Sovtek 12AX7WA / ECC 83

I initially bought these tubes trying to solve crackling and sudden sound drops on my Marshall DSL40C (which was eventually solved by replacing the powertubes but ok..). I put these in V2+V3 together with Electro-Harmonix on V1+V4 to replace all stock Marshall branded tubes (which apparently are rebranded JJs). While being sceptical on the sound difference that different tubes can make (and not solving my initial problem), I must say that this combination gave me a bright sound from the Electro-Harmonix, but the Sovteks really balanced it out to give enough punch, drive and body that a Marshall needs. Now I have a real well balanced and versatile tone!