Product model: k8, k10, k12, ksub document #: td-000487-00 initial release: february 2015 revised release: revision: a service manual qsc audio products, llc costa mesa, california, usa www.Qsc.Com k series.
2 qsc audio products, llc.
3 td-000487-00 k series service manual table of contents 1. Introduction ..................................................................................................................................................................................5 1.1 restriction of hazardous substances directi...
4 qsc audio products, llc qsc audio products, llc technical services group 1665 macarthur blvd. Costa mesa ca 92626 usa k series powered loudspeakers service manual copyright © 2014 by qsc audio products, llc. All rights reserved. Qsc and the qsc logo are trademarks of qsc audio products, llc in the...
5 td-000487-00 k series service manual 1. Introduction 1.1 restriction of hazardous substances directive (rohs) qsc k series loudspeaker products are manufactured to conform to the european union’s rohs directive, which reduces the amount of hazardous substances allowed in products for sale within i...
6 qsc audio products, llc 1.5 the well-equipped service bench hardware and software • personal computer (pc) running windows® 7 or newer operating system with available usb2.0 or newer port • total phase aardvark i2c host adapter (for programming) • digital multimeter (dmm) • oscilloscope • audio si...
7 td-000487-00 k series service manual 2. Product specification and images 1 for comparison purposes and in accordance with common industry practice, maximum peak spl specifications are theoretical calculations based upon transducer sensitivity and peak available amplifier power. 2 independent of li...
8 qsc audio products, llc 3. Firmware very infrequent dsp firmware updates have occured to k series loudspeakers during production. While firmware can be up- dated from the programming header using an aardvark i2c programmer, it’s not recommended and almost never needed to perform updates on the dsp...
9 td-000487-00 k series service manual 3.2 firmware programming instructions warning if the instructions are not followed carefully, there is a possibility that the amplifier inside the loudspeaker will stop work- ing. Because house of k loudspeakers use dsp technology, all audio signals are routed ...
10 qsc audio products, llc programming a house of k loudspeaker in order to program the loudspeaker with new firmware you must open the correct k programmer utility that works with your windows operating system. To find out what type of operating system you have, go to the system icon under control ...
11 td-000487-00 k series service manual 4. Operational description 4.1 series description converging our expertise in loudspeaker, amplifier, and digital signal processing technologies, qsc has created a spectrum of active loudspeakers designed with one common goal - accurate acoustical performance ...
12 qsc audio products, llc 4.3 ksub the ksub is a dual-12” bandpass design, constructed of premium birch. The wood enclosure is texture painted with a water-based acrylic paint color ral 9011. A single large port sits behind the front panel. The two transducers are mounted vertically on a piece a wo...
13 td-000487-00 k series service manual class d amplifier each of the bop amplifiers is a type of class d amplifier called ‘self-oscillating’, as opposed to a class d amplifier that requires a clock to switch. Self-oscillating class d amplifiers create a pwm signal solely by using feedback; although...
14 qsc audio products, llc when in off the front led is always off. By setting this switch to limit, the led is normally glows dimly but becomes bright when the dsp is limiting the amplifiers, giving some feedback to the loudspeaker operation from the front of the system. On 2-way systems, hf and lf...
15 td-000487-00 k series service manual 5. Top-box disassembly instructions to reduce the number of pages in this service manual, all top-box k-series loudspeakers have been combined into one section. The k10 powered loudspeaker is used as an example for these generic disassembly and repair procedur...
16 qsc audio products, llc 5.2 front grille removal 1. Remove the four screws that attach the front grille to the baffle. 2. Using a putty or butter knife, pry the grille outward and remove it. If the grille is stuck, gently pry along the sides in multiple locations until the grille becomes loose en...
17 td-000487-00 k series service manual 4. Set the baffle assembly face down on a work surface. 5. Gently place the main enclosure assembly on top of the baffle assembly, paying close attention to the orientation. If possible, connect the molex connector to the bop. Note: connecting the wiring harne...
18 qsc audio products, llc 5.5 low frequency transducer the lf transducer can be removed and reinstalled without removing the baffle. Removal 1. Follow the removal instructions in “5.2 front grille” on page 16. 2. Place the speaker on it’s back (or in monitor wedge posi- tion) so the lf transducer d...
19 td-000487-00 k series service manual rubber feet removal and installation notes • rubber feet are secured to the enclosure with machine screws (on the exterior of the enclosure) and nuts (on the interi- or of the enclosure). • access to the interior of the speaker assembly is required to remove a...
20 qsc audio products, llc 6. Ksub disassembly and repair procedures 6.1 bucket of power removal 1. Remove the 10 screws along the outer perimeter of the bop. 2. Partially remove the amplifier module out of the cabinet as seen in figure 6.1. Note: occasionally the module will be stuck to the cabinet...
21 td-000487-00 k series service manual 4. Partially lift the transducer out of the cabinet. 5. Disconnect the fastons from the transducer’s positive and negative terminals. 6. Lift and rotate the transducer out of the rear bop cutout hole. It will barely fit. Installation 1. Place the cabinet assem...
22 qsc audio products, llc threaded pole mount removal and installation notes • threaded t-nuts are installed in the cabinet for the threaded pole mount to secure to • remove the four machine screws and lift the threaded pole mount out of the cabinet. • verify that any new threaded pole mount has ga...
23 td-000487-00 k series service manual 7. Bop disassembly and repair procedures 7.1 faceplate removal 1. Remove the 10 screws around the perimeter of the bop. These screws secure the faceplate to the main bucket. 2. Partially lift the faceplate assembly out to gain access to the ribbon cable wire t...
24 qsc audio products, llc 7.2 psu/amplifier board removal 1. Remove the faceplate assembly to gain access to the psu/amplifier pcb. Follow removal instructions in “7.1 faceplate” on page 23. 2. Remove all screws that secure the psu/amplifier pcb to the bucket chassis. 3. Remove the rectangular plat...
25 td-000487-00 k series service manual 7.3 input/dsp board removal 1. Remove the faceplate assembly for easy access to the input/dsp pcb. Follow removal instructions in “7.1 faceplate” on page 23. 2. Remove all screws securing the xlr and rca connectors to the faceplate. 3. Remove all screws securi...
26 qsc audio products, llc 8. Testing 8.1 requirements hardware • digital multimeter (dmm) • oscilloscope • audio sine wave generator • spl meter • soldering iron • k family test adapter • distortion analyzer (audio precision recommended) • class d output filter for distortion analyzer 8.2 bucket of...
27 td-000487-00 k series service manual step 1: power up sequence this test is meant to verify the proper power up sequence. If the bop’s standby or power leds continually blink during power up, there may be an issue with the amplifier’s power supply or output section. 5. Disconnect all xlr, 1/4”, o...
28 qsc audio products, llc 5. Adjust the mode switch to “deep”. Verify a slight increase in output voltage on the lf channel. 6. On k8/k10/k12 models, adjust the mode switch to “ext sub”. Verify a decrease in output voltage on the lf channel. 7. Apply a 500 mvrms, 6 khz sine wave signal. Using a dmm...
29 td-000487-00 k series service manual 5. Apply an 8 ohm load to channel 1 only. Follow step 4 again, except test for power this time. A power graph is provided below. 6. Disconnect channel 1’s load. Apply an 8 ohm load to channel 2. Follow step 4 again, except test for power this time. 7. Test com...
30 qsc audio products, llc step 2: measuring sensitivity (sound pressure level) 1. Set the frequency of the sine wave generator to 100 hz. 2. Hold the spl meter 1 meter in front of the loudspeaker, directly on axis with its centerline. Measure and take note of the sound pressure. 3. Gradually adjust...
31 td-000487-00 k series service manual 9. Troubleshooting guide 9.1 general tips and tricks testing the line filter components for open circuit in two measurements the components in the line filter (l11, l12, l13, r140, f1) and the bridge rectifier (br1) can all be checked in two measurements taken...
32 qsc audio products, llc amplifier section tips • a quick check of the amplifier feedback path can be done by measuring resistance from the switching node (q2 source and q3 drain, for example) back to the comparator inverting input; it should be about 11.3kΩ. • you may check for amp switching by l...
33 td-000487-00 k series service manual 9.2 line filter - broken components (bop) pcb flex/vibration issues seem to cause more broken-component failures in the k12 than in the other k series models. Most common are component leads that break between the base of the component and the pcb. Most vulner...
34 qsc audio products, llc 9.3 broken capacitor c45 (bop) pcb flex and vibration issues can also cause the leads on a large electrolytic capacitor, c45, to break. While the amplifier can idle perfectly fine and play music at low power levels with the capacitor broken, the bop will power cycle under ...
35 td-000487-00 k series service manual 9.5 amplifier section, mosfet failure (bop) while not a common failure due to the dsp limiting and protecting the amplifier section from being over-driven, the mos- fets in the amplifier section can fail in certain conditions. For example, if the lf or hf tran...
36 qsc audio products, llc 9.6 power supply, mosfet failure (bop) the most common psu failure is a failed q13 or q14 mosfet. The failure can cascade down further to gate-drive compo- nents. In some cases, the psu will not start due to a pwm controller u15 failure. Symptoms: • no power • the psu atte...
37 td-000487-00 k series service manual 9.7 fan behavior there may not be a problem with the fan itself due to firmware changes. Please see “3.1 firmware revisions and program numbers” on page 8. On newer models the fan does not turn on until the bop reaches a high temperature condition. On older mo...
38 qsc audio products, llc • if the faston connector was disconnected from the transducer terminal, it’s recommended to crimp a brand new faston connector. For the lf green and green/black wire, use a 0.205” or 5.21 mm female, 14–16 awg, insulated straight faston. For the hf yellow and yellow/black ...
39 td-000487-00 k series service manual 9.10 transducer issues there are many different types of failures for transducers in k series loudspeak- ers. The most common issues found are the following: spider becomes unglued from the frame, cone tears near the surround, burnt voice coil (because of a bo...
40 qsc audio products, llc 9.11 broken baffle this applies to top-box models only. Though not a common failure, the mounting point where the baffle is secured to the main enclosure can break the abs plastic mounts. Symptoms: • very distorted sound • air leaking around the edges of the baffle failure...
41 td-000487-00 k series service manual 10. Service updates 10.1 inductor reinforcement, l13 please read qsc service bulletin kse0001 for more information regarding the inductor reinforcement. New k-series models have changed l13 to a 6-pin inductor for added stability on the board. Summary within t...
42 qsc audio products, llc sh3: b1 sh3: b2 & c3 2-way 2-way 2-way mic led sub: 0r 2-way 2-way input stage, signal presence, gain, input summing f3 = 72khz inv 2-way line 2-way 2-way 2-way 2-way mic 2-way inv 2-way 2-way sub: 0r mic 2-way sub line sub -inf at bottom +10db at top 2-way 2-way 2-way 2-w...
43 td-000487-00 k series service manual sh5: d1 sh2: a3 sh2: a3 = ((1.13k/2.21k) x 3.3) + 3.3 = 4.99v sh2: c1 hf eq/polarity sub: polarity 21.75db gain overlap sub: 0r top: vocal boost limit 01 deep 01 3rd order, f3 = 30khz tall euro header: 2p2t (sw-111) deep 10 phoenix contact 1771965 a-mstbva 2,5...
44 qsc audio products, llc sh5: c1 lm19: temp - vout 25c - 1.570v 45c - 1.327v lo = standby hi = led on temp ch1 +15v agnd -15v pgnd wire trap: molex 52004-1010 ch2 amp-sd front led hf amp in 2-way 2-way ch2 out- prep r159 off board 2-way hf pad 2-way 2-way ch1 out+ ch1 out- sync cap t94-2 60t 21awg...
45 td-000487-00 k series service manual sh4: b3 & c4 sh4: c4 & sh3: b4 sh4: b2 & c2 t106-26b 79t 18awg on about 24vac oc = 26.1a = 0.75v +85v -85v off in 30ms +7v total operating current = 32ma gate drive current: (102nc + 40nc) * 200k = 29ma ucc2893 run current = 3ma max ac detector 0.5*960uf*375v^...
46 qsc audio products, llc pc-003311-00 k-series board - top side - rev. D date: july 22th, 2010 rev.: b sheet 1 of 3 blue brown 100 - 260vac ms-10.250-fu ac line filter xf-000376-00 xf-000376-00 xf-000391-00 pfc-improving inductor re-000300-nr main dc voltage rectifier & filter capacitors 140vdc@10...
47 td-000487-00 k series service manual pc-003311-00 k-series board - bottom side - rev. D date: july 22th, 2011 rev.: b sheet 2 of 3 ch1 switching q4: positive; q5 negative ch2 switching q2: positive; q3 negative temp-to-volt sensor u9: pin1 = v+, pin2 = vo; pin3 = gnd rectifier diodes d33: positiv...
48 qsc audio products, llc 12. Component identification 12.1 top-box assembly components part number and description quantity ch-000850-01 handle,,blk,speakers, 2 pa-00024 x -01 grille assy, with logo,blk,,, for k8, use pa-000244-01 for k10, use pa-000245-01 for k12, use pa-000246-01 1 sb-00015 x -t...
49 td-000487-00 k series service manual part number and description quantity sp-000182-00 woofer,,,12”,paper,ferrite,k12/kw122 k12 only 1 sp-000184-00 compression driver,,,1.75”,petp,neodymium,k/ kw series same hf transducer for k8/k10/k12 1 wp-00331 x -00 pcb assy,universal supply includes psu/amp ...
50 qsc audio products, llc part number and description quantity wp-003314-00 pcb assy,,ksub,,universal supply 1 wp-003310-00 chassis assy,main,ksub,,universal supply 1 12.3 bop components part number and description quantity co-000436-00 plug,euro,3 pos,male,grn 1 co-000386-00 jack,iec,3 pos,female,...
51 td-000487-00 k series service manual part number and description quantity re-000300-nr ntc,2.5 ohms,8 amps,,,inrush limit 90j 1 sw-000088-gp rocker power switch 1 wp-000367-00 fan assy,,bop-2ch,, 1 xf-000376-00 inductor,common mode,toroid,4m- h,bop,,50/60hz 6.3a 2.
52 qsc audio products, llc 13. Exploded view drawings 13.1 k8 exploded view item # part number description qty 1 ch-001153-01 grille, w/no logo, blk, k8, 1.0mm (assembly available) 1 2 ch-000850-01 handle, , blk, speakers, 1 3 ch-001142-01 threaded insert, m5, steel, blk oxide, , 4 4 ch-000870-00 pl...
53 td-000487-00 k series service manual 13.2 k10 exploded view item # part number description qty 1 ch-001152-01 grille, w/no logo, blk, k10, 1.0mm (assembly available) 1 2 ch-000850-01 handle, , blk, speakers, 2 3 ch-001142-01 threaded insert, m5, steel, blk oxide, , 2 4 ch-000870-00 plate, handle ...
Qsc audio products, llc 13.3 k12 exploded view wp-003304-01.Drw as stored from pdmlink via productview march 26, 2012 11:40am drawing release level: production user name: denise delarm.
55 td-000487-00 k series service manual item # part number description qty 1 ch-001151-01 grille, w/no logo, blk, k12, 1.0mm (assembly available) 1 2 ch-000850-01 handle, , blk, speakers, 2 3 ch-001142-01 threaded insert, m5, steel, blk oxide, , 2 4 ch-000870-00 plate, handle backing, , k-series, 4 ...
Qsc audio products, llc 13.4 ksub exploded view item # part number description qty 1 ch-000850-01 handle, , blk, speakers, 2 2 ch-000870-00 plate, handle backing, , k-series, 4 3 ch-000889-00 pole mount, threaded, m20, ksub, 1 4 ms-000074-gp acoustic wool, 200x600x30, , , 4 5 ms-000259-gp caster, sw...
57 td-000487-00 k series service manual 14. Replacement parts 14.1 fg-003300-01 (120v) or fg-003320-01 (230v), k8 part number description qty. Reference comment co-000436-00 plug, euro, 3 pos, male, grn 1 lb-000747-00 label, grille tag, , k8, 1 pm-000270-gp polybag manual, 240x360x0.05, , , , 1 pm-0...
58 qsc audio products, llc part number description qty. Reference comment pl-000857-01 gasket, belt, baffle/bucket, k8, , blk, 1 qd-000312-gp led, 3mm, blue sp, slr343bb t 225419 rohm, , , 1 sb-000073-01 bucket, , k8, , blk, 1 not available for purchase sb-000076-01 baffle, , k8, , blk, 1 use baffle...
59 td-000487-00 k series service manual part number description qty. Reference comment ms-000480-00 felt pad, pole mount, k-series, , 6 ms-000496-00 spacer, led, , , 1 ms-000543-00 gasket, pe600mm x 10mm x 1.0mm thk, , , 2 ms-000593-00 strip gasket, , 5x500, eva, , 0 ms-000604-00 gasket, strip, k-se...
60 qsc audio products, llc part number description qty. Reference comment pm-000447-00 polybag, , , k10/k12, 870x845x.05mm, 1 td-000276-00 hookup drawings, k-series, 1 td-000337-00 warning sheet, pwrd amp/pwrd loudspeaker, 1 wc-000361-gp power cord, 120v, iec v-lock, 18awg, 3m, , nema 5-15, , 1 wc-0...
61 td-000487-00 k series service manual part number description qty. Reference comment sc-000303-00 scr, phh, pnh, tpg, plastite, , , , m4, 12 l, stl, blk, zinc cr3, 8 sc-000304-00 scr, phh, pnh, tpg, plastite, , , , m4, 18 l, stl, blk, zinc cr3, 8 sc-000305-00 scr, phh, pnh, tpg, plastite, , , , m5...
62 qsc audio products, llc part number description qty. Reference comment ca-110001-10 100pf, 5 pcnt, 500v, mica, dipped, 2 c126, c127 ca-110002-30 100pf, 5 pcnt, 50v, ceramic npo, 0805, 4 c75, c76, c77, c78 ca-112001-30 120pf, 5 pcnt, 200v, ceramic np0, 0805, 12 c1, c19, c20, c22, c28, c29, c30, c3...
63 td-000487-00 k series service manual part number description qty. Reference comment ic-000413-30 driver, mosfet half bridge, irs20957, smt, 2 u5, u7 ic-000420-30 voltage regulator, +3.3v, ncp1117st33, sot223, 1 u8 ic-000425-30 opto coupler, transistor output, moc205r2v-m, smt, vde approval 1 u3 i...
64 qsc audio products, llc part number description qty. Reference comment re-110002-30 1.00k, 1 pcnt, 1/10w, thick film, 0805, 100v 9 r158, r167, r18, r20, r21, r24, r29, r7, r87 re-111301-30 1.13k, 1 pcnt, 1/10w, thick film, 0805, 100v 12 r106, r107, r163, r164, r171, r177, r23, r25, r30, r31, r73,...
65 td-000487-00 k series service manual part number description qty. Reference comment pm-000444-00 insert, top, , ksub, , 120v 1 pm-000445-00 insert, bottom, , ksub, , 120v 1 pm-000449-00 polybag, , , ksub, 1120x500x.04mm, 1 pm-000491-00 insert, , , ksub, , 1 pm-000516-00 bag, , polypropylene, k-se...
66 qsc audio products, llc part number description qty. Reference comment ch-000885-00 panel, input, bop-2ch, ksub, 1 ch-001025-00 shield, line filter, short, kw series, 1 co-000386-00 jack, iec, 3 pos, female, locking 1 lb-001062-00 label, rcm logo, regulatory certification mark, , (australia & new...
67 td-000487-00 k series service manual part number description qty. Reference comment ca-410027-10 0.1uf, 5 pcnt, 100v, film, box style, 2 c109, c119 ca-468005-10 0.68uf, 5 pcnt, 100v, film, box, 3 c125, c34, c35 ca-468006-00 0.68uf, 5 pcnt, 250v, polypropylene, box, 2 c116, c149 ca-468007-00 0.68u...
68 qsc audio products, llc part number description qty. Reference comment qd-000102-30 diode, 75v, 0.075a, , imbd4148, sot-23, 4ns 12 d1, d13, d15, d16, d2, d22, d25, d27, d35, d40, d45, d7 qd-000103-30 transistor npn, 40v, 0.2a, 0.2w, mmst3904, sot-23, 5 q1, q11, q12, q17, q6 qd-000104-30 transisto...
69 td-000487-00 k series service manual part number description qty. Reference comment re-220002-30 20.0k, 1 pcnt, 1/10w, thick film, 0805, 100v 9 r104, r105, r111, r112, r84, r96, r97, r98, r99 re-229402-30 29.4k, 1 pcnt, 1/10w, thick film, 0805, 100v 1 r150 re-256002-10 56k, 5 pcnt, mini-1w, metal...
Contact information service manuals and other service documents are available for download from www.Qscservice.Com. If you need any further information regarding this service procedure, please contact qsc technical services at the addresses or numbers below. Telephone: 1-800-772-2834 (within usa onl...