# AmpliPro Streamer 4 output voltage? **URL:** \ **Category:** General AmpliPi Questions\ **Created:** [August 26, 2024, 3:49am UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326 "2024-08-26T03:49:22Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Nate](https://yyz2.discourse-cdn.com/free1/user_avatar/amplipi.discourse.group/nate/32/125_2.png) [@Nate](https://amplipi.discourse.group/u/Nate)\ **Post date:** [August 26, 2024, 3:49am UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326/1 "2024-08-26T03:49:22Z")
What is the AmpliPro Streamer 4 output voltage? I need 1.29Vrms into my amp to get max volume. ---
**Author:** ![Lohrer](https://yyz2.discourse-cdn.com/free1/user_avatar/amplipi.discourse.group/lohrer/32/7_2.png) [@Lohrer](https://amplipi.discourse.group/u/Lohrer)\ **Post date:** [August 26, 2024, 3:33pm UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326/2 "2024-08-26T15:33:34Z")
Currently the output voltage maxes out at 0.78 Vrms, or around -4.4 dB from what you want. That said, it _should_ be higher. The DACs actually output 1.1 Vrms (-1.4 dB from what you want), but we had to limit it for a limitation of the old amplified units. That limitation has since been removed in hardware, but for backwards compatibility we never updated the software config. We really are past due on a split in the config so that we can take advantage of the full voltage range on newer amplified units and streamers. I’ve added an issue here: > > > Both the streamers and main units/expanders with Preamp Rev4+ support passing 2 …Vrms signals. The older main units/expanders supported a lower ~0.78 Vrms, so our current ALSA config in \`asound.conf\` limits the DACs to outputting 0.78 Vrms. > > We should ensure each hardware type is actually utilizing it's full range! Either: > \* Create multiple ALSA configs for the different unit types > \* Create an 'unlimited' ALSA config, then at runtime if an older main unit/expander is detected lower the volume to match 0.78 Vrms. > > One gotcha is that if an Preamp Rev3- exists anywhere in the stack of main unit/expanders, then the whole thing needs to be limited to 0.78 Vrms. If you wanted to get your hands dirty, you could manually edit `/etc/asound.conf` so that `pcm.ch0_softvol.max_dB` is -4.1 and `pcm.ch[1-3].ttable.X.Y` are all 1.0 instead of 0.64. I haven’t tested it here but that should get you equalized volume across the DACs and maxed out at 1.1 Vrms. Note that I’m referring to the lastest `asound.conf` that was just updated in 0.4.3, and this config file will be overwritten the next time you update. ---
**Author:** ![Nate](https://yyz2.discourse-cdn.com/free1/user_avatar/amplipi.discourse.group/nate/32/125_2.png) [@Nate](https://amplipi.discourse.group/u/Nate)\ **Post date:** [August 27, 2024, 12:09am UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326/3 "2024-08-27T00:09:54Z")
Cool, this is useful, thanks! I don’t mind editing a file. Can I configure it for 1.29 Vrms rather than 1.1? The difference is significant. Here’s my 200W amp with various input voltages: **0.78 Vrms:** `(sqrt(200*8)/1.29*0.78)^2/8` = **73W** **1.1 Vrms:** `(sqrt(200*8)/1.29*1.1)^2/8` = **145W** **1.29 Vrms:** `(sqrt(200*8)/1.29*1.29)^2/8` = **200W** ---
**Author:** ![Lohrer](https://yyz2.discourse-cdn.com/free1/user_avatar/amplipi.discourse.group/lohrer/32/7_2.png) [@Lohrer](https://amplipi.discourse.group/u/Lohrer)\ **Post date:** [August 27, 2024, 2:32pm UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326/4 "2024-08-27T14:32:56Z")
The short answer is you can, but only for Output 1. Setting `pcm.ch0_softvol.max_dB` to 0.0 in the `/etc/asound.conf` config file will give you 2.1 Vrms on Output 1. In the config file the outputs are named as `ch0` through `ch3`, corresponding to RCA outputs 1 through 4 respectively. Outputs 2-4 are driven by a CM6206 USB DAC which is limited to the 1.1 Vrms output. Output 1 however is driven by a PCM5102A I2S DAC and can output up to 2.1 Vrms. Unfortunately the Pi 3 only supports a single stereo I2S which is why we had to use USB for the rest of the channels. I suggested setting `max_dB` to -4.1 on ch0 so that all 4 outputs will be matched in output levels (if my math is right, haven’t tried this in reality). But if you don’t care about that, you can increase ch0/output 1 past where you need. ---
**Author:** ![Nate](https://yyz2.discourse-cdn.com/free1/user_avatar/amplipi.discourse.group/nate/32/125_2.png) [@Nate](https://amplipi.discourse.group/u/Nate)\ **Post date:** [August 27, 2024, 8:13pm UTC](https://amplipi.discourse.group/t/amplipro-streamer-4-output-voltage/326/5 "2024-08-27T20:13:01Z")
Gotcha, thank you for the info!