10 gauge power cord. Too much power for tube amp?

The power cable can’t generate power however as mentioned the wrong sized cable, I.e. too small can restrict power. Put the OEM cable back on and if the problem persists, contact McIntosh or at least Audio Classics. The problem is in the unit and they will suggest a possible fix or ask you to send it in for a check up. I have dealt with McIntosh many times over the years and they are great people to work with. They have an enormous pride in their products and equal appreciation for their customers.

The gauge of a power cord refers to its physical size and electrical current carrying capacity. A higher gauge power cord will have a larger diameter and can carry more current, which may be necessary for high power applications.

For a tube amplifier, the power supply voltage and current must be carefully considered to ensure that they are within the amplifier's specifications. If the power cord is too small, it may cause voltage drops or current surges, which can affect the amplifier's performance and even cause damage. Therefore, when using a tube amplifier, it is recommended to use a power cord that meets the amplifier's power requirements.

In your case, if the amplifier shutdowns occasionally on startup, it may be due to the power cord's ability to handle the initial surge of power when the amplifier is turned on. A higher gauge power cord may be able to handle the initial surge better and prevent such shutdowns. However, before replacing the power cord, it is recommended to check the amplifier's specifications to ensure that the new power cord meets the requirements. It is also recommended to consult with a professional technician for help to ensure the safety and performance of the amplifier.

If your powercord. Is aQuality  brand then go for it , for the lower the number the

thicker the guage awg 10 is good lower resistance ,another bottle neck 

could be what do you have it plugged into ,that too might’ve restricting it 

and a dedicated  4 wire 20 amp line would be good witha common ground and separate isolated ground on its own buzz bar grounded , for line conditioner 

you have to make sure it can handle the load ,how many watts per channel is your amp ? Is it a dedicated separate amp, power amp ? I sh h the sourse, then preamp 

goon first then the amplifier, and when shutting off in reverse order.

If you do end up sending it in to McIntosh for repair bear in mind I'm told it's a 1 year wait at the moment for non-warranty repairs.This came directly from an employee.