Krell Duo 300 compared to Evo 302e or 402e?


Hi I am looking for an amp to power some Revel Salon 2s and wondering about these amps. From all I can read it seems that the 302e or 402e would be a good amp for the Salon 2s but the new Duo 300 with it's cooler running demeanor is definitely appealing. I am wondering if anyone out there has compared these or owned both and can shed some light on this?
61a8fc83 0497 4515 996b c2556036d4eaejlif
With only 1 week, I have found the Duo to sound like a Class A amp.
Much more musical than any previous Krell amp.
@ Ajpk1971, Hi, This is the very first any thing on the new Krell Duo 300 on audiogon I have seen, Do you own one, or you listened to one?, I really do not care about most pro reviews, I find them very mis-leading these days!, User reviews to me are more realistic, not getting paid,are more usefull to me, they are closer to valid that I know of, cheers.
I got a Duo 300 only problem is it came not working and has to be replaced. I'm glad to hear you are thinking it sounds musical and more like a class A amp than previous Krell. This is exactly what I'm looking for. Class A without all the energy drain and heat. I'll jump back on here and post some thoughts about mine when I get the new one.
I look forward to a detailed review from you Ejlif, cheers.
I had to return my Duo-300 to Krell for a defective power supply.
Literally within days I had a new amp.
And have been happy ever since.

Krell bass and smooth mids and highs.
The best sound thru frequency range of any Krell I have owned.
@ Ajpk1971, what krell amps have you owned?
I'm still waiting for my Duo 300 to be sorted out. Seems like they are having issues getting parts for these. I am supposed to be getting another new one but we are getting into the 6th week. I'm glad to hear you are enjoying your Duo 300. What have you compared it to?
I've heard of inital problems with the new amp design and/or parts. That being said, I'm listening to one of the matching preamps right now, an Illusion II and it is fabulous. Very sweet, dynamic and great PRAT. The aesthetic design and execution is a bit different, admitedly, but the sonics are superior to the Evo series thus far.
Again, I ask, what krell amps have any of you here have owned you are compairing the Duo 300 to?
15 years ago, I believe it was a KSA 100.
Then an FPB 250 with KCT.
Then 302e.
Now the Duo 300.

Still very happy.
@ Ajpk1971,mmm, guess you thought maybe I would not check this thread again, thankyou all the same, all that you listed is no where in the league of the krell amps I own or listened too, cheers
Audiolabyrinth,
Please tell us, what Krell amps have you owned or listened to that are so much better than those listed by Ajpk? The Krell Evo 302E is a very good amp. Not quite as good as their Evo E series mono blocks, but still excellent.
I have a modded Krell 700 CX right now, you should hear what this amp is doing, very incredible, way, way better than a stock 700cx and 302E, I have listened to the 302E many, many times, never owned one, I have owned or listened to alot other krells over the years,I had the Krell company them selfs do a complete re-build of the inside of my Krell 700cx with all new stock cosmetics to make the amp new looking along with the inside, Krell inserted all kinds of parts inside the amp to make it work with the capacitors that were not stock inside this amp when it was made in 2005, you should see the bag of parts they sent back with the amp that I requested, Huge bag of parts, I was supprised, this costed alot of money to do this, I will keep this amp likly the rest of my life to get my money back out of it, not saying I will not have or get another amp one day, it's just not feasable to sale this at a big loss in money that I have tied up in the amp, cheers.
Hello Audiolabyrinth,

Would you please share your impressions of the build quality and sound of the krell 302e?

By any chance have you ever listened to a Musical Fidelity AMS-50?

I ask because these two power amplifiers are on my short list to audition.

Many Thanks
07-21-14: Audiolabyrinth
I have a modded Krell 700 CX right now, you should hear what this amp is doing, very incredible, way, way better than a stock 700cx and 302E, I have listened to the 302E many, many times, never owned one, I have owned or listened to alot other krells over the years,I had the Krell company them selfs do a complete re-build of the inside of my Krell 700cx with all new stock cosmetics to make the amp new looking along with the inside, Krell inserted all kinds of parts inside the amp to make it work with the capacitors that were not stock inside this amp when it was made in 2005, you should see the bag of parts they sent back with the amp that I requested, Huge bag of parts, I was supprised, this costed alot of money to do this, I will keep this amp likly the rest of my life to get my money back out of it, not saying I will not have or get another amp one day, it's just not feasable to sale this at a big loss in money that I have tied up in the amp, cheers.
They replaced some of the parts in your 700 CX with current production parts, so how can you conclude it's out of this league superior to all Krells? At best, it's closer to current production models.
Hi Joecasey, I'm not sure if the modded krell 700cx I have is the best Krell ever, likly NOT, you are correct, Krell likly inserted parts and caps that are inside the brand new amps that they are selling now in my amp, then that is where you draw the line, The Krell 700cx has two huge transformers, essentially two of everything, a mono block amp in one chassis, my amp can handle 1 ohm speaker loads with ease where all the new krell amps cannot go less than 4 ohm loads of speakers, I know this to be a fact, Krell themselfs told me that information, the specs are also far greater in my amp compaired to the new krell amps as well too, my amp is a true balanced design-no RCA connections what so ever, any amp that has RCA and balanced and cast is NOT a true 100% balanced amp, I only have cast and Balanced period., the signal to noise ratio in my amp is 120 DB, the 700 cx is also more complex, The transformer uf specs is far and away greater than all the new Krell amps meaning with my exsperience can play lowest volume setting and still get the total full sound, at the end, it is really your voicing preferance, The evolution E series sounds different than the cx series, I do imagine the new amps sound closer to what I own, since that is krell's goal to go back to class A sound, however, I did live with a stock 700cx for two years, I assure you the sound now is alot better than before now that the amp is modded, I am happy, thrilled with the out come, cheers.
I also wanted to add, when and if I get another amp, I will stick to the sound I have, meaning, I will obtain a Dan D Agistino amp, The new intergrated amp looks very good if that is what any one wants, in my mind, the krell cx amps was Dans last he soley developed by himself, and the heritage carried onto his new company, The Dan D agistino audio.
Anyone care to share their listening impressions of the Krell 302e?

Many Thanks.
Recently went from 302e to Duo 300.
Seems like Krell wants to move to a tube like sound.
Warm but detailed.
Very musical.
Not fatiguing.
makes 302e sound to the cold side.
Great observation Ajpk1971, THAT IS WHY I WENT WITH A MODDED kRELL 700CX versus the 302E amp, I admitt, now you have got my curiosity stirred about the New krell amps, they are priced fair compaired to others out there, congrats on your New Duo 300, did you get to listen to the mono blocks?
I have heard of initial reliability problems with Krell's newest amplifier design. Has anyone else heard the same?

Many Thanks
I just got a Duo 300 for home demo. It certainly adds texture and makes the music more engaging. But, I like the exact, analytical nature of my 400e (and former 302e), so, Duo sounds a bit too colored. The evolution series seems to have more control of the bottom end than Duo. I need to listen and compare a bit more. Maybe it needs some burn in time to tighten up the sound.
By the way, I thought it was odd that hot air blows out through the top. I don't know if anyone would want to put anything on top of Duo as Krell suggested it can be done.
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Since its introduction, Krell adjusted Vanguard retail price to $4,500. So, it is not as a strong bargain as it seemed initially...
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I finally got my Duo 300 back (about 6 weeks ago) It's a great sounding amp. I think the other guy has the sound well described. I've only ever had a Krell s300i so I don't know how the Duo 300 compares to the likes of the 302e and such. I am running mine with Revel Salon 2s in a recording studio situation. One problem for me is the fans on the Duo 300 are often times kicking in. If I'm really blasting the music the fans can be unbelievably loud. This is pretty annoying at times. I asked Krell and they told me to plug it into a ethernet port which is kind of a pain for me as I don't have one near my studio. I would have to get a 100' cord and run it through a wall but I may do that to see if there is something wrong with my Duo 300 that the fan comes on so loud. It's a well made amp just a basic black box but good quality, the binding posts are nice they tighten easily they are the best I've ever used. The sound of the Duo 300 is very nice and nothing to complain about as far as sound goes I would just warn of the whole fan noise thing. Who knows maybe it's possible to set the fans to run less. I would be Ok with a little more heat and less fan noise.
I have the same speakers. Salon 2s are absolute current pigs and your amp is pretty light in that department with only 17 amps peak output, so I'm not surprised it heats up enough for the fans to come on when you are cranking the tunes.

By way of comparison, I went from a Plinius SB-301 stereo that could do 100 amps peak to Symphonic Line Kraft 250 monos that have even more current. I think I read somewhere they can do 150+ amps peak; although the manufacturer doesn't provide a number for them one of their lighter models pushes out 120 amps peak. In any event, they look like a late 60s muscle car under the hood and have lots of current to tap.

The Plinius had huge heat sinks and dissipated heat that way rather than through fans. It would run quite hot even though it was Class A/B, but the Symphonic Line amps don't even break a sweat at utterly ridiculous volumes, i.e. in excess of 115dB peaks.
Ejif, The reason Krell told you to connect an earthnet cord to your amp is for them to evaluate your amp on their main server their at the factory, believe it or not, your amp is computer oriented, Krell can and will literally make ajustments to your amp if the fans are working out of the ordinary with the speed and sound of the fans, I would hook the amp up inside the house to the connection,you would have to be useing the amp at full campacity when you do this, call krell on the phone, and see what they do with their main server for your amp, it's like essentially your krell in the krell shop without ever leaving your house,and the connection tells krell if there is a problem that you have to send the amp to them for work done to the amp as well, Awsome to me!
So if an amp can put out 100+ amp peak output then how does a typical 20 amp circuit respond to something like that?
I don't know how a 20 amp circuit would work. My monos are on separate dedicated 30 amp 240V circuits.

I'm also guessing that an amplifier's peak output is based in part upon the capacitors' ability to store electrical energy, but I am no electrical engineer...

ha,ha,That's a good question Ejif, +1 on this one.
Peak amplifier output current does not have to be less than the current of the circuit powering the amp. This is because power is equal to voltage times current, and since the line voltage (i.e. 120V or 240V) is in most cases higher than the amplifier output voltage more current can often be available at the output terminals to drive speakers.
Bill_k, great explaination.
I have the Krell Vanguard and my fans did go off in the summer but it's been all quiet ever since. It's smooth and very open sounding. The new Vanguard kind of reminds me of the Sim Audio I7 but less clinical sounding probably due to the class A design. They both have a lot of steps with the volume control.
If you like the Krell sound the new gear doesn't disappoint. Looks are just OK.
Thankyou Gold for your response here, the new krell equipment is still getting circulated to the users to give their opinions on the forum sites, give us more when you can, cheers.
Anyone hear the new Mono Solo's?
I've purchased a Krell Vanguard with the digital module direct from Krell. When I try to use the Blootooth it constantly drops out. I sent it back to Krell gone for a month and back in time for Thanksgiving. Alas it sadly has the same issue as before. 
  I gave up my Krell 302 and Phantom III preamp to purchase it so the entire family could enjoy the Krell. 
  Biggest mistake and the last. All I hear now is the wife completely gripping about the Bluetooth.   Cheap inputs on the back so high priced interconnects not needed. 
Coinguy37 is a Troll....Krell does not sell direct.

Hi WorldCat,

I have spent lots of time with the Solo 575 mono block amplifiers. They immediately sounded better than the EV403e I was running previously. Much larger soundstage, noticeably more speed (hits on a high-hat, fast guitar, etc.), even more tautness to the bass (even compared to EV900e mono amps), and they are just far less harsh than any of the EVO amps. They also run cool, and the fans are very quiet. There is one scenario where you can hear the fans, if you playing something at high volume, and then all of a sudden you hit pause, or the song abruptly stops, there is a ~1 sec, quick ramp down of the fans that you hear as a whoosh. It's never noticeable at any volume you are playing. And they are silent when you are in your listening position and they are idling. They only require 2 inches of clearance above them too. Most importantly they are just the best sounding Krell's ever. I'm a Krell dealer, but I'm just as critical, as I too am a user. iBias is a big step forward. Hope that helps.

-Brian

PS I have a video/text of the EV402e vs Solo 575, same track, same volume, same everything. Even with an iPhone and it's crappy mic/speakers you can hear the difference clearly. Way better dynamics, transparency, everything with the Solo 575.  Krell has moved forward. 

Dave b, krell does not sale direct, wrong again,  I bet you system to system that they do,  they have for a long time now! 
Coinguy37, I apologize on behalf of the Community here for Dave b's remark's,,, you are no troll,  you actually told the truth,  krell has been selling directly for atleast the last 3 years I know of,  however,  they will not sale direct if you have a krell dealer in your area that you live. 

Audiolabyrinth..hello....it's been over year,,just curious..have u acquired The Dan D Agostino amp?  What is your impression?  I am putting together a system. Leaning towards Krell
Guys I have a small room question can you hear the fans if you are sitting 9 ft away? How does the sound compare to say Pass or Mark Levinson,  Luxman! 
I am considering going to Krell Evo402e from Pass Labs X350.5. Is this Krell a good amp. I thought it might be a great amp but reading this folks call it harsh - I don't need a real warm amp like the pass but don't want a harsh one with. The Krell is more money. It is for Magico S5 speakers, Bricasti M1SE Dac, Simaudio Evo P-8 pre and Kubala-Sosna Emotion cable loom. 

Would love any info on the Krell Evo402e
In my opinion and defining terms (for purposes of comparison only) , your Pass Labs X350 has a very neutral sound.  It is definitely high resolution, but very neutral and very controlled.  Best I can explain it is that the Pass "Class AB" amps have a "very controlled sound" - in that the dynamics seem to be limited or "held in" in some way.  Don't get me wrong - this amp sounds wonderful to a lot of people, but it does not have a lot of slam/dynamics in the mids and midbass.  I would not really call the Pass X350 a "warm" amp.  I think it is rather "neutral".  It's definitely not warm like a Parasound amp would be, or an older NAD amp.  The Pass Labs full Class A "XA" series amps are not really that warm either in my opinion.  They have a thicker midrange, but still pretty good resolution.  However, it's definitely a different sound

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The Krell Evo402e is a conventional "Class AB" amp that is very high resolution and has a lot of dynamics, resolution, attack and excitement.  This is definitely NOT a warm sounding amp.  My friend has one and I have heard it directly.  I would say the Evo is an awsome amp, but due to its very high resolution character, it can easily become out of control if you have something like metal dome tweeters or silver elements in your cabling.  This is where many can say this amp sounds harsh (but it's really not the amp sounding harsh - it's that the amp is very revealing and the synergy with silver is causing the sound to be too fast/bright).  So, you need to pay attention when matching components with this amp.  Stay to pure copper and gold-plated or rhodium-plated connectors for all wiring (speaker cable / interconnects / power cords).  The perceived "harshness" is something you'll have to deal with when choosing any amp that is not "warm".  The Classe "Class AB" amps are another example of this.
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The newer Krell amps (Solo / Duo / Chorus) are all full biased "Class A" (even though they have a sliding bias circuit).  These have the typical very liquidy and smoothed over "Class A" sound, maybe even lush sounding (but not as lush as some other amps).  The liquidy and smooth character of these amps is definitely more forgiving for "harshness in a system" and still has good dynamics and resolution, but the sound is also less "natural" and less "real" with regard to the instruments and vocals.  You would have hear this character to know what I mean.
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In my opinion, the Krell EVO and Classe "Class AB" amps are the most real sounding of the above, but also need careful matching with other components and wiring.
auxinput

Thank you very much - this is outstanding information and just the type of information I was hoping for! Thanks so much !!!  

Thats funny you mentioned Classe. These are the two amps I am considering.

Krell Evo402e
Classe CT-M600 mono blocks

With the Krell, the guy will take my Pass on trade. 

I actually would love some more dynamic's and a higher revealing amp and my fear is I go too far the other way. I will list my gear below and provide a link to my Virtual System and would advice!

I guess something I need to worry about is the metal tweeter's in my
Magico's.

I think I have the perfect cables though. I have Kubala-Sosna Emotion's which is a neutral yet cooper cable. I just purchased a new to me preamp. The Simaudio P-8 which is fantastic IMO. Has some sheen and a dash of warmth to it also so it may work well and my DAC is not bright at all either so other than my tweaters I think I maybe ok to try out a higher revealing amps. Here is my gear. I am thinking either the Krell or Classe may  match up? What do you like better? The Classe are a bit more money and I will need to sell my amps on my own so the Krell is a better offer but in end I just want the best amp. 

My system:
amp I am thinking of replacing: 
* Pass Labs X350.5 Stereo Power Amplifier

Magico S5 Loudspeakers 
Bricasti Design M1SE DAC w/Ethernet Network Player
Simaudio Moon Evolution P-8 Reference Preamplifier 
PS Audio P10 Power Plant AC Power Regeneration
Kubala-Sosna Research - Emotion - Speaker Cables 
Kubala-Sosna Research - Emotion - Interconnects XLR 2.0M, 1.5M
Kubala-Sosna Research - Emotion - AC Power Cable 2.0M
Verastarr Grand Illusion II Power Cable 1.5M 
Elrod Power Systems EPS-2S Signature Power Cable 1.0M 
Nordost Heimdall 2 - Power Cable 2.0M 

https://systems.audiogon.com/systems/5160

Thanks again... 



  

  



   
Your Magico S5 have beryllium dome tweeters, which are NOT metal dome. They will be very high resolution, but will not have the harsh breakup of normal metal domes, so I wouldn’t worry about this. As I said, make sure all your cables have gold-plated (or rhodium plated) terminations (spades, plugs, RCA, XLR). The only thing I would really look at is your Nordost power cable. I don’t know the configuration on your Heimdall 2, but Nordost likes to use larger 16awg solid-core conductors and uses silver-plating to increase higher resolution voltage draws. If things are a little harsh with the Krell/Classe, I would look at replacing this cable first.

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The Classe vs Krell is a hard question. They are close. The Classe is very clean sounding and, If I had to nitpick, I -think- the Classe might be more accurate to the input signal. However, I have been somewhat of a Krell fanboy since 2005 when I first got my Krell HTS home theater processor. When I was ready to upgrade, I went through and tried several different processors, but I kept coming back to the Krell and finally just upgraded to Krell S1200U. There’s something about the Krell "discrete Class A" analog and driver stages that just "sing". There’s definitely a "magic" here, in my opinion. The Krell will have a lot of resolution and dynamics, and there will be no lack of "realism" that is common with warm or colored amps. Caphill may have a different opinion, as he owns and loves his Classe amps.

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Few more details. The Classe is fan cooled, so there might be a little fan noise. Classe are 89 lb monoblocks and are smaller which may be easier to move/handle? CT-M600 can be at most 8 years old.
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Krell 402e is very big and heavy at 135lbs. It can be as old as 11 years. If you are looking at power cords, the Krell requires a special C19 IEC 20A connector on the amplifier power cord socket. I recommend the Furutech rhodium variations (FI-32(R) / FI-52(R) / FI-52NCF). I actually have a couple of FI-52 connectors that I plan to put up for sale for $199 each.
Great info - thanks so much!

I thought berrillyium was a type of metal so that shows what I know... lol 


As I think I mentioned I changed my preamp from Mark Levinson No.326s to Simaudio Moon Evolution P-8 and honestly I can’t believe how much of an upgrade it was. I guess it’s not a real fair match up for ML $10k and Sim $16k but everything got so much better. I’m so happy with this change.

I also switched my audio server and that was another huge upgrade. I went from a custom built mini fanless LPS powered windows based PC that feeds the Ethernet Network Player in my Bricasti M1SE to a non windows linex based Audio only server that is power by the excellent Uptone Audio JS-2 LPS - plugged into a PS Audio P10 and this new server is super low power - it’s processer only uses 10watts it’s a 12w sever and this is another gigantic upgrade that I’m super happy with. 

Im really into some of the very best sound I’ve ever had in my life and I’ve been at it for a while. 

I’d like to pick up 3 more Kubala-Sosna Emotion PC’s so my entire cable loom will be completely Kubala-Sosna Emotion cabling and yes that makes sense to remove the Nordost.

I think my weak link if you could call it that is my Pass amp. It’s not a weak link per say but I’d like to get an amp to push along the resolution and dynamics.

Weight and all that is fine I’m after the highest resolution, most dynamics and the more musical amp with overall best sound. My gut says it’s the Krell. The Krell cost a lot more new - not that matters but they seemed to have more cost no object funds to put into it. 
Heh, I gues beryllium is metal - I had to google it.  Most metal dome tweeters are made from aluminum or titanium or maybe even magnesium.  These all have rather low frequencies where they flex/resonate and breakup (such as somewhere between 20khz and 22khz.  Sometimes you can raise the resonance frequency as high as 28khz with something like a ceramic coating.  However, these will still be in the range where it will affect brightness/harshness of the natural highs between 10khz and 20khz. 

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The Beryllium tweeter will not resonate or breakup until somewhere in the 44khz to 48khz area, so you really won't hear any breakup/harshness with these.  Diamond tweeters resonate even higher, at somewhere around 75-78khz.
Get the Krell Duo!