A/V Receiver Impedance Selector Switch

What setting is your receivers impedance switch on?

  • high setting (factory default)

    Votes: 52 72.2%
  • Low setting

    Votes: 6 8.3%
  • My receiver doesn't offer this feature

    Votes: 14 19.4%

  • Total voters
    72
D

dlaloum

Full Audioholic
The Onkyo 876 weighs 24.1 kg not 30 kg. Yes it is still heavy for a 7.1 avr.
Yes you are right .... still more than double the NR7100, or DRX3.4 - and substantially more than the RZ50!
 
P

PENG

Audioholic Slumlord
Yes you are right .... still more than double the NR7100, or DRX3.4 - and substantially more than the RZ50!
I agree those Onkyo and Integra AVRs are among the heaviest, only heavier by the Yamaha and Denon of the days.

I compiled the following top AVRs of the older days based on their measured output by S&V, you can see that Onkyo and Integra did occupy the top 2 spots based on most (not all) of the measured criteria. You can also see that weight is not always the only indicator to predict output, as the Denon in the 6th spot (I owned that one) weighed a lot less but actually measured higher in the 2 ch output and not far behind in the 5 and 7 channel driven criteria, and at lower THD+N too. That's because while power supply is obviously the key part, the output devices and heat sinks also play an important role.

1672062495166.png
 
Trell

Trell

Audioholic Spartan
No.

He claimed that "They ALWAYS produce LESS power in the low impedance mode ", but it seems not applying to Yamaha RX-V1070. I believe that RX-V1070 should be able to produce MORE power in lower impedance mode.
You believe? :rolleyes:
 
everettT

everettT

Audioholic Spartan
BTW, RX-V1070 weights more than 40lbs with a massive transformer. It handles a pair of 4ohm Altec Lansing speakers easily.
This is really simple, prove your theory by testing it with the proper methodology, it's not hard.
 
P

PENG

Audioholic Slumlord
I measured more than twice. It make sense to me.
RX-V1070 rated 110wpc / 135wpc (8ohm/6ohm) for front and center channels. Power output higher for 6ohm speakers means the rail voltages for it should be higher.
That's not how the electrical theories work. To see some detailed explanation, please refer to post#76 in which @dlaloum used calculations with numerical examples to make it easier to understand:

A/V Receiver Impedance Selector Switch | Page 4 | Audioholics Home Theater Forums

The funny thing is, you somehow found a diagram that led to believe the 6 ohm setting gives a higher voltage.
I got curious, because that would make no sense at all, so I googled for another Yamaha AVR's service manual and found one for the RX-A3050 and RX-V3079 that have comparable power output rating to the RX-V1070. You can look at another one such as the one for the RX-A3080 and I am sure you will see something similar.

Now take a look:

You will find that there are enough evidence to show/suggest that the diagram you posted had a few typo. So yes, I understand why you were led to believe that the 6 ohm setting gives higher rail voltage, because of the typos in that diagram, when in fact the opposite is true.

1672073929252.png


1672074098166.png
 
R

richardjhy

Audiophyte
That's not how the electrical theories work. To see some detailed explanation, please refer to post#76 in which @dlaloum used calculations with numerical examples to make it easier to understand:

A/V Receiver Impedance Selector Switch | Page 4 | Audioholics Home Theater Forums

The funny thing is, you somehow found a diagram that led to believe the 6 ohm setting gives a higher voltage.
I got curious, because that would make no sense at all, so I googled for another Yamaha AVR's service manual and found one for the RX-A3050 and RX-V3079 that have comparable power output rating to the RX-V1070. You can look at another one such as the one for the RX-A3080 and I am sure you will see something similar.

Now take a look:

You will find that there are enough evidence to show/suggest that the diagram you posted had a few typo. So yes, I understand why you were led to believe that the 6 ohm setting gives higher rail voltage, because of the typos in that diagram, when in fact the opposite is true.

View attachment 59243

View attachment 59244
You're ridiculous!

I have Yamaha RX-V1070 and measured rail voltages with multimeter for both 6ohm and 8ohm settings and results completely match the schematic diagram. Even more, I compared the circuit boards with the diagram and they match.

Here is the source of RX-V1070 SERVICE MANUAL.
 
gene

gene

Audioholics Master Chief
Administrator
No.

He claimed that "They ALWAYS produce LESS power in the low impedance mode ", but it seems not applying to Yamaha RX-V1070. I believe that RX-V1070 should be able to produce MORE power in lower impedance mode.
Posting an incomplete schematic doesn't prove your point. EVERY Yamaha receiver I've EVER tested produced LESS power with the impedance switch set to 6 ohms or the "lower setting". This is true whether the amp is driving a 8 ohm load or a 4 ohm load.


The only Yamaha product that wasn't negatively impacted with the low setting for up to 2CH driven is their dedicated 11CH Amp, the MX-A5000 and newer and the old flagships like the RX-Z11. However, I did see a negative impact on power with more than 2CH driven with the impedance switch set to low.


You can continue to fetishize the impedance switch if you like but the bottom line is it LIMITS power as it's designed to do so that the product can satisfy heat dissipation requirements to get the 4 ohm UL rating. I not only confirmed this with the product managers but also the design engineers AT Yamaha.
 
P

PENG

Audioholic Slumlord
That seemed ironic for you to say that..:D

When you said things like the following:

richardjhy said:
RX-V1070 rated 110wpc / 135wpc (8ohm/6ohm) for front and center channels. Power output higher for 6ohm speakers means the rail voltages for it should be higher.
No, it does not always mean that. I am sure you know the basic power formula and should therefore understand power output into 6 ohm will be higher at the same or even slightly lower voltage.

That's why AV receiver manufacturers often provide those impedance selectors to lower the rail voltage (or other methods) to limit the otherwise much increased load current when used with 6 ohm or lower impedance speakers. You said you measured the rail voltages, if they were higher for the 6 ohm selection, then something was not right but I wouldn't want to speculate what could be the causes.

Take a look of another numerical example:

Power = V^2/R (for simplicity, let's use a resistor load for the calculations).

For 8 ohm load, 110 W output:
V = sqrt(P*R)Into an 8 ohm load, Power =110 W, V = sqrt (8*110) = 29.66 V

For 6 ohm load, 135 W output:
V = sqrt (6*135) = 28.46 V, that's lower than that required for the 110 W rated output into 8 ohm, yet the power output is higher, using your RX-V1070's specs for this numerical example.

So please know that higher output into 6 ohm than into 8 ohm does not mean the rail voltage has to be higher, it depends on how much higher.

If you are not going to listen to others points, fine, but there is no need to be rude. We are here to help and/or learn from one another.

Happy holidays!
 
Last edited:
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