Hi Scott, I think that means the same thing....IOW, there isn't a further step.
I mean, all amp attenuation is AFAICT, is lowering amp sensitivity...padding its input.
...do amps even have true variable gain?
But it does, it always does. All you can do is minimize it.I'm talking about the analogue attenuation before the amp not casting aspersions on your digital prowess
My attenuation pre-dsp could have to be pretty severe- I use NCore (and other) amps, so trimming at amp definitely requires an extra pad in much of my use. Otherwise I’m knocking down the input by 50dB- too severe for me! I tend towards horns so the noise situation is key.
PC based is great but good balanced 6ch dacs (not to mention quality ADC) don’t exactly come in under budget. I suppose the thing to do is cash out my Marchand xm126 and use that to fund this adventure.
PC based is great but good balanced 6ch dacs (not to mention quality ADC) don’t exactly come in under budget. I suppose the thing to do is cash out my Marchand xm126 and use that to fund this adventure.
That could be me, I am using autoformers after 10Watt amps to power all horns system for normal listening levels. For volume control I am using digital volume (dithered?!) from player, just what Pano proposed. More than than, even the amps have only digital inputs, so the system looks like a "Powered DAC".
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Very cool!
@scottjoplin.......wow, your post about attenuation after the amp flew right by me, sorry
There's a Dante-enabled variant, as well as one for BLU link. I don't need that level of networkability and it's a couple hundred smackeroos for that added functionality.
With respect to signal sourcing, there would be a number of different sources used potentially, things like HT pre/pro outputs, digital source outputs, etc. While I'm looking for something to enable experimentation and want flexibility accordingly, the original intended application was to manage these things using hypex amplification:
http://www.jblpro.com/evo1/EVOi.324.pdf
I found them on C/L less the unreliable electronics, and the driver/horn tech is pretty sweet. This was a higher-end pro product, JBL just did a stupid on the overly ambitious electronics side. The 2430h is long in the tooth but still a well made driver, and the differential drive 14"s are really nice. The all aluminum baffle as heatsinking and venting is pretty darned cool. The horns interlock with the woofer frames, so you're almost locked into the system as-configured rather than using the drivers elsewhere.
For just the EVOI setup, I might be better off KISS principle and go with DSP power amps- a pair of the QSC PLD4.2 would probably settle the issue pretty handily, though I don't know how comfortable I am with the forced A/D. The nice thing with the dbx/computer/etc is I can run an digital in and skip the extra A/D. With integrated amplifier DSP I'm back to the input levels issue (high power/gain amps with efficient speakers at home) and noise possibilities, plus, I want to limit fans wherever possible.
Whew, lot of words there, but hopefully this clarifies.
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I does, I think. Still not quite sure what your sources are, maybe I missed that. Too bad about the added cost of DANTE, because it sure make life easy. You can run a virtual DANTE soundcard on your computer and route everything to that. No need for the extra A/D step.
How will you be getting your signal to AES format?
Pro amps have changed so much. They now have built in DSP, networking, things like DANTE, operating systems and so on. Thanks for the info on the speakers.
Still not quite sure what your sources are, maybe I missed that. Too bad about the added cost of DANTE, because it sure make life easy. You can run a virtual DANTE soundcard on your computer and route everything to that. No need for the extra A/D step.How will you be getting your signal to AES format?
Pro amps have changed so much. They now have built in DSP, networking, things like DANTE, operating systems and so on.
Thanks for the info on the speakers.badman, you have some nice toys....how do you like the NCore?
I don't know about the PLD 4.2, but the 4.5 fans are really noisy IMO.
Much more than a PL380, etc.
And like you say, the PLD's force an ADC on us...that's there major shortfall I think, lack of AES inputs.
The one thing that mitigates that a bit, is they have gain control on both inputs and outputs so you can really drop gain easy in a variety of ways...fan noise ends up being my main noise issue with them.
With a mixer, and putting a fader controlling each amp channel, I find experimenting, measuring, tuning/aligning multi-ways is really aided.
I also like the flexible output summing. I know it's a multi-channel waste, but the 4.5 makes a hell of a sub amp in 4 ch parallel mode...can drive 1 ohm loads !
But when i want quiet, it's time to set up some miniDSP icepowers (which as you probably know, do have AES in and DSP, even FIR)
I don't know about the PLD 4.2, but the 4.5 fans are really noisy IMO.
Much more than a PL380, etc.
And like you say, the PLD's force an ADC on us...that's there major shortfall I think, lack of AES inputs.
The one thing that mitigates that a bit, is they have gain control on both inputs and outputs so you can really drop gain easy in a variety of ways...fan noise ends up being my main noise issue with them.
With a mixer, and putting a fader controlling each amp channel, I find experimenting, measuring, tuning/aligning multi-ways is really aided.
I also like the flexible output summing. I know it's a multi-channel waste, but the 4.5 makes a hell of a sub amp in 4 ch parallel mode...can drive 1 ohm loads !
But when i want quiet, it's time to set up some miniDSP icepowers (which as you probably know, do have AES in and DSP, even FIR)
Pano: Sources are broad and mixed- everything from analog off a Linn to digital sources from squeezebox, roku, etc. Flexibility is key, which is why I didn't go ahead and buy something (plus, the costs here are not insubstantial to me).
Mark: NCore are sweet- I have monoblocks of the 400 and 500 models. They're both exceptionally neutral, powerful, and quiet and are superior to UCD (which is still a solid amp) and any other amps I've used. Noisy fans from the QSCs, no thank you!
The Minidsp icepowers are cool, but no 3ch variant is limiting, as is the 48khz sample rate requirement for the use of FIR filters.
Mark: NCore are sweet- I have monoblocks of the 400 and 500 models. They're both exceptionally neutral, powerful, and quiet and are superior to UCD (which is still a solid amp) and any other amps I've used. Noisy fans from the QSCs, no thank you!
The Minidsp icepowers are cool, but no 3ch variant is limiting, as is the 48khz sample rate requirement for the use of FIR filters.
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Likely a standalone switch/converter. I do have transformer based SPDIF/AES-EBU converters that work fine (lower voltage than spec, if I'm remembering the standards right , doesn't typically bother AESEBU receivers in my experience)
The Electrovoice DX46 is a nice choice too but like a number of MiniDSP configs, 48khz for FIR.
I have been meaning to build a flexible passive XO box for a long time- all these dollars and questions make me think that project might need to be front-burnered just to get things up and running. I suppose I can eke by with a 2 way setup if need be- just throwing an extra coil on one of the woofers for a 2.5 way, but that seems a waste when those EVOIs almost scream "3 way" for home use, to keep the midwoof from working too hard and make lobe management easier.
The Electrovoice DX46 is a nice choice too but like a number of MiniDSP configs, 48khz for FIR.
I have been meaning to build a flexible passive XO box for a long time- all these dollars and questions make me think that project might need to be front-burnered just to get things up and running. I suppose I can eke by with a 2 way setup if need be- just throwing an extra coil on one of the woofers for a 2.5 way, but that seems a waste when those EVOIs almost scream "3 way" for home use, to keep the midwoof from working too hard and make lobe management easier.
I bet I can guess what's inside the SPL Volume 8, and it's this chip:
Cirrus Logic CS3318
I used this very chip to solve almost the exact same issue; analogue volume control post-DSP and post-DAC for the best possible SNR. I have no complaints about it personally, I also build in static offsets in my firmware to account for differing driver sensitivities and impedances on each channel of the multi-way setup so the DAC works with as much digital level as possible even on efficient tweeters.
You'd need to add bal/unbal stages or use two chips to keep balance throughout (conversion to single ended in the box is probably better in reality) but it won't be too much work. PM me if you're interested since I have spare PCBs for this chip and may have some old firmware to get it running with a simple pot input control.
Cirrus Logic CS3318
I used this very chip to solve almost the exact same issue; analogue volume control post-DSP and post-DAC for the best possible SNR. I have no complaints about it personally, I also build in static offsets in my firmware to account for differing driver sensitivities and impedances on each channel of the multi-way setup so the DAC works with as much digital level as possible even on efficient tweeters.
You'd need to add bal/unbal stages or use two chips to keep balance throughout (conversion to single ended in the box is probably better in reality) but it won't be too much work. PM me if you're interested since I have spare PCBs for this chip and may have some old firmware to get it running with a simple pot input control.
I have used composite video switchers that were being discarded at work. They function just fine for SPDIF. I also got some Neutrik SPDIF to AES transformers for a good price on eBay. They worked fine and like you, no problems with the receiver chips and the low level AES.
But the question then comes back to the original. How to control volume? With a software player on the computer as the single source it's easy. With all those digital sources, maybe not.
I have located the original thread, the design changes quite a bit since the first post and the final board is on page 5:
CS3318 PCB Layout
See what you reckon, it's more work than an off-the-shelf controller but there may be benefits to you (mine has remote control, it can fit in aesthetically with your 19" units, you can level match your different drivers in analogue domain etc.) but I would recommend a bal/unbal stage I think, partially because the IC costs £20 so using two adds quite some cost!
CS3318 PCB Layout
See what you reckon, it's more work than an off-the-shelf controller but there may be benefits to you (mine has remote control, it can fit in aesthetically with your 19" units, you can level match your different drivers in analogue domain etc.) but I would recommend a bal/unbal stage I think, partially because the IC costs £20 so using two adds quite some cost!