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Herron VTPH-2A Phono Preamp

4 Reviews
$3,650.00
SKU: HE-VTPH2A -GRAY
Sold standard in gray, as pictured. The VTPH-2A is also available in silver or black. These are special-order options. Please call for details.

The Herron VTPH-2A Phono Preamplifier was created to address the retrieval of musical information from vinyl LPs without any compromise. The original design was only intended for use by a few dedicated music lovers in their cutting edge audio systems. The design was so good, and demand so high, that the unit was refined and engineered to meet the requirements for a more durable unit manufactured in larger quantities. In the process, important refinements were developed and discoveries were made about tolerances and the threshold of human hearing limits.

The MC Inputs

The moving coil inputs have an additional 22 dB of gain which is provided by a proprietary FET very low noise linear gain stage connected directly to the MC inputs. The moving coil FET gain section is connected in front of the tube section when the unit is in the MC mode. This moving coil FET gain section has been designed specifically to avoid the sonic artifacts found in many solid state designs.

Moving coil loading RCA resistor plugs can be inserted into the back of the VTPH-2A at the "MC Load" connectors to properly load specific moving coil cartridges. Check with your cartridge manufacturer for recommended loading.

The MM Inputs

The moving magnet inputs send the cartridge signal directly to the tube section and bypasses the MC FET gain stage. The moving magnet inputs provide all tube amplification of the signal from the cartridge. The moving magnet inputs have an internal 47k Ohm loading resistor for each channel and 100pF "Miller Effect" loading capacitance which is provided by the grid of the first 12AX7 tube.

Why Loading Plugs Instead of Dip-Switches?

  • Reason #1 - When using DIP switches the sound quality will degrade with time and potentially become grainy and bright as unwanted harmonics are added due to contact nonlinearity. Mechanical switch contact resistance (which is nonlinear with voltage) can be in the order of magnitude of the loading resistor itself particularly at the very low voltages which are generated by a moving coil cartridge. The music information can be down in the range of nanovolts. This problem will be exacerbated with time as the DIP switch contacts which are open and not sealed are exposed to air will develop oxidation and layers of contamination from environmental humidity and air pollution.

    Note A: The VTPH-2A uses electronic switching for audio signals when changing from moving coil to moving magnet mode. This is initiated by one mechanical switch which does not carry any analog audio signals.

  • Reason #2 - So we spent how much on that cartridge and turntable and we load the cartridge with DIP switch contacts and only the resistors that are connected to it? External loading plugs allow the user to hand pick the resistor brand and type if he or she is so inclined. Yes, resistor brands and types do sound very different. In a way this is comparable to tube rolling.

  • Reason #3 - The VTPH-2A will not load the cartridge at all if no loading resistors are plugged into the MC loading inputs. This is because the moving coil input stage of the VTPH-2 utilizes the electric field generated by the cartridge to amplify the voltage and no current is drawn from the cartridge (there is no load on the cartridge). This can give an extended sense of dynamic freedom and sound stage as it reduces the work done by the cartridge and cartridge/groove interaction.

    Note B: Some cartridges will need loading in order to reduce their inherent rise in high frequency response.

  • Reason #4 - You don't have to get inside the unit to change the loading, you can do it while you are listening in order to get a immediate and real sense of how the loading changes the sound. The moving coil inputs can be loaded to a particular cartridge specification by externally connecting the appropriate resistors using the "MC LOAD" RCA connectors on the back of the unit, or they can be internally soldered at the MC INPUTS circuit board (this should only be done by a competent technician).

    The moving coil inputs have no load resistors installed unless specified by the customer when the unit is ordered from Herron Audio. We recommend trying the VTPH-2 in the no-load configuration as the unit is supplied for most moving coil cartridges. 47,000 (47k) ohm RCA load plugs are supplied with the unit for optional use. Additional user specified loading plugs can also be purchased with the unit.

    The moving magnet inputs are factory loaded at 47,000 (47k) ohms, 100pF (standard loading for moving magnet cartridges).
  • Features:
  • Switchable moving coil and moving magnet operating modes with separate input connectors for each
  • Additional RCA connectors for external moving coil loading
  • Cartridge biased moving coil input stage allows for infinite load resistance (operation with MC cartridge totally unloaded)
  • Very low noise - both versions work nicely under 0.1mv in the MC mode
  • Passive RIAA equalization for accurate phase and amplitude response with no inductors for maximum emf noise immunity
  • Reversing power line (AC) polarity switch for minimizing line-to-chassis reactive currents and noise pickup
  • Low plate operating currents and controlled warm-up for cool operation and extended tube life
  • Class A operation
  • No mechanical switches in the signal path
  • Zero feedback - no feedback loops in the audio circuitry
  • Gold plated RCA and ground connectors
  • Audio path capacitors are high quality very low dielectric absorption film type
  • Hand-picked components for accurate response
  • Automatic muting at startup, shutdown, and mode selection
  • Four levels of high voltage regulation
  • Regulated soft-start DC filament and high voltage supply
  • Regulated tube bias supply
  • Toroidal power transformer
  • Front panel indicators for power, voltage, and output (mute release)
  • Technical:
  • Tube complement: (2 x 12AX7, 3 x 12AT7) - most popular, or (4 x 12AX7, 1 x 12AT7)
  • Gain MC Mode: (2 X 12AX7, 3 X 12AT7) 64 dB, (4 X 12AX7, 1 X 12AT7) 69 dB
  • Gain MM Mode: (2 X 12AX7, 3 X 12AT7) 43 dB, (4 X 12AX7, 1 X 12AT7) 48 dB
  • Frequency response: RIAA 20 Hz to 20 kHz ±0.1 dB at 10k Ohm output load impedance and higher
  • Distortion: Less than 0.03% at 2.45 volts output at 1kHz at 20k Ohm and higher output load impedance (tube selection dependent) - Note: Lowest distortion and best performance occurs with output loading above 20k Ohms - this gives the most dynamic sound.
  • Signal-to-Noise Ratio: 88 dB, A weighted
  • Output impedance: (2 X 12AX7, 3 X 12AT7) 400 ohms, (4 X 12AX7, 1 X 12AT7) 500 ohms
  • Input impedance: Infinite with no load resistors connected - Note: load resistors can be connected externally via RCA connectors or soldered internally
  • Absolute polarity: Non-inverting (all modes)
  • Power Requirements: Standard IEC connector - most international voltages available
  • Overall dimensions: 17.6" wide x 4" high (including rubber feet) x 10.25" deep
  • Warranty: 3 years, parts and labor; tubes: 90 days
  • Ratings & Reviews

    4 reviews

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    Brilliant!

    by

    Magnificent! So much better than the Parasound JC3+ and Sutherland Duo that I also tried. This one is a keeper!

    Bravo!

    by

    Beautiful sound. Bravo Herron!

    Excellent State of the Art Phonostage

    by -

    I have had the Herron for about a month. It takes time to break
    in. It adds impressive presence to music of all kinds without loosing detail. Very smooth over the entire audio spectrum.
    It is very easy to set up. I have two turntables connected to it, both VPI Prime Signatures with Van den Hul Crimson and Stradivarius (through Bob's Devices SUT to MM input) carts. In turn the Herron is connected to a Pass Labs INT-250 and in turn to B and W 802 D3 speakers.
    So if the Herron were anything but stellar this system would
    show it immediately. Happy to say that the Herron is easily up to the task of enhancing a high end system. It just keeps getting better each day.

    I like Keith Herron's philosophy of simple yet elegant electronics and customer support. Its made in the USA.
    Why pay twice as much for a foreign product and get poor customer support.

    Spectacular Tube Phono Preamp!!!

    by

    Exceptional sound and greatly improved dynamics are the benefits that I found when I upgraded from the Pass Labs XP15 phono preamp to the Herron Audio VTPH-2A. I liked the Pass unit quite a bit, but some music sounded a tad harsh, so the folks at NeedleDoctor recommended the Herron phono preamp and I could not be happier.

    This Herron unit is almost as quiet as the solid state Pass but offers greater imaging, depth and tone.

    The rest of my system includes:

    Rega RP 10 turntable with Rega Aphelion MC cartridge
    SimAudio Moon Evolution P7 preamplifier
    SimAudio Moon Evolution W7 power amplifier
    Benchmark DAC2 DX digital to analog converter
    McIntosh MR88 AM FM HD tuner
    Sonus Faber Cremona M tower speakers
    REL R328 subwoofer
    Audioquest Columbia interconnects
    Audioquest Mont Blanc speaker cables
    Furman IT Reference power conditioner