The "Crossover" is nothing more or less than two filters, one with a roll off to the upper frequency range (for the mid) and one with a roll off to the lower frequency range (for the tweeter). Of course there is more to be filtered, like the bottom of the mid (also crossover) and the upper of the tweeter (protection). And besides and maybe merely : make the frequency response more smooth than the horn normally (acoustically) allows for without aid.
The "active" part is in this latter and it only serves 3dB of more efficiency (without this feature the efficiency of the Orphean would be 115dB - now it is 118dB). So this is why two amplifiers are in order - one is to boost the tweeter more than the mid, so the inherent dip in the tweeter is now smoothed by filtering down all but the dip. I name this an "active" application because it is an amplifier which does something additional to the tweeter. In the end it is part of the filtering, which, as said, also is for smoothening bumps. Dips can't be smoothened - they need to be amplified (which is what in net comes down to in this case).

With outboard filtering the efficiency goes down by said 3dB or else this dip is there (bad for SQ of course). In the end there is thus also a different relation between mid-high on one side and the bass on the other (bass (also) needs to be attenuated by an additional 3dB if the active filtering is not present. Not that you would notice for real with the multi channel setup, because it would be one pile of "settings" anyway.


Theoretically this would be possible (if I am not mistaking) but whether it is worthwhile ... I doubt it. You (or someone else) would need to design the whole lot which thus starts with the normal filter part itself (think years of work). Notice that this has *not* been done inside of the Orelo because that is a high level filter (Speaker Level) with different components and very different impedances (all reacting differently than how they do now). It would be true, however, that there's not the downside of the additional A/D - D/A.

So this is
DAC -> Filters (Line Level) with 6ch output -> 6x Poweramp.

Thinking this over for a bit, I think it should exist - at least from older days when DSP was not available yet, but Line Level filters were (Speaker Level filters wouldn't exist anyway, IMO). I think I recall devices costing 4K or so. And they would really be active (with OpAmps).
Maybe this is far more normal than I am currently contemplating. Hmm ...
Didn't Linkwitz carry something like that ... (don't laugh now because in that case this is how you got the idea in the first place - right ?)

Peter

Many times I have been deliberating with Bert to replace the Hypex DSP with something like from MiniDSP.  And let's say that it never happened because of a lack of time or inspiration. Btw regarding the latter, like I think most people owning the Orelo MKII, I don't feel the slightest need to improve something. However, there's this awkward Hypex DSP in there (failing quite often for I think by now everybody) ...

Now please notice : The MiniDSP does not fit in there. So this holds back too. Other brands exist as well, but in all events it won't "just fit". So ... have it external ?

And this is exactly how I may start to be enthusiastic about the idea of the external amps and an "upgrade" to an external DSP. And please keep in mind : this upgrade has always been an explicit plan. But nobody really started about it, including myself ...

Assumed that the DSP of choice (could be any, when outboard) is of sufficient high quality (superb quality, actually), I think that the net result could surpass the current result vastly. I mean :

All of you use the NOS1a/G3 DAC in front of the Orelo MKII. But with a DSP like (possibly) proposed, this means
A/D
and back to D/A via the DSP itself.
This should lose the "quality" of the NOS1 ...
But what you'll get back is the bypassing of a mile of internal speaker wiring. Of course this has been set up carefully, but still there is all these wires. They will all be avoided.

So see ? it is not easy to get motivated for this, because you kind of know what you will lose (the NOS1's quality). And what you will get back can not really be estimated ...

...

A strict reason not to dive into this earlier, is the sheer fact that the DSP should be done in software. Thus, in the PC. Now there's no A/D in order and you can just use your NOS1's. Yes, indeed "1'ssss". Because you will need 3 of them. Or actually 6 channels of it.
This is how the NOS2 came into play, ever back. But that project was too large and failed.
Anyway, when the DSP is done in software, no additional A/D stage is in order and theoretically it is the best. But what comes from that is again an other DAC (6 channels all together). And still it would be difficult, because when we'd like to use that with 16x upsampling like we do today, there's no USB interface being capable (I think the fastest would allow for 4 channels, unless there's a USB3 audio interface available).

...

Net, the DSP solution between the two channel DAC and the power amps (6 channels of it) would be the only feasible option. Thus :

DAC -> DSP-6ch -> 6x Poweramp.

or

Turntable -> DSP-6ch -> 6x poweramp.

Regards,
Peter

Hi Ramesh - Good questions.

With multi channel input, what's expected is "speaker" level.
(btw, as far as I remember, you already used similar via "External Amp" for your Home Theater setup ?)

With the External Amp setting, all filtering remains active, but it is set up differently;
The filter "between" (as you call it) mid and tweeter normally is an active filter (controlled by two internal power amplifiers). When you use your own external amplifiers, that filter (the filter towards the mid and the filter towards the tweeter) are fully passive.

With "External Amp" the DSP remains active, however, the bass amps also remain active.

Now :
With Multi Channel, all filters are bypassed. The DSP for the bass also is bypassed, so you must provide your own DSP as well.
What this comes down to, is that with the Multi-Channel usage, you must provide your own filtering all externally. Regarding this, please notice that the design took the explicit standpoint that "ever" there would emerge a DSP with sufficient power (meaning : resolution) to also take care of the mid and high ... which back at the time I "forbid" with the too low sampling rate ADCs in order.

In order to understand the latter a but better, think of the situation that you could also take passive filters for mid and high (read : for the Orphean top horn) which would theoretically available from BD-Design in the form of an external box. This would be similar to the internal filtering and the "External Amp" setting, but surely not the same (the internal filtering was merely developed *) by me and my listening to the very Orelo MKII, while the externally available filter was developed by Bert and his listening on different type(s) of speakers).

*) : This is a large word, because the original base has been a development by Bert (I wouldn't have known where to start ;-), as how this was done for the Orphean Horn, when Bert created that. However, right from that start I myself further developed that filter (over a time span of many years) while Bert at some stage went his own route with it (and this own route already appeared in the first commercial speaker - the Swing). So I kept on developing the original filter and this continued with the Orphean.
This summarized : Obtaining the external pair of boxes from BD-Design would give you a head start, but it would not be to my liking at all. OTOH to be honest, while Bert never worked on his filter for the Orelo MKII (original Orelo MKI yes !!), I never listening to his filter (MKV IIRC) on the Orelo MKII. Why not ? .. it requires external amplifiers (haha).

To be continued in a next post ...

:-)

Ramesh - wow.
I wonder, would the stock cable of 1m80 have worked? At least that has been selected to work as error free as possible.

Haha, that your reporting about this possibly is not consistent. I mean, I recall that you could solve the issue (for more than one time).

The only real help could be my mentioning that it can happen that the lot is in error and stays in error until a reboot of the PC. Over here we can run into that too. When this happens, it was always encouraged for by disconnecting/connecting the main USB cable (we test all USB cables on this same (my main) system).

Because you seem to inconsistently report (read : encounter) these errors, I'd surely consider even more than you already do, external influences (like the example of your Led lights, what this ever back started with).

I propably already mentioned the combinations of the middle (grounding) switch on your NOS1 and the PE switch on the back of the Mach III (4 combinations there). I may not have mentioned the trialling you could do with Yes/No PE grounding of each of the elements you have in the chain (in your case minimally Speaker, DAC, PC).
Do notice the relation USB has to PE. Not that I ever solved USB errors with it, but it connects (the PC does that) so if you have the PC in PE I would remove that as a first (make a special cable, or easier - an extension block).

Peter

Hi Ramesh,


That is at least the same as our experience, with assembling the "good cable" also inside for its 15-20cm piece or whatever is required.

I now may wonder what happens when you'd put the Lush^2 in that position. Of course it is not a "short cable" any more in that case, but this isn't necessarily bad at all. Now I forgot whether you also have a Lush^1 but if you do, try the Lush^1 where you normally use the Lush^2 and put the Lush^2 in the "short cable" position.

I offer this option because that short cable could be highly sensitive to radiation and the isolation chips is also ...
And this is how the Lush^2 could explicitly be of help here (all the shields).

Peter

Haha, thank you for you kind words, Shreekant.

Kind regards !
Peter

Well guys ... sorry to hear this ...
For me it is the same. For "a whole world" it is the same.

I just sent a message to Tidal Support on what to do. I hope they ever answer, because I didn't contact them in years and possibly things have changed there.

Regards,
Peter

I really can't tell where it happened or what happened, but the offered download indeed does not show the a. But Scrolling works indeed (I just checked it).

Apologies for the confusion ...
Peter

Hi there Stanley,

I'm afraid it should show 2.11a. Thus you must be doing something "wrong" ...

Best regards,
Peter

So Jack ...

You're not one of the astronauts on Space-X, right ? You sound a bit like good-bye for ever.

What I certainly do get from this is how Covid-19 is getting to our nerves. Small example from this afternoon for us :

We were driving from Arnhem to the west a bit and back, just following a nice route. Hardly doable with a 1 million bicyclists on our track (they own the small roads these days), so half way we took a short cut on that route and decided to visit family in Arnhem. Our son Paul was driving (all right, he was our friendly chauffeur) and his mood went bad. Why ?

He is now more than two months performing his (EE) graduation from home while normally this would have been at the firm hospitising him for his graduating internship. On a side note : he is the only one from his group who will manage to graduate because all others failed to arrange for this "working at home" in time and the others will continue with that in October.
And thus his mood went bad; we shouldn't visit family, of which she out of all is practising physiotherapy.

And so I changed the navigation to "back home" and there (45 minutes later than could have been) I grabbed my beer (I am lying a small part here ).

The moral : in the G-D 4 hour trip nothing was open for a beer.
This is killing, right ?

Jack, next time you reach Arnhem, step on it and end up 50Km or so more north for a beer. Last time we miserably failed.

Peter

This is now solved in 2.11a.

People can download this and unRAR and paste over the XX folder of the existing 2.11 version (and only 2.11 !) :

[removed - is now contained in the normal Download files]

Peter

Hey ...
Yes, I know, this is a bug I introduced close to putting 2.11 to production and I couldn't find the solution easily.
It's in that ToDo I showed (with *) ...

I will try to solve it soon.
Kind regards,
Peter

Hi Fralippo,

The so-called Release Notes of this version, tell that I searched for this bug endlessly, but that I can't find it. And worse : this has been solved at some stage, but it sneaked in again.

As far as I can tell this only happens from album to album (so have a playlist with ten tracks from 10 different albums and it occurs after each track). So surely it happens at the end of the playlist.

If it occurs to you with an SFS of 0.39, well, then you have "noticing" ears. Of course you can hear it because a "chop off" really occurs, but this will now be so marginal that I would have difficulty in knowing. With an SFS of 10.19 it will be dead-clear alright.
And if you now tell me "but this really does not matter for chopped off length" then I have been debugging in the wrong direction ...

Kind regards,
Peter