ATC SCM40 - Which amplifier - Croft?

[kidhoward]

Any suggestion about the amplifier for ATC SCM40. Do you think Croft 25/7 will do the job?

[DSJR]

Not enough power IMO. ATC's as a breed are hugely wasteful of power, the high inertia of the drivers, coupled with tiny coils in larger gaps, demanding huge amounts, regardless of overall sensitivity and a usually benign impedance curve

I'd suggest a Quad 606 or two, 707 or two etc etc and bi-amp them. Either that or one of the better 200+WPC pro amps on the used market......... The Croft preamp should be easily able to drive two of these Quads with a suitable "Y" interconnect I think...

I did once use a Croft 30WPC OTL with some ATC20's. The sound was fine (rather good actually) but the clipping limit was very low indeed and easily reached! Yes, I know the Series 7 has lots more power, but any real dynamics will have it clipping, in my opinion and experience..

The vintage Pro amp market is a minefield where fidelity is concerned, but the better ones (I dunno, MC2 and HH VX come immediately to mind from recent experiences and there's a Yamaha 3000 summatorother IIRC) do perform at least as well as any domestic model, are usually bomb-proof, long lasting and SOUND good. The more power you can give ATC's, passive AND active, the better they sound, believe me :lol:

[Reffc]

I agree with David here. You should aim for lots more power. Heard a Parasound Halo A21 recently and that would be just the ticket! New Quad Elite QSP might be worth a look or an older model such as the 606 MkII. Add a good pre (and here the Croft 25 basic or micro are great vfm) and it should be a good match.

[hifi_dave]

As above.

The Crofts are great amps with plenty of drive for all normal speakers including electrostatics but the SCM40 is a difficult speaker which needs a lot of watts from a good, grippy amp. Anything less and the resultant sound is thin and lightweight.

I have had very good results with Naim 250s and also ATCs own integrated amps. You occasionally see them going for a reasonable price.

[technobear]

The ATC SIA2-150 is a good choice ;)

[UV101]

The ATC SIA2-150 is a good choice ;)

I know someone that uses this exact combination and is more than happy with it ;)

In fact he only got more pleased when he bi-amped it with a P1!!!

http://www.fidelityaudio.co.uk/refsystem.html

[bigmarty]

I would recommend ATC SIA2-150 as well, I also used it with the SCM40s, a great combo. Have a look at Audio Emotions pre owned section, some fantastic bargains to be had and great to deal with. http://www.audioemotion.co.uk/pre_owned.php

Marty :D

[stewartwen]

I have owned a pair of SCM-35 for some years, they are essentially the same speaker save for the extra volume of the 40. I have used CROFT and quite a few valve amps................they dont have enough current nor voltage to drive the 35. I used an American power amp, SOLID STATE, the extra power and voltage of a high powered amp made these speaks really sing. So to answer your question, Croft amps, although they are fine amps, can not drive ATC SCM 35/40 speaks very well at all.
S

[kidhoward]

Thank you for your suggestions. I am aware of SIA 2 150. But it is quite expensive. What about XTZ Class A 100D3 amplifier. It looks like that it has a lot of power and current reserve.

http://www.xtzsound.eu/en/products/electronics/class-a100-d3-svart

[stewartwen]

I am sorry I cant say, as I have never used any of those amps.

[technobear]

http://www.pinkfishmedia.net/forum/showthread.php?t=129615

[The Black Adder]

Yes, I know the Series 7 has lots more power, but any real dynamics will have it clipping, in my opinion and experience..

Hmm, even with the 7R, Dave?

[hifi_dave]

Thank you for your suggestions. I am aware of SIA 2 150. But it is quite expensive. What about XTZ Class A 100D3 amplifier. It looks like that it has a lot of power and current reserve.

http://www.xtzsound.eu/en/products/electronics/class-a100-d3-svart

As always, you need to try before you buy.

On paper, the XTZ might be a match but I've used many 'powerful' amps with ATC over the years and not many were a combination made in heaven.

Almost any amp will produce music but not many make the ATCs sing.

[DSJR]

Hmm, even with the 7R, Dave?

In any other case, I'd say the R or RS or 7 Mono's would be better, but this is ATC we're talking about.

The whole concept of ATC driver design is for a heavily damped and inneficient motor system, heavy (due to the damping goo) and held solidly to prevent the inertia taking over when the driver os asked to stop moving. Even their smaller active designs are under-powered IMO, as I remember the 200A's sounding incredible when compared to the 100A's (twice the bass/mid moving area AND rather more power to each driver), which sounded bland in comparison. Comparing ANY active ATC to their passive versions brought about the same difference in my experience, although hifi dave had Levinson at the time and their bigger amps drove passive 20's rather well he tells me :)

The SCM35 and 40 get off to a bad start because they're a three way, the bass to mid-dome crossover right where the ear can tell any potential smearing in this region. This, coupled with the need for VOLTS as well as amps to make them go, does mean that a big wattage amp is recommended. Bi-amping with big amps really seems to help here too. The slightly forward upper-mid, which modern ATC's exhibit, will also ruthlessly reproduce any clipping in the driving amp, at whatever volume level this occurs at.

Sorry to be so negative here. Passive ATC's have rules all their own here and if you get it right, they'll sound superb. Get it wrong, and they'll be on eBay within the month!

[The Black Adder]

A Chord then maybe?... Oooodles of watts.

[Ian Walker]

One of these or both will sort em,fantastic service dept at MC2 too.

http://www.ebay.co.uk/itm/MC2-MC-650-Powwer-Amplifiers-/110975735308?pt=UK_MusicalInstr_Amplifiers_RL&hash=item19d6ab560c


Ian.

[Oliver]

Not enough power IMO. ATC's as a breed are hugely wasteful of power, the high inertia of the drivers, coupled with tiny coils in larger gaps, demanding huge amounts, regardless of overall sensitivity and a usually benign impedance curve

I'd suggest a Quad 606 or two, 707 or two etc etc and bi-amp them. Either that or one of the better 200+WPC pro amps on the used market......... :

Has anybody tried the SCM 19 V2 (or the almost identical SCM20 PSL Pro) with Croft amplifiers? Will the Series 7R have enough power to drive the SCM19 nicely at low to mid volume?

[Macca]

Has anybody tried the SCM 19 V2 (or the almost identical SCM20 PSL Pro) with Croft amplifiers? Will the Series 7R have enough power to drive the SCM19 nicely at low to mid volume?

Looking at the relevant specs I'd suggest it would be sub-optimal.

[Oliver]

Yes I know, ATC recommends at least 75 watt per channel...

[walpurgis]

Bit of a catch 22 situation. ATC speakers are not cheap and definitely like a decent dollop of power behind them. Unfortunately, cheap powerful amps are not necessarily a good option, because ATCs are pretty revealing of poor amplification, so a big and probably expensive solid state amp seems the way to go. Something from the likes of Karan maybe

[DSJR]

Guys, forget Croft for making sense out of passive ATC's. The thing is, I doubt many of any of you have used ATC passive speakers at home.. They need LOADS of wattage to overcome extreme inertia, both musically, dynamically and objectively.

Look, a Croft will make a sound through ATC passives, of course it will and in terms of impedance, most ATC's are reasonable as speaker loads. What you're up against are very high inertia over damped in every way drive units with small signal coils in long gaps, which offer great things at flat-out levels when the cones are moving substantial distances in and out, but render the drive units hideously inefficient and dead sounding for typical domestic amps more used to 'turn-on-a-sixpence' speaker types. The result is a bland unmusical noise in my experience.

Look out for a half decent pro amp such as the Crown CLS1500 or bigger (Jerry used the CLS1500 and quite liked it I remember). These are cheap from Thomann and any possible slight lack of subtlety in the amp's sonics will be swamped by the speakers anyway, so won't ever be a problem and might not even exist as so many domestic amps may well soft clip a lot of the time, which is heard as a very gentle compression. MC2 used to make some serious power amps with linear supplies a few years back and apparently the 250 Watter was very good domestically according to a poster who had one.

I remember being invited to Ash James' place when he was still at ATC to hear some SCM200's. These had the same drivers as my 100A's but with several advantages in terms of dynamic range and reproduction of these dynamic shadings. Two 12" drivers doing half the work for the same output. significantly more power to each driver too (and without the hobbling of a passive crossover network with crummy filtering which was an issue for ATC three-ways then if not now). These 200A's made the 100A's of mine sound like toys, and the 100A's absolutely stomped on 99% of domestic product back then. This memory was a harsh reminder of just how limited most of our domestic stereo's really are and yes, many modern 'domestic' speakers will give more 'shape' and 'finely cut delicacy' to listening at low volume levels, but NONE will give the scale or the ability of real-life volume levels - maybe big older Tannoys, but in stock form as supplied they're rather more coloured in the mids I remember. JBL's pro/domestic models were never really represented by Harman sadly, only the 4311mk2 and then for a very short while I recall.

Hell, even doddle load speakers like *modern* Harbeths are now being recommended to be driven with as much power as you can give them, a Quad Artera and similar being a kind of minimum for them - and these are far easier to drive than any passive ATC I promise you.....

[Wakefield Turntables]

Power ATC with ATC, that's what I do.

[Oliver]

Guys, forget Croft for making sense out of passive ATC's... The result is a bland unmusical noise in my experience.

Even with the Regulated Monos?

[Macca]

It seems logical to assume they were designed and developed with ATC amplification. So the ideal amp in theory is a solid state of 100 watt absolute minimum and with very good current delivery. Which isn't really Croft.

[Floyddroid]

Best amps for ATC are ATC.

[oldius]

By far the most disappointing sound I heard in a home audio system paired ATC with Croft. There was a complete lack of dynamics and it sounded simply thin and weedy.

ATC speakers need power. Croft cannot deliver what they need.

[Oliver]

Thank you for your advice. I understand that ATC speakers would be "underpowered" with "standard" Croft amps... But has anybody specifically tried the regulated mono blocks with ATC?

[Wakefield Turntables]

I think your missing the point. Nothing Croft has to offer will drive a ATC speaker driver sufficiently. I should know I have e systems built up around both, and no the monoblocks will still be underpowered.

[Sovereign]

Back in the day, I drove my passive ATC SCM 35s with NVA A80's which worked well, then with a NVA TSS, which brought a bigger and more powerful sound.
I sold the ATC speakers because although the sound was good there was something that wasn't quite right, maybe it is what everyone is trying to explain. They sound good with most amps, but for them to perform at their best and as intended, the ATCs need something bigger and with more welly.

[The Black Adder]

ATC's need something like a Chord amp.