THD Electronics Hot Plate User Manual
Page 2
SPECIFICATIONS:
I. Main Output:
Attenuation: 0 dB to -16 dB in four dB increments; -16 dB to -∞ dB (zero output) continu-
ously variable.
Impedance: Depends on the model.
II. Line output:
Type: Mid-impedance (approx. 35KΩ), unbalanced, negative ground.
Connector: 1/4” phone jack.
Level: Continuously variable line out level (+10dB(V) to -40dB(V)).
III. Input:
Impedance: Depends on model.
Continuous power dissipation: 150W RMS
Max. recommended amplifi er power: 185W RMS.
IV. General:
Size: 2 7/8” high x 8 1/4” wide x 7 1/4” deep (7.3 cm x 20.9 cm x 18.4 cm).
Weight: 4.2 lbs (1.9 kg).
WARRANTY: The Hot Plate has a two year limited warranty.
Q. What is the function of the light on the front panel of the Hot Plate?
A. This is part of a noise reduction system that noticeably cuts down the amount of hiss
and hum that reaches the speakers. The light will glow more brightly when you are playing
through an amp set at full output.
Q. Do the settings on the front panel of the Hot Plate affect the line out signal?
A. Only the bright and deep switches. These have a very slight effect on the line out tone,
and actually CUT the treble and bass respectively in the line out signal when they are
switched on (up), because they are directing more of the highs or lows to the speakers.
Q. Where should I place the Hot Plate?
A. The Hot Plate can get warm, so do not place objects on top of it. It has a built-in fan that
draws in air through holes in the bottom of the unit, and blows hot air out the fi ns on the
top of the unit, so do not obstruct the air below the Hot Plate by placing it on a shag rug, for
instance. You can safely place the Hot Plate on top of your amp or on a hard fl oor surface.
When picking it up after extended use please check that it is cool enough to carry.
Q. Can I use the Hot Plate with a solid state amp?
A. NO! The Hot Plate and the power section of the amp will be dam aged if the amp does
not use output tubes. Thus, even if an amp has preamp tubes, it CANNOT be used with
the Hot Plate if it has a solid state output section. However, an amp that has a solid-state
pre-amp section but a tube output section CAN be used with the Hot Plate.
Q. Can I use the Hot Plate with a master-volume amp?
A. Yes. Simply set the master-volume at full output, add whatever amount of pre-amp gain
you desire, and drop the decibels with the Hot Plate. You will get the same effect of distor-
tion at lower volumes, but the tone will be much warmer and fuller because your amp’s
output tubes and transformer will be overdriven (not just its preamp tubes).
Q. Can I run a 200-Watt amp through the Hot Plate?
A. NO! The most powerful amp you should use with the Hot Plate is 185 Watts RMS.
Q. Can I still use the Hot Plate if it has a different impedance than my amp?
A. ONLY if the impedance of the Hot Plate is EQUAL TO OR GREATER THAN that of the
amp. However, this will lessen the effectiveness of the Hot Plate’s tone controls.
Q. If I am using just one speaker cabinet, can I still use the Hot Plate if it has a different
impedance than my speaker cabinet?
A. ONLY if the impedance of the speakers is equal to or greater than the amplifi er, AND
the impedance of the Hot Plate is equal to or greater than the amp. Again, this will lessen
the effectiveness of the Hot Plate’s tone controls.
Q. How do the fan and light bulb work without being plugged into the wall? Are there bat-
teries in the Hot Plate?
A. The fan and light bulb are powered by the signal coming from your amp (originally gen-
erated by you playing your guitar). Thus when you stop playing, the fan stops moving. So,
no, there are no batteries in the Hot Plate.
Q. What should I do if the lamps do not glow even when I am playing through the amp at
full output?
A. The bulbs may need to be replaced. The Hot Plate will still function, but the noise re-
duction system cannot work if the light bulbs are blown. Use a Phillips-head screwdriver
to remove the screws from the sides of the Hot Plate, then slide the chassis out. Simply
remove the light bulbs and replace them with ones of the same value (24V for the 4Ω, 8Ω
and 16Ω models; 12V for the 2Ω and 2.7Ω models). The easiest way to remove the bulbs
is by prying up one end of the bulb with a pen or small screwdriver. These bulbs are avail-
able through any THD dealer or directly from THD.
Q. Why doesn’t my 2Ω Hot Plate have a fan in it like the others do?
A. It is unnecessary. The 2Ω Hot Plate will be unlikely to ever see an amplifi er powerful
enough to justify the fan. We are not aware of any guitar amplifi er on the market over 50
Watts which is capable of driving a 2Ω load.
Q. Sometimes when I run a slave amp out of the line-out there is substantial signal to the
slave amp even when the line-out level control is turned all the way down. Why is this?
A. This signal is generated in the cable due to the very high currents involved. To eliminate
it, use a cable from the Hot Plate to the slave amp that has its shield connected on only
one end.
THD Electronics, Ltd.
3510 6th Avenue W
Seattle, WA 98119-1513 USA
T: 206.781.5500 • F: 206.781.5508
www.thdelectronics.com