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Old 28th June 2018
Gear Maniac
Cleanest 500 series preamp on the market? - Welcome to Camden 500

Cranborne Audio have finally completed the Camden 500 preamp and signal processor for 500 series, and it’s a bit of a beauty.

We’ve generated the final specs, and whilst we were expecting great performance, we’ve actually ended up with (probably) the cleanest, most transparent 500 series mic preamp on the market; and we’re going to sell it for a price that everyone can afford - $349 US Retail / £299 RRP IncVat.

Thanks to its Mojo circuit, it’s also a lot more than just a clean preamp. Mojo is a 100% analogue saturation circuit that can be dialled-in to be one of the most saturated and ‘transformer-like’ preamps in your arsenal. Or Mojo can be bypassed completely to reveal the cleanest, frequency/phase-linear preamp you've ever heard.

We know these are bold claims that we would be skeptical of… but we have the Technical Specs for you guys to analyse taken straight from our APx555 Audio Analyzer. You'll see that the Camden 500 pushes the theoritical limit of linearity, noise and distortion. With Mojo bypassed - the Camden 500 is not colouring or influencing your mic, mic placement, or source in any audible way, shape, or form - it will also continue to perform at these extraordinarily low performance figures at all gain settings.

<0.0004%, 1kHz, 35dB gain, 24dBu out

Equivalent Input Noise (EIN):
<-129.5dBu, 150 ohm source, unweighted - (that’s pretty much the theoretical limits of EIN).
<-131dBu, 150 ohm source, A-weighted
<-135.5dBu, Inputs common, unweighted

Frequency Response:
±0.25dB, <5 Hz to >200 kHz, 35dB gain
<±1dB, <5 Hz to >200 kHz, max gain - (most preamps have dramatic frequency roll-off at max gain)

Phase Shift:
<2.25°, 40dB gain, 20Hz to 20kHz
<4°, Max gain, 20Hz to 20kHz - (4° at max gain is pretty much unprecedented, it’s not uncommon to see 10-30° of phase shift on the very best preamps at max gain)

Intermodulation Distortion:
<0.0008%, 50Hz and 7kHz, 35dB gain, 20dBu out
<0.0006%, 50Hz and 7kHz, 35dB gain, 15dBu out

Max Input Level:
Mic = 17.6dBu (<0.003% THD)
Line = 26.5dBu (<0.02% THD)
Hi-Z = 24dBu (<0.02% THD)

Max Output Level:
27.5dBu (<0.002% THD, 30dB gain)

>70dB, typ >85dB, 35dB gain, 10-20kHz, 100mV Common mode

Input Impedance:
Mic= 8.9kOhms 48v Off, 5.4kOhms 48v ON,
Line = 24.3kOhms
Hi-Z= 1.5MOhm unbalanced, 3MOhm balanced

Output Impedance:
150 Ohms

Current Draw:
120mA per rail - idle
140mA per rail - typical use case

Slew Rate:
20V/uS, 35dB gain, 25dBu out

The complete technical specifications (with AP graphs) can be found here:

We’re really excited to get these out into the wild. The Millennias, Grace Designs, Forsells, Earthworks of the world are great bits of kit - we’ve all used them before - but they are not what we consider affordable, certainly not for engineers and musicians like ourselves.

We’ve truly designed a preamp that will stand shoulder-to-shoulder with those great preamps whilst costing less than half the price. We haven’t cut corners… we’ve just started from scratch by developing our own custom topology, sourcing components that have never been seen in the audio industry before, and tuning the design to the nth degree (and then some more…).

If you guys have any questions, or would like us to take a look at another preamp to see how Camden 500 compares, let us know!