A: Answers to this question is related to your budget, as well your desire for the level of sound improvement.

The general rule of thumb is:

1) Upgrade the pre-amp tubes first. These are typically the smaller tubes at the front of an amplifier (power tubes are typically at back closer to power output transformers). A sound signal from your source component (such as CD player) is sent into the amp for amplification – preamp stage is first amplification stage so money spent on upgrading preamp stage tubes will give you great improvement. Garbage in, garbage out. If you don’t get great preamp signal, you won’t get great final output signal to speakers.

2) Once the signal being amplified at preamp stage, it is further amplified at the power tube stage. If your budget allows, get the power tubes upgrade to the extent that your wallet is happy and your ears are happy too. Most common power tubes are EL34, KT88, 300B and 845. The price for these tubes are in the same sequence from low to high.

3) There is no such a thing called ‘best sounding’ tubes. All such comments are in certain context – tubes should only be compared when everything else is equal, i.e. same room, same speakers, same source etc.. No two amp owners have exactly the same set up so all impressions you heard or read online is just for reference. Let your own ears be the judge for good sound and no one else.

Happy listening.

Rachel @ Grant Fidelity