mono pure class a valve power amplifier
TRANSCRIPT
Total solder points: 600 Difficulty level: beginner 1o 2o 3o 4o 5þ advanced
MANUAL H8010P-ED1
MONO PURE CLASS A VALVE POWER AMPLIFIER
K8010 ⇒ Pure CLASS A valve sound with high quality KT88 valves ⇒ High quality chrome plated enclosure ⇒ Chrome plated valve socket covers ⇒ Easy bias adjustment with LED indication ⇒ Removable bottom for easy access and service ⇒ High quality capacitors and components ⇒ Gold plated input and speaker terminals ⇒ Standby function ⇒ Soft start circuit for power transformer ⇒ Sensitivity adjustment for exact matching of two mono amps
Specifications
• Full class A 65Wrms in 4 or 8Ω • Bandwidth: 4Hz to 90KHz (-3dB/1W) • Harmonic distortion: 0.1% @ 1W/1KHz • Signal to noise ratio: >110dB (A weighted) • Input sensitivity: 1Vrms (adjustable) • Power supply: 100, 120, 230 or 245VAC • Power consumption: 230VA max. • Dimensions: 355W x 360D x 157H • Weight: 14Kg / 31lb modifications reserved
5%
4K7= ( 4 - 7 - 2 - B )
1%
4K7= ( 4 - 7 - 0 - 1 - 1 )
COLOR= 2… 5
I P E SF S DK N D GB F NL CODE
CODICE COLORE
CODIGO DE
CORES
CODIGO DE COL-
ORES
VÄRI KOODI
FÄRG SCHEMA
FARVEKODE
FARGEKODE
FARB KODE
COLOUR CODE
CODIFI-CATION DES COU-LEURS
KLEURKODE
CODE
0 Nero Preto Negro Musta Svart Sort Sort Schwarz Black Noir Zwart 0 1 Marrone Castanho Marrón Ruskea Brun Brun Brun Braun Brown Brun Bruin 1 2 Rosso Encarnado Rojo Punainen Röd Rød Rød Rot Red Rouge Rood 2 3 Aranciato Laranja Naranjado Oranssi Orange Orange Orange Orange Orange Orange Oranje 3 4 Giallo Amarelo Amarillo Keltainen Gul Gul Gul Gelb Yellow Jaune Geel 4 5 Verde Verde Verde Vihreä Grön Grøn Grønn Grün Green Vert Groen 5 6 Blu Azul Azul Sininen Blå Blå Blå Blau Blue Blue Blauw 6 7 Viola Violeta Morado Purppura Lila Violet Violet Violet Purple Violet Paars 7 8 Grigio Cinzento Gris Harmaa Grå Grå Grå Grau Grey Gris Grijs 8 9 Bianco Branco Blanco Valkoinen Vit Hvid Hvidt Weiss White Blanc Wit 9 A Argento Prateado Plata Hopea Silver Sølv Sølv Silber Silver Argent Zilver A B Oro Dourado Oro Kulta Guld Guld Guldl Gold Gold Or Goud B
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TECHNICAL DATA* • Output power: 65 Wrms class A / 85Wrms maximum • Output impedance 4 or 8 Ohm • Ultra linear output transformer • Switch-on delay, to protect the output tubes: approx. 1 minute • Standby circuit • Built-in bias current indicator • Switch-on delay for the supply transformer : 0.5s • Power bandwidth: 8Hz - 45kHz (-3dB, ref. 50W) • Frequency range: 4Hz - 90kHz (-3dB, ref. 1W) • Harmonic distortion:
0.1% (1 kHz/1W) 0.7% (1 kHz/65W)
• Signal/noise ratio: > 110dB (A weighted wrt 85W) • Input impedance: 100Kohm • Input sensitivity min 1Vrms, adjustable. • Damping factor (100Hz): > 12 • Power supply: 100, 120, 230, 245VAC • Power consumption: 230Wmax. / 66W standby • Dimensions: 355W x 360D x 157H *Modifications and typographical errors reserved
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1. Assembly (Skipping this can lead to troubles ! ) Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully. 1.1 Make sure you have the right tools: • A good quality soldering iron (25-40W) with a small tip. • Wipe it often on a wet sponge or cloth, to keep it clean;
then apply solder to the tip, to give it a wet look. This is called ‘thinning’ and will protect the tip, and enables you to make good connections. When solder rolls off the tip, it needs cleaning.
• Thin raisin-core solder. Do not use any flux or grease. • A diagonal cutter to trim excess wires. To avoid injury when cutting excess leads,
hold the lead so they cannot fly towards the eyes. • Needle nose pliers, for bending leads, or to hold components in place. • Small blade and phillips screwdrivers. A basic range is fine.
For this projects, a basic multi-meter is required
1.2 Assembly Hints : þ Make sure the skill level matches your experience, to avoid disappointments. þ Follow the instructions carefully. Read and understand the entire step before you perform each op-
eration. þ Perform the assembly in the correct order as stated in this manual þ Position all parts on the PCB (Printed Circuit Board) as shown on the drawings. þ Values on the circuit diagram are subject to changes. þ Values in this assembly guide are correct* þ Use the check-boxes to mark your progress. þ Please read the included information on safety and customer service * Typographical inaccuracies excluded. Always look for possible last minute manual updates, indicated as ‘NOTE’ on a separate leaflet. 1.3 Soldering Hints :
Mount the component against the PCB surface and carefully solder the leads
Make sure the solder joints are cone-shaped and shiny
Trim excess leads as close as possible to the solder joint
0.000
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ASSEMBLY OF THE MAIN PCB P8010: Foreword: For best results and easy handling of the large PCB (Printed Circuit Board), we will start by putting the four large valve sockets in place. This will allow us to rest the board on the bench, without having the component leads touching the bench surface. When the component leads are put in the appropriate holes on the PCB, we recommend to gently bend the leads outwards, so they stay on the board when it is flipped over to apply solder. You gain a reason-able amount of time if you put approx. 10 components in place every time, before you flip the board, and make the solder joints.
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15mm M3 SPACER
12mm SPACER
PCB
VALVE SOCKET
20mm M3 BOLT
1. VALVE SOCKET MOUNTING Check the position of the notch in the centre of the valve socket, it must correspond to the position of the notch in the circle printed on the PCB. Connect the leads to the corresponding isles on the PCB using a small piece of supplied jumper wire. IMPORTANT: Make the connection exactly as shown in the illustration, otherwise the small piece of wire could touch the bottom of the cabinet, see further.
23
41
3
57
4
6
58
1
8
q V1 q V2 q V3 q V4
Also mount a 15 mm spacer on the following holes in the PCB (at the solder side); use a 6 mm M3 bolt: q A spacer next to TRAFO1 q A spacer next to SK15 q A spacer next to SK6 q A spacer next to R62 q A spacer next to V6
6mm M3 BOLT
15mm M3 SPACER
2 7
1
8
54
3
V...
Connect the valve socket terminals 1, 3, 4, 5, and 8 to the corresponding points at the solder side of the PCB. Use a piece of supplied jumperwire. Mount the wire in such way that it can-not touch the bottom of the cabinet. (see above illustration).
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2. JUMPERS
q J1 (mount 2 wires in the same hole) q J2 (mount 2 wires in the same hole) q J3 (mount 2 wires in the same hole) q J4 (mount 2 wires in the same hole) q J5 q J6 q J7 q J8 q J9 q J10 q J11 q J12 q J13 q J14 q J15 q J16 q J17 q J18 q J19 q J20 q J21 q J22 indicated with ‘F1’
(mount 2 wires in the same hole)
3. JUMPERS FOR AC POWER SE-LECTION For 100V input (mains), mount: q JA at the voltage selection 1
D
C
B
A
q JA at the voltage selection 2 D C B A
For 115V - 120V input, mount: q JB at the voltage selection 1
D
C
B
A
q JB at the voltage selection 2
D C B A
Note that for J1 to J4, two jumper wires have to be mounted in the same hole, for extra cur-rent handling. TIP In order to get nice straight wiring, without too
much folding and measuring, follow these hints:
• Put the jumper wire in place. • Solder one end of the lead. • Then carefully pull on the free end of the
lead until it is straight, and apply solder.
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For 220V - 230V input, mount: q JC at the voltage selection 1
D
C
B
A
q JC at the voltage selection 2
D C B A
For 240V -245V mains input, mount: q JD at the voltage selection 1
D
C
B
A
q JD at the voltage selection 2
D C B A
REMARK: Strike out the NOT used mains voltage indica-tion at the back of the enclosure !! Use a per-manent black marker
4. DIODES (Check the polarity!)
D...CATHODE
q D1: 1N4148 q D2 :1N4148 q D3: 1N4007 q D4: 1N4148 q D5: 1N4007 q D6: 1N4148 q D7: 1N4148 q D8: 1N4148 q D9: 1N4007 q D10: 1N4007 q D11: 1N4007 q D12: 1N4007 q D13: 1N4007 q D14: 1N4007 q D15: 1N4007 q D16: 1N4007 q D17: 1N4007 q D18: 1N4007 q D19: 1N4007 q D20: 1N4007 q D21: 1N4007 q D22: 1N4007 q D23: 1N4007 q D24: 1N4148 q D25: 1N4148 q D26: 1N4148 q D27: 1N5408 not on tape ! q D28: 1N5408 not on tape ! q D29: 1N5408 not on tape ! q D30: 1N5408 not on tape !
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5. ZENER DIODES (Check the polarity!)
ZD...CATHODE
q ZD1: 3V9 q ZD2: 3V9
6. ¼W & ½W RESISTORS
R...
q R1: 470 (4 - 7 - 1 - B) q R2: 220K (2 - 2 - 4 - B) q R3: 2K2 (2 - 2 - 2 - B) q R4: 2K2 (2 - 2 - 2 - B) q R5: 220K (2 - 2 - 4 - B) q R6: 100K (1 - 0 - 4 - B) q R7: 1K (1 - 0 - 2 - B) q R8: 1K (1 - 0 - 2 - B) q R9: 22K (2 - 2 - 3 - B) q R10: 3.3 (3 - 3 - B - B - 9) q R11: 3K9 (3 - 9 - 2 - B) q R12: 1K5 (1 - 5 - 2 - B) q R13: 1M (1 - 0 - 5 - B) q R14: 1M (1 - 0 - 5 - B) q R15: 1K (1 - 0 - 2 - B) q R16: 47K (4 - 7 - 3 - B) q R17: 470K (4 - 7 - 4 - B) q R18: 680 (6 - 8 - 1 - B) q R19: 3K9 (3 - 9 - 2 - B) q R20: 10K (1 - 0 - 3 - B)
q R21: 10K (1 - 0 - 3 - B) q R22: 1K5 (1 - 5 - 2 - B) q R23: 1K2 (1 - 2 - 2 - B) q R24: 560 (5 - 6 - 1 - B) q R25: 100K (1 - 0 - 4 - B) q R26: 220K (2 - 2 - 4 - B) q R27: 100K (1 - 0 - 4 - B) q R28: 220K (2 - 2 - 4 - B) q R29: 10K (1 - 0 - 3 - B) q R30: 2K7 (2 - 7 - 2 - B) q R31: 1M5 (1 - 5 - 5 - B) q R32: 1K5 (1 - 5 - 2 - B) q R33: 3.3 (3 - 3 - B - B) q R34: 8K2 (8 - 2 - 2 - B) q R35: 220K (2 - 2 - 4 - B) q R36: 10K (1 - 0 - 3 - B) q R37: 100K (1 - 0 - 4 - B) q R38: 220K (2 - 2 - 4 - B) q R39: 100K (1 - 0 - 4 - B) q R40: 220 (2 - 2 - 1 - B - 9) q R41: 100K (1 - 0 - 4 - B - 9) q R42: 47K (4 - 7 - 3 - B - 9) q R43: 220 (2 - 2 - 1 - B - 9) q R44: 220 (2 - 2 - 1 - B - 9) q R45: 220 (2 - 2 - 1 - B - 9) q R46: 2K2 (2 - 2 - 2 - B - 9) q R47: 27K (2 - 7 - 3 - B - 9) q R48: 220 (2 - 2 - 1 - B - 9) q R49: 220 (2 - 2 - 1 - B - 9) q R50: 100K (1 - 0 - 4 - B - 9) q R51: 330K (3 - 3 - 4 - B - 9) q R52: 330K (3 - 3 - 4 - B - 9) q R53: 330K (3 - 3 - 4 - B - 9) q R54: 330K (3 - 3 - 4 - B - 9)
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7. 1W RESISTORS
R...
2mm
q R55: 270 (2 - 7 - 1 - B) q R56: 10K (1 - 0 - 3 - B) q R57: 10K (1 - 0 - 3 - B) q R58: 12K (1 - 2 - 3 - B) q R59: 39K (3 - 9 - 3 - B) q R60: 39K (3 - 9 - 3 - B) q R61: 39K (3 - 9 - 3 - B) q R62: 100K (1 - 0 - 4 - B) q R63: 47K (4 - 7 - 3 - B) q R64: 47K (4 - 7 - 3 - B) q R65: 47 (4 - 7 - 0 - B) q R66: 47 (4 - 7 - 0 - B) q R67: 180 (1 - 8 - 1 - B) q R68: 180 (1 - 8 - 1 - B) q R69: 180 (1 - 8 - 1 - B) q R70: 47 (4 - 7 - 0 - B) q R71: 47 (4 - 7 - 0 - B) q R72: 180 (1 - 8 - 1 - B)
8. LEDs (Check the polarity!)
LD...
COLOR = 2...5
CATHODE
q LD1: 5mm RED (2) BLINKING q LD2: WILL BE MOUNTED
LATER, SEE SECTION 27 q LD3: 3mm YEL (4) q LD4: 3mm YEL (4) q LD5: 3mm YEL (4) q LD6: 3mm YEL (4) q LD7: 3mm GREEN (5) q LD8: 3mm GREEN (5) q LD9: 3mm RED (2) q LD10: 3mm RED (2) q LD11: 3mm RED (2) q LD12: 3mm RED (2) q LD13: 3mm RED (2) (next to R61)
9. IC SOCKETS (Check the position of the notch!)
IC...
1
q IC1: 18P
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11
10. REED RELAYS (Check the position of the notch!)
PIN 1
1
RY...
q RY1: VR05R121
11. DIP SWITCHES
1
SW...
Check that switch 1 corresponds to pin 1. q SW2: DS-4P
12. RESISTOR TRIMMERS Vertical type
RV...
q RV1: 100K q RV2: 100K q RV3: 100K q RV4: 100K Horizontal type
RV...
q RV5: 500K (470K)
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13. TRANSISTORS
T...
T...
T...
T...
q T1: BC516 q T2: BC547C q T3: BC547C q T4: BC547C
14. 5W RESISTORS
R...
2mm
REMARK: You will have one 15 Ohm 5W resis-tors left over for later use. q R73: 15 q R74: 15 q R75: 15
15. PCB BLADE TERMINALS Mount them as straight AS possible against the PCB. A good solder joint is very important !
SK...
q SK1: 4 Ohm q SK2: GND q SK3: 8 Ohm q SK4: BLUE q SK5: RED q SK6: YELLOW q SK7: GRAY q SK8: GRAY q SK9: GREEN q SK10: GREEN q SK21: EARTH q SK22: EARTH
16. CINCH / RCA CONNECTOR Mount it as straight and square as possible against the PCB.
q SK11: CINFP/90
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13
17. PCB TERMINAL BLOCK some blocks slide into each other !
Mount these terminals with the wire inputs fac-ing the PCB edge: q SK12: 2 POLE (large)
q SK13: 3 POLE q SK14: 3 POLE q SK15: 3 POLE
q SK16: 3 POLE q SK17: 3 POLE SK18 to SK20 are not mounted
18. VALVE SOCKET
5 9
8
7
4
3
2
V...6 1
Mount them straight against the PCB q V5: B9A q V6: B9A
19. SWITCH
SW...
SIDE VIEW
IMPORTANT:Don't leave a gap betweenthe SWITCH and the PCB!
Mount it as square as possible against the PCB, Also solder the metal support. q SW1: 3P ON-ON-ON
20. CAPACITORS
C...
Check the voltage rating! q C1: 47nF (473, 0.047, 47000) q C2: 100pF (101) q C3: 330pF/400V (331) q C4: 330pF/400V (331) q C5: 68n/630V (683, 0.068) q C6: 68n/630V (683, 0.068) q C7: 68n/630V (683, 0.068) q C8: 68n/630V (683, 0.068) q C9: 68n/630V (683, 0.068) q C10: 68n/630V (683, 0.068) q C11: 680n/160V (684, 0.68) q C12: 680n/160V (684, 0.68) q C13: 680n/160V (684, 0.68)
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21. POWER RELAYS The various relays have footprints that corre-spond to the footprints on the PCB: q RY2: VR10V121C q RY3: VR10V121C
RY...
q RY4: VR5V122C
RY...
22. ELECTROLYTIC CAPACITOR (Check the polarity!)
C...
q C14: 4µ7 q C15: 100µF q C16: 470µF q C17: 470µF q C18: 470µF q C19: 470µF q C20: 47µF/100V q C21: 100µF/100V q C22: 1000µF q C23: 4700µF q C24: 47µF/350V q C25: 47µF/350V q C26: 100µF q C27: 1µF
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23. TRANSFORMER
TRAFO...
q TRAFO1: 12VAC
24. ELECTROLYTIC CAPACITOR (Check the polarity!) Generally these capacitors are of the snap-in type and cannot be mounted incorrectly.
C...
q C28: 100u/400V q C29: 220u/450V q C30: 220u/450V q C31: 220u/450V
25. INSERT THE IC (Check the position of the notch!)
IC...PIN 1
1
q IC1: LM3914
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26. 6.3V VALVE WIRING
q Wiring for the 4 valve sockets V1 to V4. Use the supplied brown wire. Twist them as shown in the illustration. The polarity is not important. For safety, it is advisable to check with an ohmmeter that the two 6.3V terminals are not shorted when the wiring is completed.
VIEWED FROM SOLDERSIDE
4
3
3
4
55
6
V4
1
8
2 1
7 8
f4
6.3VAC
f4f3 f3
6.3VACf2 f2
8
8
1
675
4
1
V1
2 3
3
5
4
f1 f1
41
8
8
675
12
V2
3
3
5
4
4
3
3
4
55
6
V3
8
1
2 1
7 8
27. SPECIAL LED (Check the polarity!) q LD2: 3mm bicolor: Carefully check the mounting of this LED:
1 2
LD...2
3
1 3
5mm
5mm
LD2 ONLY !
Check the complete assembly again for errors. Pay special attention to bad sol-der joints, shorts and wrongly inserted or misplaced components !
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ASSEMBLY INTO THE CABINET:
• Mount the caged nuts into the square holes as shown in the illustration. These nuts are later used to fasten the covers.
CLICK INTO HOLE
FIG 1 • Mount the chromed feet on the four cabinet corners, with an M4 bolt. To avoid scratches on other
equipment, you can stick a piece of felt on every foot (not supplied). • Mount a shakeproof washer and a 15mm threaded spacer on the front and back studding as shown
in the illustration.
15mm M3 SPACER
M3 LOCK WASHER
M3 BOLT
FIG 2 • Position the PCB in the cabinet, and fasten at the bottom with the supplied black button head hexa-
gon socket screws (Use the supplied Allen key). At the component side of the PCB, two M3 bolts fasten the PCB on the threaded spacers we mounted in the previous step.
• The mains inlet located at the back of the enclosure will be flush mounted as shown in the illustra-tion. Use two black button head hexagon socket screws , together with a shakeproof washer and an M3 nut.
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18
M3 LOCK WASHERM3 NUT
M3 BOLT
MAINS INLET
FIG 3
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19
• Make the connections as shown. Use the supplied blue wire for the neutral (N) terminal, and brown wire for the live (L) terminal.
FIG 4 The earth terminal is hooked up with green/yellow striped wire. The female push-on connector on the
green/yellow striped wire must be soldered for best results.
SOLDER
FIG 5 Connect the earth wire to SK21 on the PCB. Remove the fuse holder lid, and insert a miniature glass
fuse. For mains voltages of 100-125VAC, use the supplied 8A slow-blow fuse, while for 220-240VAC operation the 4A slow-blow fuse needs to be fitted. The spare fuse can also be stored in the fuse holder lid.
• Mounting of the speaker terminals: Mount them as shown in the diagram. Watch the position of the plastic insulator rings : one is flat, while the other has an elevated ring on the inside. There is no need to mount the solder lugs.
NUTNUT
INSULATOR RING
SPEAKER TERMINAL
INSULATOR RING
FIG 6 HINT : For easy fastening of the speaker terminals, immobilise the terminal by inserting a screwdriver in the wire hole, while fastening the nuts. IMPORTANT: The speaker terminals must be electrically isolated from the metal enclosure. For safety, check for infinite resistance between every terminal and the metal enclosure.
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20
• Use the supplied 1,5mm² wire to make the connections. For best results, solder the female push-on connector (fig 5). Apply enough heat, in order to make a good solder joint.
FIG 7 • Mounting of the toroid transformers : The output transformer marked ZD043 must be fitted according
to the illustration, on the right hand side of the cabinet. Watch the location of the wires.
OUTPUT TRANSFORMER
RUBBER WASHER
RUBBER WASHER
M8 BOLT
STEEL DISHED WASHER
FIG 8
! IMPORTANT: Do not trim the wires of the transformers, leave them at their original length. If there is more than one conductor in an insulating sleeve, you have to make sure they are soldered together and make a good electrical connection before they are connected to the terminal block.
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21
• Connect the double yellow wire with the connector marked ‘YELLOW’ SK6. Connect the red wire with the connector marked ‘RED’ SK5. Connect the blue wire with the connector marked ‘BLUE’ SK4. Use the supplied female push-on connectors (fig 5) and solder them onto the wires ! Connect the remaining wires to the terminal blocks SK16 and SK17. Pay attention to the colors.
FIG 9
• The supply transformer must be fitted according to the illustration, on the left hand side of the cabinet. Watch the location of the wires. The sturdy grey and green wires, which supply the 6,3V filament voltage, must sit on top.
STEEL DISHED WASHER
RUBBER WASHER
RUBBER WASHER
POWERTRANSFORMER
M8 BOLT
FIG 10
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22
• Connect the grey wires to the connectors marked SK7 and SK8 (GRAY). Connect the green wires to the connectors marked SK9 and SK10 (GREEN). Connect the remaining leads to the terminal blocks SK13, SK14 and SK15
FIG 11
FINAL INSPECTION :
! WARNING : THE PCB CARRIES VOLTAGES THAT EXCEED 400V ! THESE VOLTAGES CAN KILL ! MAKE SURE NO ONE CAN TOUCH ANY LIVE PARTS
Use suitable isolated measuring equipment • Put the mains switch into its fully OFF position (all the way down). • Connect the unit to a wall outlet, by means of the supplied cord. In some countries, the supplied plug
will not fit the local wall outlets. If this is the case, cut the supplied plug, and replace it with a suitable one (not included). Make sure to wire it correctly : blue : neutral (N), brown : live (L), yellow/green : earth. If the mains voltage is present, LD2 should light continuously red.
• Turn the unit on by pushing the mains switch to its fully upward position. LD2 should now blink for a while, this indicates the standby mode. After approximately one minute, LD2 should light continuously green, indicating ‘ON’, and a relay should click.
• Now check the following voltages with a multimeter: Measure about 6.3VAC between SK7-SK8 and SK9-SK10 Measure about 6.3VAC between pins 2 and 7 of the tube sockets V1 to V4 (illustration)
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23
FIG 12
! SWITCH OFF THE UNIT AND REMOVE THE MAINS PLUG. WAIT A COUPLE OF MINUTES UNTIL THE DANGEROUS HIGH VOLTAGE HAS DISSAPEARED
(UNTIL HIGH VOLTAGE INDICATOR LD13 TURNS OFF) • Put the small valves in place:
V6 type ECC82 or 12AU7, CV491, 6189, 8136 V5 type ECC81 or 12AT7, CV455, 6201, 8162
• Reconnect the mains plug, and switch the unit ON again (switch in full upward position) Wait until LD2 lights green continuously.
• Now check all indicated voltages on the PCB with respect to ground. A suitable ground for these measurements is J4, at the centre of the PCB. The point indicated VB2 should carry approx. 3.5VDC.
REMARK : All voltages may vary a bit, due to mains voltage fluctuations. At this stage, you cannot measure the 3.6VDC voltages yet.
CALIBRATION Switch off the unit, disconnect the mains plug and wait until the high voltage has disappeared. Turn the trim potentiometers RV1 to RV4 fully counter clockwise with a small screwdriver. Put the four KT88 or equal tubes in their sockets. Watch the position of the notch. IMPORTANT : The remaining 15 Ohm / 5W resistor must be hooked up between the centre and the 8 ohm speaker terminal at the back of the unit. A valve amplifier must never be operated without a suitable load at the speaker terminals. Make sure there is a good electrical connection between the terminals and the resistor. Bias current calibration This calibration does not require a measuring instrument, as the bias level of each tube can be displayed on the LED scale. The four dipswitches allow valve selection, while each valve has its own trim potentiometer. RV1 controls V1, RV2 controls V2 etc… IMPORTANT : This calibration determines the bias current trough the expensive output valves. Therefore, it requires your absolute attention. Perform the calibration in the correct order. No signal may be present at the input of the amplifier, during the calibration. Flip all four DIP switches (SW2) to their OFF position Every switch enables the bias readout of one valve, so do not switch on more than one at a time, or the readout will be incorrect. Reconnect the mains plug, and switch the unit ON again (switch in full upward position) Wait until LD2 lights green continuously.
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24
Put the first switch in the ON position (use a pen or a small screwdriver) Gently turn RV1 clockwise until the second or third LED lights (LD4 or LD5) Switch off the first switch. Switch on the second switch Gently turn RV2 clockwise until the second or third LED lights (LD4 or LD5) Perform the same operation with RV3 and RV4 Wait for about 10 minutes, before continuing the rest of the calibration. Repeat the calibration of RV1 to RV4, but this time the trim potentiometers must be turned clockwise until one or two green LEDs light. When this operation is finished, check the 3.6V DC voltages at R65, R66, R70 and R71. Again, use J4 as ground reference.
FINALLY ! It is time to listen to your amplifier ! Switch off the unit completely before connecting or disconnecting any cables. Connect a 4 or 8 ohm speaker to the correct terminals at the back of the unit. Speakers with imped-ances between 4 and 8 ohms can be connected to the 8 ohm terminal. The common negative speaker terminal is located in between the 4 and 8 ohm positive terminals. Hook up an audio source to the RCA connector at the back. Make sure the volume control of the source is set to minimum before the unit is turned on. The ‘SENSITIVITY’ trimmer located at the centre of the board allows you to trim the amplifiers input sensitivity, so two units put out exactly the same level, which improves the stereo image. Normally, this trimmer should be set fully clockwise. If necessary, feed a mono signal to both amplifiers, and trim both sensitivity trimmers, until the sound comes from the exact centre between both loudspeakers. • Valve amplifiers run hot ! Operate them in a well ventilated area ! Do not put them in a closed
rack, stack or cabinet. • It is a good habit to check the bias current on a regular basis, especially when the valves are
new. • They need to run-in for a while, during which the bias level may shift. • For short intervals between listening sessions, put the amplifier in stand-by mode (mains
switch in middle position).
FINISHING THE ENCLOSURE ASSEMBLY • Check if none of the components on the PCB will touch the chromed cover plates, when they are put
in place. • Turn the unit, so it rests on its left or right hand side. • This allows you to fasten the bottom lid, by means of the supplied black button head hexagon socket
screws. • Click the caged nuts into their holes on the chromed vertical plate (Be careful not to scratch the sur-
face). • Mount the chromed cover plate on the chromed vertical plate with two silver button head hexagon
socket screws. Tighten by hand. • Position this assembly onto the enclosure, and put the silver button head hexagon socket screws in
place. Tighten them by hand. Connect the chromed vertical plate to SK22 (chassis earth) with a
__________________________________________________________________________________________________________________________________________________________
25
length of yellow/green striped wire and 2 female push-on terminals. Make sure you solder both ter-minals. (See fig 5)
• Mount the top cover on the enclosure (Make sure the earth lead of the vertical plate is bent down, so it does not get squeezed between the lid and the enclosure). Use the supplied black button head hexagon socket screws.
• Mount the front panel. Use the supplied right angle mounting brackets, together with the shakeproof washers and the M3 and M4 bolts. Take care of the correct position of the mains switch and LD2.
• Make sure everything fits well, and tighten all screws.
! THIS AMPLIFIER RUNS HOT, OPERATE IT OUT OF THE REACH OF CHILDREN !
CHECK YOUR MAINS VOLTAGE MAKE SURE IT MATCHES THE SELECTED VOLTAGE
REMOVE THE MAINS PLUG AND WAIT AT LEAST 15 MINUTES BEFORE REMOVING THE COVERS
SOME PARTS MAY CARRY DANGEROUS VOLTAGES, EVEN WHEN THE UNIT IS UNPLUGGED
TROUBLESHOOTING Hum coming from the speakers : To make sure the amplifier is the source of hum, short the RCA input (by means of a spare male RCA plug, which you short internally), and disconnect the earth connector SK21. As a reference, listen at about 1m (3 ft) from the speaker, there should be an negligible amount of hum present. If there’s still a reasonable amount of hum present, check the bias current of every valve. Also check the electrical connection between the PCB ground and the enclosure, which is done trough the bolt next to R1. A defective valve can also be a source of hum. If hum is only present, when the amplifier is hooked up to an audio system, then a hum-loop could be the cause. To verify if this is the case, disconnect SK21 Use good quality, as short as possible, interconnecting leads. For best results, choose equal lengths for both left and right amplifier. If the high tension is not present, check the transformer wiring and the mains fuse, located at the back of the unit, below the mains inlet. An intermitted crackling sound coming from the speakers could point to a defective resistor R62. Replace it with the same value and power rating. A continuous buzzing sound coming from the speakers or a crackling sound during bass peaks could be caused by oscillation of the amplifier. In this case, try raising the value or R46 (e.g. 2K7 or even 3K3). This will also slightly increase the input sensitivity. If your speaker system includes a piezo driver, make sure it has a 10 ohm/ 1W resistor in series with the unit. THE MODIFICATIONS MENTIONED ABOVE ARE ONLY TO BE PERFORMED WHEN REPEATED INSPECTION OF THE CIRCUIT BOARD, SOLDER JOINTS AND WIRING DID NOT POINT TO ANY OBVIOUS FAULTS OR MISTAKES OF ANY KIND.
_______________________________________________________________________________________________________________________________________________________
26
REMARK: Valves are very sensitive to mechanical shocks. Therefore, we recommend not to move the unit when the valves are hot. Always let them cool down for a while. Avoid sudden temperature changes, e.g. when the unit is moved from a cold room to a heated room. Always leave it idle for a while, so it can adapt to the new environmental condition. A valve that breaks down starts glowing cherry red. Turn off the unit immediately. Usually, the 47 ohm/1W cathode resistor of the defective valve will also need replacement. If you have the impression that for some reason, the unit still does not operate as it should, you can send it to our technical dept. for inspection. Send the PCB only, not the enclosure or the transformers. Use the original box. Include a detailed description of the fault. Check www.velleman-kit.com for your nearest Velleman dealer. Velleman wishes you many hours of listening pleasure !
__________________________________________________________________________________________________________________________________________________________
27
DIAGRAMS
_______________________________________________________________________________________________________________________________________________________
28
PCB
R37
DANGERHIGH VOLTAGE
R11
R62
R63
f2
3
D23
D22
D21
LD1
R24
R23
SW1
1LD2
R22
D24
5
4
3
R65
R70
LD11
VELLEMAN P8010'1 / P8011'1
RE
D
2
1 3
R25
R52
R51R26
R28
R27
R29
R21
LD6LD4LD3
YE
LL0W
LD5 LD9LD7 LD8
GR
EE
N
GR
EE
N
LD10
RE
D
RE
D
R69
V2
R68
V1
8
1
C3
R13
R64
V5
1 9
R34
R54R53
R71
C26
D25 D
26
LD12
RE
D
R33
IC1
R32
1
R35
R36
V3
V6
R66
R46 1
R20
R50
R19
9
SK12
L
D18
D17D19
D20
C18
AC POWER
N
R45
D12
D11B
LAC
K
BR
OW
N
YE
LLO
W
YE
LLO
W
RY3
C19
ZD2T4
R74 R75
R8
TRAFO1
12VA
C
245V
RY4
D7
D8
R44
f1
C29
6.3VACGRAY GRAY
C30
C21
C20
R9
BLU
ESK15
RY2
RE
D
D30
6.3VAC
D29
C31
R48
GREEN
D27
D28D10
D9
J2
R56
R57
C28
R49
J3
R58
J1
R42
R6
ZD1D1
R4R5
D6
D3
T2
R55
D5
C15
C16
C14T1
D4T3
D2
C17
R3
R1
R2
SK11
R7C2
C1
PCB CONNECTED TO MAINS
R72
HIGH VOLTAGE
R38
R39
!
R67
BLACK
GREEN
VIOLET
V4
SK16
ORANGE
BROWN
BLACK
J4
J5 J6
J9
J7
J8
J10
J12
J19
J20
J21
J11
R30
C9
C10
C7 C8
230V
120V
100V
0
DC
BA
VO
LTA
GE
S
ELE
CT
ION
1
A: 100VACB: 120VACC: 230VACD: 245VAC R
ED
OR
AN
GE
VIO
LET
D C B A
SELECTION2
VOLTAGE
C5R12
f4f3
J14J13
R73 R59
R60
R61
LD13
A: 100VACB: 120VACC: 230VACD: 245VAC
C24 C25
R41
YELLOWREDBLUE8 OhmGND4 Ohm
C4
R15
C6RV5
R17
R18
R47
R16
R14
C11
C12
C13
C22
R10D
14D
13 D15
D16
C23
R40
R43
f5 f6
f7 f8GREEN
SK20
31
RV1 RV2 RV3 RV4
SK19
2
1
3
4
6
5
J15 J16 J17
J18
SK1 SK2 SK3 SK4 SK5 SK6
FROM OUTPUT TRANSFORMERTO LOUDSPEAKER TERMINALS
SK7 SK8
SK9SK10
SK13
R31
SENSITIVITY
FROM POWER TRANSFORMER
FROM OUTPUT TRANSFORMER
TO POWER ON LED
TO POWER ON SWITCH
SW2
1
RY11
HIGH VOLTAGE INDICATOR
K8011: 0.4VDC
12VDC
-50VDC
390VDC395VDC
155VDC
190VDC
300VDC
80VDC
75VDC
220VDC
100VDC
VB2
VB1
K8010: 3.6VDC
K8011: 0.4VDCK8010: 3.6VDC
K8011: 0.4VDCK8010: 3.6VDC
K8011: 0.4VDCK8010: 3.6VDC
BIAS CURRENT ADJUST
VB1 K8010: 1.6VDC K8011: 0.2VDC
VB2 K8010: 3.5VDC K8011: 0.45VDC
SK14
SK17
2x
2x
2x
2x
SK18
F1
100-120V/8A Slow230-245V/4A Slow
3
4
5 8
1
3
4
58
1
5
4
3
1
8
1
2
3 6
5
4
SK22
SK21
2x J22
C27
YE
LL0W
YE
LL0W
YE
LL0W
456 3
21
2
__________________________________________________________________________________________________________________________________________________________
29
DIAGRAM POWER SUPPLY SECTION
D19
1N40
07
12V
AC
/2.5
VA
TRA
FO1
N8A S
LOW
@ 1
00/1
20V
AC
F1
MA
INS
L
7
1
0
5 311
5V
245V
94A
SLO
W @
230
/245
VA
C
LD4
RE
D18
4
R33
4.7
D26
1N41
48R
3412
K2
V-
1LD
3
RE
D
2.5
300V
DC+V
1
+V2
C30
100u
/400
V
R4
2K2
BC
516
T1
R56
10K
/1W
D11
1N40
07
D12
1N40
07BC
547C
T3
R3
2K2
LD2 L-
93W
EG
W RY
3
VR
10V
121C
3V9
ZD2
R75
15/5
W
C19
470u
RY
4V
R5V
122C
R74
15/5
W
D7
1N41
48
R8
1K
BC
547C
T4
D8
1N41
48
50V
/0.1
A
0
BLA
CK
BLU
E
120V
GR
EE
Nf3 f2 f1
6.3V
/7A
GR
AY
GR
AY
f4G
RE
EN
6.3V
/7A
YE
LLO
W
PO
WE
R T
RA
NS
FO
RM
ER
VIO
LET
245V
RE
D29
0
0
290V
/0.7
A
YE
LLO
W
RE
D
D22
1N40
07
D23
1N40
07
LD1
L-56
BH
D
GR
EE
N
D24
1N41
48
12V
DC C
1847
0uR
1
470
D18
1N40
07
D17
1N40
07
D20
1N40
07
R23 1K
2
RE
D
R24
560
D21
1N40
07
ON
SW
1
OF
F
ST
B
C16
470u
C15
100u
R22
1K5
R2
220K+V
ZD
1
3V9
C144u
7
R5
220K
D1
1N41
48
D5
1N40
07
RY
2
VR
10V
121C
C27
220u
/450
V
R51
330K
/0.5
W
R53
330K
/0.5
W
R54
330K
/0.5
W
R52
330K
/0.5
W-VR
9
22K
C20
47u/
100V
D10
1N40
07 BIA
S4
BIA
S2
BIA
S3
BIA
S1
D30
1N54
08
D29
1N54
08D
271N
5408
D28
1N54
08
D9 1N
4007
R57
10K
/1W
-50V
DC
390V
DC C26
100u
3
R32
1K5
2 431
D25
1N41
48
SW
2
6IC
1
7 8A
DJ
RLO
RE
F
1716
LM39
14
1514
9 5
RH
I
SIG
MO
DE
131210 11C29
220u
/450
V
C28
220u
/450
V
R58
12K
/1W
+V
V+
D3
1N40
07
D2
1N41
48 D4
1N41
48
BC
547C
T2
R55
270/
1W
D6
1N41
48
C17
470u
SI
LD12
RE
D
3.75
LD8
GR
EE
N
LD7
GR
EE
N
LD6
RE
D
LD5
RE
D
3.25
3 2.75
3.5
LD9
RE
D
LD10
RE
D
LD11
RE
D
4.25
44.75
4.5
C21
100u
/100
V
R59
39K
/1W
R60
39K
/1W
R61
39K
/1W
LD13
RE
D
R31
10M
100V24
230V
R73
15/5
W
BR
OW
N
100VO
RA
NG
E
230V
R30
3K9
D C B A
AD
B
C
395V
DC
NC
_______________________________________________________________________________________________________________________________________________________
30
DIAGRAM AMPLIFIER SECTION
-50V
DC R
2622
0K
R21
10K
R29
10K
R28
220K R38
220K
R20
10K
R36
10K
C1
47n
R6
100K
C2
100p
C7
68n/
630V
R13
1M
GR
AY
GR
AY
6.3V
AC
R19 3K
9
R43
220/
.5W
6.3V
AC
GR
EE
N
R40
220/
.5W
f4
GN
D
GR
EE
Nf3
RY
1V
R05
R12
1A
13
62S
I
78
114
R44
220/
.5W
R39
100K
R37
100K
R45
220/
.5W f2
C4
330p
R46
2K2/
.5W
R15 1K
f1
8
C8
68n/
630V
R64
47K
/1W
RV
3
100K
-V-V
RV
410
0K
f1f2
75V
DC
59
4
3
R35
220K
EC
C82
C25
47u/
350V
V6
INP
UT
R7
1KIN
190V
DC
RV
210
0KR
V1
100K
300V
DC
R62
100K
/1W
110V
DCR11 3K
9
R50
100K
/.5W
V5
7
EC
C81
R41
100K
/.5W
C3
330p
/400
V+V2
R63
47K
/1W
C5
68n/
630V
2
61
C10
68n/
630V
220V
DCR27
100K
C9
68n/
630V
R25
100K
-V
BLA
CK
GR
EE
N
VIO
LET
3.6V
DC
BIA
S3
R67
180/
1W
45
3
1
f3
V4
KT
882
f4R
6647
/1W
8
7
R72
180/
1W3
453.
6VD
C
1
f4f3
KT
88V
3
27
R71
47/1
W BIA
S4
8G
ND
GN
DLS
RE
D
OR
AN
GE
BR
OW
N
BLA
CK
3.6V
DC
BIA
S1
8
f12
f2
R65
47/1
W
7
3
54
R68
180/
1WK
T88 V1 1
8B
IAS
2
f2f12
7R
7047
/1W
390V
DC
+V1
V2
KT
88
54
R69
180/
1W3
3.6V
DC
1
4 O
hm
8 O
hmB
LUE
YE
LLO
W
TR
AN
SF
O3
ZD
043
6
2 38
59
4R
1868
0
R47
27K
/.5W
R16
47K
R17
470K
RV
550
0K
R14
1M
C6
68n/
630V
C13
680n
/160
V
D14
1N40
07
D13 1N
4007
D16
1N40
07
D15
1N40
07
R10
3.3/
.5W
C23
4700
u
C22
1000
uR
4922
0/.5
WR
4822
0/.5
W
R12
1K5
1
7
R42
47K
/.5W
C24
47u/
350V
155V
DC
C12
680n
/160
V
C11
680n
/160
V
80V
DC