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Integrated/power amp recommendations for Polk Audio LSIM703 - AB or D?

yavormoskov

Active Member
Joined
Apr 9, 2019
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Location
Atlanta, USA
Hi. The LSIM703s are fairly inefficient - 88 dB. They really need a lot of current. I used Marantz PM8006 but did not like the warm and well-mannered sound coming from the Marantz. I like forward, slightly bright dynamic sound that hits you in the face. The amplifier is going to be connected to my SMSL M500 MK3 DAC, which I love, using RCAs or XLRs.
I narrowed down two sets of choices. The first is two class AB amplifiers.
AB - Cambridge Audio CXA81 (manufacturer refurbished) or brand new Emotiva BasX TA2 amplifier (only RCAs)
The second set is several class D amplifiers.
B - Peachtree audio Amp500 with XLRs based on ICEpower (if I can find one because it is sold out everywhere), XTZ Edge A2-400 (also based on ICEpower, built like a tank with auto on/off and XLRs), SMSL SA400 (apparently comes with very dynamic and engaging EQ settings) and also very powerful but slightly higher noise floor. The SA400 is better priced for my budget but don't know about longevity/reliability.

Last option - to wait for the new 2 channel Buckeye Hypex NCx500 amp. It could be a long wait.

If you have recommendations or advice, let me know. Thanks.

 
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The Marantz is likely neutral and likely has plenty of power. What makes you think a neutral amp is "warm and well-mannered?" What does that even mean with regards to an amp?

If you like "forward, slightly bright dynamic sound that hits you in the face," you'd be better served looking for different speakers that suite your tastes. Or maybe bringing in some EQ. Changing the amp probably won't change the sound at all (except maybe at the extremes of output).

PS. The first amps you listed are probably class AB, not class A.
 
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The Marantz is likely neutral and likely has plenty of power. What makes you think a neutral amp is "warm and well-mannered?" What does that even mean with regards to an amp?

If you like "forward, slightly bright dynamic sound that hits you in the face," you'd be better served looking for different speakers that suite your tastes. Or maybe bringing in some EQ. Changing the amp probably won't change the sound at all (except maybe at the extremes of output).

PS. The first amps you listed are probably class AB, not class A.
You are correct, they are Class AB, not A. Regarding the sound my neighbor brought home one day Boxem amplifier which is Purifi based with added custom Sparkos labs input board from Nord which really gave me the impactful sound I am talking about but the amplifier itself and the modifications are too much money for me. Also, at an audio show I heard the same speakers connected to a Hegel amplifier and they sounded just as good, if not more. But these amplifiers are way to costly. In comparison when connected to the Marantz the sound was kind of dull with not very good bass, mediocre channel separation and subdued treble. That is why I made the list above.
 
You are correct, they are Class AB, not A. Regarding the sound my neighbor brought home one day Boxem amplifier which is Purifi based with added custom Sparkos labs input board from Nord which really gave me the impactful sound I am talking about but the amplifier itself and the modifications are too much money for me. Also, at an audio show I heard the same speakers connected to a Hegel amplifier and they sounded just as good, if not more. But these amplifiers are way to costly. In comparison when connected to the Marantz the sound was kind of dull with not very good bass, mediocre channel separation and subdued treble. That is why I made the list above.
Did you test the Marantz in the same room?
 
Did you test the Marantz in the same room?
I just tested the Marantz against two other amplifiers in the same room - SMSL AO200 and Emotiva Basx A-300. The SMSL provided more exciting and dynamic sound and the Emotiva was fuller and more balanced. But both transformed my speakers to a whole new level and blew away the Marantz PM8006. I am definitely selling it.
 
How did you level match the various amps?
 
How about that you get properly autended amp regarding high frequencies (and more important regarding class D-E-H-G) with good old fashion tone controls so you can add that little brightness you wish for and (equal) loudness one's.
 
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Actually my neighbor did it. He set a volume value on the DAC and compared it with a dB from my speakers using some kind of precision microphone connected to his laptop. It looked fairly complicated. To make sure that every test track is on the same volume level. We used hdtracks 2020 hi-rez sampler album to listen to them.
 
How about that you get properly autended amp regarding high frequencies (and more important regarding class D-E-H) with good old fashion tone controls so you can add that little brightness you wish for and (equal) loudness one's.
Tone controls are very limiting. The Equalizer APO software is much superior. You can tweak the sound to great lengths compared to tone controls. Even the good ones like Shiit audio tone control are limited.
 
Tone controls are very limiting. The Equalizer APO software is much superior. You can tweak the sound to great lengths compared to tone controls. Even the good ones like Shiit audio tone control are limited.
Physical tone controls (and with remote of cores) are very simple and acessable which is more than handy when you have to correct certain recording quality on the fly.
I recommend you to see/try a Yamaha A-S, R-N midrange offering to your likings.
Shiit is what it's name tells you and nort from good and experienced implementations.
 
Hi. The LSIM703s are fairly inefficient - 88 dB. They really need a lot of current. I used Marantz PM8006 but did not like the warm and well-mannered sound coming from the Marantz. I like forward, slightly bright dynamic sound that hits you in the face. The amplifier is going to be connected to my SMSL M500 MK3 DAC, which I love, using RCAs or XLRs.
I narrowed down two sets of choices. The first is two class AB amplifiers.
AB - Cambridge Audio CXA81 (manufacturer refurbished) or brand new Emotiva BasX TA2 amplifier (only RCAs)
The second set is several class D amplifiers.
B - Peachtree audio Amp500 with XLRs based on ICEpower (if I can find one because it is sold out everywhere), XTZ Edge A2-400 (also based on ICEpower, built like a tank with auto on/off and XLRs), SMSL SA400 (apparently comes with very dynamic and engaging EQ settings) and also very powerful but slightly higher noise floor. The SA400 is better priced for my budget but don't know about longevity/reliability.

Last option - to wait for the new 2 channel Buckeye Hypex NCx500 amp. It could be a long wait.

If you have recommendations or advice, let me know. Thanks.


...I just ordered one...the wait is reasonable...

...I was going to suggest Buckeye for cheap clean power...

...I bought a Rotel RC - 1572 MKII preamp form Crutchfield...there are still 5 more in scratch and dent condition...


...between the preorder sale on the Buckeye NCx500 amp and the scratch and dent discount on the Rotel preamp a total of like $2089...

...does the SMSL M500MK3 allow both XLR and RCA output simultaneously...???....I would want to drive powered subs off the RCA output...

...if so, I could have gone with a much cheaper and simpler solution...

 
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Hi. The LSIM703s are fairly inefficient - 88 dB. They really need a lot of current.
It's possible that you are pushing the amplifier into distortion but I don't think that's what your words are describing...

I used Marantz PM8006 but did not like the warm and well-mannered sound coming from the Marantz. I like forward, slightly bright dynamic sound that hits you in the face.
What? "...'Audiophile nonsense". ;)

With audio electronics* there is ONLY noise, distortion, and frequency response. Frequency response is almost always better than human hearing, and the same is true with distortion unless you over-drive an amplifier into clipping (distortion). Noise (background hiss, hum or whine) CAN sometimes be audible.

See Audiophoolery

and also very powerful but slightly higher noise floor.
That could be a concern but with low efficiency speakers you are less-likely to hear the noise. And if you are comparing noise specs, be aware that different manufacturers use different measurement methods & standards. If the equipment is reviewed here on ASR, of course Amir's tests are standardized and you can compare.

* With speakers you get reverb and other effects related to room acoustics, and you can get speed variations from an audio source (especially analog sources). But passive speakers and headphones don't generate any noise of their own (unless something is vibrating & rattling or something like that).
 
How loud where / are you listening when comparing? It's possible you are clipping your amp somewhat and that's what you are hearing. But we need to know how loud your are listening and the distance from the speakers to your listening position and if you are using any kind of EQ or DSP to assess if clipping is causing the issue.
Also some information on the specific music tracks you use for comparison will be useful to assess the dynamic power needed.
 
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