Bow Technologies Wazoo integrated amplifier
Now, just take a look at the Bow Wazoo. Trust your eyes. Trust the fact that it won the 1998 Golden Note Award for "Most Aesthetic Audio Design." Trust the guys from The Wiz, who delivered my new TV and, seeing the amp on the rack, said, "Man, that's cool. What is it?"
Okay. Now we can put form aside and address substance. Bow calls the Wazoo a "single-chassis amplifier" because it is a power amplifier with input selector and gain control. That's a more accurate description than "integrated amplifier," because the Wazoo has no phono or preamplifier stage. You could think of it as a power amp with a built-in "passive preamp" (dumb term). In any case (and it's a real pretty case), the Wazoo possesses all the functions and power needed for most modern two-channel audio systems.
When he delivered the amp, the first thing Bow engineer Karsten Svendsen wanted to do was to remove the Wazoo's top and show me its innards. Well, he didn't have a metric Allen key and my set was in the lab, so he used a screwdriver and hammer to jam and remove the screws! After he got the top down, I understood why he was driven to dissect the amp: the Wazoo's beauty is more than skin deep.
There is a centrally placed multiple-secondary power transformer that is both hefty and meticulously finished. Most of the main board's layout is symmetrical, and the distributed filter capacitors are located close to the output transistors. These, in turn, are mounted to the formidable heatsinks that form the left and right sides of the chassis. Large, gold-plated WBT terminals are used for speaker connections. Bituminous linings are used for resonance control. The two prominent front-panel knobs, input selector and volume control, operate long shafts that permit Bow to place the input switch right at the rear-panel inputs and the volume control in close proximity.
Between those big knobs are the Standby and Monitor pushbuttons. The former mutes the amp but keeps everything powered up and ready for action. The latter creates a loop-through or permits monitoring from a tape deck, but, strangely, there is no Loop or Tape input! The inputs are merely numbered from 1 to 5. As it happens, Input 2 serves as the tape input, and is selected by the Monitor switch. Since I do not have a recorder on hand, I could not determine if simultaneously selecting Input 2 and Monitor would create an unstable loop. There is one pair of preamp/tape output jacks.
The circuitry is simple but sophisticated. Inputs are fed to the selector switch, Input 1 having the shortest path and accessible single-ended via RCAs, balanced via XLRs. Other inputs are single-ended only. The selected input is directly routed to the volume control unless Monitor is selected (remember, there's no gain stage). Thus, the quality of the input connectors, input switch, and control must be, and are, of high quality.
In order to keep the price down, Bow uses a very good but not freaky-tweaky motorized ALPS potentiometer in a novel arrangement. Acting as a passive variable resistor to ground, the pot has less of an effect on sound quality than if it were placed directly in the signal path. Bow says this "trick turns a $10 potentiometer into a $100 state-of-the-art potentiometer as far as sound quality is concerned." It also results in a quite low input impedance of only 1.2k ohms. This should not be a problem with almost all high-quality solid-state sources such as phono preamps, tuners, or CD players/DACs. Those with vacuum-tube source components should determine suitability with care.
The attenuator feeds a high-voltage, single-ended input stage and the power amp itself. All told, there are only seven active components in the signal path, and zero overall negative feedback. The only protection device is the power fuse. Although I did not use one, there is an optional wireless remote volume control that makes use of the motor on the attenuator pot.
In the months before and after a sojourn in Connecticut, the Wazoo was used in my main system with a wide variety of sources and loads. However, its insertion into the system was a little inconvenient for me. I keep the source components and preamps close to my listening position and run 10m interconnects to the power amps, which are located behind the speakers at the other end of the room. To compare the Wazoo fairly, I didn't want to separate its passive input selector/attenuator from the source by 10m of cable. On the other hand, relocating the source (tuner, CD player, or DAC) to the speaker end of the room gave the Wazoo an unfair advantage over the resident components. (Let's not consider the cost of obtaining and using 10m of speaker cable.) In the end, I did it both ways, with surprisingly little difference in the outcome.
What did it sound like?
The Wazoo manual says that it "displays many of the characteristics found in a good tube amplifier, and it sounds like one too." We've heard such claims before. The basic sound of the Wazoo was not substantially different from that of the other first-rate amps that I have in the house, tube or solid-state. Its general character was neutral, but it offered certain generally welcome features. First, the high frequencies, from about 2.5kHz up, were soft but with high resolution. By this I mean that, although there was never a sense that any detail was missing or blurred, the upper ranges never glared or spat. This does not mean, however, that the Wazoo failed to convey presence when called for.
I listened to Livingston Taylor's whistling on "Isn't She Lovely" on Chesky's Super Audio Collection and Professional Test Disc (Chesky CHDVD171). At least twice, Taylor loses tight control of the whistling, but the recording is startling and natural. On mid-fi equipment (yes, I have some of that around), the whistling sounded like ringing or an abrasive overload. The rest of that cut confirmed the Wazoo's sweet, unaggressive midrange and treble with a lovely balance of Taylor's fundamentals, sibilants, and guitar.