The function of the Creek OBH-22 passive preamplifier is to provide input selection and volume adjustment to a Hi-Fi system from an armchair, via infra-red remote control. The unit can also be controlled directly from the front panel.
The OBH-22 consists of a high quality motorised volume potentiometer, and two stereo relays which select the desired input plus tape output, together with a muting relay that can short the signals to ground.
A built-in micro-controller decodes the infra-red signals transmitted by the handset and translates them into commands which activate the motorised potentiometer and the muting and input selection relays.
After each operation, the micro-controller turns itself off to avoid any possibility of interfering with the main music signal. LED's are used to indicate the status and mode of operation.
The OBH-22 is purely passive and does not introduce any gain or distortion into the signal path. It is therefore suitable to be used as a control pre-amplifier, provided the sensitivity of the power amplifier that is being used is high enough to be driven directly from the source. i.e. CD player or tuner etc.
The volume control can be operated manually at any time, whether the OBH-22 is powered or not, but without power only Line 1 can be utilised.
This product does exactly what it says i.e. it lets the source signal pass to the power amplifier completely undistorted. It is only there to provide control of the signal and also lets you have a couple of lines in plus tape monitor.
The unit is very small and light at 610 gr only. However, it is very nicely built and quality is evident all around it.
So, if you (like me) have a very good quality power amplifier that can drive your speakers directly with the source signal (i.e. CD) and you like this result then why change this result by adding an active pre-amp. In my opinion the more you complicate the signal path the worst it can get depending of the quality of the components used of course.
I picked up the Creek OBH-22 at Campsie HiFi (Australia), and have Christian there to thank for opening my ears to the joys of passive pre-amps. I'd dropped in to audition speakers, and ended up being more impressed with the OBH-12, which calmly beat a AU$4500 Bryston active. As I was in need of a good pre, and was not about to drop that kind of dosh on something which should simply pass a signal from a CD player to a power amp, I was rather happy about this. The OBH-22 was on the horizon, so I decided I'd give one a try. As I waited, I read up on the world of pre-amps - Passives seem to get a bad wrap from a lot of audiophiles, and they have a reputation for not working in certain systems. So by the time the unit arrived, I was almost expecting to hear reduced dynamics(particularly bass), and a lifeless and 2D soundstage. I'd end up liking passives in pricipal but not in practice. No way. The OBH-22 performs EXACTLY as I hoped it would. I've demoed a few other pre's in my system (see below), and the Creek thrashed them all. Complete openness, transparency, accuracy and detail, and a wide, 3D soundstage without a trace of grain, grit, noise, distortion or congestion. The noise floor also fell away. And what is all this crap about passive pre-amps lacking bass dynamics and defintion !? A huge bass improvement is the first thing I noticed. From there it just got better. By comparison, everything else I've heard sounds like it's 'doing' something to the signal - EQ-ing it, exaggerating it, compressing it, veiling it or blooming out the bottom end. With the OBH-22, it's all just THERE, clean and unobstructed, on any type of music (and I listen to just about everything). I've reached a point where I'm sick of reading and hearing about audio gear that's "more musical, warm, smooth, expressive, harmonic" or whatever other silly terms can be drummed up, when really, accuracy is the first casualty! So if you're like me, and want to cut the crap, and get to the REAL recording, this little box is for you. Hell - the new model even looks great and has a nice remote! I suspect a handful of people have had bad experiences only because of impedence mis-matches, which is very rare. My Arcam Alpha 8 has a 2.35Vrms output with 50 ohms impedance, and my Rotel power amp has a sensitivity of 1 volt with 33 kilo-ohms impedance. In my setup, the Creek works like a dream....
My system is...
* Speakers: VAF Research DC-X (great in every way)
* Creek OBH-22 passive pre-amp (for 2-channel music - I will have this thing buried with me)
* Arcam Alpha 8 CD player (upgraded with LClock XO3 and improved op-amps - incredible)
* Rotel RMB-1075 5-channel power amp (drives the DC-X's with ABSOLUTE ease)
* Rotel RB-971 2-channel power amp (for surrounds)
* Rotel RSP-1066 surround Pre/Pro (nice)
* Speaker cable: Belden 1810A ( quad-cable but single-wired over a 10metre run - This equals any overpriced snake-oil cable I've heard)
* Interconnects: Van den Hul D-102 MkIII (no real improvement over solidly made standard interconnects)
* DVD's come off a custom HTPC (love it...)