2 WATT I N T E G R AT E D HIGH FIDELITY AMPLIFIER MOD E L HF-12 I NS T R UC TI ON MANUAL HF "-3 ELECTRONIC 3300 NORTHERN INSTRUMENT CO. BLVD ., L. I. CITY 1, INC. N. V.
MODEL HF 12 12 WATT INTEGRATED HIGH fIDELITY AMPLIfIER general description _ 2. Two high level inputs for tv, tuner, and crystal or ceramic ca rtridge. GENERAL The HF12 is a true high fidelity 12-watt integrated ampl ifier absolutely free of the "gimmi cks" sometimes used in low-priced amplifiers. It provides complete "front end" facilities and true high fidelity performance of such exce llence that we can recommend it unreservedly for any medium-power high fidelity application.
Inverse Feedback: 20 db Stability Margin: 12db Damping Factor: above 8, 20 cps - 15 kc. Speaker Connections: 4, 8, and 16 ohms. Sensitivity (input for 12W): mag. phono - 5mv; tape head - 2mv; tuner, auxiliary - 0.5 v . Hum & Noise Level (below 12W): mag. phono - **60db; tape head - **50db; tuner, auxiliary - 75db . Tone Control Range: at 10kc, :f:13db; at 50cps, ±16db . Tubes: 3- ECC83/12AX7, 2- El84, 1- EZ81. Size: 35/8" high, 12" wide, 81/4" deep. Weight: 131bs.
mechanical installation _ a) HEAT DISSIPATION (VENTILATION): In common with other electronic equipment, the HF-12 produces considerableheatin normal operation. Unless continuous and adequate air flow is obtained around the heat producing elements, these elements will over-heat and their useful life will be greatly curtailed.
electrical Installation _ and low capacity snlelded cable (cable having as low 25mmfd capacitance per foot Is available) . GENERAL a) SPEAKER CONNECTIONS: To connect your speaker to the amplifier properly, you must know Its rated Impedance . This may be read off tne speaker nameplate. Connect one speaker lead to the" G"termlnal on the rear apron and tne other speaker lead to tne nearby terminal corresponding to the rated speaker Impedance (4, 8, or 160hms).
operation _ desired. The corresponding high level input will feed through the ampl ifler. Adjustment of the level control on each source is discussed in the" ELECTRICAL INSTALLATION" section under" High Level Inputs". PRELIMINARY: Be sure all tubes arefirmly seated intheir sockets and that the VI tube shield is making good contact with its base. As initial adjustments, set these controls as follows: VOLUME at zero, BASS at zero.
TROUBLE-SHOOTING A TYPICAL TUBE STAGE connection to the cable shield from turntable frame, pickup arm, and cartridge case), dired hum pick-up by the magnetic cartridge from the record player motor (try using a rubber mat on the turntable to Increase the separation of the pick-up from the motor), or pick-up from a power transformer or other magnetic field in the vicinity (try moving phonograph away from suspected source).
TROUBLE-SHOOTING CHART SYMPTOM CAUS E REM ED Y Amplifier causes power line fuse to blow. Power Iine fuse blows again with V6 out of socket. Line cord, J6, primary or high voltage secondary windings of T2 shorted internally or externally (wiring). Replace or repair. Amplifier causes power line fuse to blow. Power line fuse does not blow again with V6 out of socket. V6, C17, V4, V5, or T1 primary shorted internally or externally. Replace or repair. Any or all tube filaments not lit.
VOLTAGE AND RUtSTANCE CHART TUBE PIN' DC VOLTS NO SIGNAL DC VOLTS 12W OUT AC VOLTS (1 kc) 12W OUT RESISTANCE UNIT OFF ECC83/12AX7 VI 1 2 3 4&5 6 7 8 9 108 108 0.52 0 0.028 0 1.2 1.2 0 filament (12 - 14DC; 6.3VAC to pin 9) 68 68 0.028 0 0.005 0 0.009 0.6 0.6 filament 300KO lMO 4.7KO 165-1900 300KO 480KO 2.2KO 165-1900 ECC83/12AX7 V2 1 2 3 4,5 6 7 8 9 2 185 185 0 0.5 0 1.4 0.265 1.4 filament (12-14VDC; 6.3VAC to pin 9) 1.38 180 180 0.26 0 0 0.135 1.6 1.6 filament 75KQ 500KO 1.
Section Selector AUX TUNER PHONO TAPE HEAD 1 - 11, 2 - 11, 3-10-11, 3-4-11, 3- 4 4-5 11 - 12, 1-11-12, A 5-6 6-7 Switch 1 - 2 - 11 - 12, 1 - 2 - 12, B 2 - 3 - 5 8-9 3 - 5, 5 - 8, 8-9 9 - 11 Entries are numbers of those switch contacts which are connected together by the rotors at the particular position. 11 7VAC HUM ~[] I I M OO " ".,. I"!IGH F ' OE:.LlTV 1'2 W A TT AMF' LI f-l i:.R ADJUST 2 50W o I 'mm°(i)"Ci)' I OUTPUT 16 S 4 G AUX TUNER MAG.
REPLACEMENT PARTS LIST Stock' Sym. 20050 22517 22549 22514 23020 20044 20039 22529 22539 22533 23007 20043 23016 Cl C2,12,13 C3 C4,6 C5 C7 C8 C9 Cl0,11 C14 C15 C16 C17 C18 C19 C20 C21 24005 22507 22523 23014 92000 50011 50014 50016 29751 10410 10431 11526 10423 10430 10407 11504 10400 18038 18033 18034 10426 10427 10420 10853 11543 11527 10412 14600 11538 19009 10422 10520 10425 10419 60049 32005 30019 54017 54500 54002 54004 54015 54000 Description cap., paper, .25 mfd - 200 V" cap., dlsc.
c J5 (;)TAPE ~29 (14 8 C20 ":" T1 -- - __ M T2 , ~ AUX. Jl TUNER J2 le I I I PHONOJ3 TAPE J4 ~ Description cop., CI C2 cop., C3 cop., cop., C4 cap., C5 C6 cop., C7 cap., C8 cop., C9 cap., Cl0 cap., Cll cop" C12 cap., it!;!& • 25 mfd • 025 mfd 3OOOmmf, 10% 85Ommf,lO% 25mfd-6V 85Ommf, 10% .25mfd-400V .1 mfd -400V 150mmf,10'll. 200mmf, 10% 200 mmf, 10% .025mfd ~ Description ~ Description ~ C13 C14 CIS C16 C17 CI8 C19 C20 C21 )1 J2 J3 cop., cop ., cop., cop., cop., cap., cop.
GENERAL INSTRUCTIONS The section of the manual beginning with this page is the CONSTRUCTION section. All pages in this section have page numbers followed by "C" (lC, 2C, etc.). The INSTRUCTION section resumes on the pages following the CONSTRUCTION section. Note thot the CONSTRUCTION section is located centrally in the book and may be removed without desrupting the INSTRUCTION section that both precedes it ond follows it. n dered with the tip of 0 pair of longnose pliers .
e17 __ ___ r'Y nAr l /' I / I II J I '\ ---+- _ r I J r."\. I _ _______ XV4 TB6 TB11~ ~ n ---TB3 XV6/ TB9 TB5 TB2 Xl1 TB1 XV5 J5 ii'C::~;-_ , ...... J" J6 »> R30 TB10 XV3~ XV2 ------ ~~ r =--.. ~,-" _ ., ~ . ' J3-4 J 1- 2 -TB4 ~ TB7 - - - - - - - - If'J XV1 : ---------./ TB 8 Fig.
MOUNTING INSTRUCTIONS NOTE; The chassis in Fig. 1 appears in expladed view. The angles on which the tube sockets are mounted are actua Ily part of the chassis, but has been moved up, out of the chassis, to make component mountings more obvious. Refer to Fig. 3 for proper orientation of all components. 1. (J) Fig. 1. Mount the 9 pin miniature tube socket with shield base XVI as shown. Use two #4-40 screws, two'4 lockwashers and two'4-40 hex nuts. 2. ('4 Fig. 1. Mount the 9 pin.
I- . N ....
MOUNTING INSTRUCTIONS CONT'D. 1. ( ) Fig. 2. Mount the switch, S1, as shown. Note that the switch is In the maximum counter-clockwise position. Use one 3/S" lockwasher and one 3/8" hex nutas shown. Note that tab on switch slides Into small hole adjacent to mounting hole. 4 . ( ) Fig. 2. Mount the output transformer, T1 (32005) as shown. Use four 'S-32 hex nuh and four IS lockwashers . Note that the yellow lead and the brown lead face the rear of the chassis toward T82. Use one 3/S" lock- 5. () Fig. 2.
J6 R30 J3-J4 T2 J1-J2 J5 TB2 TBl Tl R28 ~ TB3 XV5 XV4 TB6 XV6 ~ ~ ~ ~~~ 7~ -;;;;- ~ C15 \ =teXV1 C18 ~~TB4 ~~ TB9 XV2 TB5 XV3 ~ elf> ~ -.a> Fig.
WIRING INSTRUCTIONS 1. ( ) Fig. 3. Cut a 6" length of black wire and 6" length of brown wire . Connect one end of the brown wire to XVl-9 (5) and one end of the black wire to XVl-4 (5) through XVI-5 (5). Twist the two wires and run along the chassis as shown. Connect the other end of the black wire toXV4-4 (C) and the other end of the brown wire to XV4-5 (C). 2. ( ) Fig. 3 . Following the above pracedure, cut a 4" length of black wire and a 4" length of brown wire.
J6 R30 ~b---" ~ J5 XV4 ~ " 0 0 _ , ~. "-"- Wi t- ~=-=.~"".:-~_~~ ...., ~I =- , 10 '-./ \ TB6 TB3 R32 R3 TB5 C21 XV3 XV6 I---R6 T2 XV5 ~ m -r-\\4 R7 XV1 C1 ~---t----r-IR 10 C8 R17 R20 R15 -=--- ~;t:==tt C5 R5 R31 C20 C2 R14 R4 TB9 XV2 R16 C18 R18 TB10 C7 TB11 ~I\TB4 ~ ~ lEi> ~ Fig.
1. ( ) Fig. 4. Cut both leads on the 22KQ (red, red, orange, gold) 5% resistor, R29, to 3/4". Connect from TB2-4 (C) to TBl (C). 17. ( ) Fig. 4. Connect a .025mfd disc ceramic capacitor, C2, from XV1-l (5) to TB9-1 (C). Cut both leads to 3/4". 2. ( ) Fig. 4. Cut both leads on a 47mmf, 10% disc ceramic capacitor, C14, to 3/4". Connect from TB2-4 (5) to TBl (5). 18. 3. ( ) Fig. 4. 4. ( ) Fig. 4. Connect a 4" red lead from TB3-2 (C) to C18-3 (C). Connect a 4 1/2" red lead from C18-2 (C) to T84-3 (C).
~ C16 52 R13 TB7 PCl R12 Rll 51 C3 R33 TB8 R9 C4 C6 Fig.
TOP CHASSIS WIRING 1. ( ) Fig . 5 . Strip the outer insulation of one end of the 4 conductor cable back 1 3/4" . Unwrap the outer shield and twist shield stronds. Cut the outer shield to 1/2 " , the brown lead to 3/4", the red lead to 1" and the yellow lead to 1 1/4" . Connect the shield wire to SI-78 (C), the brown lead to SI-6AB (S), the red lead toSI-5AB(S), the orange lead to SI -11B (S) and the yellow lead to SI-8B (S).
J4 ... ~ n J6 J3 R26 XV5 R21 R24 R1 ~~ TB6 l"'n~~/I~~~tJ~I~~~~~~e'i~~- -LJLLTB5 C10 '----~'~~~~J_h LLL C 13 C12 R36 XV2 \ \-U- XV4 ~~~:5~_~~~-ill--1ll=-R27 ~ R25 C9 R19 XV6 R22 XV3 J2 J1 R2 3 ~--r-.f--l--1l-- R2 Cll TB9 ~~ ~ R35 " GC'll -l'."JT:t:1-l~~: ~TP.l() ~ --- _._- - / T611 Fig.
6 . Connect a I" piece of bare wire from XV3-6 (S) to XV3-2 (C). ~. 6. Connect a 100KO (brown,b lack,yellow,gold) 5% resistor, KV3-3 (C) to TBS-l (C). Cut both leads to 3/4". ig . 6 . Connect a 200 mmfd disc ceramic capacitor, CIl, from to T85-1 (C). Cut both leads to 1" . ig. 6. Connect a . 025 mfd disc ceramic capacitor, C13, from to T85-2 (C) . Cut both leads to 3/4" . ig . 6. Connect a 470KO (yellow,vio let,yellow,sllver) resistor, KV3-2 (C) to T86-2 (C). Cut both leads to 3/4". ig.6 .
Control Plote Bezel .Ill n ~ ,~ '8-32'3/8 Fig.
FINAL STEPS of the cabinet from the outside, using a small screwdriver . The flat portion shou Id be the actual resting or contact surface . You have now completed .the assembly and wiring of your amplifier. When you have completed the following steps your amp Iifier wi II be ready for use. 9. ( ) Fig. 7 . Insert the perforated cover into the" rai Is" on the side pieces and slide it forward fully.
6 SERVICE ~li¥iIl'" o e r~-I .==- w Q... e e o. · _ ~ =~, , 2..-,:,g.. .. Q ::-=.~ - • 8 e Fig. 8 ... 0- n 1. ( ) Fig. 8. Remove the backings from the two labels supplied and place them on the outside surface of the bottom plate as shown. If you are still having difficulty, write to our service department listing all possible indications that might be helpful. Note the code number appearing in red under the word "Manual" on the front cover. If there is no number, state this.
