The digital-filter output is converted to an analog audio signal by four Burr-Brown PCM63 DAC chips. Four DACs are used for true differential operation: the digital signal is split into positive and negative phases in the digital domain,…
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The DSP56002 is clocked at a blazing 66MHz, and has more computing horsepower than the DSP56001 used in previous Krell processors. Consequently, a single DSP56002 does the work of two DSP56001s. The digital filter section is located on the main printed circuit board, with the DAC and analog output stages mounted on a board stacked above the main pcb.
Sidebar 1: RH's System
I put the Krell KPS-20i at the front of my playback system, playing discs on the KPS-20i's integral transport. The KPS-20i also saw time driven by the Mark Levinson No.31 transport via AES/EBU cable, using the KPS-20i as a digital processor. Further, I drove the Mark Levinson No.30.5 (fitted with the HDCD decoder/filter) and the Sonic Frontiers SFD-2 Mk.II from the Krell's digital output to assess the KPS-20i as a transport. Of course, having these superb Class A processors on hand made them natural points of comparison for the KPS-20i.
I found that the KPS…
Sidebar 2: RH's Measurements
The KPS-20i had a maximum output level of 6.6V from the balanced outputs, and 3.3V from the unbalanced jacks. Output impedance was a very low 16 ohms (unbalanced) and 32 ohms (balanced) at any audio frequency. This combination of low output impedance and high output voltage means that the KPS-20i should have no trouble driving any preamplifier or even a power amplifier directly through a passive level control. The review sample had no trouble locking to 32kHz and 48kHz datastreams. The balanced outputs conform to the pin-2–hot standard, meaning that the KPS-…
Martin Colloms reviewed the KPS-20iL in October 1995 (Vol.18 No.10):
The High End is dead? Don't believe a word of it! The High End is alive and kicking—long live the High End! Larry Archibald had it right last January (Stereophile, Vol.18 No.1, p.274) when he said that a worldwide recession does not mean that the High End is in trouble.
It's always been true that fashionable entertainments—from video to computer games, multimedia computers to Home Theater—capture huge slices of disposable incomes. High-fidelity manufacturers may well eye such sales with envy and reminisce about…
Sidebar 3: MC's System
My longstanding one-box reference CD player, the Accuphase DP70-V, was on hand for this evaluation, as was my new reference, the Wadia 16. I also had access to a Krell MD-10/Reference 64 combination and PS Audio's Reference Link driven by the Lambda transport. Other recent digital visitors to my system included the Sonic Frontiers SFD-2, the Theta Generation V/Data Basic 2 combination, and the Audio Research CD1.
Control preamplifier references included the Mark Levinson No.38, Krell KRC-2, Audio Research LS5 Mk.II, Audio Synthesis Balanced Passion passive…
Sidebar 4: MC's Measurements
As a CD player, the KPS-20iL performed very well. It's non-inverting—pin 2 is wired to be positive on the balanced outputs—and has essentially linear phase and zero interchannel phase difference. The Krell's frequency response (fig.1) was essentially flat, lacking the premature HF rolloff of some earlier DSP implementations. With de-emphasis, there was a mild loss of –0.5dB by 16kHz. This will not be very audible.
Fig.1 Krell KPS-20iL, frequency response without de-emphasis (solid line) and with (dashed) (0.5dB/vertical div.).
Channel…
Sidebar 5: Specifications
Description: CD player with remote control, optional HDCD decoding, and digital inputs/outputs; preamplifier version has remote volume control. Analog outputs: balanced on XLR jacks, unbalanced on RCA jacks. Digital inputs: two S/PDIF on RCA jacks, one TosLink optical, one AT&T ST-Type optical, one AES/EBU on XLR jack. Digital outputs: S/PDIF on RCA jack (TosLink and ST-Type optical outputs optional). Analog output impedance: 12 ohms.
Dimensions: 19" H by 5" H by 15" D. Shipping weight: 54 lbs.
Serial numbers of units reviewed: G29501249 i; not noted,…
High-end audio companies take different approaches to staying successful. One way to maintain a market position is to continue improving fundamental designs, offering a little higher sonic performance with each model. The latest products from a company employing this approach will look and operate very much like their first products.
Another approach is to completely rethink the role of an audio component, significantly changing its design in response to the evolving way products are used. This company's recent products will be radically different from their lineup of just a few…
The No.38 is the first Mark Levinson preamplifier to incorporate remote control. Via the remote handset (machined from heavy aluminum), the listener can adjust the volume, change sources, adjust the display brightness, invert absolute polarity, adjust the left/right balance, select which source is routed to which record output jacks, mute the output, and switch the No.38 into mono.
The cumulative effect of all these features is a preamplifier that adapts to your system and your specific needs. Once the No.38 was set up, its functionality and "smart" operation made it a joy to use.…
The left and right audio circuits flank the power supply and digital block for maximum isolation between channels. Rows of relays cover the rear portion of the pcb, providing the switching functions and disconnection of unselected inputs. The RCA jacks, custom-made for Madrigal, are of very high quality; XLR connectors are Swiss-made Neutriks. The No.38's layout, parts quality, build, fit'n'finish, and overall appearance are absolutely first-rate. Indeed, it's surprising that Madrigal can sell a preamplifier with these features (particularly remote control), cosmetics, and technical…