That's why it's important to make one change at a time and if at all possible kept the component you are replacing until you are sure.
I just bought a new DAC. At the dealer and initially I liked it. Then I listened to it with all types of music and was really enjoying it and then for what ever reason my brain was at odds with my ears. Was this Non Oversampling DAC tube really outperforming something with much better specs?
Fortunately I connected the original DAC and did some comparisons. The new DAC is clearly better and can be heard when switching between the two. They are definitely different presentations. I will trade a little detail for a lot of texture and tone any day.