CI Audio VDA-2 + VAC 1 for sale. Has worked flawlessly with medium use for 10 years. 7/10 rating due to age. Selling with VAC 1 power supply, Will not separate. Selling because I've reconfigured to a server based music system. Order Item # PS2424-25R Now! Complete Documentation and Tech Specs. Power Supply, 24VDC@24W, 110/220 VAC, 2.5mm Right Angle DC Plug. Switching Power Supply.
CiAudio (better known as Channel Islands Audio) is an American-manufacturer of high quality, moderately priced electronics that you can explore at the company’s. The PEQ 1 MKII is built to an unexpectedly high standard given its $995 price tag and American heritage.The outside is a sturdy milled aluminum chassis unusual at this price point as are the highest quality panel mounted Cardas™ RCA jacks. Inside is a dual mono design with each input jack going to an identically laid out, independent mono circuit, which helps to eliminate crosstalk.The input gain stage features exterior chassis-accessible dipswitch selectable resistive and capacitive loading, gain and subsonic filter choices. That’s followed by a combination of passive high frequency cut/active bass boost RIAA filter circuitry that connects to the output jacks.CiAudio claims very short signal path from input to output as well as a combination of star grounded power supply components and audio circuitry ground plane design results both quiet backgrounds and immunity from EMI/RFI. The circuit board is housed within a heavy steel faraday cage to further reject outside noise interference.Other quality components include Nichicon Muse™ NP power supply capacitors, Vishay™ 2% Polypropylene signal and bypass capacitors, Takman™ metal film & carbon films resistors, and Grayhill™ switches.The standard power supply includes an unusually robust for the price outboard “Wal-wart” type 14 volt AC output supply transformer with a single winding feeding both left and right dual AC input circuits. The connecting chassis jack and plug are also of a higher quality than is usually found at the $1000 price point.
The incoming AC feeds to independent one-per-channel filter/regulation circuits that supply power to the left and right audio stages that the company claims are equivalent to the best battery technologies minus the inconvenience. The back panel also includes a convenient chassis ground lift switch.An extra-cost ($299) power supply option features a large dual output Toroidal Transformer, AC line filtering and dual common mode choke filtering in a milled aluminum chassis.I chose to review the basic $995 PEQ 1 MKII.
Setting it up was straightforward and with the externally located dip switches, convenient though be sure to have the instruction manual handy because the switches are not identified on the chassis. CiAudio supplies a red dipswitch-friendly pen that helps to move the tiny switches. Don’t lose that either!Gain is either 45dB (MM) or 60dB (MC, HO MC). Resistive choices are 47k,10K,1K and 100 ohms. Capacitive loading choices are 100pF, 270pF and 370pF. There’s a useful subsonic filter that produces a -3dB cut @18Hz.
Output impedance is a usefully low 100 ohms. While the instructions claim “ultra-low noise”, “ultra low harmonic and intermodulation distortion (THD/IMD)” these are not actually spec’d nor are the frequency response or S/N ratio specifications, which would be nice to know but of course the proof is in the listening.(Designer Dustin Vawter responded: 'BTW, THD+N and IMD are listed in the specs, frequency response is defined as RIAA accuracy. Bandwidth is 8-80khz (-3dB). We rate absolute noise rather than S/N ratio as S/N always varies based on cartridge output level and type.Typical ratings are heavily filtered (A weighted) and not very useful. However if you like these ratings, PEQ is over 100dB at low gain and better than 93dB at high gain.' The 8 pound PEQ 1 MKII includes a five years parts and labor warranty.
100 Vac Power Supply
CiAudio has been around for a long time, which is important when considering the value of a “lifetime” warranty. Designer/owner Dustin Vawter has clearly attempted and succeeded in providing excellent American-made value at the $1000 MM/MC phono preamp price point.ListeningOne of the reasons I labeled “for entertainment purposes only” the recent, was this exceptionally fine sounding phono preamp’s not particularly impressive “blind test” vote.
I would have voted the PEQ 1 MKII above some of the others and certainly well above the $399 Music Hall pa 2.2, which though incredibly versatile (MM/MC phono preamp. Michael (are you shying away from 'Mikey'?);I am a fan of yours and all you represent but as you likely know, Mr. Hansen has been vocal on a certain enthusiast's Board about your acceptance (and JA's and others at Stereophile) of op amp centered circuits. I think I know just enough about the subject so as to realize that at $2500 let's say, or less, there are compromises to be made irrespective of design approach but can you comment on the use of op amps-by which I really mean DIP based chip packages employing negative feedback-in less expensive phono stages? Specifically, would you rather have phono stage such as this one vs.
One of the simple discrete circuit phono stages designed by Jim Hagerman and others? I would sure appreciate your comments-I suspect this hits home to you on multiple levels since you are a high-power solid state guy and since Mr. Hansen has thrown some jabs your way on the topic of your component choices overall, as well. But please, let's keep the question and issue at hand as fundamental as possible-do chip based modules employing high levels of negative feedback inherently compromise the sound?
I haven't kept up with Mr. Hansen's comments (no time), but I greatly respect him. I'm more interested in sonic results than in adhering to a political line (no op-amps, no Class D, etc.). I've heard excellent implementations of all technologies including Class D and op-amp based electronics and poor implementation as well.I certainly am not going to get into an argument with anyone about my component choices! I own a tube-based (Ypsilon) and a solid-state based (CH Precision) phono preamp and solid state (darTZeel) and tube (RM Labs) amplification.I have reviewed good and not so good implementations of all technologies. Anyone who thinks op-amp based amplification is inherently inferior hasn't hear, or refused to hear ASR electronics from Germany. I reviewed one of their impressive phono preamps back in 2005:me, it sounded GREAT.As for negative feedback, there are many opinions of that too.
I have a sneaking suspicion that you, Mikey, have not responded to my above inquiry because you feel that nothing good could come from it. I understand. But I am not some shill for Charles Hansen and I was not scheming to bring some new debate from this Board over to the one I previously alluded to. My inquiry was heart-felt if inquiries are capable, like sentiments, of being heart-felt. How about this; my question about op amps was in good faith.
If you still prefer to stay away from the topic because I gave the background for my question and referenced Mr. Hansen, so be it.
I have shied away from op-amp based pieces of gear-to my knowledge my ARC Ref 6 and ARC Ref 150se use none, and nor does my Manley Steelhead. My Aurender N100H surely does, but it's crappy digital, so who cares?:-) At least my DAC, an Abbingdon DP777 does not, or relies on op-amps minimally. I have zero engineering background or acumen. I do respect Charles Hansen though, too, and he's really been vocal lately.
I at one time used a Simaudio LP5.3 and I know it sounds great and no doubt uses op-amps. I don't need it but won't sell it. It sounds to good to sell.
I also have a Violectric phono stage with op-amps that I thought came close to the Simaudio but not quite. I again have chosen to keep it rather than sell even though the Manley Steelhead conveniently can handle both of my turntables with a simple flick of a switch.
Dimensions: 9.0 inches wide x 9.1 inches deep x 3.3 inches tall (with feet).Weight: 10.5 pounds; 14 pounds in its full double-box shipping cartons (shipping dimensions 14'x14'x9').Warranty: 3-year parts and labor (excludes shipping costs after 90 days).Made in U.S.A. Shipping anywhere in the world via Express Mail Intl. (EMS) or FedEx (custom-quoted deep discount rates by country; often less than than postal, plus faster and more secure).Includes:1 custom 5-foot DC cable. This special cable is a shielded, star-quad with 4 conductors of tinned, stranded 18AWG; paired at the connector that makes it about a heavy 15AWG. Gold/copper/brass Oyaide (5.5mm x 2.5mm) DC barrel plugs from Japan at both ends.
Just powering the computer, the difference—between the R-core and a toroidal transformer in the bass was shocking. And in comparisons powering a DAC or other audio-signal-handling component, the sonic benefits ranged top-to-bottom, cymbals and piano to deep bass. Plus R-core transformers, due to the gapless construction of the core, are mechanically silent.John Swenson on the benefits of a choke-filtered linear power supply:The traditional cap only filter (transformer, diode bridge, big cap) produces raw DC with a sawtooth riding on top. That sawtooth produces lots of high frequency components that the regulator has to deal with. Traditional regulators do very well at low frequencies, but have lousy characteristics at high frequencies which means a fair amount of those high frequency components from the cap-only filter get through to the regulator. Fancy discrete regulators do well at blocking the high frequency components, but add cost and complexity to a PS. Our approach is to use a properly designed choke-based supply whose ripple is a perfect sine wave, no high frequency components, thus a traditional regulator works very well.
The discrete regulator is not needed to deal with the high frequency components, since there aren't any.All diode types except Schottkys emit a burst of ultrasonic noise as they turn off. This noise can go forward into the load circuit AND it can go back into the AC line, and it can also excite the transformer resonance. The 'slow' diodes still have this ultrasonic noise.
Schottkys are the only type which do not have this noise. Schottkys also usually have about half the voltage drop of other diode types and are usually faster. Which type to use depends a lot on what your supply looks like and what you are trying to optimize for.With a traditional low voltage design with a large cap right after a bridge you get large current spikes, these produce a large amount of high frequency noise which needs to be filtered by what comes after the cap.
48 Vac Power Supply
In this type of circuit the slow diodes can help cut down on the extent of the high frequencies generated by the sharp high current pulse. BUT they still generate the ultrasonic noise.This is another reason why we like to use the choke-based design.
With the choke there is no steep high current pulse, so no disadvantage to Schottky diodes. You get the advantage of no ultrasonic noise, lower voltage drop (so lower power consumption in the diode) and no big massive current pulses.