Should I change my tubes to vintage or NOS (new old stock) tubes?

Feel free to try different tubes in your Summit Audio gear. The difference it makes depends on the circuit design of the product which is very different throughout the Summit Audio line. Be sure you can return the new tube if the sound is not what you're looking for or if the noise floor increases. If you need to align the product to match gains and such, please contact us for alignment information. Make sure you are changing to the correct vacuum tube (12AX7, 12AX7A or ECC83).