Well, almost everyone. The high end of the audio doesn't have much impact in the calendar year. Did not launch the product, let it shine, and then withdrew from the market in just 12 months. However, if this reviewer were to choose the most exciting product he had used in the past year, the choice would be easy: Jeff Rowland Consonance. In my experience, the features provided by this new Rowland preamplifier are unique: repeatable control-including wireless remote operation-in a way that does not affect its top sound.
The first time I saw the prototype of Consonance was in 1989 at the Stereophile Hi-Fi Show in San Mateo. It may be officially introduced to the market in 1989, but it did not become widespread until 1990. I started using it in the mid-1990s, and about an hour after I was connected, it became an integral part of my reference system. There is a story in it.
In fact, I knew that Rowland Consonance had great potential to attract this critic even before I received the review. The reason is that an important factor (for me) must be controlled in any critical listening test-the playback level. If I listen to a specific piece of music on a given system today and form a specific impression, the impression I will form tomorrow or next week will be different, unless the level is the same. It's like when comparing devices in the tried and true enthusiast way-first listen to one amplifier/preamp/anything, swap to lead to the other, then repeat the experience. Everyone knows (isn't it?) that in direct A/B, the levels must match exactly. What is not well understood is that close control of the level is required in any type of comparison. "It seems to be about the same" is just not good enough.
Using a traditional preamplifier, it is not easy to adjust the level in any precise control or repeatable way. For perfectionist enthusiasts, adding an external network and auxiliary volume control is disgusting. It is very tedious to measure the level before playing each selection (and again when switching components). Routine procedures can seriously affect the typical listening experience we want. In the past, I decided to use an overlay around the volume control (usually part of the index card fixed with tape, leaving no residue) and carefully mark the selected level on this overlay. This does not allow the type of level matching required in instantaneous A/B, but for less stringent exchanges, it keeps me within 1dB, usually less than 0.5dB.
Although stepped volume control seems to be the solution to this dilemma, it can be a mixed bag. The stepping of most of these controls is usually too coarse—usually more than 1dB. Although this is great for repeating a given volume setting with the same device in the future, it may make matching levels (for example, between two power amplifiers) almost impossible.
Rowland Consonance (although it is definitely designed for daily use, not for hearing tests) solves this problem by completely eliminating the rotation control. All of its controls are touch buttons that can control (via a microprocessor not in the signal path) sealed gold contact relays, which in turn control all preamplifier switches and level setting functions. In the latter case, the relay switches in an appropriate attenuation resistor ladder network. The 20-digit fluorescent display on the front panel indicates all selected functions of the preamplifier, including level settings. 200 individual level control steps allow fine-tuning to achieve close level matching and accurate, repeatable settings. In order to add frosting to the cake, the display separately indicates the level setting of each channel.
The balance adjustment is done through the exact same relay/resistance ladder, but different balance control buttons (labeled L and R for left and right channels increase) are provided. When the user chooses to move the balance to the left, the first action taken by Consonance is to increase the left channel level by one step. Next, the right channel level is reduced by one level. And so on, until the required balance adjustment is completed. Therefore, the overall system level remains within a fraction of a dB.
Consonance also provides a unique memory and recall mode. A specific level can be selected and stored for any or all of the six inputs. By entering the recall mode, when switching to this input, it will automatically enter the selected level. If you like instant A/B, I don't need to explain the value of this feature. If you are not, it is still a useful feature.
Each front panel control is copied to the rugged (metal, not plastic) handheld wireless remote control included as standard equipment. In addition to the above-mentioned volume and balance functions, other front panel or remote control functions include input selection, left and right cut (for system settings and troubleshooting), mono, absolute phase inversion, mute, and display blanking (If you don't want to keep the display on all the time-even though a small number is still on in blanking mode). It is also possible to select the input to be fed to the tape output jack from the front panel or remote control; it does not have to be the same input that is fed to the main output. The obvious use of this feature is to enable users to listen to one source while recording another source. But another purpose is: by routing inputs to the recording output that are different from the input that is fed to the main output, the input circuit of the connected tape drive does not reduce the load of the main source during critical listening periods (the tape output is unbuffered).
Since these 200 level settings are quite good (each step of the measurement is between 0.1dB and 0.25dB), the two additional level setting controls on the remote control (fast up and down fast) increase at a rate of 10 steps. High and low level time. (These "rough" adjustments can also be made on the front panel by using a slightly different procedure). The three additional controls on the remote control, labeled I, II, and III, currently have no obvious functions, but the microprocessor can be updated to provide future additional functions, which can be incorporated into existing units.
Two ergonomic issues are worth noting. The first is a potential source of confusion, involving input (and record) selection instructions on a fluorescent display. These only represent the selected input number, from 1 to 6. You must remember what to insert for each input; the numbers will not tell you (except for 1, which is always a phono when the pre-amp is equipped with a phono).
The second quirk may be more troublesome, but it only applies to Consonance's early samples, including ours. Suppose you have a tuner connected to input 5 and your tape drive is connected to input 6. Usually you will choose 5 as the playback source (the signal to be fed to the main output) and 5 as the recording source (the signal is sent to the tape output. Do you want to monitor on the tape? No problem, choose 6 as the playback source, assuming Your tape drive is set up correctly and you will hear the tape playback of the radio show. But if you accidentally select 6 as the recording source (you have no reason to want to do this, but assuming Murphy has already come down to listen to the show), you are most likely Will receive feedback of system damage.
You can never choose a functioning recorder as its own recording source. I have seen this unwelcome configuration in other high-end preamps. However, Rowland's ergonomic design, numbered, unlabeled inputs, and simple remote control access make this type of accident more prone than any other. Fortunately, Rowland told us that soon after we received the sample, the Consonance changed, effectively "locking in" input 6. In other words, it is not possible to select input 6 as the tape output feed. Therefore, the recorder used for recording should always be connected to input 6. If you have an old sample of Consonance and use a recorder, please proceed with caution (or contact Rowland to learn about modifications to your equipment).
Until you really try it yourself, you can’t fully understand the value of all these features—especially volume, balance, phase inversion, and mute—can be controlled from the listening position. I don't know what prevents high-end manufacturers from designing remote controls into their preamplifiers, but this is likely to be market driven. To be sure, Roland is not the first to launch this product. Meitner preamplifiers (and their newer Melior cousins) have been on the market for some time, and Meridian offers extensive remote control in some of its products, notably the 208 CD player/preamplifier and their new D-6000 amplified speaker . But none of these products provide the flexibility (or fine control of the level) of Consonance.
Other high-end manufacturers are rashly entering the field of remote control, perhaps because they are worried that their customer base is not ready to accept the concept. Roland himself told me an interesting story about the Consummate preamplifier (their top unit has control and readout functions similar to the Consonance). When visiting one of their dealers, they found that it was shown and demonstrated without the remote control-the remote control was still hidden in the shipping carton. Are the dealers lazy, careless, or just want to "hide" the existence of the remote control function?
It is true that implementing remote controls in a way that meets high-end problems is expensive. But Roland encountered this challenge here. I don't mind telling you that the remote control is not only addictive, but also surprisingly beneficial in sound. Fine-tuning-one or two steps at a time (less than 0.5dB)-can significantly improve the satisfaction of the overall reproduction. Not dramatic. Not earthshaking. But it makes a lot of sense and it's worth it. It would not be too far off to call this function similar to a function with audio focus control. Being able to make this fine-tuning on the listening chair means you can accurately and instantly assess the subjective impact of changes. As a listener, I find this ability very attractive. As a reviewer, I find it very valuable—especially when combined with the front panel reading (footnote 1). To better understand why I like the latter two features so much, please refer to the accompanying sidebar.
Although some people may argue that the control of relay activation may be troublesome, I can only observe that the relay in my sample did not malfunction during months of use. Rowland said that the repeater can guarantee 100 million activations, and I am not going to verify this statement.
Consonance's rear panel provides inverted and non-inverted RCA outputs, as well as fully balanced XLR outputs. Nearby are the socket of the remote control receiver (located in its own separate enclosure for flexible placement), detachable power cord and switch. Rowland recommends that Consonance is always powered on (it only consumes 30W when idle). Temporary mute during power-on, power-off, or power-off can prevent opening and closing surges. Whenever Consonance is powered on, its fluorescent display will show a little bit. The first is "Resonance." Then, before returning to the normal operation display (starting in all-zero mode at power-up), if the phono module is installed, it will display "Phono Player Equipped" (it can be deleted if necessary).
Internal story Consonance's internal inspection revealed the expected (at this price) high-quality layout and construction. You can see groups of relays and DIP switches for impedance matching. The other two DIP switches can adjust the operating speed of the remote control. (The latter function is not discussed in the user manual. If the remote control of other equipment interferes, the fact that the remote control can be adjusted to run on the alternate frequency is also not discussed.)
Consonance's phono and circuit level are packaged on plug-in circuit boards. The phono module (if installed) can be configured as a moving coil or moving magnet pickup via a DIP switch (located under the module). Other internal DIP switches provide 12 different settings for cartridge loading (11 low impedance settings plus 47k ohms), three line input impedances (600 ohms, 10k ohms, and 100k ohms), and two output impedances (150 and 300 ohms) ), and adjustable line-level gain (same as phono-level gain adjustment, located under the module).
The internal six-position terminal block allows Consonance to be easily configured to achieve global power compatibility. The 100VA power transformer has an independent secondary for the analog stage and the microprocessor control section. The analog power supply provides rectification and filtering; local regulation is provided in the phono and line module itself. The power supply for the microprocessor function (footnote 2) is rectified and filtered by itself, and then adjusted by a circuit if the power supply voltage is lower than 95V (for 120V configuration). This so-called "watchdog" regulator is followed by additional regulators for digital displays and relays.
All amplifier stages in Consonance are FETs operating in Class A mode. The phono amplifier module is divided into two stages. The first stage is composed of high transconductance FETs connected in parallel, with a total current of 40mA and no negative feedback. The user-adjustable switch (selecting MC or MM gain) is at this stage, and the 75µs part of RIAA equalization (the part that performs high-frequency roll-off) is also at this stage. The second stage works in current feedback mode; the feedback element here provides equalization of 3180 and 318;us part (3180µs part provides RIAA low-end boost, 318µs provides the required slope below 1kHz, and the inflection point is 500Hz). The phono stage is directly coupled (like the rest of the preamp) and contains a DC servo system to correct for DC drift. It should be noted that this phono stage provides a reverse polarity signal to the tape monitor output (though not the main output).
Footnote 1: Some high-end manufacturers demonstrated prototypes of remote-controlled preamplifiers at the recent CES in the winter of 1991. These seem to always be implemented with motor-driven pots, and do not provide Rowland's precise repeatability and information display.
Footnote 2: Roland refers to it as a digital power supply, which is technically accurate, but may be misleading: the “digital” function of Consonance is strictly a switching category.
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