FRENZEL FM-DP1 Dual Pro One Preamp User manual

FRENZEL TUBE AMPS
Owner’s Manual
FM-DP1 Dual Pro One Preamp

Frenzel Tube Amplifiers
www.frenzeltubeamps.com
2011 Copyright by Frenzel Tube Amplifiers. All rights reserved. All designs, technical data, pictures, and information are
copyrighted and may not be reproduced without the permission of Frenzel Tube Amplifiers.
Page 2
The FRENZEL FM - DP1 Dual Pro One guitar tube preamp is part of our "INSPIRED" line of
products and will give you the classic vintage tones of our Type F(Fender) and Type M
(Marshall) tube amps ....and much more. This is the same preamp we use in our FM-5E3 and
other similar voiced amps. As with all of our "INSPIRED" Line of products, this preamp was
inspired by the vintage 60's amps with the "TONES YOU KNOW"....but it's far from simply a
clone....this preamp incorporates features and mods developed over FRENZEL Tube Amps 50
plus years of building and fine tuning amps!
The preamp uses two 12AX7's with DC on the filaments for low noise. The first 12AX7 is wired as
a dual input preamp…one Type F input for the vintage smooth warm "F" tones and one Type M
input for the classic vintage "M" high mid rock tones. Each input has separate gain controls for
each preamp section. The second 12AX7 is a common voltage amplifier with a cathode follower
to drive the tone stack. The three band tone stack was designed by the “tube amp God” so no
improvements there….but we did add a Master volume. With this tone stack and Gain and
Master control combination you can get just about any sound you want.....including great clean
tones…or the classic tube preamp distortion that the vintage tube amps are famous for. Also, for
you Bass and hollow-body guitar players a Deep Bass Boost pull-switch has been added on the F
Gain control to give that Bassman 864 contour for those deep bass tones; and a Bright Switch on
the M Gain control for sparkling Treble tones. There is a Trim control on the rear panel to match
the input drive level of the amp you are using it with. Also...an added extra…..you can use an
“AB-Y” pedal on the input jacks and blend the Type F and Type M preamp sections for your own
custom sound.
The preamp is build on a small 10” x 6” x 2” chassis with a bottom cover and rubber feet. It has
laminated faceplates front and rear. The front panel controls are Type F Input, Type M Input,
Type F Gain with Deep Bass Pull Switch,, Type M Gain with Bright Pull Switch, Bass, Middle,
Treble, Master, LED, Power On/Off. The Output jack, Trim control and Power Line fuse are on
the rear panel.
The inputs are high impedance and the output is low impedance. This allows the preamp to work
as an effects amp between your guitar and the input jack of your amp....or in your amp's effects
loop. It will also drive studio mixers or PA amps. If you have never played through a tube
preamp.. you are in for a real treat. If you have, you are still in for a trip, because of the
combination of Type F smooth warm tones and Type M high-mid overdrive tones and other extras
that have been added. It makes just about any tube amp sound better......and for you guys with
solid state amps who are craving that vintage tube sound, you can insert it in front of your solid
state amp and get that classic vintage custom sound of your own.
PRICE : $295.00
UPGRADE OPTIONS:
1. STEEL CAGE - A retro style metal cage is available in as an option. Please add $80.00 to the price for this
option. (See picture)
2. RACK MOUNT CHASSIS - Studio pro grade rack mount ventilated chassis assembly. Removeable covers.Add
$245.00. ( See picture)
3. 100 - 240 VOLT POWER TRANSFORMER - for operation outside the USA. Please specify line voltage. Add
$40.00

Frenzel Tube Amplifiers
www.frenzeltubeamps.com
2011 Copyright by Frenzel Tube Amplifiers. All rights reserved. All designs, technical data, pictures, and information are
copyrighted and may not be reproduced without the permission of Frenzel Tube Amplifiers.
Page 3
4. TWO WATT POWER AMP - At the request of a lot of our customers, we have added a power amp as an
upgrade option. The power amp uses a 12AU7 as a Class A output stage which will deliver F and M crystal clear
cleans or great overdrive tones at 2 watts of power into an 8 ohm speaker. This allows you to use the FM-DP1 as
a low power practice amp as well as a preamp. With this option a speaker jack is added to the rear panel. Please
add $90.00 for this option.
5. JCM800 High Gain - Adds a third 12AX7 for three stages of high JCM800 style gain. Add $50.00
6. CUSTOM TOLEX HEAD CABS, SPEAKER CABS AND RACKMOUNT ENCLOSURES - Please see our CUSTOM
CABINETS page for complete details.
User’s Operation Guide:
FRONT PANEL CONTROLS:
F INPUT – input for F preamp.
M INPUT – input for M preamp.
F GAIN – sets the volume and the point at which overdrive distortion is produced by the M preamp. Set at ¼ for
initial setting.
PULL DEEP SWITCH ON F GAIN – When pulled enhances Bass and attenuates Treble. Affects both the F and M
channels.
M GAIN – sets the volume and the point at which overdrive distortion is produced by the BRIGHT preamp. Set at
¼ for initial setting.
PULL BRIGHT SWITCH - This switch enhances brightness at lower level settings of the M Gain control. As the
control is turned up, there will be less effect . At the max setting of the M control there is no effect.
MASTER – sets the maximum output of the preamp and the point at which the output tube saturates. The higher
the setting on the MASTER, the sooner the output tube will saturate and produce output tube overdrive
distortion. Set at ½ for initial setting. Use the GAIN to adjust the preamp overdrive. As the GAIN is increased the
preamp will begin to produce preamp overdrive distortion. Turn the MASTER up for output tube overdrive
distortion. By adjusting the settings on the GAIN and MASTER you can set your desired amount CLEAN and
OVERDRIVE tones.
TONE STACK – is a three band Bass, Middle, and Treble tone filter. The controls are interactive in shaping the
tone. You will need to experiment to find the best setting for your playing requirements. Initial settings for all
three controls is the ½ position
BASS – attenuates the Bass frequencies from 10hz – 100hz as it is turned down.
MIDDLE – is a 500 hz notch filter that dampens the middle frequencies. As you turn the control down it deepens
the notch.
TREBLE – attenuates the high frequency tones from 1000hz - 15000hz. As it is turned down, the MIDDLE control
will have less effect.
POWER SWITCH – turns power on. Pilot lamp will light up when switch is turned to ON (up) position.
REAR PANEL CONTROLS PREAMP ONLY:
OUTPUT JACK – Output of preamp. Low impedance designed to drive amps, mixer, effects, etc.
TRIM – controls the output level of the OUTPUT JACK to meet level requirements of the device your are driving
the preamp with. Set at MAX for initial setting. Then turn down to meet level requirements.

Frenzel Tube Amplifiers
www.frenzeltubeamps.com
2011 Copyright by Frenzel Tube Amplifiers. All rights reserved. All designs, technical data, pictures, and information are
copyrighted and may not be reproduced without the permission of Frenzel Tube Amplifiers.
Page 4
FUSE - protects the power supply. Use a 1 amp SLO-BLO type fuse.
POWER CORD – connects amp to electrical outlet. The power cord is a three prong grounded cord. Always plug
into a grounded outlet to prevent electrical shock. The line voltage is shown over the power cord bushing. Be
sure that the voltage matches your line voltage.
SPEAKER JACK – connects output of 2 watt power amp to speaker. Impedance is 8 ohms (This control is only
on the preamps with the 2 watt power amp upgrade. )