Fuchs Audio Technology Lucky Seven User manual


Instrument Amplifier
V 1.0
Operations Manual
For Lucky 7(head/combo)
Fuchs Audio Technology
407 Getty Ave, Clifton, NJ 07015
[phone] (fax) 973-772-4460
Website: www.fuchsaudiotechnology.com
Email: [e-mail]
 2000-2005 Fuchs Audio Technology. All rights reserved.
L7m 3/2005


A Note From Andy,
First of all, Thank You for purchasing a Fuchs Audio Lucky 7amplifier!
I designed the Lucky 7 amplifier to fill the need for a lower power amplifier having
classic rock “voicing” similar to a vintage Marshall™ or Trainwreck™ style amp. Each
Lucky 7is precision handmade by myself and the staff at Fuchs Audio, built to
extremely high standards of excellence using the highest quality components. With over
two decades experience in the service, manufacturing, and design of tube audio/music
equipment, we at Fuchs Audio are extremely proud of the quality and tremendous
musicality of our Lucky 7.
Please read this manual carefully. Although the Lucky 7was created to be a simple
amplifier to operate it will perform to its fullest glory by your full understanding of the
contents of this manual.
Feel free to call or e-mail us (we prefer emails!) with comments & questions about your
Lucky 7, or just to find out what’s new here at Fuchs Audio.
Lastly, I recommend checking out our new web site: www.fuchsaudiotechnology.com,
for product/user updates, cool links and other info benefiting our customers.
Sincerely,
Andy Fuchs
President
Fuchs Audio Technology
Fuchs Audio Technology
407 Getty Ave, Clifton, NJ 07015
[phone] (fax) 973-772-4460
Website: www.fuchsaudiotechnology.com
Email: [e-mail]
(“Fuchs Audio Technology” & “Overdrive Supreme” are registered trademarks of Fuchs Audio Technology)
L7m 3/2005

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Table of Contents (by section)
1) Introduction to the Fuchs Audio Lucky 7Amplifier
2) Please Read before powering up your Lucky 7
3) Diagrams- FRONT/REAR panels, Tube bias diagram
4) Front panel Controls, inputs & their functions
5) Rear Panel controls, inputs/outputs
6) Biasing Lucky 7 power tubes & other technical info.
7) Sample tone setting diagrams & notes
8) Warranty/repair information & mail-in warranty form
 2000-2005 Fuchs Audio Technology. All rights reserved.
L7m 3/2005

1 Introduction to the Fuchs Audio Lucky 7™Amplifier
Representing a new direction for Fuchs Audio Technology, the Lucky 7™ brings the high build quality and
awesome tones people expect of Fuchs products, to a new more affordable price range. The Lucky 7™ is
based on a dual 12AX7 preamp stage and a unique single ended 7-watt EL-34 fixed bias output stage. By
switching to a 6V6, you can reduce power to less than 5-watts. Unlike other amps in this price range, the
Lucky 7™ has a full compliment of extremely flexible tone controls. A surprising amount of clean
headroom is available before the output stage begins distorting with a sweet yet cutting rock edge.
Voiced like its bigger siblings, the Train 45™ and Blackjack 21, the Lucky 7™ has a classic rock voice similar
to a vintage Marshall™ or Trainwreck™ style amp. It provides a cutting rock edge, yet filled with harmonic
richness and chime. The circuit design also is “attenuator friendly”. (*see below) The Lucky 7™ and its
higher-powered sibling the Blackjack 21™ have a preamp stage designed to allow clean-to-mean from the
guitar volume control.
The chassis (like all Fuchs products) is aircraft grade aluminum; our internal construction is mixed PC
board and hard wired. On the Lucky 7™ and Blackjack 21™, the preamp tubes and power supply circuitry
are on the circuit card, while the power tubes and transformer are mounted on the chassis. A detachable
power cord is standard. By using single point grounding, the amp is quiet and free of hum at all operating
levels.
A single input and single ¼” output jack are provided.
Features:
¾” solid wood cabinet with durable tolex covering.
Anodized aluminum chassis with long lasting silk-screened labeling
Heavy duty Cliff brand jacks. Solid metal-shaft Alpha potentiometers.
Ultra-long-life neon pilot lamp and heavy duty AC power switch.
Simple user adjustable fixed output tube bias.
Specifications:
Size: 8” tall 10.5 inches deep 19” wide.
Weight 10-lbs.
Tube compliment: 2 X 12AX7 preamp tubes, 1 X EL-34 power tube (can use 6V6 tube, re-bias required).
Power output: 7-watts into 8 or 4 ohms.
Input Impedance -1Meg. Output impedance 8 Ohms.
(*) Watch for the new Fuchs “Conductor”™ Amplifier-Attenuator (coming out summer 2005). The
“Conductor”™ is a low-coloration power reduction device, designed for use most tube amps including this
series of Fuchs™ amps. (Not recommended with ODS or TDS amplifiers).
“Trainwreck” is a registered trademark of Ken Fischer

2 Please read before powering up your Lucky 7.
Please see Panel Diagrams in next section 3 for assistance.
1) Inspect to make sure power & pre-amp tubes are intact & snuggly seated in their sockets.
2) Make certain a speaker (load) is plugged into speaker input jack on the back of the amplifier.
Failure to have a speaker connected to the amp will result in damage to the output tubes! Your
amp is supplied with both 4 & 8 ohm impedance speaker input jacks, select the one closest to
your speaker(s) impedance.
3) Reduce Front panel GAIN control to moderate level.
4) Install instrument cable from guitar into front panel INPUT
5) Be sure both POWER switch (front panel) is in DOWN position.
6) Install power cord to amplifier (AC POWER IN) and to AC power source.
7) POWER UP amplifier by: 1) flipping POWER switch UP. Allow at least 30 seconds to 1 minute for
tubes to heat up.
8) The Amplifier is now fully on and ready to use. Feel free to adjust all controls as you see fit.
NOTE:
1) Your Lucky 7 CAN be safely used with an attenuator* device (see below). These will allow you
to obtain higher gain settings while reducing the overall volume of the amplifier.
2) The Lucky 7 does NOT have STANDBY mode.
It is either ON or OFF.
L7m 3/2005

3 Diagrams of FRONT & REAR Panels, Tube Bias Diagram
Front Panel
Rear Panel
4-Ohm 8-Ohm
Tube Bias diagram
Power Tube Bias Pot
L7m 3/2005

4 Front Panel Controls, inputs & Their Functions
Input Jack:
Input jack is a 1/4" phone plug, designed for 1-Meg impedance, guitar-level signal. This input will readily
accept pedals/effects without any loss in performance. Pedals/effects input is also inserted to this input in
series with your guitar.
Gain Control:
The gain control sets the overall gain/volume for the amplifier. Adjust to volume /tone taste. (NOTE: Your
Lucky 7 CAN be safely used with attenuator devices. These will allow you to obtain higher gain settings
while reducing the overall volume of the amplifier)
High Control:
Adjust the high control to taste, it controls adjusts the high frequency spectrum of your Lucky 7.
Mid Control:
Adjust the Mid control to taste, it controls adjusts the mid frequency spectrum of your Lucky 7.
Low Control:
Adjust the Low control to taste, it adjusts the low frequency spectrum of your Lucky 7.
There are no “correct” Gain settings, finding the desired tone setting depends on the guitars/pickups
used, as well as your own personal tastes. This amplifier works in unison with your guitar volume to
control the nature of the clean/overdrive tones.

5REAR Panel Controls, inputs/outputs
4-Ohm 8-Ohm
AC power cord input:
Using the supplied 120vac power cord. Connect to AC POWER IN on the amplifier and to AC power source.
AC power Fuse:
This fuse protects the amplifier if any malfunction occurs. Use ONLY stock fuse rating as supplied by
factory.
Speaker inputs (1 ea-4 & 8 ohm):
(You must have a speaker load inputted to the amplifier before powering on!) Each (1-4 ohm, 1-8 ohm)
input optimizes the amplifier for either 4 or 8 ohm speaker impedance. Connect using a ¼” phone plug to
an outboard speaker cabinet. If you have a Combo amplifier, connect to the combo speaker with supplied
wire/1/4” jack.

6 Biasing Lucky 7 power tubes & other technical info
High Internal voltages inside this amplifier can cause harm or Death!
The Lucky 7 (PCB) circuit board is shown below with the chassis sitting on its transformers, and front panel
facing you. There are exposed high-voltages in this chassis, even with the amplifier shut-off! If you are not
familiar with tube
amplifiers and/or high voltages, do not attempt to remove the chassis from its cabinet or to attempt to
service this amplifier. Refer servicing to the factory or to someone with experience servicing these types
of amplifiers.
Output tube Bias Setting:
Each tube is factory set for .060 Volts (60 ma or 60 millivolts). There is only one trimmer on the pc board,
and it’s for output tube bias. Bias is measured at the pin 1/8 connection of the power tube, measured to
ground and set to 60 ma. This should be set with the amp cold, then reset after the amp has run for about
an hour. Use a reliable digital voltmeter for these settings.
Power Tube Bias Pot
DISCLAIMER: There are exposed Internal high-voltages in this amplifier. Do not attempt to service, repair
or conduct tube biasing unless you are qualified to do so. Please contact Fuchs Audio beforehand with
questions in this regard. Fuchs Audio takes no responsibility or shall be held liable for any personal harm
caused or damage to this amplifier as a result of unauthorized service, repair or internal adjustments
made to this amplifier.

7Sample Setting Diagrams & Notes (make copies & use!)
NOTES:
NOTES:
NOTES:
GAIN HIGH MID LOW
GAIN HIGH MID LOW

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8Warranty Information
The Fuchs Audio Technology-Lucky 7Warranty
Fuchs Audio Technologyguarantees our products to be free from defective
workmanship or material failure for a period of FIVE years (tubes excluded)from date of new
purchase to the original purchaser. This does not apply to Fuchs amplifiers that have been
tampered with, damaged by shipping carriers, reverse engineered, or modified. Your warranty
form/information must be returned to Fuchs Audio Technologywithin 30 days of purchase, or
your warranty will not be in effect. Fuchs Audio Technologyreserves the right to suspend or
terminate the above warranty at our sole discretion, should damage from any of the above
limitations and or exclusions be detected upon examination.
Keep the information on this page for your records.
Please mail-in warranty form on next page
FUCHS MODEL : (Lucky 7)
SERIAL NUMBER:
OPTIONS INCLUDED:
PRODUCTION DATE: ____/____/____
TESTED BY: Fuchs Audio Amplification
Fuchs Audio Technology
407 Getty Ave, Clifton, NJ 07015
[phone] (fax) 973-772-4460
Website: www.fuchsaudiotechnology.com
Email: [e-mail]


WARRANTY REGISTRATION FORM
This completed form must be returned to Fuchs Audio Technology within 30 days of purchase along
with a copy of your receipt from your authorized dealer.
Please fill in all requested information on this form so we may register you for future warranty repairs
or future upgrades, should they become available.
Purchasers Name: ___________________________________________________
Address: ___________________________________________________________
City: ____________________ State: _____ Zip: __________ Country:___________
Phone Number: _______________________ E-Mail address: ________________
Model: ___________ Serial Number: ___________________________________
Date of Purchase: ___________________________________________________
Dealer Name: ______________________________________________________
Comments:
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Please return this form to:
Fuchs Audio Technology
407 Getty Ave, Clifton, NJ 07015
[phone] (fax) 973-772-4460
Website: www.fuchsaudiotechnology.com
Email: [e-mail]