Info needed to choose DAC

[GaloDourado]

Hi all,

after been reading a bit here about DACs, I could understand that I really need a DAC, but still some doubts about what to choose.

I see that Beresford products Caiman and TC-7520 are very popular here with good reviews from almost everybody using them (modded or not), so I'm almost decided to use it in the project that I'm planning... if you can help me here to confirm that it can be used for what I need with the equipment I'm planning to run.

My gear project is as follows:
Laptop -> DAC -> miniDSP's -> Rotel's -> Speakers

1. Use laptop to play FLAC files as only music source (at least at this beginning point)

2. DAC USB connected with PRE-amp
.... To be decided here

3. Dual miniDSP used as eq + xover (for triamping)
.... http://www.minidsp.com/images/documents/Product%20Brief-MiniDSP%202x4%20Box.pdf

4. Rotel RB-976 -or RB956- (mids and highs)
.... http://www.rotel.com/content/manuals/rb976_eng.pdf

5. Rotel RB-981 (woofers)
.... http://www.rotel.com/content/manuals/rb981_eng_fre_ger_spa.pdf

6. Speakers will be DIY (1x Neo3PDR, 1x Neo8PDR, 2x Dayton RS225)


So now the questions:
1. Is there a real need to use an external preamp if using a pre-amp DAC?
2. I can not see output RCA voltage info about Caiman or any other DAC, so I an unable to decide if I should go for Rev.A (0.9v) or Rev. (2.0v) of the miniDSP. Anyone knows this info or can point me some light here?
3. Do you see any problem with impedances in the chain (DAC->miniDSP->Rotels) ?

I'm writing this post thinking in following the Caiman route, but is there any better alternative (DAC with USD input + preamp) within the 200€ range?

Sorry for long post :whistle:

[technobear]

For best performance, you need to feed a fixed signal to the DSPs such that digital maximum from the source gives 2V into the DSP (the output level of the Beresfords is not specified on the Beresford website).

Because these DSPs perform analogue to digital conversion and therefore need a full-strength input signal in order not to degrade the sound, it is not appropriate to put the volume control before the DSP. You must put the volume control after the DSP.

This suggests that you should feed the 6 channels of output from the DSPs into a 6-channel AV amp to perform volume control and drive your speakers.

[GaloDourado]

How much audible sound difference can I expect from having volume control before/after the DSP?

From what I've read, there are different opinions regarding this matter, people that tell there is audible difference and others that have not found any difference when tested both ways.

I would prefer to avoid using AV preamp is possible, an also I don't know if any AV can accept 6 channel input at same time!

[StanleyB]

How much audible sound difference can I expect from having volume control before/after the DSP?

From what I've read, there are different opinions regarding this matter, people that tell there is audible difference and others that have not found any difference when tested both ways.

It depends on the equipment set up. Get a DAC and find out how much audible difference it makes in yours. Any other answer from anyone is pure guess work.

[The Vinyl Adventure]

suck it and see is the only real answer, you are the only important judge when it comes to what makes a difference and what doesn't

most passably decent av amps have 6 channel inputs for things like sacd and taking analogue connections from blurays players etc

why dont use just use an analogue pro crossover ... im looking at using a behringer cx2130... a cx3400 does 3 way stereo ...

[StanleyB]

... im looking at using a behringer cx2130...
I see a classified add coming up soon afterwards...

[GaloDourado]

It depends on the equipment set up. Get a DAC and find out how much audible difference it makes in yours. Any other answer from anyone is pure guess work.

Yes, I think it should the best way to find it out.

Do you see some problem or imcompatibility between Caiman and miniDSP regarding impedances?




why dont use just use an analogue pro crossover ... im looking at using a behringer cx2130... a cx3400 does 3 way stereo ...

miniDSP offer a lot more flexible tunnig capabilities and also give me the option to make a 4way (in case I need to add a subwoofer later)

[Peter Galbavy]

Sorry, but I'm just not getting it. You are going to go:

Digital -> Analogue -> Digital -> Analogue -> Amp ?

Every time you convert from one domain to another you introduce entropy. While a quick look at their website shows that minidsp do not do a digital input to the dual output device, it does seem like it shouldn't be too hard to avoid a seperate DAC entirely and either use their other kit or get something similar and cut out 3 of the conversions...

[The Vinyl Adventure]

I see a classified add coming up soon afterwards...

shit is it?

[Reid Malenfant]

This is just a suggestion & it'll cut out a load of digital/analogue conversions :)

Why not get a USB to S/PDIF interface & then making a small transformer on a ferrite bead mount this inside of a decent phono plug & run a balanced 110 ohm digital line to a Behringer DCX-2496 as this will accept a digital input of up to 24 bit & 96Khz. The DCX is a digital crossover which then converts to analogue on up to three outputs per channel.

You'd then need a single 6 way ganged volume control or stepped attenuator for volume control. It keeps everything in the digital domain up to the outputs of the DCX crossover

DCX-2496 Ultradrive Pro (http://www.behringer.com/EN/Products/DCX2496.aspx)

[Reid Malenfant]

shit is it?
If you call an accurate crossover with distortion as low as a quality pre amp shit then yes, i guess it is :eyebrows:

Given the choice between any passive xover & a shitty Behringer i know where i'd put my money. Do we like 0.5% distortion or do we prefer less than 0.005%?

Years ago i designed & built a really crappy 3 way active xover on vero board that wasn't in a box or anything. This fed a load of ILP HY60 amp modules which powered my DIY loudspeakers. The result was absolutely stunning & i used bloody awful LF347 ICs, not low noise ones as fitted in the Behringer ;)

[Vincent Kars]

Maybe a multi channel sound card and a tool like this?
http://www.thuneau.com/allocator.htm

[GaloDourado]

Sorry, but I'm just not getting it. You are going to go:

Digital -> Analogue -> Digital -> Analogue -> Amp ?

Every time you convert from one domain to another you introduce entropy. While a quick look at their website shows that minidsp do not do a digital input to the dual output device, it does seem like it shouldn't be too hard to avoid a seperate DAC entirely and either use their other kit or get something similar and cut out 3 of the conversions...

Yes, you are right.

Only now I saw that they are selling also the "miniStreamer" that should do exactly the same as an external DAC... but I did not find any review about the sound quality you get with that combination.

I would need and aditional control volume in this case, but it seems to be not so dificult based on the manual instructions, only a 10k linear potentiometer.


This is just a suggestion & it'll cut out a load of digital/analogue conversions :)

Why not get a USB to S/PDIF interface & then making a small transformer on a ferrite bead mount this inside of a decent phono plug & run a balanced 110 ohm digital line to a Behringer DCX-2496 as this will accept a digital input of up to 24 bit & 96Khz. The DCX is a digital crossover which then converts to analogue on up to three outputs per channel.

You'd then need a single 6 way ganged volume control or stepped attenuator for volume control. It keeps everything in the digital domain up to the outputs of the DCX crossover

DCX-2496 Ultradrive Pro (http://www.behringer.com/EN/Products/DCX2496.aspx)

I don't think I have the knowledge to try that :(