dLive Insert Gain

[ParkerA1996]

Hey All,
I have recently added a Neve MBP to my live rig with DM0/S5000. I am using surface sockets to perform the insert. I have tried all insert operating level settings, but obviously it seems this piece should be operating on Analogue. The main issue I am having was discovered through some strange behavior of the hardware that resulted in me looking to calibrate all clip points in the system. Whether being driven by the internal signal generator or external, the problem persists. Essentially, with the unit in full bypass (and also confirmed with an XLR between the send and return), I am seeing a level increase when the insert is placed in circuit. Something around +4.5dB when set to analogue. Has anyone else experienced this? TIA!

[Nicola A&H]

Setting the Insert operating level to Analogue should compensate for the +4dBu on the XLR outputs, so that the overall gain of the circuit is 0dB. I have tested this on both MixRack and Surface sockets here, with an XLR cable, and cannot reproduce what you’re seeing.

Is it possible that your Neve unit also have a +4dBu nominal output? It is fairly common in the audio industry.
Another explanation is if a Scene was recalled after the operating level was set. And if this Scene had a previously stored preamp gain for the socket assigned to your Insert return, that would affect your return gain regardless of the selected operating level. You can get out of this situation by unassigning and reassigning the Insert send and return.

If you can still reproduce the +4.5dB with an XLR cable, please grab a video and open a ticket at support.allen-heath.com so we can look into it further.

[ParkerA1996]

Hi Nicola,
Thanks for the quick reply! While I don’t think I have any scenes that recall surface socket offset, unassigning and reassigning the insert has restored normal functionality when placing an XLR loopback in and out of circuit.

As a follow up question – it does still seem the clip points change when the analog loop is in versus out – a 1kHz tone from internal SigGen clips internally at +18dB and looks/sounds clean at +17dB. When the insert is engaged, the loop now seems to clip at + 14dB(clean at +13). Is this normal operation and performance given the DAC and ADC loop?

Thanks,
Parker

[ParkerA1996]

Hi Nicola,
After much testing and follow up discussions with Mike, we have determined and isolated the issue I was experiencing. I will create a feature request thread if you would like and elaborate further. The basics of the findings (tested with Audio Precision analyzer) are as follows:

Surface Inputs clip @ +18dBu
Surface Outputs clip @ +23dBu (+22.8 as tested)

Tie Line from Input port to Output port measures +5dBu of gain.

“Insert” assigned to Analogue measures ~0 dB of gain. I cannot seem to figure out what the digital setting does when assigned to analog surface ports.

This leads to the problem experienced – there is no gain across an insert, such as an XLR loop in this case, however when outputs are driven above +18dBu output, they will inevitably clip the insert return. This creates problems where a mixbus may not be clipping anywhere in a signal chain, however by assigning an insert, it immediately clips. I have set the limiter section of my Stereo Buss processing to +18dBu to ensure that this does not happen, however this is not an ideal situation.

Ideally, it would be great for the output ports to “recalibrate” when assigned to an insert path, meaning that now 0dBFS is +18dBu to ensure that input and output have the same clip point.

Thank you!

[Author]

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