How to set gain on the power amp

[rkumarblr]

I have an eversolo DMP A8
Per its manual the sensitivity of the output on the RCA and XLR connectors is:
RCA : 2.1 Vrms and XLR: 4.2 Vrms

When using the eversolo DMP a8 as a pre-amplifier how to set the gain on a power amp connected to it using RCA or XLR cables.

Some power amps come with the ability to set input gain for RCA and XLR to specific db values, some just have a high and low toggle and some have no option to set the gain.
So how can one decide what is the right gain to set on the power amp.

If it helps to explain this using a specific power amp such as the ROTEL RB 1552 MKII or Audiolabs 9000A, that would be great. Since their published values for them are available.

Thanks in advance for inputs on the same

 

[Yelamanchili manohar]

I have an eversolo DMP A8
Per its manual the sensitivity of the output on the RCA and XLR connectors is:
RCA : 2.1 Vrms and XLR: 4.2 Vrms

When using the eversolo DMP a8 as a pre-amplifier how to set the gain on a power amp connected to it using RCA or XLR cables.

Some power amps come with the ability to set input gain for RCA and XLR to specific db values, some just have a high and low toggle and some have no option to set the gain.
So how can one decide what is the right gain to set on the power amp.

If it helps to explain this using a specific power amp such as the ROTEL RB 1552 MKII or Audiolabs 9000A, that would be great. Since their published values for them are available.

Thanks in advance for inputs on the same

Hi

If the power amp had a variable input gain, then unless the poweramp costs a lot, best to leave it at the max gain setting. As usually there is a cheap variable resistor ladder at the amps input to reduce the strength of the incoming signal from the preamp.

Where power amps have fixed gains, which are not variable, then doesnt matter which one your goodselves use. Where there are dip switches to choose amp gain level, I would choose the one with the higher gain, as the lower gain input again will just have resistor in series to lower the signal strength.

Coming to the amps in question, both have fixed input gains, albeit different gains on their rca and xlr. Without opening up the amp, cant recommend what sounds best, so I would go with whichever input has the maximum gain.

 

[mbhangui]

I have an eversolo DMP A8
Per its manual the sensitivity of the output on the RCA and XLR connectors is:
RCA : 2.1 Vrms and XLR: 4.2 Vrms

When using the eversolo DMP a8 as a pre-amplifier how to set the gain on a power amp connected to it using RCA or XLR cables.

Some power amps come with the ability to set input gain for RCA and XLR to specific db values, some just have a high and low toggle and some have no option to set the gain.
So how can one decide what is the right gain to set on the power amp.

If it helps to explain this using a specific power amp such as the ROTEL RB 1552 MKII or Audiolabs 9000A, that would be great. Since their published values for them are available.

Thanks in advance for inputs on the same

I had the same issue with my V3 mono blocks which is a pure power amp with RCA and XLR inputs. The RCA input has two gain settings (high and low which as pretty useless). But the RCA output of your eversolo can be fed to a passive/active pre-amps. I'm using Nelson Pass B1 buffer preamp. @Kannan has one for sale I believe. It is a fantastic buffer designed by the famed guy named Nelson.

In my hunt for controlling XLR volume I came across many solutions. Mostly expensive just for nothing. However I came across This device which I'm now using to controlling volume. It is a passive pre-amp with quad volume control. I'm enclosing the circuit diagram and also the device which is available on Amazon. The only issue was that this XLR passive box was introducing 50 Hz hum, which I eliminated by connecting the metal box to the ground of my DAC. This XLR passive control accepts both Single ended and Balanced inputs/outputs.

For the RCA output I'm using Nelson Pass B1 Preamp, which is a fantastic unity gain preamp.





There are other solutions too. Take a look here https://www.audiosciencereview.com/...balanced-monitor-amp-controller-preamp.11891/

 

[rkumarblr]

I had the same issue with my V3 mono blocks which is a pure power amp with RCA and XLR inputs. The RCA input has two gain settings (high and low which as pretty useless). But the RCA output of your eversolo can be fed to a passive/active pre-amps. I'm using Nelson Pass B1 buffer preamp. @Kannan has one for sale I believe. It is a fantastic buffer designed by the famed guy named Nelson.

In my hunt for controlling XLR volume I came across many solutions. Mostly expensive just for nothing. However I came across This device which I'm now using to controlling volume. It is a passive pre-amp with quad volume control. I'm enclosing the circuit diagram and also the device which is available on Amazon. The only issue was that this XLR passive box was introducing 50 Hz hum, which I eliminated by connecting the metal box to the ground of my DAC. This XLR passive control accepts both Single ended and Balanced inputs/outputs.

For the RCA output I'm using Nelson Pass B1 Preamp, which is a fantastic unity gain preamp.

View attachment 88037

View attachment 88038

There are other solutions too. Take a look here https://www.audiosciencereview.com/...balanced-monitor-amp-controller-preamp.11891/

When you use this on the XLR are you bypassing the eversolo as a pre-amp and using it only as a streamer or is it still doing the function of a pre-amp and what is the volume setting on the eversolo in this arrangement ?

 

[rkumarblr]

Hi

If the power amp had a variable input gain, then unless the poweramp costs a lot, best to leave it at the max gain setting. As usually there is a cheap variable resistor ladder at the amps input to reduce the strength of the incoming signal from the preamp.

Where power amps have fixed gains, which are not variable, then doesnt matter which one your goodselves use. Where there are dip switches to choose amp gain level, I would choose the one with the higher gain, as the lower gain input again will just have resistor in series to lower the signal strength.

Coming to the amps in question, both have fixed input gains, albeit different gains on their rca and xlr. Without opening up the amp, cant recommend what sounds best, so I would go with whichever input has the maximum gain.

The Audiolabs 9000A has an option to set input gain from -6db to +6db. So mathematically calculating the setting
4.2 Vrms (Eversolo output) - 2 Vrms (Audiolab input) = 2.2 Vrms difference
Converting this to decibels:
20 log(2.2 Vrms / 2 Vrms) ≈ 6.9 dB

So setting it to -6db is what it indicates. But not aware if it’s using a cheap variable resistor ladder etc.

Gain can make such a difference on the load on the amp and also avoid clipping and distortion. So it’s surprising that this is not a standards or fully addressable even in amps that are not cheap by any means.

 

[mbhangui]

When you use this on the XLR are you bypassing the eversolo as a pre-amp and using it only as a streamer or is it still doing the function of a pre-amp and what is the volume setting on the eversolo in this arrangement ?

I don't use eversolo. I have made by own own streamers (two with touch screens) and 3 others using the RPI platform.

Case 1
The dac D10B (with balanced output) is connected to the RPI. The XLR output of the DAC is connected to a DBX 31 band graphic equalizer. The Balanced output of the graphic equalizer is connected thorugh two balanced cables to the Vault passive volume control. The Balanced output of the Vault control is connected to V3 Mono XLR inputs. This is case 1 where the connectivity is balanced throughout. The Dac also has hardware volume control but it has a problem with DSD files where volume below 100% causes nasty hissing sound. So I don't use the DAC hardware volume control.

For case 2 and 3 below I have a toppings E50 dac which can be connected either to my RPI or to my Mac Mini using a simple printer selector switch

Case 2
RPI hat based dac (Piano 2.1 DAC) has 4 RCA outputs. Two for subwoofer low pass (L+R) and Two high pass (L+R). The two High pass dac output goes B1 preamp input 1. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp

Case 3.
RPI which has the Piano 2.1 DAC. Using the printer switch I connect the E50 dac to the RPI. The single ended switch goes to the B1 Preamp input 2. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp.

Case 4 (for apple music)
Topping E50 dac with balanced and single ended output is connected to a Mac Mini running apple music. The single ended switch goes to the B1 Preamp input 2. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp.

Case 5 (for apple music)
Topping E50 dac with balanced and single ended output is connected to a Mac Mini running apple music. The balanced output goes to the V3 Mono Balanced input. I turn on E50's dac internal preamp. The volume is controlled by E50's remote.

Actually it is lot more complicated that I have explained, but that is the gist. Sometimes I myself forget which switch to press. So I have made these 3 slides that help me choose the input and outputs between 3 amps, 2 pair of speakers and 5 dacs. It depends on my mood what to select. The piano dac sounds the best (subjective opinion) because it has Precise high quality clocks feeding the Piano 2.1 dac.

musicroom

RCA IN RCA Out HiFI Preamplifier Output Selector Switch

docs.google.com

 

[rkumarblr]

I don't use eversolo. I have made by own own streamers (two with touch screens) and 3 others using the RPI platform.

Case 1
The dac D10B (with balanced output) is connected to the RPI. The XLR output of the DAC is connected to a DBX 31 band graphic equalizer. The Balanced output of the graphic equalizer is connected thorugh two balanced cables to the Vault passive volume control. The Balanced output of the Vault control is connected to V3 Mono XLR inputs. This is case 1 where the connectivity is balanced throughout. The Dac also has hardware volume control but it has a problem with DSD files where volume below 100% causes nasty hissing sound. So I don't use the DAC hardware volume control.

For case 2 and 3 below I have a toppings E50 dac which can be connected either to my RPI or to my Mac Mini using a simple printer selector switch

Case 2
RPI hat based dac (Piano 2.1 DAC) has 4 RCA outputs. Two for subwoofer low pass (L+R) and Two high pass (L+R). The two High pass dac output goes B1 preamp input 1. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp

Case 3.
RPI which has the Piano 2.1 DAC. Using the printer switch I connect the E50 dac to the RPI. The single ended switch goes to the B1 Preamp input 2. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp.

Case 4 (for apple music)
Topping E50 dac with balanced and single ended output is connected to a Mac Mini running apple music. The single ended switch goes to the B1 Preamp input 2. The single ended output of B1 Preamp goes to an ancient Kenwood Graphic equalizer and the single ended output of the equalizer goes to the single ended input of V3 Mono. Here I use the volume control on the B1 Preamp.

Case 5 (for apple music)
Topping E50 dac with balanced and single ended output is connected to a Mac Mini running apple music. The balanced output goes to the V3 Mono Balanced input. I turn on E50's dac internal preamp. The volume is controlled by E50's remote.

Actually it is lot more complicated that I have explained, but that is the gist. Sometimes I myself forget which switch to press. So I have made these 3 slides that help me choose the input and outputs between 3 amps, 2 pair of speakers and 5 dacs. It depends on my mood what to select. The piano dac sounds the best (subjective opinion) because it has Precise high quality clocks feeding the Piano 2.1 dac.

musicroom

RCA IN RCA Out HiFI Preamplifier Output Selector Switch

docs.google.com

Wow that is quite a calibrate setup. I was considering a Rasberry with a Hat and a linear power supply for a streamer but was not too happy with the content provider software. So settled for the more convenient eversolo DMP A8

 

[mbhangui]

Wow that is quite a calibrate setup. I was considering a Rasberry with a Hat and a linear power supply for a streamer but was not too happy with the content provider software. So settled for the more convenient eversolo DMP A8

You can't do decent apple music with rpi

 

[rkumarblr]

You can't do decent apple music with rpi

Yes that is the other reason I did not go for rpi. Apple Music since I wanted lossless music. With all the gear it was appropriate to at least have the source of CD quality.

 

[mbhangui]

Yes that is the other reason I did not go for rpi. Apple Music since I wanted lossless music. With all the gear it was appropriate to at least have the source of CD quality.

But I believe eversolo must be having a volume control which controls the hardware volume control of the internal dac. Do you know which DAC IC is used in eversolo. From the specs we can find out of the IC has a hardware volume control. In that case you can use the eversolo volume control without loosing quality.

 

[mbhangui]

Your eversolo DMP A8 has a hardware volume knob which controls the pre amp.You can use that itself.

In fact you can. It has a very good quality pre-amp. This has been taken from

Second opinion: Eversolo DMP-A8 review | Darko.Audio

John Grandberg gets his hands on the successor to 2023's hottest hi-fi product.

darko.audio

Upgrades
For that extra coin, the larger DMP-A8 moves significantly upfield in multiple ways. While the DMP-A6 was primarily a DAC with integrated streaming and file playback, it did offer volume control thanks to the integrated capability of its dual ESS DAC chips. That digital attenuation method could be useful in some cases but I’d consider it something of a bonus feature, whilst the DMP-A8 has a much more robust solution in mind: a fully balanced analog preamplifier section complete with R2R volume control and a pair each of RCA and XLR inputs.

That makes it a more complete no-compromise integrated solution in which users just add power amp or active speakers and control everything from the Eversolo itself, with no outboard preamplifier needed.

 

[rkumarblr]

Yes that is true. The DMP A8 can function as a streamer, DAC, Streamer plus DAC and a complete pre-amp with RCA and XLR out. Has DSP settings (I did not bother with that though) and most importantly, It supports Apple Lossless through the streaming service and hires through the Apple App. It also has an R2R analog volume control which it claims is more precise and less noisy. However my question for this topic was gain settings on the power amp given the 2.1 Vrms on RCA and 4.2 Vrms on XLR outputs when the eversolo is used as a pre-amp. In that mode I control the volume on the eversolo but I am still unclear if the gain on the power amp needs any specific settings when that option is available on the power amp and if so what to set it to.