BP50 Volume RCA out and digital out

Bluetooth Products
1

As the BP50 is supposed to act as a preamplifier, I would like to know whether the output level of RCA, Coax and optical is synchronized or if it can be changed seperately. Means, if I turn the BP50’s main volume knob, does it alter the volume of all three output channels or, maybe, only RCA out for example?

2

Hi Tobias_Leveque,
Thank you for your message. Yes, RCA, coaxial and optical can be output simultaneously. Turning the knob will also change the volume.

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3

Hi Tobias,

The digital and optical outputs are a set level, changes to the volume or gain of these signals would happen once the signals are decoded.

4

Hi there,
thanks for your quick response to my questions. Your answers leave me with the following assumptions:

  1. No matter what the input source is (RCA, optical or coaxial), volume level changes on each output port simultaneously (?)
  2. If my input source is, for example, connected via Toslink, the BP50 routes the sound also to the RCA output (?)
  3. The BP50 acts exclusively as a preamplifier with variable output level, meaning there is no way to lock one of the output ports at 0dB (maximum level) while the other output ports still react to the volume knob (?)
5

  1. No matter what the input source is (RCA, optical or coaxial), volume level changes on each output port simultaneously (?)
    A. The volume control will change the level of the input you have chosen

  2. If my input source is, for example, connected via Toslink, the BP50 routes the sound also to the RCA output (?)
    A. Yes, you are correct.

  3. The BP50 acts exclusively as a preamplifier with variable output level, meaning there is no way to lock one of the output ports at 0dB (maximum level) while the other output ports still react to the volume knob (?)
    A. I don’t believe that is possible.

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6

Hello, I’m just going to jump on the end of this question thread to double check I understand how the digital outputs work.

If I was using HDMI ARC as input for example (but assuming this is the same for any digital input) - at the RCA line outs I would be getting variable output from the BP50 preamp volume control, while simultaneously the digital outputs (toslink, coax) are acting as a digital pass through from the HDMI Arc source (with as you say, any decoding and/or volume control to come with whatever DAC or device they connect into from there ) . Is that correct ?

Thanks in advance .

Patrick

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I’m asking, because I intend to replace my Denon 2807, which currently acts as preamp for two B50s. The Denon 2807’s rec-out port (line-out) is connected to a vu-meter. The ideal solution for me would be a preamplifier with a fixed level (dedicated) line-out port and a variable preamp-out port. Anybody here who knows a way or a workaround to solve this?

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Tobias if I have understood the functions of the BP50 correctly and I understand your situation clearly, the workaround for you would be to connect one of the BP50’s digital outputs (toslink or coax) into another DAC that has optical or coax in. This secondary DAC could be something cheap like a FiiO D03K (~$35 AUD) - the RCA output from the Fiio D03K would then be full line level delivered to your VU meter.

If this is correct and this fixed output is solely for your VU-meter (and it’s audiophile quality is not important) then you could find an even cheaper DAC to accomplish the same thing. If you search ‘optical rca dac’ you’ll find more examples for half the price of the Fiio (I see many for $17 to $20 AUD).

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Thank you Patty for your tremendous effort. I greatly appreciate your suggested workaround and since I still have one of those cheap DACs somewhere in my drawers, I will give it a try. Once again, thank you for your help. I will post the result of it…
Still, I wonder about the output level of toslink and coax. Is it possible, that there simply is no output level just as the RCA connection, since it’s a digital signal? Meaning, that Toslink and Coax output are always “full line-out”?

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Hi Tobias. Yes that is my understanding of the digital outputs, they are always transmitting a full signal as they have to rely on being decoded down stream (ie. sending as 1 instead of 0 with no in-between).

If you were looking to have preamp controlled outputs going to multiple devices, you could always run RCA splitters to your two B50’s (which it would seem you may already?) and the VU-meter (so the RCA output split 3 ways). Not ideal but also it doesn’t have a huge effect provided the input impedances of the devices aren’t too low.

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11

Hello Patty,
I just wanted to let you know that I have solved the problem exactly as you suggested. I connected the VU meter via an RCA Y-cable and it works perfectly. Funnily enough, I was unnecessarily worried because the VU meter has a built-in AGC. So the line level doesn’t really matter.