After about 1 month of ownership, I found that the sweet spot of the SR1a – in the context of my system where I have the Abyss TC and the Riviera AIC-10 (10W only) amp – is, as per my previous post, with acoustic music listened at moderate level.
Baroque, jazz, vocals, solo stringed instruments all sound wonderfully realistic, and the timbre matching between the AIC-10 (equipped with a warm-ish tube like a Mullard vintage CV4003) and the SR1a is extremely satisfying, and can be further finely tuned with a very modest EQ (in my case some bass boost under 80Hz and a slight dip around 7.5kHz).
Outside this sweet spot, I use my Abyss TC (no EQ needed) and I could live pretty content with this complementary setup, of course.
But, being an audiophile, I could not resist the itch to investigate whether / how much I can expand the envelope of situations where the SR1a outperforms the TC.
Plan A would be to find an amplifier able to drive both TC and SR1a at their max, thus replacing the AIC-10. This is most likely to end up being a very expensive plan, because to match the AIC-10 sound quality and at least 100W of output power is not going to be easy.
Nevertheless, this is what I am investigating right now.
I visited a high-end audio shop a few days ago, where I spent a whole afternoon trying a few nice amplifiers with my two headphones.
I first started with a Krell 300-I (150W on 8Ohm). This session was very brief, as I did not like the pairing with the SR1a at all, due to an excessively bright and hard sound signature.
Next came the NAGRA Classic Amp (100W). Much better! A very transparent and liquid presentation with both SR1a and TC, with a pretty neutral and refined character. Compared to the AIC-10 / Mullard, tonality was slightly colder.
The additional power allowed much more satisfying listening levels with the SR1a, a more spacious and layered soundstage (especially noticeable with large orchestral works). However, the lack of bass oomph that prevents me from considering the SR1a an all-rounder within the whole of my listening programs still stays. Organ, the lowest resonant notes of tympani or double bass section attack, or hip hop / electronica sub-bass rumble were basically non-existent with the SR1a, thus robbing a significant part of my enjoyment of some tracks of my playlist. The Abyss TC still provide an overall better experience, in my opinion / tastes, for musical content where the energy, volume and extension of the sub-bass region is necessary.
By looking at the NAGRA VU meter, it reached the end of the scale (100W on 8Ohm) several times when I tried to listen to quietly recorded classical music at spirited levels, when the bass kicked in. Soft clipping was audible with some extreme tracks played at first-row concert-like SPL (e.g. Rikard Nordraak Funeral March, Reference Recordings).
My last audition was also the longest and the more enjoyable: enter the DarTZeel LHC-208.
This is an all-in-one streamer-DAC-amplifier (200W) which sits at the entry level of the DarTZeel offering. It lists for 17kEuro, where the next amplifier from DarTZeel is the 28kEuroCTH-8550 (which I could neither afford nor audition, sadly).
The LHC-208 has a warm, inviting sound with a very sweet treble, a rich (not over-)saturated midrange and a bloom in the bass which – all put together – significantly change how the SR1a (and the Abyss TC) present sounds to your ears compared to a more linear amplifier like the NAGRA.
If you want to further leverage on the unique strengths of the SR1a (speed, transparency, resolution, treble extension etc.), this may not be the best option.
However, in my case I was happy to trade-off some transparency for the added meat to the bone the DarTZeel provided to the RAAL in the low end (more present bass, longer decay times), the additional harmonics richness of the midrange and the softer treble.
Also, with 200W on tap I found no situations where the DarTZeel was struggling to handle even dramatic dynamics swings at any listening level / frequency range. The additional body in the bass region made the SR1a feel warmer overall, and ... bassier of course, yet still the sub-bass response was not extended enough to capture some atmospherics rumble and render appropriately the heft of tympani strokes or the lowest notes of the organ.
As much as I liked the pairing of the LHC-208 with the SR1a, I was much less convinced by its performance with the TC, where the bass came out a bit overdone and slow, and the transparency loss was too noticeable. The Riviera AIC-10 remains the best match, to my ears, I have auditioned so far with the AB-1266.
My takeaways from this listening session were:
- With an appropriate amplifier pairing (like the LHC-208) I could actually enjoy the SR1a more than what I am doing right now with my underpowered amp;
- No matter the power available, the sub-bass response is not going to reach the quantity levels I feel as necessary for part of my listening, hence I do not see the SR1a as able of entirely replacing my Abyss TC;
- Power is not the only figure to look at, as the utterly transparent nature of the SR1a is going to show the weaknesses of any amplifier. So good quality is necessary and – at least to my preferences – also the right tonal matching (as blasphemous as it may sound for whom see amplifiers as 'wires-with-gain' gear).
My research is going to continue in the next months, being the next step to audition a VIVA Solista and possibly some other great tube amps suitable for both SR1a and TC.
In the meantime, when the Jotunheim R becomes available, I could give it a try, as it is too appealing as a solution (read: cheap, simple, small) to pass.
interesting test, but as other headfiers have advised you, I would not go on such expensive amps as Dartzeel, I would separate the one for Abyss, Riviera, and the one for sr1a.
Have you ever tried a class D like the Nuforce, a friend has taken it and works wonders, you could listen to the Viva and the Nuforce from Audio Graffiti to Pandino, if you want I can pass you the contact of Sergio Pozzi who is always very helpful and curious about these test.
Then I'm waiting for a Powersoft demo and I remind you that a very hifi close friend sold his 15k Burmester to get a Powersoft that costs only 2k with a huge advantage for the wallet ...
. I am very curious about what you will discover with the Powersoft, in comparison with the ultra-linear Benchmark AHB2 you are using right now. Please keep us updated!
