Is the ARC Ref 75 enough for TAD CR-1's ....

[joeinid]

If I don't crank my music? Could I get away with it? My Dart is 160 wpc @ 4 ohms and it is sufficient. Thoughts ?

SPECIFICATIONS

POWER OUTPUT: 75 watts per channel continuous from20Hz to 20kHz. 1kHz total harmonic distortion typically 0.6% at 75 watts, below 0.05% at 1 watt.
Approximate actual power available at ‘clipping’ 76 watts (1kHz). (Note that actual power output is dependent upon both line voltage and ‘condition’ i. e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical.)
POWER BANDWIDTH: (-3dB points) 7Hz to 60kHz.
FREQUENCY RESPONSE: (-3dB points at 1 watt) 0.7Hz to 75 kHz.
INPUT SENSITIVITY: 1.4V RMS BAL for rated output. (25 dB Bal gain into 8 ohms.)
INPUT IMPEDANCE: 300K ohms Balanced.
OUTPUT POLARITY: Non-inverting. Balanced input pin 2+ (IEC-268).
OUTPUT TAPS: 8 ohms, 4 ohms.
OUTPUT REGULATION: Approximately 1.0dB 8 ohm load to open circuit (Damping factor approximately 8).
OVERALL NEGATIVE FEEDBACK: 15dB.
SLEW RATE: 10 volts/microsecond.
RISE TIME: 4.0 microseconds.
HUM & NOISE: Less than 0.06mV RMS – 112dB below rated output (IHF weighted, input shorted).
POWER SUPPLY ENERGY STORAGE: Approximately 520 joules.
POWER REQUIREMENTS: 105-125VAC 60Hz (210-
250VAC 50Hz) 410 watts at rated output, 500 watts maximum, 230 watts idle.
TUBES REQUIRED: 2 – Matched pair KT120 – Power Output; 2 – 6H30 Driver.
DIMENSIONS: 19" (48.3 cm) W x 8.75" (22.2 cm) H x 19.5" (49.5 cm) D. Handles extend 1.5" (3.8 cm) forward.
WEIGHT: 47 lbs. (21.3 kg) Net; 63 lbs. (28.6 kg) Shipping.

[Puma Cat]

I dunno...why bother?

It can't possibly be any better than your Dart...

[cmalak]

Joe...it all depends on how far you sit from the speaker and how loud you like to play your music. My guess is it will be able to drive it as long as you don't crank it too much. At 87 dB sensitivity for the TADs, I assumed you sit 3 meters or about 10 ft from the speakers and if you listen at an average SPL of 90 dB, you would need 36 wpc of amplifier power. Of course, another 3 dB of required SPL and you will get close to the Ref 75's rated power output requirement but you will clearly hit a ceiling on dynamic passages.

From the speaker's impedance standpoint, it should play nice with a tube amp given that it spends most of the upper midrange and treble region above 7.5 ohms, dropping to 4 ohms between 40 and 225Hz. The only place where it will put strain on the partnering amp in terms of current delivery is at 34 Hz where the impedance is 5 ohms but the capacitive phase angle is -48 degrees, which will be a tough load on the partnering amp.

Here is Stereophile's measurements of the TAD CR-1s Impedance/Phase Angle vs. frequency:

[joeinid]

Originally Posted by Puma Cat

I dunno...why bother?

It can't possibly be any better than your Dart...

True, but I like having a different flavor every now and then.

Originally Posted by cmalak

Joe...it all depends on how far you sit from the speaker and how loud you like to play your music. My guess is it will be able to drive it as long as you don't crank it too much. At 87 dB sensitivity for the TADs, I assumed you sit 3 meters or about 10 ft from the speakers and if you listen at an average SPL of 90 dB, you would need 36 wpc of amplifier power. Of course, another 3 dB of required SPL and you will get close to the Ref 75's rated power output requirement but you will clearly hit a ceiling on dynamic passages.

From the speaker's impedance standpoint, it should play nice with a tube amp given that it spends most of the upper midrange and treble region above 7.5 ohms, dropping to 4 ohms between 40 and 225Hz. The only place where it will put strain on the partnering amp in terms of current delivery is at 34 Hz where the impedance is 5 ohms but the capacitive phase angle is -48 degrees, which will be a tough load on the partnering amp.

Cyril,

Thank you so much. It might be just under the required power to comfortably run the TADs. I think the Ref 150 might be better, but then going up to that level opens up another level of amp availability. I was just thinking out loud. At 150+ watts, ART-sa, Ref 150, dual MC275-VI's are viable alternatives along with others.

[cmalak]

Joe...I think you're probably right. I would say that a bridged pair of MC275s would double the power into half the impedance so I am not sure that is a great solution. The Ref 150 would give you much more headroom and ease of drive, as would the ART-sa. I don't think you can go wrong with either.

[joeinid]

Originally Posted by cmalak

Joe...I think you're probably right. I would say that a bridged pair of MC275s would double the power into half the impedance so I am not sure that is a great solution. The Ref 150 would give you much more headroom and ease of drive, as would the ART-sa. I don't think you can go wrong with either.

I appreciate the advice. I promised myself I would not get get back into tube amps in a big way. I am really satisfied with my SS choices and keep thinking well maybe tubes would/could be reliable and enjoyable.

Is there any way to download the ARC owners manuals?

[cmalak]

Originally Posted by joeinid

I promised myself I would not get get back into tube amps in a big way. I am really satisfied with my SS choices and keep thinking well maybe tubes would/could be reliable and enjoyable.

Joe...I think sticking with SS with your TADs probably makes more sense. If you want to introduce tubes, keep it in the preamp stage like you did with the GAT. My sense is going Class A SS that is voiced to the warm side of neutral might give you what you are looking for without the hassle of tubes.

Originally Posted by joeinid

Is there any way to download the ARC owners manuals?

Joe...I am attaching a copy of the manual

[joeinid]

Thanks Cyril. I am now using the Vac Sig IIa with the 911's and Dart along with the Pass XP-30 (which is actually a great preamp). I already have someone who wants to buy the XP-30 and if the 911's sell I am adding the Dart preamp to my Dart amp. That will leave the VAC lonely. So the hunt (I mean fun) continues.

[cmalak]

Originally Posted by joeinid

Thanks Cyril. I am now using the Vac Sig IIa with the 911's and Dart along with the Pass XP-30 (which is actually a great preamp). I already have someone who wants to buy the XP-30 and if the 911's sell I am adding the Dart preamp to my Dart amp. That will leave the VAC lonely. So the hunt (I mean fun) continues.

Joe...I hear you. I of course knew you were using the VAC pre in the chain Why not just go with a partnering VAC tube amp?

[joeinid]

Originally Posted by cmalak

Joe...I hear you. I of course knew you were using the VAC pre in the chain Why not just go with a partnering VAC tube amp?

I am entertaining the idea. It's a bit more of a commitment. With all the ARC love lately, I was intrigued.