Enough Power?

[Guitarist]

As previously mentioned, I want to upgrade my amp for use with my Theos. My Sony STR6400ES puts out 140 watts per ch into 8 ohms in multichannel mode; it actually drops to 130 into 4 ohms if I'm reading the manual properly! I thought a stable amp would approximately double its 8 ohm output at 4 ohms. Anyway, I'm wondering if a Parasound Halo A51 (rated 250/400) would actually be overkill since I don't blast death metal at concert levels! At half the price (and power), would the A52 be a significant improvement over the Sony and easily drive the Theos? Again, I'm not looking for ear-crushing volume--just overall better sound, enough power, and more stability. Thanks.

 

[Gordon Gray]

My sense is that the Parasound will provide better sound and alot more headroom.

There is a point where it is overkill but, in this case and as witnessed by many who have gone this route, all have reported this to be a worthwhile expense.

If you can swing it financially, I don't think you will be disappointed in the results.

Volume is one thing. Having sufficient headroom to handle loud instantaneous transients, without strain or clipping, is another.

GG

 

[tsv_1]

I'll second Gordon's comments. For some speakers, it takes a surprising amount of juice (and joules) to accurately recreate musical transients - especially with moderate speaker efficiency - further compounded by speakers whose impedance curves dip low (e.g. MLs). That said, there's no magic W/Ch number. Different musical tastes, different room geometries and acoustical signatures, different speakers, different amplifier damping factors... they all play a role in perceived adequate (or inadequate) amplifier power. I my case, I err toward the side of significant reserve Of course then it gets really fun when you start looking at tubes vs SS vs Hybrids and Class A vs Class A/B vs Class D... and on and on

 

[Rehan Azim Hashmi]

Hello Guitarist!

A Harman Kadon HK 990 integrated amplifier is an EISA award winner. It outputs 150 watts at 8 ohms and doubles at 4 ohm. At 2 ohms before distortion it provides max. around 400 watts. It has twin toroidal transformers. In an advertisement it was stated that it provides 200 amperes of instantaneous power. It has balanced input. I have not heard this integrated but i have read its review in Stereophile magazine. It had a positive review in this magazine. It retails in U.S.A for around $2400.

The second integrated from a brand nearly every audiophile is familiar with is the Krell S-300i. It retails in U.S.A for around $2500. The Krell brand needs no introduction. It should be very good. Its designed in U.S.A but manufactured in China.

The problem with the above 2 integrated amplifiers is that they ( if i am not mistaken) do not use MOSFETS. I believe first tubes and then second MOSFET based amplifiers sound best with the previous generation of ML's. From a small sample size i have reached the conclusion that some idea contributers to this Website prefer Pass over Krell. Because it sounds better. Could be the difference in quality of sound provided by MOSFETS when compared to Bipolar transistors. Pass electronics integrated would be my recommendation however, Pass unfortunately does not make an integrated amplifier in the $2000 to $3000 price range.

Tubes sound very good and if you like tube sound then the Rogue Audio Cronus Magnum tube integrated amplifier may be the right one. It does not have balanced input. It retails for around $2200. Its hand crafted in U.S.A.

Its best to listen to electronics before buying.

I am a subscriber to Stereophile. A years subscription before post charges is valued at around $13. Why do you not become a subscriber to stereophile magazine? Through Stereophile you will always be aware of the recent entry's in the home audio electronics marketplace.

 

[Guitarist]

Thanks RAH. I want a power amp, not an integrated amp, as I plan to use my Sony just as a pre/pro until I buy a separate pre/pro. And I do subscribe to Stereophile.

 

[JayGee]

An amp that can deliver 300 watts into 4 ohms is what should be your target. Martin Logan speakers require an amp with enough headroom to deliver the occasional 2 ohm highs so power output is not about loudness...it's headroom. Anything less would most likely be a disappointment.

 

[tsv_1]

Depending on budget, you might consider an amp specifically designed for ESLs

 

[Spike]

An amp that can deliver 300 watts into 4 ohms is what should be your target. Martin Logan speakers require an amp with enough headroom to deliver the occasional 2 ohm highs so power output is not about loudness...it's headroom. Anything less would most likely be a disappointment.

This over-simplistic generalization does not help the OP at all. For example, my 50 watt tube monoblocs are MUCH MORE musical than my 300 wpc Classe' which is spec'ed at 300wpc into 8 ohms, 600wpc into 4 ohms, and 1200wpc into 2 ohms.

Spike

 

[danvu]

This over-simplistic generalization does not help the OP at all. For example, my 50 watt tube monoblocs are MUCH MORE musical than my 300 wpc Classe' which is spec'ed at 300wpc into 8 ohms, 600wpc into 4 ohms, and 1200wpc into 2 ohms.

Spike

Same thing for me. My 80w(8ohm)/120w(4ohm) Monarchy amp sounds a lot better than my Emotiva 200w(8ohm)/350w(4ohm) amp. Sound quality depends more on the amp design and power supply than the mere wattage/power rating.

 

[jmstpierre]

ok, so can anybody explain why a 50w class A is adequate for ML compared to the higher power amp.m really confused. i know class A have no distortion but surely a powerfull amp will not distort easily. goshhh, m even confusing myself asking the question...how much headroom is there with a 50w amp??

 

[MPS]

Typical ML ESL would require 2-3W to play at 90dB SPL, so for 100dB you need 20-30W and for 110dB 200-300W per channel at rated load. These are maximum SPL values , listening to dynamic recording a headroom of average power x 10 would be nice.

 

[roberto]

Yes! it is better quality Watts than quantity Watts. Your ears can tell. Trust your ears! Happy listening!

 

[tsv_1]

I think it's all of the above - great design, adequate power, and sufficient headroom. For example, I used to drive my CLXs with a wonderful pair of KT88 based tube monoblocks (80W/ch ultralinear mode). The sound was heavenly, BUT I could hear them running out of steam on more than a few occasions (granted, the CLX require more power versus others in the ML line, given the planar LF driver). So, for me with my speakers in my room, I needed more power. As Roberto says, trust your ears. It may require some experimentation before you find the amp that sound best to you given your setup and musical preferences - but isn't that a big part of what makes this hobby so much fun?

Cheers

 

[Spike]

ok, so can anybody explain why a 50w class A is adequate for ML compared to the higher power amp.m really confused. i know class A have no distortion but surely a powerfull amp will not distort easily

Ask and you shall get the gory mathematical details... Follow this link:
Dynamic Range and Power Claim

how much headroom is there with a 50w amp??

A simple answer is that there are lots of variations on 50w amp! It all depends on the design and execution of the amp. For example, the Krell KSA-50 (50wpc) and the Pass Aleph 30 (30wpc) are highly regarded in the audiophile circle for being bullet-proof and musical.
This goes back to my previous statement that over-generalization won't help the OP. Everything has to do with one's taste in music and what one is looking for from his/her system. What works for me can only be used as one reference point in someone else's system search, but it most likely will not match with his preference.

 

[JayGee]

This over-simplistic generalization does not help the OP at all. For example, my 50 watt tube monoblocs are MUCH MORE musical than my 300 wpc Classe' which is spec'ed at 300wpc into 8 ohms, 600wpc into 4 ohms, and 1200wpc into 2 ohms.

Spike

I don't agree. My point was valid based on the information provided. The poster is looking for a budget friendly amp that will do the job...Not some esoteric piece.

 

[Spike]

JayGee,

An amp that can deliver 300 watts into 4 ohms is what should be your target. Martin Logan speakers require an amp with enough headroom to deliver the occasional 2 ohm highs so power output is not about loudness...it's headroom. Anything less would most likely be a disappointment.

You're telling Guitarist to look for a musical amp which is 150 watts into 8 ohms, double to 300 watts into 4 ohms, with enough power going into 2 ohms, AND budget friendly? Last time I looked at an amp satisfying those conditions depends on one's definition of "budget friendly"! A $2k budget might be "friendly" to me, but not for someone else, that's the point. For the benefit of the OP, will you also clarify what you mean by "anything less will be a disappointment"? Remember that his previous system consisted of ML ReQuests and Levinson gear AND that he is a musician so I assume that he knows what's he is looking for.

Spike

 

[Gordon Gray]

Best advice if the OP can do it.

Drive before you buy.

GG

 

[roberto]

Hola. I am going to copy MPS ..."Typical ML ESL would require 2-3W to play at 90dB SPL, so for 100dB you need 20-30W and for 110dB 200-300W per channel at rated load. These are maximum SPL values , listening to dynamic recording a headroom of average power x 10 would be nice"... if you want to play at disco level, you need a lot of power. The old tech of the ML stat panels require three times more power for about the same SLP 85dB to 90dB. With the CLXs, you do not need big power to drive them nicely, 50 Watts are good with great clean sound with tubes. I have a customer that were he is using a VTL in Triode Mode, and he gets only 70Watts out of 4 6550s output tubes. His sound is very, very nice!!! All depends of how loud do you want to listen your system, and on the other hand, because ML diaphragm is so big, it moves a lot of air, making this, no need to play your system loud, to have the right size of the instruments, and also the harmonic texture of the musical intruments. All, it is a matter of liking. Some of us, like big power, others, like clean sound. Power is not related with transparent and clean sound in our beloved musical world. Power is for playing loud, but keep in mind that with the new stat panels, to get 90dB of SPL you need only 3Watts!. Happy listening

 

[jmstpierre]

wow spike, thanks for your related thread, very informative.Are you some kind of audio engineer or work for ML to figure that out, . I am an electrcian,and at uni part time doing a degree in civil engineering and i would not have come up with that..
the other thing m a little confused is the dB rating.I can t really visualized what 90dB represents.What s the best way to know what 90dB sounds like. is it loud or low level listening?
regartds

 

[roberto]

Hola. Some time ago, with my SLP level meter, I measure from the 3 Rod at our National Theatre, our Symphonic Orchestra playing the 9th Symphony of Beethoven, and the highest reading was 93dB!!! Over 100 musicians playing at the same time, and that was what I got. Very interesting, right? The distance from the stage to the place that I was, about 30 feet/ 10meters. But a rock group in the same place, I measured 115dB!!! Happy listening!