Having collected early user feedback by then, Raal Requisite found that "approximately half (or most) will find their tonal balance 'too open', 'tilted upward', 'too hot on top' etc." As such, they promptly introduced a very simple de-emphasis mod which disconnects one half of eight paralleled resistors in the adapter box with two simple cuts through the solid-core copper conductor. This doubles their de-emphasis resistance which stock was set for a flat measured response. By 2dB, the new resistive value lowers the presence region plateau of the open baffle which pivots at ~1'400Hz. After the snips, "the remaining four resistors increase dissipation by 47% each but won't double because increased resistance lowers the current. These particular resistors are already the cool units of the circuit which only start conduction above 1.4kHz where there's little sustained music power." Would I like to try this? Alex could send me a beater box sample with a hard-wired switch to compare on the fly. Naturally I agreed.
"I ended up making a 3-switch system that can leave all the de-emphasis resistors on or remove up to four in increments of one. Toggling any switch makes the change for both channels. Please find the below graph to show what happens. Switching is additive. If you want three resistors off, turn off both the 2R and 1R switches. This was so I could easily explore all meaningful options. I made one for you too. It turns out that I personally can take off one resistor but don't really want to do more. With my own recordings, I don’t need any taken off. Maybe I'd live with just one as that's a small difference but for me that'd be the max. For production, so many settings and switches are confusing so we'll keep to one, perhaps two. But first we want to establish which settings get the votes."
When the demo switch box arrived, I'd already acclimated to the SR1a's original de-emphasis value and loved it. Would I still hear any benefits? To stack my cards in favour of the switches, I moved downstairs to approximate Alex's setup. For amps I picked our 1MHz LinnenberG Liszt as probably our closest equivalent to his Benchmark Media. For a preamp, it was the actively buffered passive of Wyred4Sound STP SE MkII. For a source, it was Gold Note's CD-1000MkII with op-amp outputs, for software three unmastered albums with uncut dynamics and bandwidth before a mastering engineer dumbed things down for mass consumption. This would let me hear closer to what a recording engineer hears.
iMac ⇒ Audirvana 3 ⇒ Soundaware D300Ref ⇒ Gold Note CD-1000MkII ⇒ Wyred4Sound STP SE2 ⇒ LinnenberG Liszt ⇒ impedance interface ⇒ SR1a.
In this context of hardware and software, I found the SR1a's signature speed of steep transients and quite explosive dynamic tracking to completely dominate regardless of selected de-emphasis values. Should you relate to the audible effects of such mega reflexes as bright, hard or too explicit, even a 2¾dB shelving of the 1'400Hz hinge won't address it. In short, I didn't hear those aspects as frequency-response related. I heard them as direct results of zero energy storage hence blinding speed and very low distortion. What would shift things in your direction is to maximally fatten up your source feed.
I had on hand a Gold Note CD-1000MkII, its optional PSU-1000 power supply and optional T-1006 six-tube output stage. Combining CD-1000 + T-1006 built out body, weight and tone mass. That combo created a perception of 'slowing down' or 'softening' the leading edges and making dynamic changes a bit less drastic. CD-1000 + PSU-1000 enhanced dynamic elan. That worked the other way again. This was true also for the CD-1000 + PSU-1000 + T-1006 triplet. My takeaway was that should one desire to rein in the SR1a's reflexes, load up your source on tone mass and gravitas. If you need more, season with an amp like our Pass Labs XA-30.8. A paunchy valve preamp should work in the same vein. I'd consider that a bit like putting retreads on a powerful sports car but home hifi is purely about personal satisfaction. Whatever it takes is allowed.
But relative to feeling the switches, I had a problem. I had no use for them. To properly judge them, I had to revert to my state of ear/mind prior to the SR1a's arrival to hear the ribbons as once again slightly bright. Back upstairs it was to see whether I'd be a candidate for any higher de-emphasis than the original. Could I go back in time? Or had the SR1a trained me too well by then?
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