Have you tried using the BHA-1 balanced input with some other source? Input stage of an amplifier can overload with a high voltage signal. However, I checked the Schiit website and it states a maximum output of 4 V for the Iggy, therefore the same as a Bryston BDA-2 so this shouldn't be an issue.
Yes I did.. Bryston BDA-1, Hugo TT, Gustrad x20, all balanced connected with Bryston and all good!
This Bryston "allergy" to Schiit Yggdrasil is very interesting to understand and eventually resolve.
Seems it somehow bryston amp too sensitive to yggdrasil form balanced input. Strangely not by voltage (it is not higher then other DACs, i measured, it's 4,22 to be precise), but something like resistance/current intolerance between them?
What is interpreting, if I still use balanced interface between Bryston and Yggy BUT use single ended output for headphones instead of balanced output... all sound perfect again. As i understand in this case Bryston will use just half of its power..
I am going to try -10dB attenuators for XLR connection and see if it may help. But really looking for the way to decrease Bryston gain.
From other comments I've seen some other amps often implement attenuation select for balanced input. Apparently briston do need it as well to be more friendly and universal.
Any help how to decrease Bryston gain is vert welcome. I have 2 Bryston amps, and want to modify one to be less powerful! please help.
.. and considering i have this non linearity strongly in low spectrum. It like bass depression. This seem like sort of overload at some stage.
Get reply form Bryston about eventual mod.
The mod can reduces overall gain by around 12db in both modes (High and Low), leaving around 2 db and 8 db of gain.
For details you need to contact Bryston support directly.
XLR in line attenuators -10dB arrived.. balanced output improved a bit, but still single ended output is much better when yggdrassil connected to Bryston via balanced XLR.