Split Yamaha RX-A1070BL Pre-amp Output

B

bigbair45

Audiophyte
Building my first theater:

Yamaha Aventage RX-A1070BL
Monoprice Monolith 5x200
Polk Speakers
RTi A9
CSi A6
RTi A1
FXi A4
80 F/X RT
(2) PSW-110

My question is:
Can I split my FL FR Pre-amp outputs with a RCA-Y from my Yamaha to the Monolith 5x200? Going to amplify the CSi A6 on the center channel then wanted to bi-amp the RTi A9's with the other 4 channels from the Monolith. Has anyone done this or heard of doing this? Also could I just reassign a different set of pre-amp outputs to the FL FR to achieve my bi-amp for the monster towers?

Thanks!
 
P

PENG

Audioholic Slumlord
Building my first theater:

Yamaha Aventage RX-A1070BL
Monoprice Monolith 5x200
Polk Speakers
RTi A9
CSi A6
RTi A1
FXi A4
80 F/X RT
(2) PSW-110

My question is:
Can I split my FL FR Pre-amp outputs with a RCA-Y from my Yamaha to the Monolith 5x200? Going to amplify the CSi A6 on the center channel then wanted to bi-amp the RTi A9's with the other 4 channels from the Monolith. Has anyone done this or heard of doing this? Also could I just reassign a different set of pre-amp outputs to the FL FR to achieve my bi-amp for the monster towers?

Thanks!
You can use Y splitters but you cannot reassign pre-outs. The reassign feature is only for bi-amping FL and FR using the internal amps of the AVR.
 
D

Drunkpenguin

Audioholic Chief
Also, bi-amping is considered by many to be a waste of amps.
 
B

bigbair45

Audiophyte
Also, bi-amping is considered by many to be a waste of amps.
I agree with you on the bi-amp. But this setup, I'm going to use two channels per tower from an external amp. Two channels for the lows & two for the highs. I've read that the RTi A9's don't perform nominally without some extra power. I'm thinking that 400 watts per speaker, should theoretically make them sing quite nicely. With the 5th channel (200 watts) for my CSi A6 center. Just the surrounds & Atmos will be powered by the AVR.

I just needed to get a pros' perspective on splitting my FL/FR pre-amp output. By splitting the signal it should allow me to use the four channels on two speakers?
 
D

Drunkpenguin

Audioholic Chief
I've never split mains but I dont see why not. I've been splitting the sub output for years and never noticed any issues.
 
P

PENG

Audioholic Slumlord
I agree with you on the bi-amp. But this setup, I'm going to use two channels per tower from an external amp. Two channels for the lows & two for the highs. I've read that the RTi A9's don't perform nominally without some extra power. I'm thinking that 400 watts per speaker, should theoretically make them sing quite nicely. With the 5th channel (200 watts) for my CSi A6 center. Just the surrounds & Atmos will be powered by the AVR.

I just needed to get a pros' perspective on splitting my FL/FR pre-amp output. By splitting the signal it should allow me to use the four channels on two speakers?
What you read about those RTI are partially true, as it really depends on your spl requirement and your seating distance. People exaggerated their need for power without ref to spl and distance just for excuses.

As I mentioned, you can use the y connectors, it is the right way to do it. Passive bi-amp may not make a difference, but it should at least give you a little more headroom and that can help if you listen at reference level sitting far away, say more than 4 meters. I'm if you have the spare channels, use them.
 
M Code

M Code

Audioholic General
Note that when U use the RCA Y connectors, essentially now the (2) stereo pre-outs are in parallel..
Most likely this will reduce the pre-out voltage slightly but U should have enough output voltage swing that the drop may not be noticeable...

Just my $0.02... ;)
 
P

PENG

Audioholic Slumlord
Note that when U use the RCA Y connectors, essentially now the (2) stereo pre-outs are in parallel..
Most likely this will reduce the pre-out voltage slightly but U should have enough output voltage swing that the drop may not be noticeable...

Just my $0.02... ;)
If the input impedance of the power amp is high enough, even just 10k ohm, there should be no voltage drop to worry about as it won't even be slightly, but negligibly arguable speaking.:)
 
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P

PENG

Audioholic Slumlord
Monolith is spec'd at 28 kiloohms...
Thank you, I had one too many zero, corrected now.

Yamaha pre out specs:

Rated Output level / Output impedance

Pre Out except subwoofer (1 kHz)..............................1.0 V/470 ohm
Maximum output level..................................................2.0V or more

May as well do the math right here just for fun, and since in this case everyone seems to know Ohms law.

V = I*Z0 (Z is load impedance, i.e. input impedance of the Monoith)

Say V = 1 V

Z = 28,000 ohm

I = V/Z = 1/(28,000+470) = 0.000035125 A, or 0.035125 mA

Voltage drop = IXZout (Z0 is the output impedance of the RX-A1070)

So voltage drop = 0.000035125 X 470 = 0.0165 V, or 16.5 mV

For two power amps in parallel per @M Code

I = V/Z = (1/(28,000/2)+470) = 0.0000691 A, or 0.0691 mA

Voltage drop = IXZout = 0.0000691X470 = 0.03248 V

So the slight drop (extra drop due to the lower parallel input impedance of the Monolith) is:

0.03248 - 0.0165 = 0.01597 V or 15.97 mV

15.97 mV difference in output is negligible, but M code is absolutely right about the slight difference, especially if the preamp has relatively high output impedance (e.g. passive preamps) and the power amp has relatively low impedance. In the case of the RX-A1070 and Monolith 200 WX5, there should be no issue.
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
So the answer is ........... YES, you can absolutely SPLIT the Front Left and Right outputs from your Yamaha 1070 into the 4 CH on your Monoprice amp for bi-amp.

Tell us if you notice any differences at all when you bi-amp. And we don't mean any "subtle" differences. We mean any significant differences. :D
 
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