Q-Watt Audio Power Amplifier
Lots of power with low distortion
Gerber file
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Extra info / Update
Components
The BOM (Bill of Materials) is the technically exhaustive listing of parts and other hardware items used to produce the working and tested prototype of any Elektor Labs project. The BOM file contains deeper information than the Component List published for the same project in Elektor Magazine. If required the BOM gets updated directly by our lab engineers. As a reader, you can download the list here.
Want to learn more about our BOM list? Read the BOM list article for extra information.
Component list
Resistors
(5%, 0.25W, unless otherwise stated)
R1,R3 = 390Ohm
R2,R4,R17,R18,R22,R23,R30 = 15kOhm
R5 = 8.2kOhm
R6,R20,R28 = 1.2kOhm
R7 = 220Ohm
R8,R9 = 100Ohm
R10,R11 = 0.2Ohm 1% 5W, low inductance (Vishay Dale LVR05R2000FE73)
R12,R13 = 3.9Ohm 5% 5W
R14 = 220kOhm
R15,R16 = 10MOhm
R19 = 27kOhm
R21 = 470kOhm
R24 = 1MOhm
R25,R26 = 820kOhm
R27 = 68kOhm
R29 = 1kOhm
P1 = 470Ohm trimpot, horizontal
Capacitors
C1 = 4.7?F 63V, MKT (metal/polyester), 5mm or 7.5mm pitch
C2 = 1 nF/400 V, MKT (metal/polyester), 5mm or 7.5mm pitch
C3 = 18pF 500V (replacement for the original trimmer 5-57pF 250V)
C4,C6,C7 = 100nF 100V, 5mm or 7.5mm pitch
C5 = 47nF 400V, 5mm or 7.5mm pitch
C8,C9 = 4700µF 100V, 10mm pitch, snap-in, 30mm diam. (Panasonic ECOS2AP472DA)
C10 = 2.2µF 63V, 5mm or 7.5mm pitch
C11 = 33nF 63V, 5mm or 7.5mm pitch
C12,C13,C16 = 10µF 100V, 2.5mm pitch, 6.3mm diam.
C14 = 1µF 250V, 2.5mm pitch, 6.3mm diam.
C15 = 220µF 16V bipolar, 5mm pitch, 10mm diam.
Inductor
L1 = 450nH: 13 turns 14AWG (1.5 mm) enameled copper wire, 7mm inside diam.
Semiconductors
D1,D2 = 15V 0.5W zener diode
D3,D4 = 1N4004
D5 = 1N4148
D6 = LED, red, 3mm
T1 = BD139
T2 = MJE15032
T3 = MJE15033
T4 = MG6330-R
T5 = MG9410-R
T6–T10 = 2N5550
IC1 = LME49811TB/NOPB
IC2 = OPA177GPG4
IC3 = 4N25
Miscellaneous
K1 = 2-pin pinheader, 0.1’’ pitch
K2–K6 = Faston (blade) plug, PCB mount, 0.2’’ pitch
K7 = 3-way PCB screw terminal block, 5mm pitch
RE1 = relay, PCB mount, SPCO, 16A, 48V coil, 5.52kOhm (TE Connectivity/Schrack type RT314048)
TO-220 isolating washer for T1, T2, T3, Kapton MT film, 0.15mm, 6kV
TO-3P isolating washer for T4,T5, Kapton MT film, 0.15mm, 6kV
TO-220 3-mm isolating bush for T2,T3
Heatsink, 0.7K/W (e.g. Fischer type SK 47/100 SA)
Heatsink for IC1, dim. 25x 80 mm, 2 mm thick aluminum
PCB # 110656-1, see www.elektor.com/110656
Power Supply (for one amplifier)
Power transformer: sec. 2x40V, 500VA (e.g. Nuvotem 0500P1-2-040 for 230 VAC mains)
Bridge rectifier: 200V, 35A (e.g. GBPC3502) (Fairchild)
Four 10,000?F, 100V electrolytic capacitors (2 in parallel on each supply rail)
We buy at:
Discussion (0 comments)
Shadders 4 years ago
Not sure why the Q-Watt was featured on the Elektor News page, as the LME49811 is discontinued, and has been for 3 years.
Regards,
Shadders.
Lauren A Scott 4 years ago
NEW ORIGINAL IC LME49811 TO-247-15
https://www.alibaba.com/product-detail/NEW-ORIGINAL-IC-LME49811TB-LME49811-TO_60686274224.html
Buy at your own risk. Many of these suppliers are bogus.
There also may also be a way to redesign the amplifier to use a combinations of newer discrete parts to replace the LME49811 in an updated design.
I built a great sounding Class AB amplifier kit back in the 1980s, which like this design ran heavily into class A territory. It ran for two decades but the build was a little wonky and I think the capacitors were getting tired and I shelved it and never got back to refreshing it.
Seeing this retro design, with the added little challenge of the EOL part, has got me interested in designing something new, with comparative performance, taking this classic design in the future to live for another 20 years.
Challenge accepted. I'll have a look at it.
Lauren