Intg Amps: Hegel 590 vs NAD M33 Masters vs Gryphon Diablo 120

Hi All: I am getting an itch to upgrade my integrated amp from Hegel 190 to something more robust that facilitates future speaker swapping.  And no, I'm not presently interested in separating components that much further (e.g. separate DAC; separate amp; clock; etc. etc).  I mainly interested in the following 3 on a used basis:

Hegel 590 OR NAD Masters 33 OR Gryphon Diablo 120

Max budget is $7500 if I choose to go towards the Gryphon (used), but curious if it's really THAT much better.   I'm particularly interested to hear from people that have had or auditioned at 2 out of 3.  The room correction on NAD is very appealing but I quite like my Hegel and it's tight control, and so something nice about staying true.


Current Setup:

* Unideal Brooklyn Apartment living room into Kitchen

* Hegel 190

* Monitor Audio Silver 7G 500

* Pine Tree Audio Cables

* Dual 1216

* Schiit Mani 2 (though I hear the phono preamp on some of above may make this superfluous)

* Spotify/Tidal (main streaming source)


I’ve had the opportunity to audition all three of the great integrated amps that you’re considering, extensively, and here’s my assessment (I auditioned the Gryphon Diablo 300). The NAD M33 is great for the money, but system matching is critical with it. The NAD M33 isn’t in the same league as the other two. The Gryphon Diablo 300 outshines the Hegel H590 when it comes to build quality (although the Hegel H590’s build quality is outstanding as well), and aesthetics. But, that’s about as far as it goes. Firstly: The Hegel H590 should be compared to the Gryphon Diablo 300, along with all other best-in-class reference integrated amps currently on the market.  When comparing the Hegel H590 to the Gryphon Diablo 300, honestly, I could go either way. I use an outboard DAC, so I’m referring to the sound quality of the amp/preamp sections of each integrated, exclusively.  To my ears, the Hegel H590's awesome sound quality didn’t have to take a back-seat to any other high end integrated on the market, including the renowned Gryphon Diablo 300 (the Hegel H590 is pretty "renowned," too). I strongly believe that the H590 is a much better value than the Gryphon Diablo 300, as it’s very comparable to it in terms of sound quality (and I do mean "Comparable"). I’m not one of our more well-heeled audiophiles.  High end audio is expensive enough as it is. I definitely don’t have money to burn.  So, for my money, I'd undoubtedly go for the Hegel H590, save a bundle of dough, and just forget about the rest.  The Gryphon Diablo 300 is one of the best, but so is the Hegel H590 (for less). To be totally candid with you, I auditioned several other integrated amps as well, including the above mentioned, and I has prepared to spend more money for something like the Gryphon.  But, I was so blown away by the Hegel H590, I purchased it and never looked back.  Kudos to Hegel Music Systems for producing such an absolutely fabulous product.

Auditioned many integrateds including the 3 the OP is asking about, bought the 300, to my ears the best of the lot.

Here is my informal ranking of the integrateds:

Gryphon 300

Accuphase E-5000

Aesthetix Mimas

Mcintosh MA12000

Hegel 590 <-> Gryphon 120

Luxman 509


My system:

B&W 804 D4s

Lumin P1 streamer/DAC

Lampizator Baltic V4 DAC

Linn LP12 Selekt TT

Primaluna EVO 100 phono stage

Transparent and Audioquest cabling

Puritan power conditioner and ground system

The Accuphase I suspect for most ears is as good as the Gryphon, just not to my ears for my musical tastes which run the gamut from ambient electronica to jazz to chamber music to classic rock etc. Those with less broad musical tastes - vocals and acoustic instruments for example - might even prefer the Accuphase for its more refined tone/timbre. The gap between the 300 and the Accuphase and the rest of the amps on the list is large IMHO.

Gryphon and Accuphase will last for decades. They almost never break. Listen to some people here - get one of those depending on your taste and forget about the rest. I would definitely add Boulder 866 to the list. Those three know how to do solid state amplification. Don't waist you money. Please.


Hard to compare a NAD Masters M33 to the Gryphon Diablo 120.  I consider the NAD as a convenient lifestyle swiss army knife product that really doesn't excel at anything. The amp of the NAD doesn't deliver ample current to control speakers and I find it to be severely harsh sounding at moderate volume levels.  While convenient, the NAD's built-in DAC / Streamer is average at best.  I did find the BluOS control system and the DIRAC room correction to be nice to have's but again fit into the convenience lifestyle category. 

Before purchasing my Gryphon Diablo 300 I auditioned the Diablo 120 and found it to have the same sonic footprint as the Diablo 300 with the same incredible build quality that Gryphon is famous for.  The Gryphon Diablo 120 has ample power to drive your Monitor Audio Silver 7G 500 speakers and most any future speaker upgrades you may consider. 

Don't be fooled by Hegel watts compared to Gryphon watts. Gryphon wattage ratings are always conservative and typically double down based on speaker resistance as you can see in their specs.  Hegel's specs only state wattage at 8 ohms.  Speaker resistance varies at different frequencies and rarely operate at 8 ohms.  This is the area where Gryphon excels. 

My Diablo didn't have the optional DAC module as I use a dCS Rossini as my DAC/Streamer.  I did have the Gryphon phono module which will allow you to get rid of your Schiit Mani 2 phono stage.  You'll be amazed how good a turntable can sound with a good phono stage. 

I can't comment on the Hegel 590 as I've never owned or auditioned Hegel equipment.  Based on others in this forum, it seems that a Hegel 590 would also be a great option. 

I saw someone recommend a Boulder 866.  I love Boulder and have owned many of their components.  The 866 build quality is terrific but the 866 SQ doesn't really live up to high praises I have for their separate components.  And you must use Roon with the 866 as the MConnect app that Boulder recommends as an alternative is horrible. 

There's really no comparison between the NAD and Gryphon.  The NAD feels like a plastic toy compared to the amazing build quality Gryphon provides.  The Gryphon speaker terminals are a good indication of how serious of a component the Diablo is.  And the Gryphon remote is what you'd expect from a $50,000 component.  

If you want your last integrated, I highly recommend the Gryphon Diablo 120.