It’s easy to make a passive preamplifier, I’ve made several. Buy a 50k ohm potentiometer from RS Components or suchlike, wire it up to four phono sockets, and if you’re feeling adventurous, put it in a box and add a knob! Fairly decent results can be had for pennies, so much so that you wonder why some people spend tens of thousands of pounds on preamps. Still, put this through a good system, and things don’t sound quite so impressive. That’s why, back in 2003, many people thought it was worth spending £299 on Creek’s (then) new OBH-22…
It’s a passive preamp on steroids, the Rolls Royce of passives. Well actually, given that there are now some very expensive transformer-based designs around, maybe you should call it the Ford Mondeo Ghia. The Creek starts with a high quality motorised volume potentiometer and adds basic input selection by two stereo relays, plus a tape loop and a muting relay that can short the signals to ground – all controllable remotely. This is why it needs its accompanying OBH-1 power supply, and comes with Creek’s SRC1 system remote handset. The built-in microprocessor which handles all this automatically sends itself to sleep, so it doesn’t interfere with the signal, after a short period of non-use.
You don’t need any power, or indeed the remote, to make the OBH-22 work as a simple system volume control, although input 1 only works if you do this. I tended to run it this way, because the benefits of a passive pre include simplicity and small size. Run in basic mode, the wee Creek offers both – it’s tiny at 150x100x66mm, and weighs just 610g. It’s nicely finished and doesn’t feel cheap, although you’d never call it a luxurious or glamorous thing to have adorning your listening room. As for looks, well only its mother could love them!
Where the Creek does reach new levels of splenditude is its sound. It is a great performer, and back when launched there was nothing around that I had heard that could touch it at or anywhere near the price. Indeed, I had one knocking around in my system for years, and it would routinely slay all manner of new active preamplifiers that came along. It was just very clean and open, with relatively little interference to what is fed in. Given that it’s so good, it’s easier to describe how it sullies the sound rather than what it does right – which is most things.
The main downside is its sense of tonal ‘greyness’, and it also slightly flattens dynamics and reduces depth perspective. All of these effects are subtle, and everything else – especially the timing and low level detail – are kept very much unspoiled. The result is a snappy, crisp, open and well-defined preamp that makes listening fun. It also makes almost all active preamps sound rather coloured, plump, harsh, and/or possessed of rather too much character for their own good. The only preamplifiers I have heard that do significantly better are the Townshend Allegri and the MF Audio Passive Pre, and these are substantially more expensive of course.
These days, Creek’s OBH-22 is becoming increasingly overlooked for two reasons. First, it’s just not very sexy to look at, and secondly people don’t seem to want to look at any amplifier unless it has a DAC inside. But if you need something to feed your power amplifier – provided its sensitivity is high enough to be driven directly from the source – I can think of few if any other devices that offer better sound per pound. Expect to pay around £200 on eBay for a mint, boxed, example. They’re surprisingly thin on the ground however – obviously those who have them are hanging on to them!