LHZ Preamp Sound

The LHZ preamp does exactly what the original 80’s HazLabs did: the EQ was specifically tuned for US Spector® basses. The circuit design is unique in that the initial stage greatly boosts the treble before the EQ stage, and then that boost is removed.

Fig 1. HazLabs and LHZ preamp EQ stages

This causes the preamp to generate high frequency harmonic content that acts somewhat like an exciter to bring out more detail, particularly when the EQ is boosted.

Fig 2. Orange lines indicate harmonic overtones that are created when played aggressively.

The end result depends on your playing dynamics. If you play with a light touch, you’ll likely only notice that the EQ range is very complimentary to the bass. (Particularly if you currently have TonePump or EMG preamp and have been struggling to get the sound right.)

Fig 3. Impact of performance volume on overtones at 9-volt operation

If you play with a heavier touch, you’ll find it more responsive to dynamics. It’ll feel like there is a very slight amount of compression on the bass, which brings out the articulation of your playing and the natural tonal characteristics of your pickups. That same compression makes the bass “bite” more when you pluck or pick hard an drive the JFET preamp into the non-linear zone.

To be clear: it does NOT sound like a compressor. And it does not sound like an overdrive where you engage it and it completely sounds different. It’s a subtle difference (probably where there is so much discussion and debate over “the HazLab sound” online!) that highly depends on how dynamically you play.

Your bass will still sound just like your bass: it’ll just have more bite and articulation.

When paired with EMG pickups, the LHZ preamps turns the more affordable Spector® models from “great, but not quite a US Spector®” to being sonically equivalent to the high-end US models.

This is also why we have several international touring bassists using Euros, NS2000’s, Rebops, Legends, and Fortes with the LHZ on tour: They don’t have to risk taking their very expensive US models on the road AND they get the same performance and tone out of them.

The HazLabs preamp (that is only sold in the US basses) is definitely one of the variables that make the US models sound different than the European models, and the LHZ allows players to bridge that gap.