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AlanH  
#1 Posted : Wednesday, December 17, 2014 6:20:33 AM(UTC)
AlanH

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Hi,
Just finished putting together a BIIISE with Legato. Powered it up for the first time today and it sounds lovely. However, the signal (from the SE - I don't have balanced inputs into my equipment) is very quiet. Like, I have the gains on my amp absolutely maxed out just to get a normal listening level. Is this normal? I read that you can swap components in the Legato to achieve higher gain, but want to check, before I take this step, that I haven't missed anything obvious. Anything I can do to increase the output signal as it is right now?

Legato is powered by Placid BP, delivering 14.75V. All other parameters set as per manuals/fantastically helpful Integration Guide

Thanks so much,
Al
AlanH  
#2 Posted : Wednesday, December 17, 2014 7:45:25 AM(UTC)
AlanH

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.

Edited by user Wednesday, December 17, 2014 7:52:20 AM(UTC)  | Reason: Not specified

AlanH  
#3 Posted : Wednesday, December 17, 2014 7:50:51 AM(UTC)
AlanH

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Pic if it helps
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Jordo  
#4 Posted : Wednesday, December 17, 2014 10:36:30 AM(UTC)
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Hi AlanH,

I'm not sure how it works with the SE but I miss the volume control.

The times I forgot to connect it, it played at maximum volume so again I'm not sure but it could be something to look at.

Good luck!

Jordo
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AlanH  
#5 Posted : Wednesday, December 17, 2014 11:00:41 AM(UTC)
AlanH

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Yes I left out the volume control. In the Integration Guide it says 'the pot is not in the signal way,
it is just a means of measuring the desired attenuation'. I understood by this that the dac output signal can be attenuated if desired by means of the volume control. As I didn't require attenuation of the signal, I omitted the volume control. Is this wrong? Does the volume control actually boost the signal?
Brian Donegan  
#6 Posted : Wednesday, December 17, 2014 2:09:56 PM(UTC)
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The volume control is always active. If you want to bypass it, there is a shunt jumper you can use on the volume pot kit. Install the the pin header, and as the jumper between "3.3V" and "PB4."

Here is the reason....

The volume control works by supplying 3.3V and GND to the volume pot. Using the ADC in the firmware microcontroller to monitor the voltage returned from the pot as you turn it, we determine how much attenuation to apply. Full voltage means no attenuation. So, by using the jumper, it appears as full voltage, and the attenuation is bypassed.
LeonvB  
#7 Posted : Wednesday, December 17, 2014 6:27:07 PM(UTC)
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Originally Posted by: AlanH Go to Quoted Post
Yes I left out the volume control. In the Integration Guide it says 'the pot is not in the signal way,
it is just a means of measuring the desired attenuation'. I understood by this that the dac output signal can be attenuated if desired by means of the volume control. As I didn't require attenuation of the signal, I omitted the volume control. Is this wrong? Does the volume control actually boost the signal?

The guide also says: "If you don’t want to use the on-board volume control, connect PB4 to the 3.3V pin on the ADC connector (ADC, 15). Otherwise, wire up the pot like described in Adding volume control."
As Brian just explained, you now have "infinite" resistance, leading to maximum attenuation. If you don't want that, place the jumper.
AlanH  
#8 Posted : Wednesday, December 17, 2014 8:40:40 PM(UTC)
AlanH

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Aha! Of all the things that could've gone wrong on this project, that is a hilariously basic oversight. Thanks so much for your replies, it's all sorted and I am a very happy camper.
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