Simple Time Align ?

[Mr. Widget]

I try and keep the signal path as simple as possible I use a SPL 2602 Volume 2 Volume control after the DAC to the Ashley and direct to the power amps. Its a surprise to most people that a volume control can be an relatively expensive piece of equipment and itself can have a profound influence on the sound.

I have used a couple of different passive volume controls... they are theoretically a great solution, but they need to be carefully impedance matched to your source and load or they will very markedly change your frequency response. I have never been able to make one work for me as well as a good active line stage. Even when the response wasn't rolled off there was a lack of punch and immediacy... in your system you seem to have gotten it to work for you. Changing your crossover or other gear will change this delicate balance.

As for DEQX... it is fussy but powerful. I think it is a fantastic tool for designing and playing around in the DIY world, but short of using their digital in and out model with outboard A to D and DAC it isn't as good as a better all analog system. Their new HD versions are better (anecdotally, I have no personal experience) but there are other DEQX issues... for the right person I'd recommend them, but in general I'd go in that direction with caution.


Widget

[pos]

The SPL volume2 is an active volume control.
I am using the volume8 (8 channels version) in my setup and like it a lot. But on the other hand all my amps (old yamaha pro amps) also have a passive volume attenuator...

[grumpy]

Thanks for posting that ... Looks like a nice unit with
several applications... Some of which would be otherwise
difficult or messy... particularly the 8ch tracking.

[Mr. Widget]

The SPL volume2 is an active volume control.

So is it a unity gain line stage without input selection capabilities?

Widget

[pos]

I don't think it is strictly unity gain. There are no input selectors.

http://spl.info/hardware/monitor-con...surements.html

One thing I will check is the matching between channels at different positions.

[grumpy]

(Noting that I have a particular application in mind... but only peripherally related
to time-alignment)

To do much 'better' (e.g., 8ch balanced active with stepped attenuators) would be
-much- more costly. SPL may be converting to SE internally (fewer potentiometers)
then back to balanced, but I expect (opinion warning here) that this type of box
would be good or better than using an A/V receiver's 7.1 inputs to throttle multi-channel
DAC outputs before going into an active 4-way speaker system... a third alternative being
to reduce the DAC systems gain digitally (or A/D/A input level); which seems like a
non-optimum path to go down.

[pos]

yes it goes to unbalanced using custom made circuits (they do have very low CMR), and then throug an ALPS potentiometer.

here is a photo of the internals of the 2 chanels version :


the input/output cards are on the top left.

the 8 channels version is very simlilar, only with 8 of these cards and a longer potentiometer

[David Ketley]

Another upgrade that's proved very cost affective using the Musical Fidelity USB V-link bypasses the sound card and gives a very clean signal to the DAC. All digital volume controls on max as it seems to affect the sound?
CD still sound best ripped to hard drive then played rather than direct not sure why? I run 4 Musical fidelity power amps direct with no pre in circuit hence the SPL Volume2.