Richter’s forays into electronics, after a quarter of a century spent building loudspeakers, have been going gang-busters. It’s meant huge changes at Richter, because whereas all its speakers are made in Australia, its amplifiers are made in China. However, whereas its first amplifier, the Mystique, released two years ago, was a re-working of an existing amplifier, this new Sorcerer is a brand new design, but in order to keep manufacturing costs down, the Sorcerer appears to have been shoe-horned into exactly the same chassis as that used for the Mystique.
You don’t have to be an electronics expert to spot the obvious — and all-important! — difference between the two valve amplifiers. Whereas the Richter Mystique used four power valves (6L6G types) the new Sorcerer has only two power valves. But they’re not just any valves, they’re the brand-new KT-120 types, which have proved so good they’re displacing that previous ‘king’ of valves, the KT-88. And whereas most manufacturers are using KT-120s to build higher-powered Class-AB amplifiers, Richter has turned that paradigm on its head by using the KT-120s to deliver high-power in pure Class-A mode.
Since it uses the same chassis as the Mystique, it’s not surprising that the front panel of the Sorcerer is identical, with a single volume control at the far right, an input selector with positions for Line 1, Line 2, Line 3, Aux and USB DAC, a mains power switch and a 6.35mm gold-plated headphone socket. Richter has improved the quality of the lettering on the front panel, which we found hard to read on the Mystique, but the input selector knob is the same, with only a thin groove inscribed on it to indicate where it’s pointing, so in day-to-day use it’s hard to see which input is selected.
In the centre of the amplifier is an old-fashioned analogue needle-style VU (Volume Unit) meter. And when we say ‘old-fashioned’ we don’t only mean the look and style of the meter… the motion of the needle across the dial face appears to be controlled by a standard d’Arsonval meter movement, which was invented way back in 1882 by famous French physicist Jacques-Arsène d’Arsonval. The reason for using a VU meter rather than any other type is that a VU meter reflects the perceived ‘loudness’ of an audio signal better than a peak-reading meter because the d’Arsonval movement is quite slow and so mechanically ‘averages’ the audio signal in much the same way as the human ear averages the sounds it hears.
The rear panel of the Sorcerer is identical to that of the Mystique, which means that Richter has not addressed an issue raised by Best Buys in its 2013 review, which was that although the Line 1, Line 2 and Line 3 inputs use standard gold-plated RCA sockets, the Auxiliary input is a nickel-plated 3.5mm phone-jack socket. Evidently it’s designed this way so you can easily plug in the analogue output from your iDevice or mobile phone, but if this is indeed the case, why isn’t the input on the front panel, where it would be easy to access? If you regularly plug in a mobile device, we’d recommend running an extension cable from the socket on the rear to somewhere handy at the front. This will also save wear and tear on the 3.5mm socket. We’d also recommend using a USB male/female extension cable to run the USB input around to the front, where it will be more useful. There are no ‘Record Out’ outputs on the Sorcerer, nor are there any ‘Pre-Out’ sockets.
The speaker terminals are extremely high-quality, gold-plated, colour-coded WBT lookalikes and the USB input is a standard Type A USB connector which leads to a Texas Instruments PCM1502 stereo 32-bit 384kHz DAC.
Our main photograph of the Richter Sorcerer (left) shows it without the casing (right) that would normally go over the valves to protect them (as well as prevent anyone from touching the valves, which get very hot). The casing on the Mystique is a perforated steel cage that’s fitted with a large Perspex ‘window’ at the front, so that you can see the valves. To attach or detach it from the amplifier requires you to remove or re-fit two Philips-head screws. So long as you have a long-shafted screwdriver you’ll find them easy to remove; we found them very difficult to replace.
In what is still quite unusual for a valve amplifier, Richter’s Sorcerer comes with a remote control. However the remote control is itself unusual for three reasons. First because it’s not the usual infra-red type, but instead uses radio signals to communicate with the Sorcerer. Second, because it’s made not from plastic, nor even metal, but wood! (Very green, Richter!) Third, it allows control over only the volume of the amplifier, via ‘up’ and ‘down’ buttons. There is no muting button, nor can you switch between sources.
When it comes to valve replacement, the current price for Richter’s KT-120s is $399 for a matched pair (the 12AX7/ECC83s are $179 per pair). You can, of course, source these valves (possibly at a lower price) from dozens of specialist valve suppliers, but whatever you do, make sure you buy only from a reputable supplier… there are an awful lot of fake KT-120s, KT-88s, 12AX7s — and other valve types — being sold on the internet.
Richter has improved the quality of the lettering on the rear panel, but has continued with its difficult-to-read colour scheme (grey paint on a black background) and also with printing the ‘Left’ and ‘Right’ labels for the speaker outputs underneath the speaker terminals, where they’re nigh-on impossible to see. It’s also continued mirror-imaging the speaker terminals, so the positive terminal is to the right of the ‘0’ terminal on the left channel but to the left of the ‘0’ terminal on the right channel. This means that if you’re not careful it would be very easy to accidentally connect one speaker to the 4-ohm tap and the other speaker to the 8-ohm tap. (This won’t damage the amplifier, but it will certainly result in very strange sound!)
Class-A amplifier circuit designs really fall into the ‘keep it simple’ category, and keeping it simple has many benefits when it comes to the amplification of music. The first benefit is that the audio signal isn’t amplified all that much, so the amplifier’s open loop gain is low — in turn requiring little overall feedback to be used, which ensures excellent amplifier stability and phase. Another benefit is that the open loop gain is constant, which in turn means superior transient response and dramatically reduced Transient Intermodulation Distortion (TID). The only disadvantage (not counting mains power consumption, which is higher for Class-A amplifiers than for any other amplifier type) is that Class-A amplifiers are, as a rule, low-powered. (There are exceptions, but they’re very expensive.) This means that for best sonic results you should use Richter’s Sorcerer in conjunction with loudspeakers with sensitivity ratings of 87dBSPL or higher.
Once you hear the sound from a Class-A amplifier, you’ll know why all audiophiles agree that it delivers the best sound quality of any amplifier class. Even audiophiles who don’t use Class A because they want higher volume levels than Class-A amplifiers are capable of delivering agree that Class A sounds better. So what will you hear? So long as you work within the Sorcerer’s power limitations, you’ll hear amazingly fluid, contiguous music with all instruments perfectly balanced against each other and any vocals. You’ll hear a total lack of ‘grain’ to the sonics. Most of all, you’ll hear an incredible ‘openness’ in the soundfield… it’s just all-enveloping and completely effortless. Rest assured that the sound of Class A may be difficult to describe, but it’s very easy to hear.
If you’re looking for magic sound, you’ll find it when you listen to Richter’s new Sorcerer. Richter has really pulled one out of the hat this time. We don’t want to know how the trick is done, we just want one. Class A rules!
VERDICT & SPECS
Richter Sorcerer integrated stereo amplifier
PLUS: Class-A sound, Radio remote, 32/384 DAC
MINUS: Aux socket location, No record output
Power output: 2 × 20W
Frequency response: 20Hz–40kHz ±1.0dB @ 1-watt
Distortion: 1.0% (at 1kHz, at 4-watts)
Signal-to-noise ratio: 83dB
Input sensitivity: 220mV
Input impedance: 100kohm
Output impedance: 4 or 8ohm
Inputs: Line1, 2, 3, Aux, USB/DAC
Maximum input (Line): 3.5VRMS
Headphone impedance req.: 32–600 ohm
USB DAC: 32-bit/384kHz
Preamp & driver tubes: 12AX7 × 2 (ECC83 × 2)
Power tubes: KT-120 (Matched Pair)
Overall negative feedback: 39dB
Power consumption: 180W (max)
Dimensions (whd): 380×160×295mm
Warranty: Two years (Six months on valves)