Solid State Power Amp Reviews

ELAC Alchemy Series DPA-2 power amplifier Associated Equipment

Sidebar 2: Associated Equipment

Digital sources: dCS Rossini SACD/CD transport, Rossini DAC, and Rossini Clock, and Network Bridge; Synology 5-bay DS1019+ NAS; Roon Nucleus+ music server, Uptone Audio etherRegen, Small Green Computer Sonore opticalModule, TP-Link gigabit Ethernet media converters (2) with multimode duplex fiber optic cables, Linksys routers (2), and Arris modem, all powered by 300W (3) four-component linear power supplies; external hard drives, SSD USB sticks, iPad Pro; 2017 Macbook Pro computer with 2.8 GHz Intel i7, SSD, 16GB RAM.
Preamplifier: Dan D'Agostino Momentum HD.
Power amplifiers: Dan D'Agostino Progression monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia 2.
Cables: Digital: Nordost Odin 1 & Odin 2 & Valhalla 2 (USB) & Frey 2 (USB adapter), Wireworld Platinum Starlight Cat8 (Ethernet). Interconnect: Nordost Odin 2. Speaker: Nordost Odin 2. AC: Nordost Odin 2 & Valhalla, AudioQuest Dragon HC, Kimber Palladian.
Accessories: Grand Prix Monza 8-shelf double rack & amp stands, 1.5" Formula platform, Apex footers; Nordost QB8, QX4 (2), QK1, and QV2 AC power accessories, QKore 1, 3, and 6 with QKore Wires, Titanium and Bronze Sort Kones, Sort Lifts; AudioQuest Niagara 5000 power conditioner & NRG Edison outlets & JitterBugs; Tweek Geek Dark Matter Stealth power conditioner with High Fidelity and Furutech options; GreenWave AC filter; Ansuz Darkz T2S resonance support feet; Wilson Audio Pedestals; IsoAcoustics Orea footers; Stillpoints Aperture panels; Resolution Acoustics and GIK Acoustics room treatment; Stein Music Super Naturals, Blue Suns/Diamonds, Quantum Organizer; Bybee Room Neutralizers; Absolare Stabilians; Symposium Ultra Platform; Marigo Aida CD mat.
Room: 20' L × 16' W × 9' H.—Jason Victor Serinus

COMPANY INFO
ELAC Americas
11145 Knott Ave., Suites E&F
Cypress, CA 90630
(714) 252-8843
elac.com
ARTICLE CONTENTS

COMMENTS
Glotz's picture
Submitted by Glotz on May 12, 2021 - 11:42am

That relationship (in time) seems to be the reason I keep away from Class D amplification.

I know it can be corrected with additional product investment, but isn't that the real question? Is this a product of all Class D or is this a design/cost issue?

I am in the market for a stereo amp or monoblocks in this price range, and yes, I obviously need to hear these first.

Kudos to Peter here... to impress Jason takes a lot!

What about the Odyssey Stratos Mono Amps for a future review? They seem to still be going strong as well...

cgh's picture
Submitted by cgh on May 13, 2021 - 6:52am

Compared to old fashioned linear amps it's probably impossible to talk about class D without knowing what's inside the box. Slew rate limiting, negative feedback, filtering, signal/power bandwidth, ..., you-name-it and that leading edge has slope on the output. I am biased. All my time with playing and building guitars and violins we focus on that onset transient and the subsequent coloration in the decay. Don't mess with that onset! Flamenco is percussive and classical is not.

tnargs's picture
Submitted by tnargs on May 12, 2021 - 7:50pm

It’s hard to imagine why you wouldn’t use Class A for the input stage.

Maybe you just mis-reported it.

John Atkinson's picture
Submitted by John Atkinson on May 13, 2021 - 7:41am
tnargs wrote:
It’s hard to imagine why you wouldn’t use Class A for the input stage. Maybe you just mis-reported it.

Yes, it was a typo, now corrected.

John Atkinson
Technical Editor, Stereophile

tonykaz's picture
Submitted by tonykaz on May 12, 2021 - 8:17pm

Hello Jason,

I thought that I'd let you know that China is doing a Big Bicycle Show, just now.

I've owned Bicycle Manufacturing so I have some involvement in Bicycle Accessories.

As far as I can tell, the Shanghai attendance is low.

I'm not seeing much in the way of USA Shows waking up from their Rip Van Winkle naps, same for Europe.

The World still needs about 6 Billion more Vaccinations before any 'Herd-immunity' comfort levels make Big Public Gatherings seem safe.

I had to delay a trip to Port Townsend for the Tally Ho project because of the darn plague. ( I have a Covid travel passport )

The entire World is probably jealous of your lovely Natural Setting, ( I'm hearing that ) parts of NY City are a Hell-hole just now, and that NY'rs are just starting to escape to restaurants for a rare outing.

This Class D probably isn't for the upper Caste folks and may never be but it's a useful solution for folks reaching up with lesser buying abilities, it probably deserves to belong here with us.

Anyway, it's nice reading you again.

Wishing you well,

Tony in Venice Florida

a.wayne's picture
Submitted by a.wayne on May 13, 2021 - 12:13am

I have always found class D to have timbre issues when ran below 8ohm , measurements here makes it pretty obvious this one is a solid 8 ohm load guy , with plenty power for the Clipsters....!

Regards

PS: Careful John ,brain damage from NPR signal is irreversible ...! :)

Dpl53's picture
Submitted by Dpl53 on May 20, 2021 - 9:55am

I really enjoyed this review, the fact that you were able to favorably compare this amp to your reference amp at a much higher cost is impressive. I would also like to note that I checked out Brian Bromberg after reading this review and really like his music. Always nice to discover a new jazz artist!!

Jack L's picture
Submitted by Jack L on August 25, 2022 - 1:41pm

Hi

Yes, this is the correct way of design for balanced input stage using bipolar junction devics, ie. JFET. Sonically it beats the very popular balanced I/P stage design using cheapie op-amps with tons of gains & feedbacks, currently used by many many brandname amps.

This shows the designer does get skptical musical ears !!! Full marks for that ! It cost more for such design/build for better sound.

That is the major reason why I won't go for amps with balanced inputs using op-amp topology employed by nearly all brandname amps with balanced I/P stages, musically & technically !

As a die-hard tube DIYer, I would not jump on the wagon of the todate's so popular trench of solid state balanced I/P topology as technically it is dispensable due to very short runs of interconnects used for home audio. We are NOT running miles of audio cables like recording studios !

If I were to design/build a line-amp or power amp with balanced I/P stage one day just for fun, I would surely use a pair of triode for the dfferential balanced inputs, Simple but musically sound better.

Less electronics better music !

Listening is believing

Jack L

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