I have an SLO 30. I dig it! I feel all frequencies are present in this amp. Thick low mids and mids, high mids and highs. As some one already stated cranking the presence brings out the high mids and highs. Use the treble to control the highs. Also as someone else recommended the Tungsol in V1 will cut a bit of the lows and low mids and highlight the other frequencies. Also, like many amps, if you’re playing at lower volumes the low end can be a bit flubby. The higher you get the volume the more it firms up.