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Hi-end DSP based multi-channel integrated Preamp/Crossover/DAC project

For what i understand about this dsp/dac/preamp, it's an unbelievable bargain! Sure i'll get one as soon as i have enough money! It's hard to believe that price could be lowered, even with mass production...
Anyway, are onboard opamp replaceable for opamp rolling?
If they aren't, could a customer request dip sockets onboard instead of opamps?
 
performance measurements

I possibly missed this along this thread, but some measurements have been taken? (distorsions, THD+N vs frequency, noise floor, balanced frequency response (in path-through mode), etc ?)

Would also like to know these in part because they are (to me anyway) essential to know before buying and also to see how well they compare to a high quality analogue active crossover.
 
Have done some preliminary measurements through an EMU0404 external USB sound card and the measurements look very favourable. Until I get some well specced and calibrated test and measurement equipment there's probably not much point in publishing the results as you don't know how much you are measuring is the DUT and how much is the imperfection of the measurement device.

cheers
 
For what i understand about this dsp/dac/preamp, it's an unbelievable bargain! Sure i'll get one as soon as i have enough money! It's hard to believe that price could be lowered, even with mass production...
Anyway, are onboard opamp replaceable for opamp rolling?
If they aren't, could a customer request dip sockets onboard instead of opamps?

There's two problems with that idea. Firstly there is not enough board space to incorporate DIP sockets and secondly different opamps require different compensation schemes.

cheers
 
Managed to fix up some driver issues with my E-MU 0404 sound card and downloaded the latest trial version of Spectra Plus. Here are some distortion and noise measurements. The crusty bits in the HF spectra on one channel(top trace) is from the sound card because when I swap outputs it still remains on the same channel. The source generator is a precision 32 bit sinewave generator built into the Ultimate-Preamp. Note that these are not measurements that are done on a reference grade calibrated measuring instrument.

Distortion and Noise at 50Hz:

DistortionTest@50Hz-20dBfs.png

Distortion and Noise at 1kHz:

DistortionTest@1KHz-20dBfs.png

Distortion and Noise at 10kHz:

DistortionTest@10KHz-20dBfs.png
 
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Just ordered a full up variant (my retirement present).:D

Soooo looking forward to its arrival.

Took a while to get my head around digitizing EVERYTHING (even vinyl playback) but i figured that the virtues of this device and design far outweigh any perceived drawbacks (and they are really just prejudices on my part).

It will be driving six channels of Tom Christiansen's MODULUS 86 which is built and working with very pleasing results.

As the snow boarder's say..."totally stoked".

Matt
 
Yes the online shop is correct. Most of the small initial production run of pre-assembled Preamps have been sent out to customers and the feedback has been very encouraging to say the least. We are now working on producing the next batch of preamps with the focus on streamlining the manufacturing process with less manual intervention now that the design has been proved.

We'll be making an announcement in March as to our plans and stock availability. Thanks for your patience.
 
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Hi David;

Just a couple of questions about the capabilities of the pre-amp.

1. Is it possible to store more than one configuration in the unit and call it up (i.e. a couple of different crossover configurations , slopes, delays etc.) without re-connecting to a PC?

2. Is it possible to say use six of the eight outputs to as crossover outputs to power amps while also using the other two as full range outputs driving a headphone amp? I would think that this one is a no brainer yes.

Sorry if these are already answered somewhere.

Thanks (can't wait!)

Matt
 
Hi David;

Just a couple of questions about the capabilities of the pre-amp.

1. Is it possible to store more than one configuration in the unit and call it up (i.e. a couple of different crossover configurations , slopes, delays etc.) without re-connecting to a PC?

2. Is it possible to say use six of the eight outputs to as crossover outputs to power amps while also using the other two as full range outputs driving a headphone amp? I would think that this one is a no brainer yes.

Sorry if these are already answered somewhere.

Thanks (can't wait!)

Matt

1. I did inquire about this a while ago so not sure if they have added it. If not I will post this request on the dspconcepts forum.

2. Most definitely you can do this.

regards
david
 
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:cop:

This thread has now been moved to the vendor forums.

The reason is because it appears to fall outside the general forums remit (as opposed to vendor and commercial forums) of normal 'diy' construction, which would necessitate sharing of circuit details, PCB's and the like.

Thank you for your understanding.
 
I can't wait to order one of these.

1) Is the 5-way configuration which uses the digital output in combination with the analog outputs working yet?

2) Is there a way to feed 4 analog inputs into this and mix them within the DSP?

Hi Pultzar

Still working on it. Should be OK.

The ADC chip we use only has two ADC's. There is a version that is a drop in replacement that has 4 ADC's but the I2S output uses TDM and so requires different programming of the DSP but we have not tested it.

Regards
David