Hello jack,
Thank you for writing in.
Is the part number of your unit #090011?
Could you please tell us your order ID or the link of the product so that we can ensure which product your are referring to?
With your help, we can find a solution more quickly.
Looking forward to hearing form you.
Best regards

Hello Kevin,
Thank you for writing in.
Here the PDF file is the datasheet of the product, please check it.
DATASHEET_090028
Hope this can help you.
Best regards

Hello Yoann Serna,
Thank you for your reply.
Because the Audio Out port is for headset.
If you plug in that port, the speakers which are connected to the first amplifier will turn off automatically.
If you want to chain the amplifiers together, you need to use the audio cable with the plug which is shown in the following image to plug it into the Audio Out port.
And the 3.Common part should be vacant then the speakers will not turn off.

Hope this can help you.
Best regards

Hello Paul Lancaster,
Thank you for writing in.
Yes, it can.
As the following image shown, there is two solder joints which are marked by yellow arrow and red arrow, yellow for “increase value” and red for “decrease value”. When you adjust the value, you need to use a thin conductor, i.e.thin wire,tweezers. One side of the conductor is connected to the negative side of the power supply and the other side is shorted to the corresponding joints. At the same time, observing the value displayed on the display.
Shorting for about 2 seconds, the display will display the current speed override. The display will display “1.00” in default, which means one pulse signal represent one revolution. If you want to adjust the value of the pulse for one revolution, you need to short the “increase value” joint or the “decrease value” joint to increase/decrease the value to you need.

Hope this can help you.
Best regards

Hello Ben Summers,
Thank you for writing in and your valuable suggestion.
So sorry that we do not have the current transformer sold separately.
We will take your suggestions into account.
Beg your forgiveness and understanding.
Best regards

Hello Don Lundgren,
Thank you for writing in.
Could you please tell us your order ID or the link of the product so that we can ensure which product you are referring to?
It is better that you can tell us more details of your operation, such as the input voltage/current, the load, the wiring, the working environment.
If you can, we sincerely hope that you can send us some images to let us check the problem details.
With your help, we can find a solution more quickly.
You can send this information to us by email (service at droking dot com).
Looking forward to hearing from you.
Best regards

Hello Rob,
We have checked that we have not received your reply.
However, we have issued a partial refund to you, please check your account.
Hope this can make up your loss.
Best regards

Hello Colt4547,
Thank you for writing in.
Could you please tell us more details of your operation, such as the input voltage/current, the wiring?
If yo can, we sincerely hope that you can send us some images to let us check the problem details.
You can send this information to us by email (service at droking dot com).
Looking forward to hearing from you.
Best regards