DSP units. (48/96/192 being more typical). We do plan to release plug-ins allowing each of these sampling rate (inc 44.1khz), but just haven't had the time to get to it yet. Right now focus for the past few months has been building a hardware and plug-in portfolio. Adding different SR versions can be done from there.
Yes to both answers, please have a look at our FAQ's for more info.
No date as we don't want to make anybody feel we ought to release a plug-in even if it hasn't been tested to our expectations. It will come out but requires quite some redesign from the current firmware. We're so far busy with new hardware cards and other features our miniDSP community members asked for, so this feature may have to wait for maybe few weeks.
Our tests show >98/99dB for SNR. We say > because we always de-rate our measurements.
Errh, wasn't the exact same question just asked right below??? Do i need to say it again?
Also bear in mind that the USB is for control only. miniDSP kits are not a USB audio streaming device, so playback isn't going to happen.Boards run about 250mA @5V so well within the specs of USB self powered. Please check spec sheet and our website for more information.
Hope this information helps,
THX for the feedback.
Sorry - I missed your FAQ.
I think 44.1khz and 48db slopes are pretty basic features for a DSP crossover.
I'll for sure wait until these are supported.
No idea if that has been asked before:
What's the maximum delay I can apply per channel?
What's the overall latency? How big is the input buffer?
So - now I'll read your FAQ.
Cheers
Sorry - I missed your FAQ.
I think 44.1khz and 48db slopes are pretty basic features for a DSP crossover.
I'll for sure wait until these are supported.
No idea if that has been asked before:
What's the maximum delay I can apply per channel?
What's the overall latency? How big is the input buffer?
So - now I'll read your FAQ.
Cheers
Let me try to clarify a couple of things about Sampling Rate.
- If you decide to input I2S to the miniDSP kit as a Master. So the question is: Which device would you use to input I2S @ 44.1kHz? Most likely, you'll get 44.1kHz if you use a digital source like an SPDIF source from a cd player. If that's the case, then use our SPDIF I/O card with Sample Rate Converter embedded to get the I2S to 48khz. As for putting the miniDSP in between 2 digital devices (I2S in&out), ask yourself which one will be the master/slave first.
This being said, we'll one day release the 44.1kHz, but I just wanted to clarify what sounded like a mis-understanding about SR and that the fact that it doesn't support it currently may be a non issue depending on how you're using the board.
What would be the case where you would need 44.1kHz input?
- If you decide to input I2S to the miniDSP kit as a Master. So the question is: Which device would you use to input I2S @ 44.1kHz? Most likely, you'll get 44.1kHz if you use a digital source like an SPDIF source from a cd player. If that's the case, then use our SPDIF I/O card with Sample Rate Converter embedded to get the I2S to 48khz. As for putting the miniDSP in between 2 digital devices (I2S in&out), ask yourself which one will be the master/slave first.
This being said, we'll one day release the 44.1kHz, but I just wanted to clarify what sounded like a mis-understanding about SR and that the fact that it doesn't support it currently may be a non issue depending on how you're using the board.
Please have a look at our plug-in spec sheets since it depends on each DSP configuration. Most of them support 7.5ms/ch.
We did some measurements for each plug-in but don't have them in front of me as our engineering staff is on Chinese New Year Break. I remember being in the order of 1.5ms or so, but can't be definitive. will look into it and get back to u.
98% of music data is 44.1.
Upsampling of 44.1 to x*48 should be avoided in any case. Your sound quality will drop.
Not only that the filtering done by your DSP will deteriorate the sound ( which might be an acceptable compromise in comparison to a HW crossover), you'll also face losses
due to resampling. That's IMO too much.
Serious audio equipment should support native sample rates.
I do understand that going the x*48khz route is the more easy way for you guys at the current stage. I am just saying that many people - including me - won't buy the board exactly due to that reason.
And again 48db slopes are also a must. Even a Behringer DCX2496 at 200$ can do that and a lot more. The Behringer I'd consider a kind of Benchmark for you guys.
Please consider this as constructive feedback. There are not very many use cases for your board. Using a PC as DSP (at 64bit!) would be by far more efficient in most cases. With a PC you can even run a convolution engine beside the crossover.
Your DSP comes in if you want to go active with a Squeezebox or a CDP, where just one I2S channel is available.
If you can hook up your board against a master clock, you might be able to use it also as reclocker of the I2S stream. In this case the Jitter performance of your device becomes
pretty relevant. The least one would expect is that your device runs at x*MCLK to avoid interferences with the signal.
Cheers
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In terms of functionality yes... it leaves a lot to be desired in sound quality -- at least the one i tried.
BTW, price is closer to $300.
dave
I guess you are aware of the DCX tweaking threads over here at DIY-A.
With some easy and low budget mods it'll play in a different league.Agreed. Price is 200€ over here
( I got mine at 100€ on Ebay.)Anyhow - we shouldn't forget that DACs, PS is all included. I still consider the DCX as
benchmark (price-features-performance) for the miniDSP for now.
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