Cary Audio VT-500 Valve Phono Stage
In stock
Features
| Remote Control | No |
|---|---|
| Brand Color | None |
| Warranty The length of time your product is protected by warranty | 2 Years |
| Product Type | Other |
Tech Specs
- Circuit Type - Direct Coupled Single-ended Class A
- Frequency Response - RIAA Curve + 0.5 dB, passive RIAA circuit design
- Gain - MM – 38 dB, using triode vacuum tubes
- MC – 65 dB, using input transformers and triode vacuum tubes
- Noise and Hum - -78 dB below full output
- Input Impedance - MM – 47kΩ
- MC – Selectable 50Ω, 100Ω, 200Ω, 500Ω, 1000Ω
- Output Impedance - 660Ω
- Power Supply Design - Fully Regulated Power Supply with 1 ea. – R-Core transformer
- Output Polarity - Non-Inverting
- Vacuum Tube Complement - 2 ea – 6SL7 Head Amp
- 2 ea – 6SL7 RIAA EQ & Amp Gain Stage
- 1 ea – 5AR4 Vacuum Tube Rectifier (located in external power supply chassis)
- AC Power Requirements - 100V-120V @ 50/60 Hz or 200V-240V @ 50/60 Hz
- Power Consumption - 15 watts
- Warm-Up Time - 5 Minutes
- Break-In Time - 100 hours of music playing time
- Finish - Fine textured black powder coat aluminum chassis, Black or Silver anodized aluminum faceplate
- Weight - 22 lbs.
- Dimensions - 5″ H x 17.25″ W x 13″ D
Description
The Cary Audio VT-500 Valve Phono Stage is a top-of-the-line phono preamp with dual inputs for MC and MM cartridges. It also has an external power supply to minimize any noise pickup. Vinyl playback has made a comeback over recent years and this exotic unit will extract every nuance and detail from the music.
This is a valve preamplifier that uses four 6SL7 dual triode valves. Moreover, the MC stage uses transformers to boost the signal to create a low-noise floor. Finally, you can select the input loading to match any cartridge.
The circuit and power supply
The four 6SL7 dual triode valves used by the Cary Audio VT-500 Valve Phono Stage are used on either side of the passive RIAA equalization circuits. This ensures an accurate playback curve. Records are recorded with equalization where the bass is cut to prevent overmodulation of the groove. The treble is also boosted.
As a result reverse equalization has to be used for playback. The bass is boosted and the treble is cut. This has the effect of reducing surface noise. Next, the external power supply is regulated and fitted in a robust shielded enclosure. This ensures extremely quiet operation.
About cartridges
The Cary Audio VT-500 Valve Phono Stage has two switchable inputs for moving magnet and moving coil cartridges. The most common type of cartridge is the moving magnet type. These are easier to manufacture and have a small magnet mounted onto the cantilever that holds the stylus.
The magnet moves inside a pair of coils to generate the audio signal. The output is around 5mV with an impedance of 47k. Notably the Cary Audio VT-500 Valve Phono Stage has a range of switchable input loadings. This is due to the variability of different cartridges.
Moving coil cartridges are preferred by audiophiles as they have lower mass and improved tracking at high frequencies. However, they have a very low output of less than 1mV. As a result, extra matching and amplification are needed. The Cary Audio VT-500 Valve Phono Stage uses input transformers to boost the signal with MC cartridges.
Why valves?
Valves are known for their warm sound and musicality. Hence they are loved by those looking for extra detail in the music. Valves are inherently Class A so can have no crossover distortion or transistor noise.
Also, the power supply is only lightly loaded as valves run at a high voltage and need little current. As a result, there is very little hum or noise.
Valves are known as thermionic devices. Triodes, as used by the Cary Audio VT-500 Valve Phono Stage, have three main terminals and two heater pins. The heaters run at 6.3 volts and cause the cathode to emit electrons. The anode or plate is kept at a high positive voltage.
As a result, electrons are attracted to the anode. To control the current flow a grid is placed between the two electrodes. The grid is kept slightly negative of the cathode and controls the electron flow. The audio signal is fed to the grid via a capacitor and an amplified version appears on the anode.
About capacitors
In the past capacitors had a paper dielectric that deteriorates over time and can go electrically leaky. In fact, the most common problem with vintage valve equipment is leaky or shorted capacitors.
Capacitors have several hundred volts placed on them; any issues can damage the valves. As a result, modern equipment such as the Cary Audio VT-500 Valve Phono Stage uses Polystyrene or polypropylene capacitors. These modern materials will last for decades.