An A/V Receiver or a Preamplifier and Power Amplifier for KEF Blade Twos?

To Doug Schneider,

I have a question about what equipment [I need] to power a pair of KEF Blade Twos.

Would I really be able to hear a difference if I powered the Blade Twos using a class-D3 receiver (e.g., Pioneer SC-LX901), compared to if I used a preamp and amplifier (components)? In other words, spending about $2000 on a receiver versus spending $20,000 on a preamp and amp setup?

You can assume the music being played is modern rock/pop/R&B (e.g., Top 40), so I assume we’re dealing with stuff that’s been digitally compressed (low dynamic range). In other words, source material that isn’t musically demanding to playback on a speaker system. You can also assume it won’t be played at very high volumes (e.g., >100dB).

Given the above listening conditions, would using a high-end receiver be more than enough to power the Blade Twos?

Mike
United States

I hate to brand an entire product category as poor performing, but to the get to the nuts and bolts of my answer quickly, that’s what I feel I have to do. So here goes -- while all-in-one receivers, such as the one you mentioned, are impressive in terms of how many features they have and the number of channels of amplification they pack into a single box, all the ones I’ve heard come up short on sound quality, as well as power output. I think that it simply comes from jamming too much stuff into that box -- everything gets compromised.

For instance, let’s take a look the SC-LX901 you mentioned: On Pioneer’s website, they claim that its power output into a 6-ohm load is 200W, but they’re also honest enough to say that’s with only one channel being driven and the test is not even across the audioband -- it’s for a 1kHz test signal. You can be sure that if they used 20Hz to 20kHz as their bandwidth and drove two channels, the power output would be considerably lower. What’s more, they say that its distortion level is 0.9% for that 1kHz test, which is high for a modern solid-state amplifier. I wouldn’t assume that the music you play will mask any of those deficiencies -- rock, pop, and R&B can be pretty demanding, particularly in the bass. Those musical genres also tend to sound best played fairly loud. Given that the Blade Two has a nominal impedance of about 4 ohms, I suspect that this receiver will not only have trouble driving a pair of Blade Twos to any decent volume level, its distortion will be rather high as well, so you won’t be getting the clean sound that you can get from better-quality amplification.

Have I talked you out of that receiver for the Blade Twos yet? I hope so. But before I finish, I don’t want to leave you thinking that you have to spend $20,000, as you mentioned, or that you even need separate components. If you do want separates, though, you might be surprised that companies such as Bryston, McIntosh Laboratory, and Parasound all have outstanding amplifier/preamplifier combos that would work that are priced under $10,000. You can spend more if you want to, but you really don’t need to. Alternatively, there are some super-high-performing integrated amplifiers to consider as well. For example, you could go with the Hegel H590 integrated amplifier-DAC, which Hans Wetzel reviewed for this site in October 2018 -- it is priced at $11,000 and more than surpasses it’s power rating of 301Wpc (8 ohms), with very low distortion. KEF used the H590 to power a pair of Blades at the 2018 High End show, in Munich, and the sound was great, even in a very big room. If it can power the Blades that well, it can power the Blade Twos. McIntosh has the 300Wpc (8 ohms) MA9000 integrated-amplifier DAC, which retails for $10,000. Jeff Fritz reviewed the MA9000 on SoundStage! Ultra one year ago and loved it. Those integrateds are at the high end of the price spectrum, so you could also get something suitable priced quite a bit lower -- even as low as the Pioneer receiver you are considering -- though they are not likely to have that kind of power output that the H590 and MA9000 have. All told, what I want to really stress is that if you’re going to the expense of getting KEF Blade Twos, get all you can from them with a proper amplification setup. . . . Doug Schneider