Barney Oliver Amplifier Manual
Contents
1. PT Too A SS AAA eme s SS SS S N I M M A a ee 2 1 MODE FILTER STEREO MONO REV DIR DUAR 8 10 R L JEE 5 20 L R S2 SS 10V 10V 20V L e d i l R23 RIS 1 96K lOOK gt g O S RI7 IOV i 5 S2 A 1001 CL ST cour R25 x S a a d RIA I TO POWER AMP lei 10K STEPPED E Cel a ATTENUATOR R21 82 5K gt y c27 20V IOV LI 0082F 31 6mH L S go 52B O O LI O O o ACTIVE FILTER HIOV 10V 20V F lt R24 o Y 4 y sec 1001 O O na 6 O O RIB C12 O i t 0039u F 7 4 C22 CI I OQI25HF 00125uF TO POWER AMP IOK STEPPED ATTENUATOR 151618 0334 F C20 014F 13 PNP 2N3906 1853 0036 AE LINA MEIN AT A BE EE E El MPN 2N3904 1854 0215 Notes This Board Utilizes Two Seporate Connectors Terminois on the Larger Connector ore Labled 1 thru 22 Terminals on the Smaller Connector are Shown os 1 thru 10 Ail Resistors 1 8 W Metal Film Unless Otherwise Noted C27 and C28 Selected To Center 10 KHz Notch at JOKHz E IOGOHZ VIB Filter and Controls S K Output with Volume at Fuli Adjust for OV at Output with Volume at Zero R4 SOK QI 2N55512. BOOST OUT i i tT i m 1 H N 500 1000 FREQUENCY SOK 100K CONTROLS Cont d FILTER Controls active h f roll off filter gt 18 dB octave with corner at 5 8 10 or 20 kHz Includes 30 dB notch at 10 kHz in 5 and 8 kHz positions VOLUME Dual precision attenuator 60 dB range 2 dB steps Eliminates need for balance control BASS FLAT BOOST Response RIAA 6 dB 6 dB SIZE 16 72 425 mm wide 5 0 127 mm high 10 93 278 mm deep behind panel WEIGHT Approximately 20 pounds net without case POWER REQUIREMENTS 115 or 230 V A C 10 50 60 Hz 20 W standby power 135 W at full output into 16 both channels The Barney Oliver Audio Amplifier Front Panel Controls SECTION II FRONT PANEL CONTROLS Simplicity of operation has been achieved with a minimum of controls It is a good idea to mark with a colored dot the normal settings of special purpose controls so that the inexperienced or technically naive operator need only check these settings and achieve good results using only the input selector and volume control A INPUT Selector This switch allows a choice of any one of five inputs From left to right these are TUNER Accepts input at line level 0 dBm from FM AM or FM AM tuner TAPE Accepts input at line level 0 dBm from an equalized stereo or single channel tape deck PHONO Accepts input from a magnetic ster
3. 20 Normal position Introduces a maximally flat 18 dB octave cut off at 20 kHz D VOLUME Control A dual precision attenuator allows adjust ment of the sound level in 2 dB or scarcely perceptible steps over a 60 dB range Because the attenuation is precisely balanced and because the feedback assures equal gain in both channels the nuisance and hazard of an improperly set 2 1 Front Panel Controls balance control are eliminated Note Identical speakers are assumed Good quality speakers of good manufacture will ordinarily be within 1 dB of each other over the audio range Likewise for the two channels of a good phono cartridge How ever the perfectionist may want to test his components and introduce appropriate loss into the hot side E Phono Equalization Switch 6 dB RIAA 6 dB Below the INPUT selector control and effec tive only in the PHONO position of that control a three position slide switch allows some compen sation for recording defects In the center Nor mal position this switch provides the standard RIAA equalization In the left position the high frequency response is dropped by 6 dB while in the right position the response is enhanced by 6 dB Some manufacturers such as Deutsche Gramophone conscientiously adhere to RIAA spec ifications while others names supplied on request 2 2 The Barney Oliver Audio Amplifier enhance the high end to compensate for the deficiencies of
4. C6 c8 120 pF O27 LF Amplifier Input from Daven Attenuator RI Adjust for OV at 2 51 10 i Q6 2N5551 urrent Source Current Source R18 10K NOTES La X Select for Speaker Protection 2 0A 3AG Maximum Located on Back Patel All Resistors 1 8W Metal Film Unless Otherwise Noted AR 4 Digit Number by Diodes is Derived from Part Number CRI 1901 0040 1 040 i F i P a eee R23 909 0 QS CR3 2N5401 gt Q9 R3 OS A 2N5551 Q11 10 0 si 12 Es 40V R25 e e O 6 MUS 100 0 Q13 J5 ut with 5 CR 0271F R7 51 LI l CT 500 Audio TULF Out O J7 PI OY RI7 O 20K e QIO CR2 2 N4036 s i O O W i JE oe CD LON as j 2N5551 my CK 2N555 lon Gurrent ca Source Oli F R24 FU cu i 1 96K IT Soup l R28 100 VAV Se ee EE S BOOST d Br Phone Jack FLAT W VIC Power Amplifier One Channel mmm ee A A RI 10 9 H 26 CI SSOHF O 4 CRI C3 115 T10 V 3A E 50 400 D gt SKE CRA HA ca ZI 1SKuF CR2 O 4C CRB 115V MODELS ONLY H_cz 350 pF e Notes Re o CRIO CRI2 Power Transformer Primary Circuit Shown for 26 115V Models Only For 1157230V Models See YI De 4 Digit Number By Diodes and Transistors 1041 is Derived from Part Number QI 1853 0045 3 045 R2 All Resistors 1 8 W Metal Film Unless Otherwise Noted 56
5. slow blow Satisfactory operation will be obtained with line voltages within 10 of the nominal 115V or 230V value The line frequency should be 90 Hz or greater A grounding or three wire socket is recommended but not essential If the chassis is not grounded through the power cord a separ ate ground may be needed to get rid of hum on phono mike or other low level inputs F 115V 230V AMPLIFIERS European Units Units shipped to Europe and in a few cases within the United States are equipped with 115 230V power transformers Units shipped to Europe will be connected for 230V operation and will be equipped with 0 8 amp slow blow fuses Because of the variety of ac plugs used amplifiers shipped to Europe will not include line cords The line connector on the rear of the amplifier is compatible with European line cords and it is assumed that the user can obtain the proper cord Units connected for 230 operation will be prominently tagged 115 230 V amplifiers shipped within the United States will be connected for 115V operation will use 1 6 amp slow blow fuses and will be equipped with standard line cords These units will be tagged to indicate 115 230 capability Amplifiers with 115 230V power transform ers may be reconnected by the user for either line voltage 115V operation requires connecting the two halves of the transformer primary in parallel for 230V the two halves must be connected in series NOTE Wh
6. The phono cartridge should be located as far as is convenient from any transformers motors or other source of AC magnetic field With proper installation and a good cartridge no AC hum should be audible even at the full setting of the volume control and with bass boost B USE OF PHONOGRAPH PICKUPS OTHER THAN SHURE V15 TYPE II The phonograph pre amplifiers as shipped are optimized for the Shure V15 Type II pickup Other good quality pickups can be used but a resistor change on each of the phono pre amp boards may be required The resistors in question are designated R1 as shown near the left side of the pre amp schematic in Section VI A To determine the optimum value for R1 for a given pickup the inductance and resistance of the pick up must be known The value for resistor RI may then be calculated by using the following equation E Ri o x10 100R 20K 1 75 O Where Lo is pickup inductance in Henries Ro is pickup internal resistance in ohms and R1 is in ohms Once the value for RI has been calculated RI resistors on each of the two phono pre amp boards should be changed to the proper value For additional information see Section V A LEFT SPEAKER is ba The Barney Oliver Audio Amplifier C SPEAKER CONNECTIONS The amplifier may be located at any con venient distance from the loudspeakers Twisted pairs of No 18 wire or larger or ordinary zip cord may be used to connect the amplifiers to the
7. 0698 0083 R17 R18 R19 R20 1K 0757 0280 R21 R22 5622 a watt 0757 0815 R23 R24 R25 R26 10K 0757 0442 E DECK PARTS Reference Designation Stock Number C1 C2 C3 C4 C5 C6 CR1 CR2 FI F2 F3 Ji J2 J3 JA Jo JO J7 J8 J9 J10 J11 J12 J13 J14 J15 J16 J17 J18 0047 u F 01 4 F ceramic disc cap 01 u F mylar 200V diodes Motorola MR 841 line fuse 1 6A slo blo for 115V BA slo blo for 230V speaker fuses 2 amp max AC power connector power receptacles line fuse holder nut washer fuse clips speaker output jack mates with P1 phono jack ring tip sleeve phono preamp p c connector 18 pin power amplifier p c connector 18 pin filter and control p c connector 27 pin filter and control p c connector 10 pin input jacks fibre washers 0160 0155 0150 0093 0160 0161 1901 1038 2110 0005 2110 0020 2110 0003 1251 2357 1251 2073 1400 0084 2950 0038 2190 0068 1400 0008 Cinch Jones S 202 B Switchcraft 12B 1251 0141 1251 0141 1251 0172 1251 0166 GC Electronics 33 804 3050 0108 7 5 Parts List The Barney Oliver Audio Amplifier E DECK PARTS Continued Reference Designation Stock Number J19 J20 sockets for Q12 Q13 1200 0041 anodized insulators 1200 0043 LI inductor 134 H special Pi speaker output plug mates with J7 Cinch Jones P 202 CCT Q12 power transistor pnp Motorola MJ4502 Q13 power transistor npn Motorola MJ802 RIA amp B dual 1
8. 11002 0757 0424 R4 R5 9119 1 8 W m f 0757 0416 R6 TON 0757 0346 R7 R8 100K 0757 0465 R9 46 4K 0698 3162 R10 209 0757 0458 R11 R12 0 11K 0757 0438 R13 10K 0757 0442 R14 120K 0757 0467 R15 26 1K 0698 3159 R16 56 2K 0757 0459 R17 2002 0757 0407 R18 10K 0757 0442 R19 R20 R21 21511 0698 3441 R22 10K 0757 0442 R23 R24 5118 0757 0814 R25 R26 R27 91 14 0757 0394 R28 21 5K 0757 0199 R29 R30 0 11K 0757 0438 1 1 Parts List The Barney Oliver Audio Amplifier B FILTER BOARD 7 2 Reference Designation Description Stock Number C1 C2 C38 C4 22 u F mylar 0170 0086 C5 C6 C7 C8 10 4 F 20V electrolytic 0180 0374 C9 C10 100pF mica 0160 2204 C11 C12 008394 F mylar 0160 018 C13 C14 00125 u F mylar 0160 0297 C15 C16 018 F mylar 0160 0302 C17 C18 033 u F mylar 0160 0163 C19 C20 01 4 F mylar 0160 0161 C21 C22 001254 F mylar 0160 0297 C23 C24 68 u F mylar 0170 0039 C25 C26 0047 F mylar 0160 0157 C27 C28 0082 u F mylar See Schematic VI B 0160 0160 LI L2 Inductor 31 6 mH special Q1 Q2 Q3 Q4 transistor pnp 2N3906 1853 0036 Bio QLL dle QI transistor npn 2N3904 1854 0215 Q13 Q14 Q15 Q16 transistor pnp 2N3906 1853 0036 R1 R2 23 1K 0698 3158 R3 RA 100K pot 2100 2516 R5 R6 4 7 meg carbon 0684 4751 R7 R8 100K 0757 0465 R9 R10 1002 carbon 0684 1011 R11 R12 82 5K 0757 0463 R13 R14 1 96K 0698 0083 R15 R16 4 7 meg carbon 0684 4751 R17 R18 10022 carbon 0684 1011 R19 R20 100K pot 2100 2516 R21
9. 3004F SO SH e NP NP l j O 16 m e seme ee ee eee ee 1 A o DI rr et ite a at ee ee 1r _ r P teta Q3 R19 3 020 SS 1 04 20V R23 SH D R7 100K R8 I CRI 100K CII 1 040 Ti000pe CR2 1 040 QI 4 22 VA CHA CHA 1 020 1 040 OUTPUT TO SELECTOR SWITCH 18 R9 46 4K 20V R14 C4 120K 300 pL F LOOP o o RIO COL c5 l NE LOOP O d a i EE J bo ob RI Ex 10 100 Ro 20K Lo INH Ro IND b5myY PRODUCES 1 VOLT OUT AT IKHz ALL RESISTORS 1 gW METAL FILM UNLESS OTHERWISE NOTED VIA Phono Preamplifier TA TUNER RS 4 7 M INPUT 8 PHONO 20V ON PE AUX 1 Hi aux 2 Gg SI i 100K AUX 2 lovo O 10V AA AUX de Cl C3 RQ h SIA 5 22uF 22uF TA He UN PHONO RT 100K c9 100pF RIS MONITOR 10K Me OUTPUT RI R13 23 7K 1 96K e 4 10V 20V RUMBLE FILTER R AUXI 4 7 M Nb c2 c4 i a RIO h Ua e E Ke AND BUFFER AMP 20V HIOV O O RI2 I 82 5K R4 x 100K AUX 2 I 10VO Q IOV PJ PHONO TAPE U R8 100K C10 100pF TUNER RIG Q8 MONITOR TOK NS OUTPUT S R14 23 7K koer O a 10V 20V A MODE FILTER STEREO _ MONO REV Sie DUAL 8 10 R L 5 20 L R S2 53 a TT ap da ry 2i
10. option was included with your amplifier it may be assembled as outlined below See Section III J for picture of assembled enclosure The enclosure kit consists of the following Two wood side panels one right and one left Black vinyl clad aluminum top cover with retaining screw Four 10 32 flat head Allen screws and nuts for attaching side panels to amplifier Wood side panels have been sanded but not finished It is recommended that the wood pieces be finish sanded with fine sandpaper such as 400 or 600 grit They can then be finished as you please One quick simple and beautiful finish which can be done by most anyone anywhere is an oil finish with or without stain Most paint stores and many hardware stores sell Danish oil finish materials one brand is Watco If a high gloss finish is desired it will be necessary to apply filler to the wood before stain ing and applying finish For this process the user is referred to his friendly paint store or cabinet shop 3 3 Installation ASSEMBLY INSTRUCTIONS Attach the wood side panels to the amplifier with the Allen screws and nuts It will be noted that the side panels are notched across one end to clear the front panel overhang and to allow the wood panel to extend slightly forward of the front panel Near one edge of each wood panel is a slot extending the full length The panel should be attached so that these slots are at the top of the amplifier and face inboa
11. proper position the sound should appear to originate from dead ahead of you In the improper position this illusion disappears and both sources are heard independently Unless the speakers are matched the above test is difficult but with identical speakers the illusion is very striking and the test is easy to perform Reconnect the speaker pre serving the proper polarity This test need only be done once Return the MODE switch to the normal STEREO DIRECT position If on the average one channel seems louder than the other throw the MODE switch to the STEREO REVERSE position If the loud channel shifts to the opposite speaker the signal source or program material is defective If the loud channel stays with the same speaker the other speaker is less efficient If the speakers are supposedly identical the weak one may be defective Check the d c resistance of the speakers These should be the same within 5 The use of different speakers for the two channels is not recommended ll SPEAKER So lt _N Note dy must equal d Figure 3 4 1 The Barney Oliver Audio Amplifier Circuit Description SECTION V CIRCUIT DESCRIPTIONS A PHONO PRE AMPLIFIER The phono pre amplifier uses a combina tion of series and shunt feedback to the input terminals to provide a resistive input impedance of the proper value to produce together with the self inductance of the pickup the required RIAA high frequency roll off abov
12. providing the loops shown This minimizes the magnetic coupling to the power transformer and reduces the hum below audibility If you notice any hum it s from coupling directly to the cartridge Because the input impedance is low about 10 KQ cable capacitance has no effect on the high end response for lengths up to 10 or 20 feet depending on the cable used Many of the components that may puzzle you such as Q3 or CR8 or such as CRI CR2 CR5 etc are there to avoid turn on transients or avoid emitter base breakdown Everything has a function but invincible fatigue prevents me from going into all the gory details B FILTER BOARD The filter board provides a sharp low end cutoff below 16 Hz to protect the speakers against large useless cone exursions and a control lable high end cutoff to suppress the high fre quencies with noisy or distorted program material The board contains four unity gain amplifiers consisting of two cascaded emitter followers ex ample Q3 and Q5 with constant current supplies example QI and Q7 This combination provides very high input impedance very low output im pedance and low distortion The two input unity gain amplifiers are coupled to the input selector switch through active high pass filters that drop rapidly in transmission below 16 Hz example C1 R1 C3 R7 Q3 Q5 The output of these feed the mode selector switch The output unity gain amplifiers provide drive for the d
13. the pro tective fuses In addition all power supply outputs are either current limited or fused so that shorts from test probes will in general cause no damage Finally considerable effort was devoted to reducing switching transients A balanced build up and decay of power supply voltages and careful balancing of function drops minimizes the turn on transients in the amplifiers A slow turn on in the low voltage regulated supplies further reduces the turn on transient from the pre amplifiers 1 1 Description The Barney Oliver Audio Amplifier SPECIFICATIONS OUTPUT PER CHANNEL SPEAKER Z CONTINUOUS AUDIO PEAK 16 336 W 90 W 250 VV 160 VY vu 80 W HARMONIC DISTORTION lt 0 01 2 mw to max power all fregs HUM AND NOISE Power Amplifier 100 db below max output Phono Preamp 84 db below one volt output INPUT VOLTAGE FOR FULL OUTPUT Tuner Tape Aux 1 Aux 2 lt 1 0 volt rms Phono lt 5 mv rms INPUT IMPEDANCE Tuner Tape Aux 1 Aux 2 100 K 2 Phono Optimized for SHURE V 15 Type Il Pickup CONTROLS INPUT TUNER TAPE PHONO AUX 1 AUX 2 MODE STEREO DIR ect REV erse L R MONO DUAL L R Both channels operating simultaneously at maximum output Continuous high power operation at less than 8Q not recommended See instruction manual Hum pickup by phono cartridge may cause this figure to be exceeded 1 2 RESPONSE dd FREQUENCY RESPONSE BOOST IN Ji
14. 0K stepped attenuator Daven CPD 134 M H 4C687P 2dB step with detents R2 1 96K 0698 0083 R3 RA 100 2w 0698 3601 R5 R6 8 2021 Ww 0699 0003 RU 052 0811 1826 R8 51 10 w 0757 1000 R9 1001114 w 0757 0198 R10 ATK Y w 0684 4731 R11 R12 R13 R14 3 16K 1 3 w 0757 0279 R15 R16 10K 1 8 w 0757 0442 S1 input switch special 52 mode switch special S3 filter switch special 54 phono equalization switch 3101 0106 S5 bass switch 3101 1235 56 off on switch w pilot lamp 3101 0100 Ti povver transformer 115V only 9081 0876 115 230V 5081 5280 7 6 QEVLETTJUN PACKARD pis FROM TO ui dl y 1501 Paga Mill Road Pala Alto California 94304 Telephone 415 493 1501 TWX 910 373 1267 Dan Lansdon one May 1973 Barney Oliver Amplifier Oyner Corrections to Amplifier Manual The following corrections should be made Lo the Barney Oliver Amplifier Manual Page 1 2 Cit bh Part No should read Ol 60 0156 Page 7 3 R2 R3 Part No should read 0684 1551 Page 7 4 CRO LO dd E Part No should read 1901 0040 R27 R28 Part No should read 0684 1011 Page 7 6 RI10 Part No should read 0684 4731 INSURANCE POLICY BARNEY OLIVER STEREO AMPLIFIER To insure the spectacular performance of which this fine instrument is capable it is respectfully requested that you read the instruction manual very carefully especially Sections II III and IV Certain connections are critical Unless instructions are followed meticulously the sy
15. 20 d sov RI 10 1 O 20V R25 ok O 10V O O IOV R26 IOK O 20V 2N4036 3 045 R4 3 020 CRIO CRI2 26 1K R2 8 i 1041 gp e O 50V Q2 2N2405 A SQ 4q 352 _ _ _ VI DI Power Supply 230 10 V 50 400 115V 230V CONNECTED FOR 230V OPERATION 115 10 V 50 400 115V 230V CONNECTED FOR 115V OPERATION VI D2 Primary Circuits The Barney Oliver Audio Amplifier Parts List SECTION VII PARTS LISTS A PHONO PREAMPLIFIER Reference Designator Stock Number Cl 30pF mica 0160 2199 C2 Lo 04 Gb 300 uF np 3V 30D1614 C6 C7 C8 CH 15 uF 20V tantalum 0180 1746 C10 C11 1 000pF ceramic 0150 0050 CIZ 154 F10 mylar 0160 0303 ni Se a GE silicon diode 1901 0040 Q1 Q2 transistor npn X2N4044 1854 0221 Q3 transistor pnp special 1853 0020 Q4 transistor npn X2N3904 1854 0071 Q5 transistor pnp special 1853 0020 Q6 transistor npn X2N3904 1854 0071 Q7 transistor pnp special 1853 0020 Q8 Q9 transistor npn X2N3904 1854 0071 Q10 transistor pnp special 1853 0020 Q11 transistor npn X2N3904 1854 0071 RI Value is dependent upon characteristics of the phono pickup used R1 909K for the Shure 0757 0195 V 15 Type II Otherwise calculate R1 per Section III D R2 20K 0757 0449 R3
16. 5 1 1 1 3 1 4 7 5 The Barney Oliver Audio Amplifier Description SECTION DESCRIPTION A GENERAL The Barney Oliver Amplifier is a high quality all solid state audio amplifier designed for two channel stereo sound reproduction in the home in studios and in small to medium sized auditoriums It is intended for use with full fre quency range 8 to 16 ohm speaker systems and with signal sources phonograph pickups tape decks AM and FM tunners that are themselves flat enough to require little or no equalization In addition to the power amplifiers the unit includes phono preamplifiers designed to operate from any of several magnetic phono cartridges These pre amplifiers provide the necessary equalization for the RIAA recording characteristic Additional plug in preamplifier boards have been designed for direct moving coil microphone input or for direct input from low level high impedance sources Adding this feature will require that the user build the preamplifier boards install and wire printed circuit connectors in the deck drill front or rear panel holes as required and modify selector switch wiring Hum and distortion are inaudible As a result of careful attention to filtering and to lead routing on printed circuit boards the residual hum is well below thermal noise which itself has been minimized by optimum input stage design The output stages of the amplifiers are operated class B to reduce standby powe
17. 5 11K 1 8 w m f 0757 0438 R22 PO 1 8 w m f 0757 0398 R23 9092 1 8 w mt 0757 0422 R24 1 96K 1 8 w m f 0698 0083 R25 1002 1 8 w mt 0757 0100 R26 10K 1 8 w mt 0757 0442 R27 R28 1002 1 4 carbon 10 0684 1011 D POWER SUPPLY Reference Designation C1 C2 C3 C4 C5 C6 C7 C8 EE CIL CI CR1 CR2 CR3 CR4 CR5 CR6 CR7 CR8 CR9 CR10 CR11 CR12 CR13 CR14 CR15 CR16 CR17 CR18 Q1 Q2 Q3 Q4 Q5 Q6 Q7 1 4 3504 F 15V electrolytic 150004 F 50V Sprague electrolytic 1004 F 15V electrolytic 1000pF ceramic diode rectifier 3 amp 100V diode rectifier 4 amp 100V diode silicon diode Zener 21 5V diode Zener 9V diode silicon transistor pnp 2N4036 transistor npn 2N2405 transistor npn X2N3904 transistor pnp special transistor npn 2N2405 transistor pnp 2N4036 transistor npn 2N2405 transistor pnp 2N4036 transistor npn 2N2405 The Barney Oliver Audio Amplifier Stock Number 0180 2216 6821 Type 36D 153G050CC2A 0180 0061 0150 0050 1901 0200 1901 0158 1902 0040 1902 3245 1902 3149 1901 0040 1853 0045 1854 0352 1854 0071 1853 0020 1854 0352 1853 0045 1854 0352 1853 0045 1854 0352 The Barney Oliver Audio Amplifier Parts List D POWER SUPPLY Continued Reference Designation Stock Number RI R2 102 0757 0346 R3 R4 26 1K 0698 3159 R5 R6 R7 R8 562 Q Va watt 0757 0815 R9 R10 23 7K 0698 3158 R11 R12 42 2K 0698 3450 R13 R14 22K 0684 2231 R15 R16 1 96K
18. HP Archive This vintage Hevvlett Packard document vvas preserved and distributed by www hparchive com Please visit us on the web Thanks to on line curator Kenneth Kuhn for supplying and scanning this vintage document Deen Olive AMPLIFIER The Barney Oliver Audio Amplifier Section I I III IV V VI VII TABLE OF CONTENTS DESCRIPTION A General B Specifications FRONT PANEL CONTROLS INPUT Selector MODE Switch FILTER Switch VOLUME Control Phono Equalization Switch 6dB RIAA 6dB BASS Switch FLAT BOOST o TOW gt INSTALLATION Phono Connections Use of Phonograph Pickups Other Than Shure y 15 Type Il Speaker Connections o Speaker Placement Line Voltage Frequency and Line Fusing 115 280 Volt Amplifiers European Units Installing Amplifier in an Existing Cabinet Assembly of Walnut or Teak Enclosure Rack Mounting Cabinet Lo Pictures and Outline Drawing SH MORROW gt LOUDSPEAKER PHASING CIRCUIT DESCRIPTIONS A Phono Pre Amplifier B Filter Board C Power Amplifier D Power Supply CIRCUIT DIAGRAMS A Phono Pre Amplifier B Filter and Controls C Power Amplifier one Channel D1 Power Supply D2 Primary Circuits E Deck Wiring See Sections VI A B C and D PARTS LISTS Phono Pre Amplifier Filter Board Power Amplifier Power Supply Deck Parts HUWS Table of Contents 5 1 5 2 9 2 6 1 6 2 6 4 6
19. R22 82 5K 0757 0463 R23 R24 1 96K 0698 0083 R25 R26 4 64K 0698 3155 The Barney Oliver Audio Amplifier Parts List C POWER AMPLIFIER Reference Designation Description Stock Number C1 01 u F ceramic 0150 0093 C2 50 F 50V electrolytic 0180 0141 C3 1004 F 6V np 30D603 C4 22 y F tantalum 0180 0228 CD 50 u F 50V electrolytic 0180 0141 C6 120pF mica 0160 2205 C7 AT F 0170 0064 08 027 y F 0170 0066 C9 36pF mica 0160 2308 C10 1 000pF ceramic 0150 0050 GLECI2 C183 3504 F 50V electrolytic 0180 0141 CR1 CR2 CR3 CRA CRo CR6 CR7 CRE silicon diode 1901 0040 CR9 CR10 CR11 CR12 CR13 L1 L2 220 4 H inductor 9140 0129 QI Q2 transistor npn 2N5551 1854 0474 Q3 transistor pnp 2N5401 1853 0264 QA transistor npn 2N5551 1854 0474 Q5 transitor pnp 2N5401 1853 0264 Q6 transistor npn 2N5551 1854 0474 QT transistor pnp 2N5401 1853 0264 Q8 Q9 transistor npn 2N5551 1854 0474 Q10 transistor pnp 2N4036 1853 0045 R1 51 12 1 8 w 0757 0394 R2 R3 1 5 meg 1 4 w carbon 0684 1551 RA R5 DOK pot 2100 2517 R6 R7 10K 1 8 w m f 0757 0442 R8 3 16K 1 8 w 0757 0297 R9 5 11K 1 8 w m f 0757 0438 R10 10K 1 8 w m f 0757 0442 R11 R12 2002 1 8 w m f 0757 0407 R13 R14 5 11K 1 8w m f 0757 0438 R15 34 8K 1 8 w m f 0757 0123 1 3 Parts List C POWER AMPLIFIER Continued Stock Number R16 5 11K 1 8 w mt 0757 0438 R17 20K 1 8 w mt 0757 0449 R18 10K 1 8 w m f 0757 0442 R19 5 11K 1 8 w mt 0757 0438 R20 20K 1 8 w m f 0757 0449 R21
20. e 2120 Hz If L is the pickup inductance and Ro the resistance and if R is the input resistance to the pre amp we require that FIR 75 Xx 1076 seconds O This leads to the value of R1 given in the sche matic As supplied RI is appropriate for the Shure V 15 Type II cartridge To provide the 6 dB variation of high end response the shunt feed back is halved or doubled The series feedback is applied to the low end of the pickup windings which places these ends normally the outer shields of coaxial lines 102 above ground To avoid hum and RF pickup it is recommended that an outer shield insulated from both inner shields be used This shield should connect the record player frame to the amplifier chassis A balanced differential stage is used at the input to avoid drift and RF rectification The remainder of the amplifier is similar to the power amplifier except for power level The output Class B stage can supply a 600 line or headphones at line level 0 dBm without appreciable distortion The low end bass boost of the RIAA charac teristic below 500 Hz is provided by C12 and R3 R4 R5 R6 and R28 The low end cutoff is provided by C2 and C3 together with C4 C5 and R10 This combination provides unity d c external gain and a fourth order maximally flat low end cutoff at about 16 to 20 Hz Great care was used to make the projected area of the input circuit zero in all directions by properly routing the conductors and by
21. een any two terminals or between any terrninal and the metallic case of the pickup See Section IH A shooting in your area fail to achieve results please get in touch with Dan Lansdon hp Labs Palo Alto Ext 2706
22. en reconnecting transformer primaries care must be taken to insure that windings are connected in an aiding sense instantan eous flux produced by both windings must have the same polarity The line fuse must be changed when changing the line voltage 1 6 amp for 115V 8 amp for 230V Installation G INSTALLING AMPLIFIER IN AN EXIST ING CABINET If the amplifier is to be installed in an ex isting cabinet careful attention should be paid to the outline drawing shown in Section III J Because certain components especially the power supply capacitors are quite large 1t will be seen that the overhang at the top of the front panel is not very great and at the bottom edge is virtually zero This will require considerable care in cutting the necessary hole in the cabinet It is strongly recommended that the amplifier be examined in detail before laying out this hole to prevent costly mistakes Referring to the side view in the out line drawing in Section III J it will be seen that overall front panel height is 5 that the rear panel height is 4 85 and that the side gussets are 4 48 high This will make possible the use of a hole somewhat less than 4 85 high if the amplifier can be tipped slightly as it is inserted Front panel overhang at each side is approxi mately 44 requiring less precision in the horiz ontal dimension H ASSEMBLY OF WALNUT OR TEAK EN CLOSURE If the walnut or teak enclosure
23. eo phonograph pickup AUX 1 Accepts inputs from any line level audio circuit such as tuners AUX 2 tape decks or other sources B MODE Switch This control allows the left and right chan nels of the input to be delivered to the speakers in various ways The center position is normal for stereo operation From left to right the modes are L Left stereo channel only to left speaker R Right stereo channel only to right speaker REV Stereo channels reversed Left channel to right speaker right channel to left speaker DIR Direct presentation Kach stereo channel to corresponding speaker Normal position DUAL Both channels mixed and deliv ered to both speakers L Monophonic reproduction of left channel over both speakers R Monophonic reproduction of right channel over both speakers The L and R positions allow monophonic tapes and other signal sources to be reproduced over either one STEREO side or both MONO side speakers C FILTER Switch This control allows various high frequency roll offs to be introduced From left to right the positions are 5 Introduces a high frequency cut off at 5 kHz with a null at 10 kHz Useful for noisy 78 rpm records and AM reception 8 Introduces a high frequency cut off at 8 kHz with a null at 10 kHz Useful for good 78 rpm records and AM reception 10 Introduces a maximally flat 18 dB octave cutoff at 10 kHz Use ful for slightly noisy conditions
24. g turn on and turn off is determined by the two stage active filters comprising R9 C5 R13 and R15 C7 and transistor Q3 for the 20V supply and R10 C6 R14 and R16 C8 and transistor Q4 for the 20 V supply Diode CR17 compensates for junction drops in Q5 and Q7 while CR18 compensates for junction drops in Q6 and Q8 Resistors R11 and R12 compensate for the initial charging currents in C5 and C6 so that these currents do not flow through R17 R19 CR17 and R18 R20 CR18 The Barney Oliver Audio Amplifier Circuit Description Resistors R17 and R19 as well as R18 and The 10 and 20 volt supplies are regulated and R20 are dividers to develop the 10V reference essentially ripple free The 10V outputs are taken from emitter followers Q7 and Q8 The maximum steady current ratings of the various supplies are Supply Max Current CR15 and CR16 provide short circuit pro 10V 13 ma tection and transistors Q9 and Q10 protect the 20V 70 ma emitters of Q7 and Q8 against reverse voltage 40V 3 amps from shorts between the 10 and 20 volt supplies 50V 0 5 amps SECTION VI CIRCUIT DIAGRAMS i n gare e m e e E e i Pr SHURE V15 ETC QI Q2 4 22 4 22 _ 2 1 SR vi CR3 CR4 RI 1 040 1 040 R1 909K 8 Ci 30 pF o Zb qa NIN 4 071 l R9 46 4K O S4 14 0 O 6db g t dh ca RIAA R6 I OA 3004F LOOP s o R 2 R3 s no0n C C3 3004 F TY
25. nd Q2 whose emitter currents are supplied by QA The input signal is applied to the base of Q1 and the feedback to the base of 2 The output collector swing of Q1 is limited by CR2 and CR3 to protect the emitter base junctions of the second stage comprising Q5 and Q The loop gain at d c and low frequencies is extremely high gt 100 dB The primary cutoff for the loop gain at high frequencies is the base collector capacitance of Q7 Thus the loop gain falls at 6 dBjoctave to reach a value of about 60 dB at 10 kHz Inductors Ll and L2 introduce a second pole at 16 kHz above which the loop gain falls at 12 dB octave to about 200 kHz where C6 begins to shunt R16 producing a high end cut off in the amplifier and reducing the loop gain cutoff rate to 6 dB octave once more Gain crossover is at about 1 MHz The bridged T comprising C3 C4 R11 and R12 increases the loop gain below 16 Hz and reduces the external gain to unity at d c The poles in the external gain are slightly complex so the low end response rises slightly at the low end before dropping off In the bass boost position C7 and CH together with R16 and R17 produce a pole at 16 Hz and a zero at 80 Hz in the external gain Thus the gain rises at 6 dB octave below 80 Hz to compensate for the low end roll off of most loudspeakers ocated on chassis See righthand portion of Power Amplifier Schematic Section VI C 9 2 The Barney Oliver Audio Amplifier Transisto
26. outer shield around but insulated If in doubt visually inspect these fuses not with an ohmmeter from the left and right channel leads and ground E this outer shield only to the amplifier chassis thumb screw and to the turntable or changer chassis See E If you have a signal source other than phono i e tuner tape unit Section JIT A audio oscillator etc try it first in any or all in turn of the following inputs on the rear of the amplifier TUNER TAPE G If your phono pickup is other than a Shure V 15 Type II please AUX 1 AUX 2 Be sure the input switch is in a position sec Section Ni B corresponding to the input which is connected Also be sure the l mode switch is in the STEREO NORMAL posilion H lf after you have carefully gone through steps A G together with the admonitions and caveats in the instruction manual your F H step D works out then connect the phono pickup leads from system still does not work please try to get some help from turntable or changer to the phono inputs but first an electronic friend in your area Since this is a G joboperating on a shoestring we have no funds for trouble shooting or repair except for major problems defective power transformer defective attenuator etc The likelihood of such problems is very small on the other hand if conscientious efforts at trouble 1 Be sure the pickup cartridge has four independent terminals with no metal or wire connection belw
27. r Q3 supplies current to two poten tiometers R4 and R5 which are adjusted so that the currents through R2 and R3 supply the base currents of Qi and Q2 By adjusting R5 with the input terminals shorted volume control at mini mum and R4 with the input terminals open or with the volume control at maximum to give zero volts out of the amplifier this condition will hold for any impedance the amplifier faces any volume control setting D POWER SUPPLY All supply voltages 50V 40V 20V and 10V are available in both polarities The main supply 40V is rectified by diodes CR1 CR2 CR3 and CR4 in a double full wave configuration Filtering is by capacitors C3 and C4 This supply has a substantial amount of ripple especially under load but the power amplifier by passing is such that this produces negligible hum in the amplifier output VARNING The terminals and leads of C8 and C4 are not current protected Do not short to ground or to each other You ll ruin your screwdriver The 50V supplies are really 10V supplies floated on the 40V supplies respectively They will show about the same ripple as the latter Tran sistors QI and Q2 with their associated circuitry provide protective current limits on the 50V supplies Zener diodes CR13 and CR14 establish the reference voltages for the 20V supplies obtained from the cascaded emitter followers Q3 Q5 and 496 The rate of rise and fall of these supplies durin
28. r drain and are biased and locally degenerated to reduce crossover distortion A large amount of overall negative feed back ranging from over 100 dB loop gain at de and low frequencies to over 50 dB at the top of the audio range further reduces any remaining har monic and inter modulation distortion Since the u circuits are direct coupled overload produces no long time constant transients the peaks are simply clipped and the original waveform resumes at its proper value immediately afterward Be cause of the large amount of feedback signals only a fraction of a dB below actual overload typically show a total distortion over 75 dB below the fundamental Bridged tee networks in the B circuits of the amplifiers and active filters in the mixing and control board enable the low end response to be maintained down to 20 Hz and to fall off very rapidly below the audible range This prevents the amplifier and loudspeakers from being driven beyond their linear excursions by low frequency transients arising from such sources as warped records or breath blasts into microphones The high end response is reduced at 18 dB per octave above 20 ke by another pair of active filters to protect the amplifiers against overload by or rectification of strong r f signals The power amplifiers are protected against damage from accidental short circuits at their out puts Momentary shorts will have no effect but sustained shorts may blow one or more of
29. rd The aluminum top cover slides into the slots just mentioned with the front edge fitting into a slot at the top rear of the front panel The rear edge of the top cover lies on the top of the back panel and is secured with a single 3 4 The Barney Oliver Audio Amplifier screw through the top cover It may be necessary to adjust the positions of the wood side panels to permit the top cover to slide into place without interference from side gussets or other amplifier parts I RACK MOUNTING CABINET If your amplifier was furnished in an HP type cabinet it can be rack mounted by use of the standard rack mount kit shipped with the instrument Instructions are included with the kit J PICTURES AND OUTLINE DRAWING See following page 38 in 10 93in 10mm 278 mm T f 4 ABin 4 85in 114mm 123mm 5 00 in 127 mm 16 22 in 412 mm 425 mm NOTE CASE IS AN EXTRA PRICE OPTION The Barney Oliver Audio Amplifier Loudspeaker Phasing SECTION IV LOUDSPEAKER PHASING Proper stereo reproduction requires that the loudspeakers be properly phased To check this insert a reversing switch in the leads to one speaker as shown in Figure 3 Turn on the power and the signal sources and bring up the volume Set the MODE switch to DUAL Station yourself exactly midway between the speakers and about three feet in front of the plane of their front baffles Try reversing the switch In the
30. speakers if the distance is under 100 feet For longer distances heavier conductors are recom mended In general the d c resistance of the cables or cords should not exceed 54 of the speaker impedance Connection to the amplifier outputs is via the two terminal polarized Jones sockets at the rear of the amplifier The cords or cables must be soldered to the mating plugs provided taking care to avoid internal short circuits from wire strands or solder bridges It is good practice to insulate the wire and lugs from each other with electrical tape or heat shrinkable tubing inside the plug sleeve after soldering D SPEAKER PLACEMENT The loudspeakers should be located at the ends of the base of an isosceles triangle with the listener at the apex The apex angle of this tri angle i e the angle between the lines of sight to the two speakers should be about 150 to 459 as shown in Figure 2 Good sound quality will then be heard up to 45 on either side of the perpendicular bisector of the line between the speakers RIGHT SPEAKER X BISECTOR r Figure 2 The Barney Oliver Audio Amplifier E LINE VOLTAGE FREQUENCY AND LINE FUSING Unless specifically tagged otherwise amplifiers operate only on 115V ac line 115V amplifiers have single power transformer primaries and cannot be connected for 230V operation An external 230 115V step down transformer may be used The proper line fuse for 115V units is 1 6 amp
31. stem PROBABLY WON T WORK AND COULD BE DAMAGED To help you avoid pitfalls already encountered by some users here are a few tips A Be certain that speaker leads are well insulated Beware of 2 Make certain there are separate shielded leads from ancient zip cord which may be partially shorted each side channel of the pickup cartridge Be sure there is no connection between leads for left chennel B Make sure that leads are well soldered to speaker plugs and i and right channel Some changers use a common that there are no frayed wires or solder bridges between the shield this will not work on this amplifier Also be terminals An ohmmeter check is advisable after soldering sure the leads and shields are not grounded to the leads to plugs and before connecting leads to speakers turntable or changer chassis or to anything else Some turntables or changers will have to be rewired C Be sure there is no connection belween left and right speakers i Some existing systems use a common lead 3 Connect the amplifier chassis thumbscrew on rear panel to the turntable or changer chassis In D Be careful to avoid even momentury short circuiting of the many cases this can be done wilh a piece of insulated speaker outputs or leads Short circuits will blow speaker wire If you still notice hum when phono input is fuses located under the black cover on the rear of the amplifier selected install an
32. the usual playback system If your speakers are flat the 6 dB position will help correct this practice If you find the 6 dB position better in the majority of cases your speakers or your ears need attention F BASS Switch FLAT BOOST Located below the high frequency FILTER control is the two position BASS switch In the BOOST position the switch raises the response at 6 dB octave from 80 Hz down to 20 Hz In the BOOST position approximate compensation is provided for the usual low end roll off of good speakers Two poles at 40 50 Hz If you are fortunate enough to have an overdamped pair of woofers with real poles at 80 Hz and 20 Hz such as LE 15A s or ALTEC 411 A s in 9 cu ft or larger enclosures the BOOST position will closely compensate the low end roll off down to the bottom of the audio range For very high sound levels the FLAT position is recommended The Barney Oliver Audio Amplifier Installation SECTION HI INSTALLATION A PHONO CONNECTIONS Special precautions must be observed for the PHONO input Because a combination of shunt and series feedback is used to control the imped ance faced by the cartridge and thereby produce the high end roll off required by the RIAA record ing characteristic the LOW side of each input is not grounded inside the amplifier and THESE MUST NOT BE GROUNDED OR CONNECTED TOGETHER externally See Section V A for further information If coaxial or shielded
33. ual precision volume control and are coupled to the mode selector switch via active low pass filters These are three pole filters two of the poles being provided by the input RC net works and the remaining poles and zeros by the shunt branch at the output Potentiometers are provided to supply the base currents of the input emitter followers and thereby enable the voltages at terminals 5 4 20 and 21 to be set equal to zero This eliminates transients when the mode and filter switches are switched 9 1 Circuit Description C POWER AMPLIFIER The output stage of the power amplifier is a cascaded complementary emitter follower com prising transistors Q12 and Q138 with Q10 and 411 as their drivers Operating point stability is provided by resistors R5 and R6 and by currents from current source 8 flowing through CR7 CR9 R22 CR8 and CR6 The power diodes CR1 and CR2 shunt R5 and R6 at high signal levels to avoid large voltage drops in these resistors Inductance L1 protects the output stages from the effects of capacitive cable loads at very high frequencies while R amp eliminates any series reson ance with this capacity Diodes CR10 CR11 CR12 and CR13 provide output current limitation To gether with fuses F these provide output short circuit protection The output stages are driven by emitter follower Q9 which has current limita tion in the collector The input stage consists of a differential pair QI a
34. wires are used for each channel the two inner shields OUTER SHIELD INNER SHIELD TO SE PHONO INPUT d JACKS ON REAR gt a OF AMPLIFIER p s INNER SHIELD j TO GROUND CONNECTION ON REAR OF AMPLIFIER NOTE Inner shields must not be grounded at either end Also inner shields must not be connected together at any point including at or inside pickup Cables should have insulation over shields Outer shield must not make contact with any must be insulated from each other and from the outer shield around both as shown in Figure 1 In some cartridges the LOW side of one or both channels is grounded to the case by a thin strap at one or both LOW terminals IF PRESENT THESE GROUNDING STRAPS MUST BE RE MOVED BY PRYING THEM OUT AND OFF WITH A LARGE NEEDLE OR PICK The overall shield should be connected to the turntable frame at one end and to the amplifier chassis at the other end using the binding post provided After this is done test that both channels are isolated from ground before connecting them to the amplifier PHONO PICKUP INSULATION LI D TO CHASSIS OF TURNTABLE OR CHANGER lead connecting pickup to amplifier including inner shields In some locations the outer shield may not be necessary in such cases tumtable or changer chassis should be connected to amplifier chassis ground terminal on rear with a separate wire preferably insulated Figure 1 Phono Connections 3 1 Installation
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