ATC SCM150 Amp and Preamp recommendations

About the OP  desire for very powerfull mono blocks amplifiers .

Do very powerfull mono blocks amps  means  ´´ musical ´´  amplifiers ?
The OP speakers are 91 DB sensativity .

Would that made much difference  on a musicality stand point ?

Is there such a thing as   ´´ the quality of the watt ´´  ?

Or is ´´ a watt ´´   only ´´ a watt ´´  ?
 

Get the ATC SC-2 pre-amp to start with. This opens up the sound in a spectacular way.

You can add any amp you like. From tube or solid as for your liking. The ATC P1 and P2 are surely great but not the endgame, the SC-2 however is..

First , the OP  wants to listen to the gears at home.

And that’s the way , it should be.  no specifications will tell him about the emotional 

perception , he will have .  And IMHO  , music is about emotions . Our taste and ears are all different .

Second , I am in the camp that you buy ounce and you keep your gears a long long time. No need to change and change if you did your home work .  Buying gears raise the serotonine but it doen’t last  very long . And this pattern gets expensive .

It is not about ´´to keep up with the Joneses ´´

This hobby may be expensive .  But what is realy expensive is when you get gears in and out , non stop.  Think about marriage  😉

Just my 2 cents

As ounce said Warren Buffet :  to get rich , have a good  job

To remain wealthy , have a good martiage 😂😂😂

[[I don't see how the active version could sound better ]]

no analog crossover to eat watts, ring, distort etc.?

@ltmandella 

I’ve listened to both the active and passive versions extensively, and I actually far prefer the passive. It’s not just about the flexibility to experiment with different amplifiers—though that’s a big plus for me—but I also personally didn’t like the sound of the active version at all. It simply didn’t connect with me musically the way the passive setup does. Passives are far more engaging. 

fair enough, I would not argue with your preference.  And I agree flexibility in choice of amps is a good thing.

However your point that I was addressing was how actives could possibly sound better.  What electrical components or characteristics would allow that?

Which I feel is still a valid point regardless of your personal preference.

@OP A pair of Passlabs XA160.8s and an XP32 pre could fit your needs well - lots of power and dynamics, plus natural timbres.

@itmandella - the manufacturers of studio monitors are not necessarily the best amplifier designers - that's a general observation, not a criticism of ATC.

Also, a loudspeaker cabinet is the worst environment in the world in which to place a power amp.

@yoyoyaya 

 

Passlabs160W into 8 ohms simply won’t be nearly enough for the SCM150s. I’m currently running Classe Delta with more power, and they’re barely moving that 15” woofer. These speakers demand far more current and headroom to truly come alive, especially with large-scale classical music.

Also, good point about amplifiers inside speaker cabinets—I hadn’t considered that aspect before, but it makes a lot of sense. Heat, vibration, and limited space for power supply design definitely aren’t ideal conditions for an amplifier

I'd try to audition Pass labs if possible.  I had great results with the XP-22 preamp and a couple of different amps (JC1 mono's and CH Precision).  The X350.8 has always been a favorite of mine.

If a loudspeaker enclosure is a poor environment for an amplifier, then it's an equally poor environment for a loudspeaker crossover.

Perhaps ATC should offer outboard line level crossover units so that audiophiles could pick and choose their own amplifiers without incurring the downsides of high level crossovers.  I suspect the people at ATC would say "why not just buy our powered loudspeakers?"  But based upon this thread there could be a market demand for such a product.

 

 

@OP This is a classic case where specifications don't tell you everything. Pass amplifiers tend to sound more powerful than their nominal specifications suggest. If you have the opportunity to listen to them, it will be worthwhile. If you find the Class A models too smooth sounding then, as per hk_fan's comment above, the class A/B amps may be preferred. They are slightly less refined when played loud, but have more slam when played loud.

Also, re hk_fan's post, I previously owned a pair of Parasound JC1s - great amps, but bettered by a pair of Pass XA60.8's despite the Parasound's being a lot more powerful on paper.

I have a small room, so don't need big amps, but I have used and auditioned 160s in very large rooms and they are in no way short of power or dynamics.

to the OP

I own the PassXa25 and drives the 2nd pair of ATC SCM19 to satisfying levels, even if the specs dont seem to jive. 
so with that said, i say, look into the Pass X260.8 power amps for your SCM150

for Preamp, i highly recommend the LINEAR TUBE Audio Microzotl pre. and roll the tubes to fit your taste

Great choice of speakers! I also have the SCM150 passive (walnut finish). They LOVE power and after trying a few different options I went with McIntosh MC1.25kw and MSB Premier DAC/Pre.

 

@audiotroy You said .8 on your earlier post instead of 8M and that's why I missed it. In all fairness I also missed the 8M though! I own the #8 stereo version with the unicorn blue meters.

I wouldn’t be so quick to assume that a kilowatt of solid state power is the ticket.  While it might be, I recently had an extended demo of the ATC SCM50s and I was very impressed how well balanced and DYNAMIC they sounded driven by a 100 watt Rogue tube despite being specified to have a sensitivity of only 84 dB.  That combo was able to crank out Led Zeppelin like nobody's business.

My 2 amps are very powerful. The incredible CODA #16 and the shockingly good $2k Schitt Wotan (needs a lot of break-in).

The CODA has some serious current because the 150 watts of power are way more powerful than some other higher watt amps I have heard. It has 100 watts of Class A. I use the #16 on the Yamaha NS5000 which has a 12-inch Zylon driver.

The Wotan is not as refined as the #16 but I think it is playing in the same league as $8k amps I have owned. It is not better, but it may be as good and cost $2k. The Wotan has some serious power.

@dpac996 You should try the $3k streamer that PBD sells for the Dream DAC. I had the older one called the STREAM-IF and compared it to the Lumin X1, which seems identical to your Lumin U2. Both were great and sounded rather different. Using Plink on the Dream was my intention. Though I changed plans on the PBD gear. I sold my STREAM-IF to someone who owned a Dream DAC.

 

https://youtu.be/6HUCvifOnjE?feature=shared

@erice64 Did you mean the ATC SCA2?

If so, I would agree, especially with the actives. Often synergy between like brands trumps everything else.

@vinylvalet yes I do. The SC-2 drives an ARC 250 to Magico S5, simply lovely😁 Also the preamp has a low output impedance especially for driving the active speakers, hence the synergy. Guess thats also the reason why my tube amp is driven with ease and force.

I am the US importer.  The actives will outperform the passives every time, not due to amplifier issues but do to control of phase.  There is no way to control phase in a passive crossover.  This a huge performance issue very few talk about. 

In a passive, a well built crossover has a TON of wire in between amplifier and drivers.  There could be hundreds of feet, especially in air core inductors.  I don't see in any scenario how that could be an improvement over hooking the amp directly to the driver with 1 foot of wire.

Next the ability to calibrate each amp precisely to the driver itself (efficiency of a completed drive unit can vary in the very best of the best manufacturing from 1/4 to 1/2 dB.  1/4 to 1/2 dB across an entire band is very audible.   .    

Next is the ability to sustain large bass dynamics while not affecting the top end HF amp or Midrange amp in any way.  A full range amp cannot do this, as the bass running the amp out of power is well understood.  The way most of us get around the obvious there is through massive OVER power delivered at the speakers, accounting for the loss of power and reduction of dampening factor down as little as 10 feet of cable.  Linear analog amps seem better at this as they have larger reserves inside a power supply.  The why ATC's own amps are class A/B and have a large linear power supply.

Maybe look at trying an ATC P2, which is 300W /channel as a first step.  that will tell you if it's enough and you need the Titan.  Keep in mind a 800w amp vs 300w amp is only about 3-4dB of average level increase.  At 110dB SPL, 3 db more SPL is a small amount.  DO the math on the 150s and see how loud 300W will be.  

Active ATC 150s will play at around 115dB or so long term, depending on dynamic range of the source.  I cannot listen that loud and I ve never run into a hi fi customer that does.  Most people cannot get much over 105dB SPL before they start freaking out.  The 95dB SPL is LOUD, and the 115dB SPL capability (20dB of reserve) is for peaks.     

Is this helpful?  I would think a 300W amp on passive 150s would make one very happy and allow some money to buy a great preamp and a great DAC, Streamer etc.

Brad

Lone Mountain Audio (ATC Hi FI USA)

TransAudio Group (ATC PRO USA) 

 

@lonemountain 

Hi Brad,

 

Thank you for the detailed and thoughtful response. I appreciate your insight as the U.S. importer and certainly respect ATC’s engineering philosophy—especially the precision and integration of their active systems. The technical points about phase coherence, component tolerances, and amp-driver calibration are well taken and valid from a design purity standpoint.

 

That said, I chose the SCM150 passives very deliberately, not as a compromise, but because they allow me to shape the sonic outcome exactly as I want it. My priority is extracting a harmonically rich, dynamic, and lifelike presentation—qualities I’ve been able to enhance by pairing them with an ultra-high-current Class AB amplifier and a well-matched tube preamp. The transient performance and low-end authority I’m getting now are exactly what I was seeking.

 

While I understand the argument about passive crossovers and inductor wire lengths, in practice, the performance delta depends heavily on system synergy and listener priorities. The subjective gains I’ve achieved through amplification choice—particularly in tone density and spatial realism—outweigh the theoretical drawbacks of the passive network in my setup.

 

Regarding power: you’re right that +3 dB isn’t a night-and-day difference on paper, but in dynamic music like large-scale orchestral works, the added headroom of an 800W+ amp translates to more effortless macro- and microdynamics at live-like levels, especially with complex low-frequency content. For me, it’s not about listening at 115 dB, but about having total control and composure when the music demands it.

 

Ultimately, this comes down to different paths to musical satisfaction. I fully understand the merits of the active approach, but I’ve found that the passive route—with the right amplification—gives me the flexibility and sonic character I value most.

 

I sincerely appreciate the dialogue and hope we can stay in touch as I continue refining the system.

 

Rotel Mitchi M8 is a nuclear weapon when it comes to power. Stereophile has a review on these monos. I have heard the stereo version of the M8.

@ei001h 

You’ve put forth the only argument that wins.  It for this reason that we still build passives as many in the hi fi hobby love the ability to "craft their own" so to speak.  The technical virtues of "the lowest distortion way" dont always win as we can easily see with those that love tubes.

 

My experience is that when active is chosen, it does not diminsh this "craft your own" part of the hobby and actually strengthens it.   Once the distortion of so much wire is removed, and phase is now linear, the items IN FRONT of the actives take on new meaning and greater dimensionality.  Cables, turntables, line level cables, streamers all become more different, more obvious than before. I ahve found that changes in front of the actives are now even more significant than before.

 

All that being said what most people focus on is tone, how a trumpet sounds, a piano, a vocal; in this the active and passive are remarkably similar.  the times I have done this comparison, many in the room cannot tell the difference or just take a wild guess.  What does affect choice that is easy to miss is tiny differences in level, comparing two things; this can make a dramatic impact in perception of which one sounds more full or warmer.  Slight differences in level appear as better bass or less bass, more treble or less (thank you Fletcher Munson curve). 

The source material can also influence this choice as many records or albums have more or less bass or more or less treble than another record.  IF I play Led Zeppelin you’ll be convinced there is less bass  (these LZ records are notorius for no bass).  If I play Patricia Barber you will be convinced there is more bass and better midrange (I know the engineer who records her and he uses very expensive hand made tube microphones i sold him many years ago that have tremendouos definition) . 

The casual or rough demos we expereince in trade shows or at someones’s house can really lead you astray, as many factors influencing perception are hidden: look no further than continuously variable gain controls on preamps which are impossible to match or repeat from one source to the other.  A tiny 1 dB level difference will make you 100% certain one of the two things has more bass or treble.   Often we attribute differences that we hear to something other than level as level alone is tough to hear. 

For example, conviction that the 800W amp vs the 300W amp is signitificant   enough to hear the differences in dynamic range may not be true depending on just two factors: the efficiency of the speaker you are comparing them on and the "sound" of the amp itself on that particular pair of loudspeakers.  I think those two factors could sway your choice one way or the other, regardless of which one has the larger power output.  SO if you are actually listening at 85dB SPL on a 90ddB 1w/1m speaker, it may not show that a 800W amp as better than a 300W amp dynamically.  O a 80dB 1w/1m speaker, it may show this easily. 

 

Brad      

@lonemountain 

I actually remember when I first reached out to you during my decision process between active and passive SCM150s. You strongly recommended going with the actives, and I took that advice seriously. I spent time listening to them—really trying to connect—but while they were undeniably impressive in terms of clarity and control, I found myself oddly unengaged. Something about the presentation just didn’t draw me in.

 

So I went with the passives—and as you’ll recall, you kindly arranged to have them shipped directly to my home. That moment marked the beginning of a very different journey. With the passives, I was finally able to shape the sound in a way that felt personal. Pairing them with an ultra-high-current Class AB amp and a tube preamp brought out the harmonics, tone density, and transient realism I’d been chasing. The system came alive in a way the actives simply didn’t.

 

I do understand and respect the technical benefits of actives—better phase coherence, reduced component variability, and so on. But in my experience, the real-world gains of external amplification—especially in bass authority, dimensionality, and tonal nuance—have made a bigger musical impact. For someone like me, who listens primarily to large-scale classical and acoustic recordings, that nuance is everything.

 

You also made a great point about how level differences and source material can color perception. It’s something I try to control for when I’m evaluating gear. But those same small differences don’t invalidate what we feel when we’re genuinely moved by a system. At some point, it’s not about which one measures better—it’s about which one connects.

 

So while I completely respect the elegance of the active design, for me, the passives were never a compromise. They were the doorway to shaping a system that feels uniquely mine—and that makes music feel more human, more alive. Edward 

 

 

@lonemountain thank you for participating.  Perhaps ATC will pickup my suggestion of an outboard active crossover?

I imagine the OP made the best choice for his specific situation.

@ei001h  : I pretty much did the same thing as you: auditioned the active and passive version of ATCs and preferred the final system sound with a Moon North amp driving the passives (same exact front end, which included the insanely phenomenal ATC SCA2 Preamp). Based on your descriptions of what you like, I strongly feel you would love the Simaudio Moon 861; maybe just get the a single stereo amp and if you find you still crave extra drive or something (hard to imagine as the 861 is an absolute beast of an amp) you can always add the 2nd and go mono. You might find, however that while you gain authority/maximum headroom you loose something in the process of monos. Only know by trying though, eh?
@yyzsantabarbara I have a Playback Designs USB-X4 on the way for a home demo. I think this is the one that is around 3K msrp. The other playback streamers that I know of are much more expensive.

@dpac996 I was reading a post by someone who got the $3k streamer from PBD and also owned the more expensive PBD one. The person said they kept the cheaper one and sold the uber streamer.

BTW - Nagra licensees the streamer tech from the PBD USB-X4 and sells it for $5k. They do something similar with their $50k DAC which uses the 3rd-tier PBF FGPA  boards.

@ei001h 

Sounds like your journey ended up in the right place.  Ultimately the thing that makes ATC the MOST different is the low distortion drivers.  This is is something both passive ad active users can appreciate when it helps them hear things they otherwise wouldn't.   

Funny how distortion in drivers appears to our ears: not necessarily as a change in tone or audible distortion, but as masking, the veil obscurring information.  Remove that and a world opens up!

The only negative to low distortion is the recods you loved for the music can sometimes soumnd rather awful.  I remember the first time I heard Genesis "Selling England By the Pound" on a pair of ATCs and I was quite disappointed: NO bass at all, almost like it had been rolled off at 400 Hz!  This was likely caused by the mix monitors or mastering monitors having too much bass in the studio and therefore the engineers thought they had ait rght when they didn't.  This was common until they finally realized that a flat speaker or one with less bass was best to mix on.  Getting your monitors right is important to make sure that your fans get to ehar what they expect. 

Brad   

@onhwy61 

 

ATC actually did make an active crossover years ago, before they made the "amp packs" with everything built in.  I’ve asked about making another one over the years, but calibrating a system properly is not easy.  I use an Audio Precision here in our shop (10K piece of test equiipment) plus an expensive calibration microphone and a treated room; this is almost impossible at home.    This calibration is critical to the entire active idea.  Asking end users to do this at home sucessfully sounds like a lot of complaint phone calls coming in to me!  Its a complex process to correctly calibrate and check your work, especially when trying to stereo match a pair of speakers in different locations in the room.  A 1/2dB level difference across an entire band is quite audible.  Its nearly impossible to measure correctly in a living room with all the irregular surfaces and 1st reflections., windows, etc.  Using a DIRAC or REW or other such method makes it very diffeicult as all these systems look at a single point in space so it doesn apply to the entire room.  Trinnov is better, a lot of advantages in that mic they developed.     

Brad

Thank you for your response.

No disrespect to the OP, but I couldn't imagine not getting the powered ATCs.  It would be comparable to getting the big MBL Radials and not using matching MBL amps.  Both are designed as loudspeaker systems.  But others clearly disagree.  It's possible that the details of calibration might actually appeal to those looking to achieve their desired sound profile.  Probably a very niche market.

@lonemountain Many thanks for chiming in. As a latecomer to the ATC party, I’m super happy I finally arrived. As Doug MacLeod says, “there’s a difference between late and too late”. I have a pair of SCM40 passives which hooked me then got the SCM50 passives. I love them 😍. It is way too easy to raise the volume due to the super low distortion. There is zero, I mean zero sense of strain or compression. It’s really cool. The midrange openness and sheer sense of transparency is spine tinglingly good. I did audition for hours, the active versions and for me the passive with a Moon amp did the trick. ATC definitely knows how to design a proper crossover and speaker system, as these are the best passives I’ve ever heard and have had in my space. I do like the ability to have some flexibility with amps and cables, and so whatever real world trade offs there are b/t the active and passives melts away once I sit and listen. What I don’t understand is why everyone doesn’t own ATC speakers active or passive. The engineering of the drivers stands on its own. They really nail the whole package beyond the raw drivers too. I guess we are just a bunch of audio fools in the end and we like what we like. 
 

@yyzsantabarbara I wonder if the USB-X with Lumin U2 will match the MPS-X streamer. I have really gotten used to Lumin and have no issues with the performance but there is something nice about all PBD and one box solution 
 

 

USA BRANDS THAT FIT THE OP’s BILL

CODA affordable excellence

BAT almost affordable excellence

CONSTELLATION unaffordable excellence

@ei001h 

 

It would be interesting to know , what gears  you have finally chosen.

And did they meet your expectations.