Please advice: is 30w x2 class A enough to drive ATC SCM19?

[robhifi]

Has anybody here tried using either Accuphase e550/560 or MF AMS 35I with ATC SCM19?

Currently, I am using Accuphase C2420 pre and A35 power (also 30w class A) with ATC SCM7.

The bass is a little lacking so I am thinking switching to scm19 instead.

I don't think anybody in this part of the world (I am from Shanghai) actually may have the same Accuphase pre-power combo, so i guess e550/560(also 30wx2) and MF ams35 should the nearest thing to ask.

Thanks !!

 

[Neuphonix]

I'm not familiar with ATC speakers but have owned an AMS35i for a short period. Looking at the specs I'd say that it would drive them fine.

Only issue you might have is getting your hands on one. there were only 50 made & I think that they are all gone.

I bought one last year and had a few problems with it (long story). But when I demanded a brand new one after the second problem they were unable to provide one. So I ended up being traded up to a separate pre/power for a little extra.

Can highly recommend the sound if you can find one though. good luck

PS. Presume you have air-con over there, you'll need it

 

[robhifi]

Thanks a lot Neu.
I did read the posts regarding your unfortunate encounter with the ams35.
Sad to say,AMS35i is not popular at all here in China.

A35, being 30w class A,is surprisingly not hot at all. That has something to do with the huge heat sinks I guess.

 

[CnoEvil]

As you are probably well aware, I also own the 35i, which is the best amp under £10k that I've heard.........ideally, it likes speakers of high sensitivity (90 dB+) and low impedance, to get the most from it's doubling of power as impedance halves. This will be the case with most Class A.

The Sugden Masterclass are nice sounding amps, but the IA-4 only gets to about 45W @ 4 Ohms.

Luxman are also worth looking at, as I'm sure you know.

I have not heard the 35i drive the SCM 19s, but if you like to play your music loud, it may not be the best choice....but should work at moderate levels. Though saying that, the 35i has more power than it has any right to, given its rating......if you can find one. :wall:

 

[Neuphonix]

As you are probably well aware, I also own the 35i, which is the best amp under £10k that I've heard.........ideally, it likes speakers of high sensitivity (90 dB+) and low impedance, to get the most from it's doubling of power as impedance halves. This will be the case with most Class A.

The Sugden Masterclass are nice sounding amps, but the IA-4 only gets to about 45W @ 4 Ohms.

Luxman are also worth looking at, as I'm sure you know.

I have not heard the 35i drive the SCM 19s, but if you like to play your music loud, it may not be the best choice....but should work at moderate levels. Though saying that, the 35i has more power than it has any right to, given its rating......if you can find one. :wall:

Don't they understand that you are out on the cold face trying to push their product! This years Xmas bonus is looking a little shaky!

Will be interesting to see where MF go from here. They've obviously made a decision to focus on the M series. Have you heard much about the M8 stuff?

Wonder what comes next for them in terms of high end A class? Will they do another prduction run of AMS series or realease something new.

 

[CnoEvil]

Don't they understand that you are out on the cold face trying to push their product! This years Xmas bonus is looking a little shaky!

Will be interesting to see where MF go from here. They've obviously made a decision to focus on the M series. Have you heard much about the M8 stuff?

Wonder what comes next for them in terms of high end A class? Will they do another production run of AMS series or realease something new.

I was so successful selling the 35i, that they ran out! :roll:

In the current recession, and with the cost of lecky, I can see the AMS series being phased out.

I wouldn't be surprised to see the AMS, especially the 35i, becoming a classic.

 

[Neuphonix]

Don't they understand that you are out on the cold face trying to push their product! This years Xmas bonus is looking a little shaky!

Will be interesting to see where MF go from here. They've obviously made a decision to focus on the M series. Have you heard much about the M8 stuff?

Wonder what comes next for them in terms of high end A class? Will they do another production run of AMS series or realease something new.

I was so successful selling the 35i, that they ran out! :roll:

In the current recession, and with the cost of lecky, I can see the AMS series being phased out.

I wouldn't be surprised to see the AMS, especially the 35i, becoming a classic.

I suspect that you are right, whichis a real pity.

As much as i like the M series stuff I don't see it as "special". Good but not good enough toset them apart from the competition.

The smaller modular M1 range perhaps?

Have you heard anything about the M8? Not much on the net about them yet.

 

[CnoEvil]

I suspect that you are right, whichis a real pity.

As much as i like the M series stuff I don't see it as "special". Good but not good enough toset them apart from the competition.

The smaller modular M1 range perhaps?

Have you heard anything about the M8? Not much on the net about them yet.

While I rate the M6i as good, I preferred my AVR600 to it, so I'm inclined to agree.

I have seen very little about the M8.

I suspect SS will gradually move over to Class D, and Actives will become more prevalent. Unless outlawed, I see Valves continuing as a niche market, in the same way as vinyl has.

 

[robhifi]

Thanks Cno.
I listen 99% classical and jazz in a small but dedicated room (about 140sq feet, acoustic treated with4 bass tubes and 4 diffusers ),so extreme high volume is not required.

Among Chinese audiophiles, ATC and Dynaudio are notoriously known for being " very hard to drive to full potential'.
It is commonly believed that, if the amp is not at least 3 time more expansive than the ATC/DYNA you are using, it's a waste of money, because you won't be hearing the real ATC/Dyna sound. The common amps used for ATC/Dyna speakers here are Bryston, Pass Lab,Gryphone and more recently, Bladlius. Sad to say,none British.

What do you think of that?

I have already placed order for SCM19, if I fail to drive it well with my current Accuphase power amp, would you recommend a power amp (under 4k pounds) just for 'hard to drive' speakers like ATC and Dynaudio(my next target is C1)? Please , no tube amp, and ATC amp is not available here in China.

Thanks again

 

[Exoticsounds]

ATC-SCM19 have a sensitivety of 85db, so would need some heavy duty power to play loud.

But aslong as you dont need to "rock" the house, your current amp should be able to drive them just fine.

From Accuphase's own description of A35:

The power supply of an amplifier is its ultimate source of energy. Unless it provides ample reserves, sound quality will suffer, and even basic performance parameters may not be met. The A-35 has a massive power transformer and two 47,000 μF smoothing capacitors specially selected for their sonic properties. This sustains an output power rating of 120 watts into 2 ohms, 60 watts into 4 ohms, or 30 watts into 8 ohms per channel, and it enables the A-35 to perfectly handle even very-low impedance speakers or speakers with wildly fluctuating impedance characteristics.

 

[CnoEvil]

Thanks Cno. I listen 99% classical and jazz in a small but dedicated room (about 140sq feet, acoustic treated with4 bass tubes and 4 diffusers ),so extreme high volume is not required. Among Chinese audiophiles, ATC and Dynaudio are notoriously known for being " very hard to drive to full potential'. It is commonly believed that, if the amp is not at least 3 time more expansive than the ATC/DYNA you are using, it's a waste of money, because you won't be hearing the real ATC/Dyna sound. The common amps used for ATC/Dyna speakers here are Bryston, Pass Lab,Gryphone and more recently, Bladlius. Sad to say,none British. What do you think of that? I have already placed order for SCM19, if I fail to drive it well with my current Accuphase power amp, would you recommend a power amp (under 4k pounds) just for 'hard to drive' speakers like ATC and Dynaudio(my next target is C1)? Please , no tube amp, and ATC amp is not available here in China. Thanks again

There is a good chance that you will get away with your A-35, which seems to behave very like my MF....and may be hard to beat without spending a fortune.

FWIW. Power amps that I would recommend are (but may be much too expensive for driving the SCM19s):

Sugden MPA-4 Monos

Electrocompaniet AW180

Audio Analogue Class SE Power

Plinius SA-103

Classe CA2300

Musical Fidelity AMS 50

I have heard Bladelius, which sounds well. Bryston will give a very clean, powerful and neutral sound; and Pass Lab has a tremendous reputation.

Let us know how you go, and hopefully you will be fine without changing your beautiful amp.

Cno

 

[MajorFubar]

There's a lot of misunderstanding about Watts and amps. A 30 Watt amp will go loud enough to make your ears bleed in an average room and with average speakers. It's not Wattage that's important it's clean current delivery.

 

[fr0g]

http://www.crownaudio.com/how_much_power.htm

 

[Neuphonix]

Just been having another look at the specs on the smc19. One question, how much more bass do you think you'll be getting? i mean sure its going to be an improvement over your current scm7 but they are only spec to go down to 54Hz.

Maybe the Dynaudio Confidence C1 would have been worth holding out for. What is the price difference?

I really cant see your amp having any dramas.

 

[Craig M.]

There's a lot of misunderstanding about Watts and amps. A 30 Watt amp will go loud enough to make your ears bleed in an average room and with average speakers. It's not Wattage that's important it's clean current delivery.

I'd agree with this ONLY if the 30w amp has a lot of dynamic headroom. If 30w is all it can put out full stop, then it's not nearly enough for a lot of speakers at an average listening distance - unless you actually want lots of clipped peaks and damaged speakers. Remember, clean undistorted volume doesn't actually seem that loud - distortion seems loud. A clipping amp sounds loud. Read the Distortion segment of THIS.

A good example of a dynamic 'low powered' amp would be Cno's, it can put out waaay more than 35w for short bursts.

From memory, the SCM19s have a fairly flat impedance curve that only dips to around 5 ohms so don't need loads of current, but they are inefficient so lots of dynamic headroom will be needed if you want to make the most of their excellent dynamics.

THIS article explains it well.

 

[CnoEvil]

There's a lot of misunderstanding about Watts and amps. A 30 Watt amp will go loud enough to make your ears bleed in an average room and with average speakers. It's not Wattage that's important it's clean current delivery.

I'd agree with this ONLY if the 30w amp has a lot of dynamic headroom. If 30w is all it can put out full stop, then it's not nearly enough for a lot of speakers at an average listening distance - unless you actually want lots of clipped peaks and damaged speakers. Remember, clean undistorted volume doesn't actually seem that loud - distortion seems loud. A clipping amp sounds loud. Read the Distortion segment of THIS.

A good example of a dynamic 'low powered' amp would be Cno's, it can put out waaay more than 35w for short bursts.

From memory, the SCM19s have a fairly flat impedance curve that only dips to around 5 ohms so don't need loads of current, but they are inefficient so lots of dynamic headroom will be needed if you want to make the most of their excellent dynamics.

THIS article explains it well.

My speakers have a Sensitivity of 90dB, as opposed to the 85dB of the SCM19s, which makes quite a difference where only 30-35W are on offer. The Refs also drop down to 3.2 Ohms, which again plays to the strength of an amp that has high current delivery...compared to the benign impedance (5 Ohms) of the ATC.

So I agree with all the comments on this thread, with the very slight caveat, that the SCM19s may ideally be more suited to to an amp with more Watts, if loudish volumes in a largish room are involved......@ OP - What is your ceiling height?

I still think the OP will be all right, but am cautious by nature....especially when giving advice.

 

[robhifi]

Due to the small drive and cabinet size, ATC SCM7 is not giving me enough amount of bass.
So it's the amount of bass,overall "larger sound" and scale I am expecting from the 19, not extension.
With bookshelf speakers, one can not ask too much for extension.

Also, listed spec is for reference only. For example, Proac D2 claims its bass going down to 30hz :roll: .

As for Dynaudio C1, it is possibly one of the most expensive bookshelf today. In China, the latest C1 mk2 costs 5k pounds, that' 2.5 times of ATC 19. So I guess they don't belong to the same calibre , but C1 is also my target, in the near future that is.

 

[robhifi]

Thanks for your comments. Would you think otherwise if Accuphase A35 could actually do 50w x 2 class A? In the lab test results that came with the manual, it shows that A35 has a max output of over 60w at 8ohm,130w at 4 ohm and 160w at 2ohm, 20hz, both channel driven. It also states that that A35 can actually be considered as a 50w amp because the clipping point is set at 50w. My point is,for Accuphase, the printed data is very conservative.

 

[robhifi]

Please Cno, your recommendations are highly appreciated but they are a little bit on the expensive side.
My budget is under 4k pounds.

How would you comment on MF m6prx power amp(260w x2)?
They are assembled in Taiwan/China and can be bought for 2.2k brand new.
What do you think of m6prx's capability of driving low-sensitive, low impedence speakers to their full potential (ATC, Dynanudio etc)?

Friends tell me m6prx is powerful but less "expensive" sounding (In Chinese, that means less refined sounding). Your view?

Thanks

 

[MajorFubar]

There's a lot of misunderstanding about Watts and amps. A 30 Watt amp will go loud enough to make your ears bleed in an average room and with average speakers. It's not Wattage that's important it's clean current delivery.

I'd agree with this ONLY if the 30w amp has a lot of dynamic headroom. If 30w is all it can put out full stop, then it's not nearly enough for a lot of speakers at an average listening distance - unless you actually want lots of clipped peaks and damaged speakers. Remember, clean undistorted volume doesn't actually seem that loud - distortion seems loud. A clipping amp sounds loud. Read the Distortion segment of THIS.

A good example of a dynamic 'low powered' amp would be Cno's, it can put out waaay more than 35w for short bursts.

From memory, the SCM19s have a fairly flat impedance curve that only dips to around 5 ohms so don't need loads of current, but they are inefficient so lots of dynamic headroom will be needed if you want to make the most of their excellent dynamics.

THIS article explains it well.

Yes, correct, clean power is very important, as is the need to produce clean peaks. But my point was (and I'm sure you understand this, though many people generally don't) is that you don't need a lot of power to go very loud. It's how well that powr is delivered. A speaker with a sensitivity of eg 88db means one Watt will produce 88db one meter away (usually a 1kHz tone), and 88db is quite loud itself..

 

[SpursGator]

My prediction - without really knowing but hopefully an educated one - is that the A35 has enough power to drive the SCM19s. But as others have said, so much of this is dependent on listening volume. As always there is a loudness point where a system stops sounding good and you'll have to hear whether the volume you want is below that. But surely this setup ought to sound good?!?

Another factor is your preamp. I know nothing about the C-2420 but so much of what makes for a great preamp is a high-current output, which enables the power amp to work more efficiently. I am assuming based on Accuphase's reputation and the fact that the two amps should mate well, that this is the case. Class A watts are like dog's years and given that you have a nice preamp, I think you should be fine.

I do think the SCM19s are a poor choice, generally, for your amp given their low efficiency. They are hyper-accurate but their lowish efficiency may not give the dynamics that a SS class A amp is capable of going into a higher efficiency speaker. Though 85 db isn't that bad for a smallish speaker.

If your goal is to drive those speakers to their potential, and you have access to the domestic Chinese hifi market, then I have to ask: Why would you not buy a monster power amp from the best Chinese companies? What is the mainland price of, say, two top of the line JA-100 Jungson monoblocks? I am pretty sure you could buy these locally for less than $1000 USD. It's different for us, since we have to pay shipping, customs duty, etc. which doubles the cost, and then we've got a gray market product that nobody can support or repair. But if I lived in China and was operating in that ecosystem...much as I love British (and American, Danish, and Italian) hifi stuff, the fact remains that I'd have to spend 12x that amount of money get something that good from a British company. Just saying.

 

[CnoEvil]

Here is my opinion, which is really just my best guess.

- The M6 PRX is good, but I don't think you will be happy with it after the Accuphase (I think your friends are right).

- If the A-35 can deliver the power in the lab tests, it will be fine....though I would be suprised if it can achieve this in full Class A. I believe a rule of thumb is that you will get 1 deg heat for each Watt produced (50 Deg C?). Nb. The MF AMS 50 costs £8900, weighs 60kg, and gives 50W into 8 Ohms.

- The sound to which you have now become accustomed, will not be easy to achieve outside Class A / Valves, or some very carefully chosen AB amps.

- Your choice of speaker will not hide any Solid State "hardness", unlike Sonus Faber for example. So particular care needs to be taken.

- Some of the brands I've listed do worthy amps at a more sensible price.

- It may be academic, so wait until you hear the result, and if needed, I'm sure we'll be able to come up with more wallet friendly suggestions.

 

[robhifi]

Thanks for the suggestions Spurs.

I like to have a taste of everything within my reach. The quest of searching for the best HIFI system(if there ever will be one) should last for a life time. At least that's what I hope for.

I completely get your point about the Chinese HIFI products. But you see, why would one go back to a GOLF GTI after driving 3.0t BMW for years?
No offence to the GOLF owners, GOLF in highly respected here and worldwide . That was just a example.

Meanwhile, enjoy your DIY/Homebuilt hobby. Maybe one day, I will get into DIY as well.

 

[robhifi]

Cno, I tried to attach and show you a photo of the performance graph but failed.

Any way, another safe choice is buying one more A35 and play in bridged mode.

A35 becomes a 120w 8ohm,240w 4ohm monoblock when turned (x4 the normal output) .

WOW, I really can't imagine what that will be like. >) >)

 

[Macspur]

Hi,

I see from your sig you've got the SCM19's... how are you getting on with them? are you happy with the results, or are you still looking to change amplification?

Mac