Tube Amplifier - would ATC work well?

[Dr Beat]

Hi out there

My brother was at first looking at a solid state amp for his lounge at his new flat, but is now looking at this tube amp, Prima Luna. The specs are as follows (copied from the maker's website); So the question is, would this amp drive (and nicely do so) floor standers like the Spendor A6, ProAc D18 or the ATC SCM40? These are the basic speakers that have been shortlisted when we were considering the solid state amps.To date the ATC is what he prefers.

Wondering if the same speaker choices will work well with a tube amp with these kind of specs. Would the sound change ? The agent is only the agent for Martin Logan speakers and nothing else, and no, they do not allow home trials

. BTW, the agent for the speakers have only solid state amps dealership. Any thoughts?

Thanks for any feedback and thoughts.

Output: 38 watts x 2 ultralinear, 21 x 2 triode

Freq. Response: 10Hz-30kHz +/- .5dB

THD: Less than 1% at full power

S/N Ratio: 89dB

Input Sensitivity: 270mV

Power Consumption : 250 watts

Dimensions: 15.2" x 8.3" x 16" (WxHxD)

Weight: 63.8 lbs
Inputs: 5 pair RCA / 1 pair HT bypass

Outputs: 4 and 8 Ohm speaker taps /

1 pair RCA fixed tape output

Tube Compliment: 2 - 12AX7, 2 - 12AU7, 4 - KT88

 

[a91gti]

The figure to bear in mind is the sensitivity rating of the speakers. As a rough generalisation anything over 90db will be fine with most valve amps. My speakers are about 91db and a valve amp with 8 watts a side drove them wonderfully.

 

[chebby]

One of the best amps to drive a pair of LS3/5A speakers (notoriously inefficient) is the old Rogers E40a valve amp so efficiency is not the whole story.

It also depends on what volume levels you are hoping to use.

Personally I would go for something like the Harbeth P3ESR or Spendor S3/5R or Stirling Broadcast LS3/5A V2 or AVI Neutron V.

I have a friend's pair of ATC SCM11's sitting in a box in our house right now (26Kg!) and he is going to be using them with a Primare i30 amp (bit of a powerhouse) and - without doubt - at very robust volume levels with mostly rock/metal.

I really think ATCs are not going to be the right choice with a circa 35 - 40watt valve amp and not just because of efficiency.

SCM40's even more so.

For intimate listening in a small room at reasonable volumes - with acoustic/vocal material - then low efficiency will not be an issue with a pair of sealed cabinet 'near field' monitors, but ATC SCM40's in a (presumably) larger room at louder volumes, I think might be a wee bit err... unwise.

 

[Anonymous]

Valve amps typically prefer to deliver higher volts rather than higher currents. Generally a valve amp is happy with inefficient speakers (provided you have the Watts) but is a lot more unhappy with difficult impedance loads. ATC and Spendor speakers are well designed and don't present such awkward loads, i.e. they really just need volts to get them to sing. Avoid speakers that are awkward loads like Dynaudio.

 

[MUSICRAFT]

Dr Beat:

Hi out there

My brother was at first looking at a solid state amp for his lounge at his new flat, but is now looking at this tube amp, Prima Luna. The specs are as follows (copied from the maker's website); So the question is, would this amp drive (and nicely do so) floor standers like the Spendor A6, ProAc D18 or the ATC SCM40? These are the basic speakers that have been shortlisted when we were considering the solid state amps.To date the ATC is what he prefers.

Wondering if the same speaker choices will work well with a tube amp with these kind of specs. Would the sound change ? The agent is only the agent for Martin Logan speakers and nothing else, and no, they do not allow home trials

. BTW, the agent for the speakers have only solid state amps dealership. Any thoughts?

Thanks for any feedback and thoughts.

Output: 38 watts x 2 ultralinear, 21 x 2 triode
Freq. Response: 10Hz-30kHz +/- .5dB
THD: Less than 1% at full power
S/N Ratio: 89dB
Input Sensitivity: 270mV
Power Consumption : 250 watts
Dimensions: 15.2" x 8.3" x 16" (WxHxD)
Weight: 63.8 lbs
Inputs: 5 pair RCA / 1 pair HT bypass
Outputs: 4 and 8 Ohm speaker taps /
1 pair RCA fixed tape output
Tube Compliment: 2 - 12AX7, 2 - 12AU7, 4 - KT88

Hi Dr Beat

The ATC's will be fine as long as your brother is not planning to play them at disco like levels. ATC's drive units are very constant allowing an amplifier to deliver it's full power all the time (prior to clipping). The impedence is far more important than the efficiency.

For me the SCM40's are the pick of the bunch. They also have a massive performance potential which will accomodate many future component changes. The D18's and A6's are both excellent speakers (imo the A6's being superior) however the SCM40's are better. All of my clients have chosen the SCM40's over the A6's in the comparisons that have been done so far irrespective of the associated components (in some of the demonstrations i used modestly priced and powered amp 50w/cdp) were done or locations used for the demonstrations.

Thanks

Rick @ Musicraft

 

[Frank Harvey]

Dr Beat: Hi out there

My brother was at first looking at a solid state amp for his lounge at his new flat, but is now looking at this tube amp, Prima Luna. The specs are as follows (copied from the maker's website); So the question is, would this amp drive (and nicely do so) floor standers like the Spendor A6, ProAc D18 or the ATC SCM40? These are the basic speakers that have been shortlisted when we were considering the solid state amps.To date the ATC is what he prefers.

Wondering if the same speaker choices will work well with a tube amp with these kind of specs. Would the sound change ? The agent is only the agent for Martin Logan speakers and nothing else, and no, they do not allow home trials

. BTW, the agent for the speakers have only solid state amps dealership. Any thoughts?

Thanks for any feedback and thoughts.Even though many valve amps seem a little underpowered, they will drive inefficient speakers much better than an equivalently powered Class A/B amplifier. It will be fine driving any of the models you mention.

Which speaker you go for can only be your choice. We keep all three you mention as well as many others at this price point, and tend to find sales of those three pretty split. They all have their own characteristics, which some will suit some, and some will suit others. Because of the vast range of speakers we keep, we find that there's no one speaker that is the be all and end all at any given price point - because we're all so different in our perception of sound, we all tend to like different things. If there was a single answer, we'd not need to keep the range we do!

The ATC's are a fairly neutral sound, easy positioning, and the most even in room response of all three. The ProAc's are slightly on the warmer, sweeter side of things, and the A6's are the most laid back of all three.

Your brother's best bet is to pop along to a dealer and compare them all with his style of music. If he can take along his valve amp that would be a great help, as all of these speakers are going to sound quite different on the end of valves.