The signature control on a Blackstar is the ISF knob — it sweeps the voicing from American (tight, scooped) to British (mid-focused, looser). Set that first, then dial gain and EQ.
Set the ISF knob. ISF fully <b>left = American</b> (tight low end, scooped mids, great for metal); fully <b>right = British</b> (mid-forward, looser, great for classic rock and blues). Start in the middle and sweep to taste.
Metal / high-gain. Use the overdrive/high-gain channel. Gain 7–8, ISF toward American (left), Bass 6, Middle 5, Treble 6. Add a noise gate for tight mutes.
Rock. Overdrive channel, Gain 5–6, ISF middle to British, Bass 5, Middle 6, Treble 6.
Blues / classic rock. Overdrive at low gain (3–4) or a pushed clean, ISF toward British (right), mids up. Cleans up with your volume knob.
Clean. Clean channel, Gain low, Bass 5, Middle 5, Treble 6, a little reverb.
💡 The ISF knob is your voicing: American (left) for tight metal, British (right) for mid-rich rock and blues. Set that first, then gain and EQ.