Notifications
Clear all
Topic starter
September 3, 2025 12:48 am
Can anyone confirm that their FB21 causes your audio amplifier to hum very load? Makes no such noise when on grid power.
This is typically caused by a not so clean sine wave. Tomorrow I will capture an oscilloscope recording.
just curious if anyone else is experiencing this as well? Or maybe I have a unit that needs to be replaced?
thanks,
This topic was modified 3 weeks ago by mrwkbrdr
Topic starter
September 3, 2025 1:26 pm
Stumped on this one? FB21 sine wave is cleaner than my grid power, but my audio amplifier makes a loud buzz/hum noise when powered by Flexboss 21?
Anyone have any suggestions?
Prolly not a ground issue based on the sine wave.
September 6, 2025 3:09 pm
I deal with this all the time with 3 phase VFD’s and AM radio. A mile away from the VFD the radio has to be shut off. We use line and load reactors to try and smooth the interference out but they don’t do much. I assume your inverter is doing the same thing since they are similar to a vfd. It’s probably coming from the conversion of DC voltage to AC voltage. I know that information doesn’t help your problem but that’s what’s going on. I’m not sure there is a fix but maybe someone else can chime in.
September 7, 2025 12:30 am
No buzz for me on any of my audio systems. Your sine wave looks good. Sounds like you need a ground lift on your amp, or maybe a conditioner. Some of my previous "separates" systems used to do this type of thing with everything grounded (not power related/prior to going solar).
I'm using Monster power conditioner on main Sony ES/Klipsch system in the living room that I use most frequently but sun room has no conditioner and no audible noise with the Yamaha receiver. Basement NAD, Carver and Anthem HIFI systems sound no different to me on inverter verses grid either (these do have conditioners as well). I consider myself an audiophile and pretty certain I could hear any fidelity differences. I ran power conditioners on everything even before I went solar just for protection and illimitation of the slight hiss you hear when things go quite at extreme high gains (critical listening) but I bypassed them and ran off battery for a while today to see and not hearing anything on my gridboss/flexboss21 system.
Topic starter
September 11, 2025 12:20 am
No buzz for me on any of my audio systems. Your sine wave looks good. Sounds like you need a ground lift on your amp, or maybe a conditioner. Some of my previous "separates" systems used to do this type of thing with everything grounded (not power related/prior to going solar).
I'm using Monster power conditioner on main Sony ES/Klipsch system in the living room that I use most frequently but sun room has no conditioner and no audible noise with the Yamaha receiver. Basement NAD, Carver and Anthem HIFI systems sound no different to me on inverter verses grid either (these do have conditioners as well). I consider myself an audiophile and pretty certain I could hear any fidelity differences. I ran power conditioners on everything even before I went solar just for protection and illimitation of the slight hiss you hear when things go quite at extreme high gains (critical listening) but I bypassed them and ran off battery for a while today to see and not hearing anything on my gridboss/flexboss21 system.
Topic starter
September 11, 2025 12:25 am
Thanks for your reply. However it’s not a ground issue or some ac filter quick fix. The hum is only heard from the amplifier power transformer. There is zero noise in the speakers. Transformer hums loud as soon as the amplifier is plugged in. I have 3 diff brand amplifiers all 3 have power transformer formers and all 3 hum loud. Zero hum when on grid power.
A 120 to 24v transformer makes zero hum when powered up.
Im pretty confident I have a defective flex boss, and will be seeking an RMA.
THANKS,
