Minimum rec. resistor wattage?

[ro9397]

System comprises three matching receivers all operating in pure analog mode.

Receiver #1 is line preamp gain/remote volume only. Its speaker outputs drive a "Bridging Circuit" comprising series 9k (source side) and parallel 1k (load side) resistors for preamp level at the power amp inputs (performs better than the RCA preamp output). Both resistors only 1/8W.

Receivers #2 and #3 site next to speakers. Compared to even -22dB volume setting (LCD reading) I'm convinced performance improves at -25dB. I want to audition greater attenuation/less input gain but fear Bridging resistors may fry.

Owner manual lists "Input Sensitivity/Impedance" as 200mV, 47k. Please clarify if this spec coincides with volume at maximum/0dB attenuation.

Bridging Circuit resistors are soldered in the RCA plug so I can't tell if they run hot.

What is minimum wattage for Bridging Circuit resistors with receivers #2 and #3 set for -25dB? What about another 6dB of attenuation (-31dB)?

Thanks for your time!

 

[KatieandDad]

At line level you don't need to worry about power handling.

 

[llwhtt]

I'm confused, are you calling the voltage divider (the two resistors) a "bridging circuit"? Usually a "bridging circuit" is to combine two channels, one out of phase, to create more power.

Craig

 

[ro9397]

I'm confused, are you calling the voltage divider (the two resistors) a "bridging circuit"? Usually a "bridging circuit" is to combine two channels, one out of phase, to create more power.

Craig

My apology. I'm only repeating Jack Elliano's term which he used in describing it several years ago. Since then others used the term too. IIRC he said it was commonly used in recording studios "back in the day."

 

[llwhtt]

Then maybe it's not a voltage divider, the 9k resistor goes from speaker + to the center conductor of the RCA and the 1k goes from speaker + to speaker - and RCA outer?

My first thought was one end of the 9k resistor to speaker + the other end to one end of the 1k resistor and the other end of the 1k resistor to speaker - with the signal taken from the junction of the two resistors. That's a voltage divider.

Craig

 

[ro9397]

Then maybe it's not a voltage divider, the 9k resistor goes from speaker + to the center conductor of the RCA and the 1k goes from speaker + to speaker - and RCA outer?

My first thought was one end of the 9k resistor to speaker + the other end to one end of the 1k resistor and the other end of the 1k resistor to speaker - with the signal taken from the junction of the two resistors. That's a voltage divider.

Craig

Resistors in RCA plug:
9k series speaker + to RCA pin
1k parallel RCA pin to RCA shield

I'll call it whatever makes the most sense!

What is absolutely safe minimum resistor wattage? Rather than presume anything I humbly request specific minimum magnitude suitable with power amp volume setting of "-31dB." "1dB" on the LCD scale sounds like 1dB and I presume is actual dB.

Thanks!