I'm just burning in a very lovely Graham Slee Solo MC headphone amp to use with my AKG K-701 cans. As I'm new to headphone listening, I have a dumbass question.
A bit of background...
My source is a Squeezebox 3 running FLAC into a CIAudio VDA2 DAC via co-ax. At the moment, the DAC then goes straight into the Solo head amp (the DAC also feeds my MF A3.5 > Dynaudio S1.4 speakers at the flick of a switch).
I'm, not bothered about any switching control (the DAC can route the sound to my speakers when needed) because I will only use the head amp with this source.
So, bearing this in mind, is there any point [sonic advantages, as opposed to practicality] in me instead connecting the Solo to the Tape Line Out on my integrated, so it gets the DACed signal from there? Or would I just be passing the signal through circuits for the sake of it?
It seems circuitous, Michael. Is the switch between headphone amp and the MF on the dac? Is so, then you are plumbed in the way that I would do it as well.
Yeah, the DAC has two analogue outs - one connected to the Solo and one to the MF.
The only catch is that if - for whatever reason - I wanted the speakers on at the same time as the phones, one of them would have to be out of phase. The DAC has a 'phase' switch as opposed to a straight source selection switch - the two outputs are 0 and 180 degrees, with a 0 or 180 switch on the front.
But I suppose I could always reverse wire my speakers so they would really be 0 when the switch was on 180. Then both would be on 0 all the time. If you see what I mean...
Hard to explain without a visual, or unless you've seen a VDA2.
Just to clarify - at the moment, the source + DAC will feed both amps if they are switched on. But one of them will be out of phase. But that's the one I'm not listening to, so it's no biggie.
Tape loops are typically the simplest circuits in any pre amplifier. They include no gain circuitry which is where the majority of your problems begin in a pre amp or power amp. The switches for the loop function are normally the most deleterious devices in line with a tape loop, so consider how much you feel switches add or detract from the sound of your unit. There may be some buffer circuits in the tape loop to ensure impedance consistency between inputs and outputs but, unless you consider only "straight wire" type circuits to be of value, tape buffers are, for the most part, benign in their sonic effects. So, the tape loop should be OK for what you want to accopmplish.
Regarding the reversal of speaker leads, there is such a thing as "absolute phase". Some gain type devices, pre amps and power amps typically and a few devices such as CD/DVD players, will reverse the absolute phase of the signal. This results in a drum strike which should produce a rarefaction of the air - an in-going woofer - to become a compression of the air - an out-going movement of the woofer. Some people are more sensitive to this change in absolute phase than others and modern recording techniques often skew the absolute phase of various instruments within a single recording which then renders absolute phase of the signal to be not much more than a joke since none of the instruments are in absolute phase with the others. Multi-mic'd recordings can even produce single instruments that are not in absolute phase with themself - think ten microphones on a single drumset.
Listen to a few recordings you know well and reverse the absolute phase of the speakers, swap both speakers not just one which would thrown the system out of phase with itself, to determine whether absolute phase is an issue for you. If it is not, then your scheme should work. If it is, then you should consider another approach to getting both transducers - headphones and speakers - in phase with each other.
Just out of curiosity Michael, how does your SB3 compare to whatever digital source it replaced (I'm assuming you had a cdp previously ?). I have the VDA2 as well (fed by an Oppo disk player), and have been contemplating different implementations of frontending that. Just wondering about your experience if you don't mind sharing.
Even my non-cone Maggies are subject to absolute phase 'effect'. Some (most, actually) of the music I listen to most is not effected by the absolute phase switch. Some, mainly solo acoustic stuff IS. As luck would have it, since I sure didn't plan it that way, both my current integrated and my old NAD tuner/pre both had such switches.
I've opted to put the signal through the MF while I'm burning in the head amp and 701s, for convenience as much as anything, so that I don't have to shut the cans in the kitchen while I'm listening to a different source to the SB3. Plus, the SB3 > VDA2 > MF > S1.4 set-up is so sweet I just dont want to complicate it with phasing - even if it works out fine. But I'll probably end up routing the SB3/DAC signal straight into the Solo once it's all run in, just because its it's the most direct line to my ears.
To be fair, I can't actually tell the difference between via MF and direct at the moment (I'm no golden ears), but I am hoping for subtleties to be more apparent once the Solo and AKGs are fully up to speed.
With regard to Chris' query (and I'd refer you back to my earlier 'golden ears' statement), I can't really give you any true audiophile analysis. Previously I only had a NAD C315BEE running direct into the amp (which was fine, but I dig having all my music cued up at all times, so the CDP went) - the DAC was an SB3 motivated purchase. Along with a cheap (£15) linear PSU for the SB3 (CIAudio one might just follow at some point, if I ever decide I have too much money).
...Not that the SB3 was bad using its analogue outs, but with the Dynaudios (the AKGs are too young to really make a judgment, and I have been spoiled by those speakers), relegating it to transport duty with the addition of the VDA2 via co-ax made a biiiiiig difference.
All I can really say is that the set-up I now use all the time is as good as the A3.5 CDP I trialed (even if I still wanted it), albeit without an outboard DAC (which may or may not have made any difference other than creating a £1k transport, as opposed to a £200 one which does the same job).
Now, I have an obsessive personality (as I assume most people on here do) and I'm not feeling any immediate urge to upgrade my source at all. In short, it rocks and that's enough for me. For now...
BUT, if you have quality amp and speakers with that VDA2 (let alone neutral headphones and dedicated amplification) don't even think of playing any lossy files - you'll really miss those stray ones and zeroes [especially] in the lower end.
Thanks Michael. That helps. It's been something I've wanted to try for awhile. I haven't purchased any audio gear for over 6 months, but the rig is sounding so good I haven't felt the urge to mess with it.
