Audio Research's New Reference SE Amplifiers

Big Dog RJ

Well-Known Member
Feb 2, 2012
1,242
463
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Melbourne
new kt 150 tubes

Yes agreed with the write up from ARC ref to the kt150's.
In my experience with these new tubes is that the circuit must be made for the kt150.

Unlike the kt120, they are not drop in replacements for kt88, kt90 or 6550. In order to get that special sonic upgrade from the kt150 the amp must be designed for it.

Overall I have compared both tubes side by side and have found the only a marginal improvement in overall sonics. The kt120 presentation as of now is more than good enough for me.
Unless the kt150 is going to seriously impress, I don't think it is worth the upgrade. What I see here is ARC trying to make extra business tapping into the consciousness of audiophiles, knowing that whatever upgrade is definitely good. ..
Afterall this is a business!

I would not fret over this one bit.
I have still yet to hear an amplifier that has excelled over the kt120 by a far margin, not a small margin.
Cheers, RJ
 

number95

Well-Known Member
May 14, 2014
384
7
250
Yes agreed with the write up from ARC ref to the kt150's.
In my experience with these new tubes is that the circuit must be made for the kt150.

Unlike the kt120, they are not drop in replacements for kt88, kt90 or 6550. In order to get that special sonic upgrade from the kt150 the amp must be designed for it.

Overall I have compared both tubes side by side and have found the only a marginal improvement in overall sonics. The kt120 presentation as of now is more than good enough for me.
Unless the kt150 is going to seriously impress, I don't think it is worth the upgrade. What I see here is ARC trying to make extra business tapping into the consciousness of audiophiles, knowing that whatever upgrade is definitely good. ..
Afterall this is a business!

I would not fret over this one bit.
I have still yet to hear an amplifier that has excelled over the kt120 by a far margin, not a small margin.
Cheers, RJ

Hello Big Dog RJ,

Can you please be a bit more specific in terms of comparing kt-120 to kt-150? In which ARC power amp(s) have you compared those and then decided the improvement is only marginal? Thanks for your help.
 

rblnr

Member Sponsor & WBF Founding Member
May 3, 2010
2,151
291
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NYC/NJ
I find going to the KT150s from the 120s to be a very legit upgrade in the Ref 75. You cannot replace the 88s, for example, with 120s in the Ref 210s w/o a transformer upgrade. The 75 requires no such upgrade to swap tubes.
 

Big Dog RJ

Well-Known Member
Feb 2, 2012
1,242
463
1,155
Melbourne
Hello Big Dog RJ,

Can you please be a bit more specific in terms of comparing kt-120 to kt-150? In which ARC power amp(s) have you compared those and then decided the improvement is only marginal? Thanks for your help.

I first came across the KT150's used with the new GS series of ref amps by ARC. There was only one particular power amp on display/demo, which also happens to be the same dealer/distributor for McIntosh and Sonus Faber in Melbourne. They had just this one power amp to compare and it was a very interesting demo indeed.
The first system was connected to an all McIntosh front end, with the ARC amp driving a pair of SF extremas (special edition the store has just received selling for 100 grand!) The sound was great! Then came along the MC452 with the same front end driving the bigger SF Stradivari, sound was splendid! Then came along the wonderful MC275 driving the SF extrema's again; sound was spectacular!

Then I go home and listen to my c-j gear with KT120's and it all sounds "just right"

I am not disagreeing with ARC's statement, the KT150 is quite a fantastic tube, and so is the KT88, KT90, KT120 and the 6550c. These are all great sounding tubes and there really is no so called "better sounding" tube. It all depends what YOU want to hear and listen to. The KT90 is widely used in all high powered amps from Manley Labs (ask Eve Anna Manley, she'll tell you that tubes rule!). The KT120 is now widely used in most c-j products because they are drop in replacements to the 6550 and do generate a "fuller" sound overall. The KT88 is widely used by McIntosh and is still used by Mc to this day, and it sounds awesome. It thrashes all notions of KT88's being too sluggish, it has a wonderful full bloom to its mid-range that really no other tube can match. Similarly the EL34 is also another fantastic tube when it comes to sound-stage, depth and palpable mid-range. Then comes the SET amps from Ayon, Lamm, CAT, BAT and the like and these are in a totally different league altogether...

Having compared the KT150 side by side with a host of others, it "did not" knock the socks off the KT120 or even the KT88. It's just that some aspects for example, bass, seemed to be presented in a more "solid state" manner compared to the KT120. The mids were still as smooth so were the highs... The sound stage was still fantastic, excellent depth, imaging, layering, spacial balance between performers, well balanced timbre, a live and natural tonal quality with perhaps a bit more dynamism. Having said that, is this what everyone is after? Perhaps some would rather prefer the laid back relaxing tone of the EL34, or even the KT88 for that matter.

Therefore, I for one still prefers the KT120's with c-j amplification. The day c-j puts out a KT150 design would be interesting. Certainly Eve Anna Manley is not overly excited on this tube, nor is Luke Manley from VTL or the chaps at McIntosh. Hence, why has ARC jumped on the KT150 so fast... again I see it solely as a business strategy to get the bucks rolling with that "must upgrade" attitude targetted towards the discerning audiophile.

If the KT150 is a so called super tube, then it should be carefully designed with the new circuit and much more heavy duty transformers according to the norm. However, in terms of actual technical data, it really is no different to the KT120. The KT120 in a well executed design is capable of producing very wattage along with some very impressive voltage. The KT150 is also capable of producing this at probably a more easy load since they would be cruising along without a sweat... and guess what? the 6550 can do exactly the same!

Therefore, at the end of the day it all depends on what type of sound you're after. I have a few fellow mates here who actually prefer their EL34 based amps compared to the kT120's, and there are quite a few who still believe in the 6550 as being the true all out pentode power beam tube of the century, period!

Try the amps out for yourself and you'll understand what I'm saying. Now if someone was to upgrade from a EL34 or 6550 to a KT150, and get that sudden jolt of extra dynamism, then of course they'll claim that the KT150 is superb! And this is what ARC is saying. However, comparing it with someone who has actually lived with nearly every type of push-pull output tube made commercially available, I really don't think the cost of that ARC upgrade is justifiable...

Try them out for yourself and you will have a hard time deciding which is "better", vs. which you "prefer".
Cheers, RJ
 

joeinid

Well-Known Member
Mar 14, 2011
1,543
12
400
NY
Love your opinion RJ.

How can you compare ARC and CJ? Conrad Johnson ROCKS! Ha! As you and CJ say, "It just sounds right" Amen!

Seriously, I'm sure the ARC Ref SE sounds great. Could be interesting if CJ comes out with amps or an update for the KT-150.
 

Big Dog RJ

Well-Known Member
Feb 2, 2012
1,242
463
1,155
Melbourne
Love your opinion RJ.

How can you compare ARC and CJ? Conrad Johnson ROCKS! Ha! As you and CJ say, "It just sounds right" Amen!

Seriously, I'm sure the ARC Ref SE sounds great. Could be interesting if CJ comes out with amps or an update for the KT-150.

Hey Joe mate, how's it going? Trust your strads and arts are rocking! Yes mate no doubt, as you claim, c-j does sound just right! Always has and always will!
I sincerely think cj will take a long hard look before employing a dedicated circuit for the kt150. They are currently on a roll with the kt120 designs with the Art monos, the lp125sa, the Art stereo, the lp125m and of course the classic 60se, all are kt120 based amps.
VTL also confirms the use of kt120 as the finest tube they're currently offering. McIntosh still sticks with their trusted kt88. Therefore, it will take quite some time before cj really views the kt150 as being an overallimprovement to what's already on offer.

I sincerely think that ARC should do theirupgrades free of charge. Especially after the customer has already spent a considerable amount of money on an existing amp, now has to cough out extra couple grand just for an upgrade because ARC says the tube is better. This to me is a load of Bollocks with a capital B!

Cheers Joe, and keep enjoying your strads!
Let me know if ever you get tired your strads or Art monoblocks, I'll gladly take ownership of them anytime mate!
 

joeinid

Well-Known Member
Mar 14, 2011
1,543
12
400
NY
Thanks RJ,

Just when I think I can get better, I hook up my ART monos again and all is right with the world. My Strads are amazing to me. Sure , some don't like them and want the latest technology but I am so happy. We'll have to talk about any fire sales. Ha!

Another bonus is that the KT120'S are one half to one quarter of the price of the KT150'S.
 

Big Dog RJ

Well-Known Member
Feb 2, 2012
1,242
463
1,155
Melbourne
Yes mate, no doubt the Art amps are awesome stuff. When I'm ready for it, I will get hold of the Artsa, the stereo version is more than plenty for the Quads. The Artsa with stats is superb! I certainly prefer it.
Take it easy mate, and have a good one!
Enjoy the strads, they are very special!
Cheers, RJ
 

number95

Well-Known Member
May 14, 2014
384
7
250
I first came across the KT150's used with the new GS series of ref amps by ARC. There was only one particular power amp on display/demo, which also happens to be the same dealer/distributor for McIntosh and Sonus Faber in Melbourne. They had just this one power amp to compare and it was a very interesting demo indeed.
The first system was connected to an all McIntosh front end, with the ARC amp driving a pair of SF extremas (special edition the store has just received selling for 100 grand!) The sound was great! Then came along the MC452 with the same front end driving the bigger SF Stradivari, sound was splendid! Then came along the wonderful MC275 driving the SF extrema's again; sound was spectacular!

Then I go home and listen to my c-j gear with KT120's and it all sounds "just right"

I am not disagreeing with ARC's statement, the KT150 is quite a fantastic tube, and so is the KT88, KT90, KT120 and the 6550c. These are all great sounding tubes and there really is no so called "better sounding" tube. It all depends what YOU want to hear and listen to. The KT90 is widely used in all high powered amps from Manley Labs (ask Eve Anna Manley, she'll tell you that tubes rule!). The KT120 is now widely used in most c-j products because they are drop in replacements to the 6550 and do generate a "fuller" sound overall. The KT88 is widely used by McIntosh and is still used by Mc to this day, and it sounds awesome. It thrashes all notions of KT88's being too sluggish, it has a wonderful full bloom to its mid-range that really no other tube can match. Similarly the EL34 is also another fantastic tube when it comes to sound-stage, depth and palpable mid-range. Then comes the SET amps from Ayon, Lamm, CAT, BAT and the like and these are in a totally different league altogether...

Having compared the KT150 side by side with a host of others, it "did not" knock the socks off the KT120 or even the KT88. It's just that some aspects for example, bass, seemed to be presented in a more "solid state" manner compared to the KT120. The mids were still as smooth so were the highs... The sound stage was still fantastic, excellent depth, imaging, layering, spacial balance between performers, well balanced timbre, a live and natural tonal quality with perhaps a bit more dynamism. Having said that, is this what everyone is after? Perhaps some would rather prefer the laid back relaxing tone of the EL34, or even the KT88 for that matter.

Therefore, I for one still prefers the KT120's with c-j amplification. The day c-j puts out a KT150 design would be interesting. Certainly Eve Anna Manley is not overly excited on this tube, nor is Luke Manley from VTL or the chaps at McIntosh. Hence, why has ARC jumped on the KT150 so fast... again I see it solely as a business strategy to get the bucks rolling with that "must upgrade" attitude targetted towards the discerning audiophile.

If the KT150 is a so called super tube, then it should be carefully designed with the new circuit and much more heavy duty transformers according to the norm. However, in terms of actual technical data, it really is no different to the KT120. The KT120 in a well executed design is capable of producing very wattage along with some very impressive voltage. The KT150 is also capable of producing this at probably a more easy load since they would be cruising along without a sweat... and guess what? the 6550 can do exactly the same!

Therefore, at the end of the day it all depends on what type of sound you're after. I have a few fellow mates here who actually prefer their EL34 based amps compared to the kT120's, and there are quite a few who still believe in the 6550 as being the true all out pentode power beam tube of the century, period!

Try the amps out for yourself and you'll understand what I'm saying. Now if someone was to upgrade from a EL34 or 6550 to a KT150, and get that sudden jolt of extra dynamism, then of course they'll claim that the KT150 is superb! And this is what ARC is saying. However, comparing it with someone who has actually lived with nearly every type of push-pull output tube made commercially available, I really don't think the cost of that ARC upgrade is justifiable...

Try them out for yourself and you will have a hard time deciding which is "better", vs. which you "prefer".
Cheers, RJ

Very well said! Thanks for a nice summary.
 

XV-1

Well-Known Member
May 24, 2010
3,591
2,576
1,860
Sydney
I prefer 6550's on my cj amps every day of the week.

KT120's are like a big cadillac - nice big easy sound with lounge chair pace rhythm and timing. :D

the 16 x KT120's sit in their boxes relegated to leaning and holding the wall up. ;)perhaps I'll take them out of the box again and power up.
 

joeinid

Well-Known Member
Mar 14, 2011
1,543
12
400
NY
I prefer 6550's on my cj amps every day of the week.

KT120's are like a big cadillac - nice big easy sound with lounge chair pace rhythm and timing. :D

the 16 x KT120's sit in their boxes relegated to leaning and holding the wall up. ;)perhaps I'll take them out of the box again and power up.

Hmmmm, maybe that's why I love them :)
 

Lee

Well-Known Member
Feb 3, 2011
3,210
1,738
1,260
Alpharetta, Georgia
I find going to the KT150s from the 120s to be a very legit upgrade in the Ref 75. You cannot replace the 88s, for example, with 120s in the Ref 210s w/o a transformer upgrade. The 75 requires no such upgrade to swap tubes.

Indeed. Carl Marchisotto at NOLA added in the KT150s to the original Ref 75 and it made a big difference on his show rooms. The KT150 is a nice upgrade. I've heard the difference. Much more low end weight.
 

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