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Question Chorus 706 Amplifier Match Question

bseej

Member
Feb 11, 2020
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Hi all,

Newbie here. I will not bore you with my long term history with audio components (mostly NAD and Castle). Lately I have been up (or maybe down) grading my equipment. I run a 2.0 system. I first bought a Yamaha RX-V481 (5.1), which was nice but needed a factory reset every week or so to sound it's best (a pain to re-program that often). I recently purchased some Focal Chorus 706 speakers which sound amazing (when the Yamaha is at its best). So, I replaced the V481 with a Marantz NR1200. Again, sounds good, but, as with the Yamaha, it struggles (which isn't surprising, since it is 75wpc instead of 80wpc). By struggles, I mean some distortion at higher volumes (mostly high frequencies, but really anything complex).

So here is/are the questions:

1) Power amp? Speakers rated to 25-120w (if that is realistic), a 250-300w amp?

2) Sub? to take some stress off the 55hz-28khz speakers?

3) Get rid of it all and by a clock radio with bluetooth?

Most music is streamed through a Late 2013 Mac Mini (I have used optical, a Firefly and Heos (on the NR1200, uPnP on the V481)) using Audirvana.

Musical tastes: Classical, Acoustic, Bluegrass, World, Classic Rock.

Any advice is welcome.

Regards
 
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chris661

Well-known member
Oct 30, 2019
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There'll be no audible difference between a 75 and 80-watt amplifier run up to clipping.

If there's distortion when the music gets complex, that suggests to me that the drivers themselves are struggling, and you're hearing inter-modulation distortion etc.

If you're near Sheffield, I can bring a measurement mic round and see what's going on.

Chris
 

Esra

Well-known member
Feb 20, 2011
59
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18,545
Something seems wrong with the speakers,driver or binding post,internal crossover.Its a 90db? speaker and easy to drive.No problem for a 481 and 1200.It needs around 6W for 95 dBSPL and has 4 Ohm minimum.
 
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bseej

Member
Feb 11, 2020
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20
There'll be no audible difference between a 75 and 80-watt amplifier run up to clipping.

If there's distortion when the music gets complex, that suggests to me that the drivers themselves are struggling, and you're hearing inter-modulation distortion etc.

If you're near Sheffield, I can bring a measurement mic round and see what's going on.

Chris
Thanks for the response Chris. Unfortunately, I'm probably out of range for a home visit (Canada). I'll keep trying things. Want to rule out a few more things before deciding on next steps.

BJ
 

bseej

Member
Feb 11, 2020
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Something seems wrong with the speakers,driver or binding post,internal crossover.Its a 90db? speaker and easy to drive.No problem for a 481 and 1200.It needs around 6W for 95 dBSPL and has 4 Ohm minimum.
Thanks Esra. I will keep checking into things.

BJ
 

bseej

Member
Feb 11, 2020
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Just an update so I do not leave everyone in the dark.

I noticed that the PS3 and CD player (old Sony) sounded pretty good (for their age) playing cd's. The PS3 is fed using HDMI and the CD player via optical, both to the NR1200 This got me thinking about the Mac mini end of things.

I made a few changes:

1) I moved the Mac Mini away from the NR1200 and used a separate wall outlet for that side of things.

2) I installed some snake oil (Jitterbug), and upgraded a Dragonfly Black (1.5) to a Dragonfly Red. (I needed the Black for work anyway), which is fed into analogue inputs on the NR1200.

Things improved considerably (ok ... maybe incrementally?) when fed over the Dragonfly DAC end (less harsh upper end). Less so over HEOS/Network Audio end (hard wired). Optical from the Mac mini to NR1200 did not change and was still harsh in the mid-upper range (especially the upper registers of violins, say 240-1000 mhz).

All psychosomatic, I am sure, but slightly more satisfied.

Could be the DAC in the NR1200 just isn't to my tastes when mixed in with the rest of my system.

I still can't help but wonder if adding something like a Marantz 7025 would reduce the stress on the NR1200 given I need about 50% gain to get the volume I want?

It could be just my ears...I'm pushing 60 (with a broom) and used to shoot trap/skeet every weekend:)

Thanks for all of your comments.

BJ
 
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Esra

Well-known member
Feb 20, 2011
59
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18,545
So you ruled out anything is broken!



Psychosomatic influence should be not underestimated in the world of hifi.;)



If you think adding a stronger amp will help you to feel better and enjoy your hifi more,go for it.It should not make things worse for sure.

From a objective side of view upgrading/changing speakers will result in most considerable improvement /change in your setup .
 
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bseej

Member
Feb 11, 2020
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So you ruled out anything is broken!



Psychosomatic influence should be not underestimated in the world of hifi.;)



If you think adding a stronger amp will help you to feel better and enjoy your hifi more,go for it.It should not make things worse for sure.

From a objective side of view upgrading/changing speakers will result in most considerable improvement /change in your setup .
Esra,

Thanks again for the response. As for things broken, the Sony CD player (over rca) works well and over optical seems to work reasonably well (but not as good as over rca). The PS3 and Apple TV over HDMI seems to work reasonably well. However, these, for the most part, aren't used for music these days (except movies, etc. which, for me, is not as important.)

I actually just "upgraded" to the Focal's from some older Klipsch RF-15's after auditioning quite a few speakers in a few "showroom"'s, so another speaker upgrade will have to wait (The Focal's sound great actually with non Mac input). My listening room is also my living room, so not the greatest in terms of treatments. I am about at the limit of SWMBO's level of understanding :)

I am really just rambling on now...

Again, Thanks for your input. It is much appreciated.

BJ
 
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Esra

Well-known member
Feb 20, 2011
59
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18,545
Ok ,it seems things worked out for you (distortion/high frequencies problem in your first post gone) and you can enjoy your setup as you say the focal sound great now with non Mac input and other non digital connections.

I don´t know Macs well but maybe there is some software upsampling going on in your mac which you dislike when connected to your system if the harshness /distortion just appears with the Mac as a source.Same maybe with PS3 and your Apple TV over HDMI which is maybe not bitperfect too as you prefer your Sony CD Player over RCA most .



Wish you best
 

bseej

Member
Feb 11, 2020
9
0
20
Ok ,it seems things worked out for you (distortion/high frequencies problem in your first post gone) and you can enjoy your setup as you say the focal sound great now with non Mac input and other non digital connections.

I don´t know Macs well but maybe there is some software upsampling going on in your mac which you dislike when connected to your system if the harshness /distortion just appears with the Mac as a source.Same maybe with PS3 and your Apple TV over HDMI which is maybe not bitperfect too as you prefer your Sony CD Player over RCA most .



Wish you best
Thanks Esra, you pretty well summed it up: I am all over the place :). Take care!
 

bseej

Member
Feb 11, 2020
9
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Thanks Esra, you pretty well summed it up: I am all over the place :). Take care!
Ok ,it seems things worked out for you (distortion/high frequencies problem in your first post gone) and you can enjoy your setup as you say the focal sound great now with non Mac input and other non digital connections.

I don´t know Macs well but maybe there is some software upsampling going on in your mac which you dislike when connected to your system if the harshness /distortion just appears with the Mac as a source.Same maybe with PS3 and your Apple TV over HDMI which is maybe not bitperfect too as you prefer your Sony CD Player over RCA most .



Wish you best
Esra,

Sorry to bother you again.

If trying to determine amplifier power/headroom, is the Dynamic Range (DR) number useful from, say, Audirvana? If my music library has, say, 75% DR numbers less than 18 and 25% greater than 18 (not my situation), would that indicate that 18dB would be a reasonable value for the headroom requirement? Perhaps I would only need the median value of DR for a reasonable headroom value? I ask because, if I understand this value correctly, it is the peak dB over the average dB, and hence would give an indication of any transient requirements in an amplifier for my particular situation/library.

I also ask because you mentioned my amp (Marantz NR1200, 75wpc - 2ch.) should be sufficient for my speakers (Focal Chorus 706's - 25-120w) and, based on the median DR, you are probably correct and I should look to speakers for improvements. Based on, say, the 75th quantile, things get a little murky since it is the tunes with high DR I seem to have the most issues with (aside from those whose loudness values (R128) values are ridiculously high).

Again...hate to bother you. Insights/comments/recomendations appreciated.

BJ

P.S. I hate this hobby!
 
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gasolin

Well-known member
Mar 17, 2013
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19,070
One thing i forgot to mention is to find out the sensitivity, how many watt you for the reference db which is 96db, if you need something like 10 watt multiply it with 10, than you have as a rule of thumb what you should have to get a god dynamic and loud sound.

usually don't fail unless you have a very big room and if small you of course don't have to use all of the power
 

bseej

Member
Feb 11, 2020
9
0
20
One thing i forgot to mention is to find out the sensitivity, how many watt you for the reference db which is 96db, if you need something like 10 watt multiply it with 10, than you have as a rule of thumb what you should have to get a god dynamic and loud sound.

usually don't fail unless you have a very big room and if small you of course don't have to use all of the power
Not sure this was meant for me. Maybe a reply on another thread?
 

Esra

Well-known member
Feb 20, 2011
59
18
18,545
To keep things simple you are right if you say 18dB-20dB of headroom is a reasonable value for peaks above average listening level i.m.o..On a scientific base you can calculate the associated power demand and get an idea.

Try playing with this SPL calculator too.

 

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