I had teased a bit about this
here ... but for those that have been interested in the SR1a and not wanting to deal with a speaker amplifier, or that have been aware of "Weldenheim", now formally called "Jotunheim R", I've now had, with
@Jason Stoddard's kind indulgence, almost a full week with one of the "production" qualifier units.
This is a direct-drive amplifier; this means you do not need a speaker amplifier, nor the RAAL-requisite "Amp/Ribbon Interface"!
What is a "production qualifier"?
It's a production-intent build of the unit, using all the same parts, processes, and suppliers/manufacturers, with final tuning etc. In essence it is the final step in qualifying a product before saying "go build more of these, just like this one". Absent any issues cropping up with a "production qualifier", its the same product that'll ship (note the sticker near the IEC socket):
I'll do a full review of this, as well as include it in the amp comparisons for my pending full SR1a review, but I did want to share a few thoughts here and there ahead of that.
First 24-48 Hours:
First, this unit benefits from somewhere between 24 and 48 hours burn-in/break-in. It sounds great fresh out of the box, but there were occasional hints of added bite and aggressiveness with some music (mostly things that tend to excite that sort of behavior in the first place). The SR1a can be quite aggressive and "bitey" anyway, so this is a minor thing, but the hint of extra aggressiveness here does go away in the first day or so of running the unit.
The other fresh-out-of-the-box observation of immediate note is that the profile of the "Jotunheim R", especially in the low-end, is a lot more compelling than most amplifiers when they are running with the interface. There's more bass, and sub-bass, presence and impact here than with, say, a Vidar or an AHB2 and the interface box. This will, I expect, be quite welcome for most listeners, due to the native tonal profile of the SR1a.
High-Level Impressions (48 hours and beyond):
I would swear there is more detail in evidence and the micro-dynamics are more nuanced with Jotunheim
R direct vs. running via either a single or dual-mono Vidar configuration, or from several other amps, via the interface box.
Bass and sub-bass level/presence seems slightly elevated over Vidar, and a bit more so vs. the Benchmark AHB2. I like this. It yields flexibility in where you put the drivers, and puts things more on a “neutral” footing vs. “studio neutral”.
Higher treble feels like it has a tad more energy than via Vidar too, whereas Jotunheim R vs. AHB2 sounds so close in the treble as to be indistinguishable to me. And the Benchmark piece sounds leaner overall where as both Vidar and Jotunheim
R have more body and weight to their delivery, with Jotunheim R having the most weight (if not by much vs. Vidar).
Vidar, in single or dual configuration, has a
slightly darker signature (but certainly not
dark … I’m not sure it’s possible to get the SR1a into “dark” territory without EQ).
There’s a TON of headroom here …
Even with dual Vidars, fed from the XLR outputs of a Phonitor X, quality source material, with the EQ I was initially running with (bass/sub-bass lift primarily), was not leaving a lot of room on the volume dial for more spirited listening. With the Jotunheim
R, even with the quietest source material, the half-way mark on the volume dial is further than I dare take things.
Resolution and dynamics are superlative. No idea if that’s because the interface box isn’t involved or if it’s just the raw performance of the Jotunheim
R. Overall, it bests 1x and 2x Vidar and 2x Aegir, the Benchmark AHB2, so far, for me, and may worry other solutions as well.
More comparative listening required, but
very impressive so far.