Vacuum Tube
OTL Amplifier Model-B Prototype
Part # VT-OTL-B

** PLEASE NOTE ** We are sold out of the OTL Amp Model-B.  If you are still interested purchasing a unit, please contact us.

Contents
Product Summary
Key Features
Specifications
Bottom View
Ordering Information
 

Product Summary

      It is improved by the modern, higher quality components that are available to us today.  This amplifier is quality built using all Teflon wiring and heavy duty, turret type component mounting boards. This type of board allows easier component changes for the experimenter.   (See CAUTIONARY NOTES)  The Russian 6C33C-B output tubes are run well within their ratings and should provide long life.  This amplifier comes with all vacuum tubes and has been operated for a number of hours after the bench test.  

      This amplifier is being offered AS IS, so please read the CAUTIONARY NOTES.  The burgandy finish is powder coated for durability.  

      The cooling fan is operated at a slow speed for lowest noise but will go into its high speed mode if the temperature on the 6C33C-B heater power supply exceeds > 60 Deg C.  Comes with all service / operating instructions and spare fuses.  Speaker protection is provided by speaker fuses and +/-160 Volt supply fuses for each channel.  If either of the 4 fuses should blow, the speaker relay disconnects the speaker from the amplifier and the blown fuse is indicated by one of four Red LED's in a window on the left side of the amplifier.  Upon power up, a timing circuit delays the speaker relay until the vacuum tube heaters have warmed sufficiently.  The speaker fuses are mounted on the back panel of the amplifier and may be replaced by the user.  The +/-160 volt supply fuses are mounted inside the amplifier chassis and should be serviced only by a qualified technician.  (See the CAUTIONARY NOTE)  The main line fuse is also mounted on the rear panel. 

      For more information, ask for an email copy of the Operating, Adjustment and Maintenance pages.

IMPORTANT CAUTIONARY NOTES: This amplifier produces a lot of heat and therefore, must be placed in an open area where no flammable materials exist.  The glass vacuum tubes are also subject to breakage, this makes it extremely important that this amplifier be used in an area where small CHILDREN and PETS cannot come in contact with it.

Unlike solid-state amplifiers, vacuum tube amplifiers often require more service, mainly due to the need for tube replacement from time to time.  Vacuum Tube amplifiers also use much HIGHER operating VOLTAGES.  This amplifier should only be serviced by a QUALIFIED electronic TECHNICIAN and one who is familiar with vacuum tube amplifier circuits and the precautions necessary to SAFELY service such equipment.

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Key Features

• High temperature, Teflon insulated wire is used for all interconnect wires
• Chassis is finished, inside and out with a durable, powder coat finish

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Specifications

• Power Output (Both Channels Driven, Power stated is for One Channel):
  ~ @ 4 Ohm - 15 Watts
  ~ @ 8 Ohm - 25 Watts
  ~ @ 16 Ohm - 35 Watts
• Output Impedence: < 1 Ohm
• Damping Factor: @ 4 Ohm - 8 / @ 8 Ohm - 16 / @ 16 Ohm - 32
• Feedback Ratio = 17 or 24.5 db
• Input Sensitivity: 2.40 Volts RMS = Full Power with 8 Ohm Load
• Input Impedence: 250 K
• Input Jacks: RCA Style unbalanced
• Frequency Response @ Full Power: Essentially Flat from 10 Hz. to 50 KHz
• Power Consumption: 360 Watts @ Standby (No Signal Input) 1000 Watts @ Full Power (Both Channels Driven)
• AC Input Voltage: 110 - 130 or 210 - 240 (Switch Selectable) 50 / 60 Hz
• Vacuum Tube Complement:
  ~ 12AT7 (2ea.)
  ~ 12SN7 or 6SN7 (2ea. Amplifier may be configured, by jumper selection, for either heater voltage)
  ~ 6C33C-B (4ea.)
• Dimensions: 18 1/2" Deep x 13 1/4" Wide x 9 1/4" High, Net Weight: 31 Lbs (14 Kg.)
• User Adjustments: DC Balance via zero - center meter and controls on the front panel (Switch selects: Left - Off - Right)
• The Output Stage Bias Voltage may be changed over a limited range via an inside chassis control (See CAUTIONARY NOTES)
• Power Control: Off / On from front panel or low - power control from a preamp
• AC Power Cord, IEC (Supplied)
• Power Control Cable, two conductor, non - polarized (Supplied, for optional On / Off control of amplifier from a preamp)

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Bottom View

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Ordering Information

To place an order for the Vacuum Tube OTL Amplifier Model-B; Part # VT-OTL-B, click here to contact us.

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