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Re: SuSy dynahi v2

PostPosted: July 17th, 2015, 6:05 am
by mloutfie
Aside from ground noise on single ended. Will not grounding properly causes slight hiss on balanced output?

Re: SuSy dynahi v2

PostPosted: July 17th, 2015, 12:40 pm
by amb
Maybe. A very low level hum (especially one that is rich in harmonics) could be perceived as a hiss.

Re: SuSy dynahi v2

PostPosted: July 21st, 2015, 10:35 pm
by mloutfie
I'm still scratching my head sorting the ground issue. What about putting in a ground loop breaker. is it a good idea?

Re: SuSy dynahi v2

PostPosted: July 21st, 2015, 11:20 pm
by amb
If the cause of your hum is due to a ground loop, then yes. Disconnect your source and see if you still hear the hum. If you no longer have hum, then it's probably due to a ground loop.

Re: SuSy dynahi v2

PostPosted: July 24th, 2015, 3:31 am
by DEFL
DEFL wrote:Is e12 protection board compatible with SuSy Dynahi?

amb wrote:Yes, just treat it like a 4-channel balanced amp.

Ti,
Pls. look what KG said about e12 when coupled with SuSy dynahi:
http://www.head-case.org/forums/topic/9 ... ntry694419
http://www.head-case.org/forums/topic/9 ... ntry694446
By no means I question anyone, but could you comment it please? It's because I'm planning to use e12s with dynahi, but now I'm stuck and confused if they will really do their job of DC offset protection.

Re: SuSy dynahi v2

PostPosted: July 24th, 2015, 4:12 am
by amb
For simplicity, and to reduce its size footprint, the ε12 uses a summing amplifier at its input to detect DC offset from all channels at the same time. But there is a downside to this arrangement, since all channels are summed, let's suppose one channel's DC offset goes to -2V and another channel goes to +2V, then the two will sum to zero and not be detected. This is however quite an unlikely situation, where one channel's DC offset would be exactly the same as another channel but inverted in polarity.

If you want to avoid this situation, you can use a separate ε12 for each channel.

Re: SuSy dynahi v2

PostPosted: July 24th, 2015, 4:35 am
by DEFL
So 4 boards for SuSy dynahi?

Re: SuSy dynahi v2

PostPosted: July 24th, 2015, 4:52 am
by amb
If you wish to do that, then yes.

Re: SuSy dynahi v2

PostPosted: September 6th, 2015, 7:07 pm
by mloutfie
Thanks for all the support all. The Dynahi is finally completed

Re: SuSy dynahi v2

PostPosted: April 28th, 2019, 7:04 am
by thuanth43
I am thinking of building the the SuSy Dynahi with onboard heatsinks. From what I read, Kevin suggested biasing 375mV instead of 750mV due to the limited heatsinks. I wonder if I should replace any resistors from the original BOM before powering up for testing. My boards have 50 ohm biasing resistors, instead of the 100 ohm as in schematic.