Review: Boulder 1060 Amplifier

Category: Amplifiers

It’s taken some time to come around to this review, but after tracking down an excellent German Walther 32a connector to re-terminate one of my Acoustic Revive Reference pc’s & putting around 300hrs on my Ayon CD-5s I was finally able to do some critical listening.

Previous amps owned – Classé Cap-2100 integrated, Ayon CD-5 (pre), Nakamichi Amplifier 1 integrated.

My musical tastes include – classic pop, female voice, jazz, blues, world/ambient, classical & a little alternative/indy.

As I related in a previous thread, I still had a few question marks after jumping in and buying the Boulder 1060 after I was offered a good example. Reviews and forum comments seemed inconsistent, so I asked Rich Maez at Boulder about this & received the following response -

“If you go hunting on-line, you'll find commentary that claims we're bright, dark, fast, slow, etc. In general, when none of the commentary is consistent, we take it mean that we're transparent or neutral. That's what we aim for - we don't voice our equipment to sound a certain way and instead make it as faithful to the recording as possible - if a recording has an up-front presentation, the 1060 will, if it has a "back of the hall" presentation, so will the 1060.”

I also read another comment from member Khrys –

“Horses for courses, but I think Boulder is among the most mellifluous of SS amps, along with Burmester, Dartzeel and the BEL 1001, sadly no longer in production.”

Both comments proved to be true as I later found out. My tastes do run along the lines of a balance between solid state drive & tube virtues of warmth, body, dimensionality, liquid sound & the sweetness. Amps that I’ve heard and enjoyed include the Boulder 865, Modwright KWA-150, Dartzeel NHB-108/NHB-18s, Rowland 625/Corus & Vitus SIA-025. The Bladelius Ymer/Idun pairing also impressed me with natural sound & some serious bass. All had their pros & cons, but I think I made the right choice going for the Boulder.

If the pre-amp is the heart and soul of your system, your power amp is certainly the engine that drives it. And the Boulder ticks all the boxes with serious power reserves, exceptional circuit design and build quality, great sound & pride of ownership.

So what about the sound? Based on my personal preferences, forum comments & having read the Inner Ear magazine review of the Vac Renaissance Signature Mk2 pre (which paired the Boulder 1060 and Vac), it was clear the Boulder was best matched with a reference balanced tube pre, and I had a likely candidate fresh out of the box in my Ayon CD-5s. And after 300hrs run in, all I can say is “wow!” Already understanding the character of my Ayon CD-5s, through the run in process I was able to determine the sound of the Boulder which I would describe as natural sounding, authoritive, transparent, fast, detailed without etch & tomb quiet in operation. What my Ayon CD-5s added was tube virtues of warmth, dimensionality/holography, liquid flow & a bit of sweetness.

Tonight, after warming up my system for several hours I sat down for a final listen before writing this review. On one of my reference cd’s; Christy Baron - “I thought about you” (Chesky) I found myself turning up the volume more and more, but was surprised when the actual speaker volume didn’t change that much. I found myself searching for something more….then I had a eureka moment…what I was searching for was the background noise (aka “volume”) i’d been accustomed to hearing from most other systems! There it was, I was listening to a small, intimate music piece exactly as David Chesky intended it to sound. Music emanated from a jet black background with proper weight, scale, accurate tonality, liquid flow & warmth.

I kept listening, and on track 3 of my Pink Floyd Pulse cd and track 6 of Deep Forest “World Mix” I was following sounds which stretched to every corner of my room across a wide, holographic sound stage. This thing was imaging like crazy! The only experience I can think of which compares was an experience I had 20 years ago when I had the opportunity to audition a pair of Infinity IRS-V’s in a Dealer’s showroom paired with Electrocompaniet mono blocks. Of course the IRS-V’s were on a completely different level, but still this was pretty amazing for a pair of stand mounts.

Of course a system is the sum of all its parts, and I recall Leif Oloffson remarking “Compared to the original Coltrane the sound of the Altos is slightly warmer and actually the midrange resolution is as good or better than the Coltranes.” The midrange magic was also helped by my CD-5s which has really impressed me as pre & the addition of Origo cables.

The Boulder is much more authorative than my previous Classé amp. There is now solid bass which can go deep when the music calls for it. The bass is also well textured and resolved. Attacks and decays are long and at times spine tingling! Piano and strings in particular are eerily real sounding. On track 10 of “Come away with me” I closed my eyes and just shook my head. It was like the guitarist was sitting on a stool in my listening room. Piano also sounds amazing with perfect tone, weight, flesh & speed. Female voice is also wonderful. Play a more dynamic pop cd and that’s how the Boulder sounds. Play Nora Jones and Nora’s sassy voice as well as the natural warmth, brassy tone and intimacy of the original recording are preserved. The Boulder is really a chameleon in the way it adapts to any kind of music and just reproduces it perfectly.

On the technical side, the Boulder 1060 is a true differentially balanced, direct coupled, dual mono, class a/b amplifier which operates in class a for the first 17 watts before switching to class ab. Boulder put a lot of effort into perfecting the circuit design (including the biasing) and spent a lot of time notching out crossover distortion. As a result the 1060 is linear in operation like a class a amp. Now 17 watts in class a might not sound like much, but as Rich Maez explains “If you start out with a much better circuit design to begin with, you don't need to over-compensate with higher biasing.”

The design and specifications of the 1060 are just astonishing. Virtually every component of the amp is designed and manufactured in-house (Including the cad-designed cnc machined/hand-finished chassis), whilst those that are not are custom-made to Boulder’s specifications. Nothing is off the shelf. The 1060 features twin potted 1.5kva transformers, bridge rectification, 48 filter capacitors (24 per channel), 56 bipolar output devices & Boulder’s proprietary 983 gain stages. Protection circuitry is also reassuringly robust. Boulder guarantee 300 watts continuous power into any load, but the 1060 feels more powerful than that and one suspects that figure is conservative. But for all that power, the 1060 only pulls around 60 watts at idle, and 15 watts in standby, meaning you’re not hurting your power bill (or the environment).

Depending on your requirements, Boulder offer two great value matching pre amps; the 1010 & 1012. (The 1012 includes a pretty serious dac, making it the ideal partner for all your digital sources). The 1010 & 1012 are built with the same extreme build quality & sonic performance as the 1060, and you've got the further benefit of 'Boulder Link' which can control the 1060 & displays error messages from the 1060's protection circuitry...cool! If you're like me however, you'll probably be in Heaven running some NOS valves upstream. Am I impressed? You bet!

Cheers,
Melbguy1






Associated gear
- Ayon CD-5s (matched NOS 6H30p-DR output tubes & 6C4P rectifiers. Upgraded Burson single HD op amps)
- Oppo BDP-83SE (upgraded Furutech IEC)
- Marten Coltrane Alto speakers
- IC's - Jorma Origo xlr
- Speaker cables - Origo biwire
- PC's - Acoustic Revive Power Reference
- Racks - Taoc ASR series
- Conditioner - Acoustic Revive RTP-6 Ultimate
- Tweaks - Acoustic Revive/Alto Extremo
(Note: With my vinyl rig still packed away in boxes, my source for this review was my CD-5s).

Similar products
- Boulder 865
- Modwright KWA-150/LS-100
- Bladelius Ymer
- Dartzeel NHB-108/NHB-18s
- Rowland 625/Corus
- Vitus SS-010
- Vitus SIA-025