Detail improvement?

discussion of magnetic volume control design for both line and speaker levels.

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mantisory
Posts: 3
Joined: Tue Nov 08, 2011 4:09 pm

Detail improvement?

Post by mantisory »

Hi everyone,
So I finally put together a passive attenuator using Dave's AVC modules, and I must say it is pretty fantastic! Very balanced and pleasing sound, top to bottom. It's a good thing, because I really am a bit ham-fisted and may not take well to playing with gapping them :)
Anyway, I had a chance last night to compare it directly to a Nagra PL-L and, while the AVCs were by far preferable (the Nagra is cold, steril and just lifeless with no PRAT or musicalty), the Nagra did present loads of detail and texture that the AVC simply did not. Especially in the upper bass and lower mids...
So, I suppose I am wondering - what is it that determines the amount of detail that is getting through on a signal? Is there a point, such as in the Nagra, where detail overrides the sound, and the essence of the performance itself is lost? Is there something that can be done with AVCs to bring out more detail without killing their overall great sound?
I realize these questions are perhaps not super-technical and may open a can of worms, but, well, I am just wondering :)
Thanks for any ideas and/or suggestions you may have.
Byron
mantisory
Posts: 3
Joined: Tue Nov 08, 2011 4:09 pm

Post by mantisory »

guess not, eh?
:)
I actually spoke to another user of autoformer-based preamp and he had the same experiences, so I suppose it's really something inherent to autoformers in general?
I don't mean to sound negative at all, because I really DO like the sound of these AVCs...
byron
beeah
Posts: 1
Joined: Thu Nov 10, 2011 1:33 pm

Post by beeah »

Give them a few hundred hours, then report back - I think you'll be, as they say across the pond, gobsmacked.

Mine have just recently (and suddenly) "opened up" after a month plus of nightly listening, and the difference is not subtle.
mantisory
Posts: 3
Joined: Tue Nov 08, 2011 4:09 pm

Post by mantisory »

yeah, that's kinda what i've been thinking. thanks for that.
b
DrGizmo
Posts: 1
Joined: Sat Jun 11, 2016 6:27 pm

AVC Detail Retrieval

Post by DrGizmo »

AVCs, as with all magnetic field derived signal devices, require some break-in time. The amount of time varies with signal amplitude, along with driving and load impedance. Purchased 2 sets of Slagleformers from Dave a couple of years ago and noticed detail improvement after just 40 hours of use. Also found that mounting the magnetics in a dedicated metal enclosure produced more favorable results than collocating them near field producing electronics. I have mine inside a copper enclosure where the metal case shares the 0V return (ground).

FYI: The input of the AVCs are driven by an Audioquest Dragonfly v1.2 DAC, and the output feeds directly to the input of a home brew hybrid tube / MOSFET class A 22 WPC amplifier.
dirkwright
Posts: 56
Joined: Sat Jul 25, 2015 9:50 pm

no "break in' time

Post by dirkwright »

There's no such thing as "break in" time when it comes to magnetic devices. There is simply no relevant feature or quality of the device that would require any kind of "break in". The voltages are far too low to make any difference to anything. The magnetic circuit does not change either. I don't get it with these fantasies that audiophiles create. It's really all in your head.
dirkwright
Posts: 56
Joined: Sat Jul 25, 2015 9:50 pm

Re: Detail improvement?

Post by dirkwright »

mantisory wrote:Hi everyone,

Anyway, I had a chance last night to compare it directly to a Nagra PL-L and, while the AVCs were by far preferable (the Nagra is cold, steril and just lifeless with no PRAT or musicalty), the Nagra did present loads of detail and texture that the AVC simply did not. Especially in the upper bass and lower mids...
So, I suppose I am wondering - what is it that determines the amount of detail that is getting through on a signal? Is there a point, such as in the Nagra, where detail overrides the sound, and the essence of the performance itself is lost? Is there something that can be done with AVCs to bring out more detail without killing their overall great sound?

Byron
If you are using the autoformer on its own with no active electronics, then your particular implementation of the device will determine how it performs, including cable lengths and type, as well as other issues like the source and load impedance for the autoformer. If you have a long cable on the output, then you are probably going to lose a lot of information because the capacitance of the cable will interact with the inductance of the autoformer and limit bandwidth dramatically.

The lack of an active device is the main issue as I see it. The Nagra is an active tube preamp. At the very least, you should have far less noise with the autoformer. If you have more, then there is a problem with your implementation.

To make these things really sing, you need an active buffer on the output of the autoformer.
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