There are two parts lists for this amplifier design. The first list is the assembly parts list, and the second is the purchase parts list.
The assembly parts list itemizes each part in alphabetical order, there is a check box next to each part. It is recommended that this list be printed on paper. Check off each part as it is installed. This makes it far easier to keep track of your progress. It is especially valuable if you can’t finish the whole board in a single session.
The parts purchase list shows each unique part and the quantity of each that are required per board. Also listed are suppliers and part numbers for each part. It is used to order or gather up all of the parts needed to build a complete amplifier. Some parts such as tubes and transformers, are available in varying quality and power levels and they have their own page. The optional parts are covered on the upgrades page.
This is the assembly parts list. It is used to assemble the PC board, and the complete amplifier. First go over the list to verify that you have all of the parts and they can be properly identified. Mark out parts that are not being used in your amplifier design. R1 is not used if you are using the optional power supply choke. Next make any corrections to component values for your particular build. The cathode bias resistors (R17 and R27) may be a different value in your amp. The power supply capacitors C1 and C2 may be different also. When you are finished marking up your assembly parts list, make a copy of it and use it as the check list when assembling the amplifier.
|R1||150ohm 5W||Omit if using optional choke.|
|R17||560ohm 5W||Cathode bias resistor. See text.|
|R27||560ohm 5W||Cathode bias resistor. See text.|
|C1||47uF 500V||Power supply capacitor. See text.|
|C2||120uF 500V||Power supply capacitor. See text.|
|U10||CCS with heat shield|
|U20||CCS with heat shield|
|T1-RED||3-pin terminal strip|
|T2-PRI||3-pin terminal strip|
|T3-PRI||3-pin terminal strip|
|T1-YEL||2-pin terminal strip|
|T1-GRN||2-pin terminal strip|
|T1-RED-YEL||2-pin terminal strip|
|T2-SEC||2-pin terminal strip|
|T3-SEC||2-pin terminal strip|
|SW1||2-pin terminal strip|
|L1||2-pin terminal strip|
|IN||2-pin terminal strip|
|IN||2-pin terminal strip|
|Output Transformer (2x)|
|Completed PC board|
|6L6 or other output tube (2x)|
|Power Socket with fuse holder|
|Binding Post red (2x)|
|Binding Post black (2x)|
|RCA jack (2x)|
|Volume Control (50 K pot or other as preferred by builder)|
|GZ-34 or 5AR4 tube||Used if tube rectifier is desired.|
|Rectifier Switch||Used to switch between tube and SS rectifier.|
|Mode Switch||Used if Triode/UL switch is desired.|
|Feedback Switch||Used if Cathode feedback disable switch is desired.|
|Power Choke||Used to improve power supply. Recommended for most amps.|
|Auxiliary power supply cap||Used to improve power supply. Recommended for high end amps.|
|Note||Qty||Description||Mouser P/N||DigiKey P/N||AES P/N||Ref||Spacing (mm)|
|Note 4||1||47uf 500V Electrolytic cap||5985-85-500V47||P7442-ND||C1||10|
|Note 4||1||120uF 500V Electrolytic cap||P7451-ND||C2||10|
|Note 4||2||1500uF 63V Electrolytic cap||647-UPW1J152MHD||P10334-ND||C12 C22||7.5|
|2||1500uF 6.3V Electrolytic cap||647-UPW0J152MPD||P10203-ND||C10 C20||5|
|Note 1||2||0.22uf 450+V coupling cap||539-150224J630LE||C11 C21||37.5|
|1||0.47 100V Mylar cap||140-PM2A474K||EF1474-ND||C3||7.5|
|Note 2||0/1||150ohm 5W wirewound resistor||280-CR5-150-RC||150W-5-ND||R1||32.5|
|Note 3||2||560ohm 5W wirewound resistor||280-CR5-560-RC||560W-5-ND||R17 R27||32.5|
|4||100ohm 1/4 W metal film resistor||271-100-RC||100XBK-ND||R12 R16 R22 R26||14|
|4||220K or 221K 1/4 W metal film resistor||271-220K-RC||221KXBK||R11 R15 R21 R25||14|
|2||220ohm 1/4W metal film resistor||271-220-RC||221XBK||R10 R20||14|
|2||10K 3W metal oxide film resistor||283-10K-RC||R14 R24||25|
|1||150K 3W metal oxide film resistor||283-150K-RC||R2||25|
|1||10k 1 W metal oxide film resistor||281-10K-RC||P10KW-1BK-ND||R3||14|
|2||1K 1/4 W metal film resistor||271-1K-RC||1.00KXBK-ND||R19 R29||14|
|2||330 or 332 ohm 1/4 W metal film resistor||271-330-RC||332XBK-ND||R13 R23||14|
|2||100ohm 2 W metal oxide film resistor||282-100||100W-2-ND||R18 R28||17.5|
|1||150K 2W metal oxide film resistor||282-150K-RC||150KW-2-ND||R4||17.5|
|2||1200 PIV FRED diode TO-220 pkg||D1 D2|
|3||Octal Socket||P-ST8-193||V11 V21|
|9||2 pin terminal strip||277-1258-ND|
|3||3 pin terminal strip||277-1259-ND|
Note 1: This is the coupling cap. The part number is for a Mallory “150” capacitor. This is a good compromise between cost and performance. Many users will upgrade this part. I use “Auricaps” in high quality amps. The value is also a matter of personal taste. It should be at least .1uF and the voltage rating should be at least as much as the amps B+ voltage.
Note 2: No resistor is placed in this location if a choke is used in the power supply. If no choke is used, place a 150 ohm resistor in this location. A power supply choke is recommended if you have efficient speakers, or they have good low frequency response. I have found that a cheap choke usually works better than a resistor.
Note 3: This is the cathode resistor. This sets the bias for the output tubes. 560 ohms is a typical value for tubes operated at 440 volts. Consult the simulations for the starting value for your operating conditions. If you are not sure, choose a value at the high end of the possible range. Then you can increase the tube current by adding a resistor in parallel to the one on the PC board without unsoldering.
Note 4: A 500 volt capacitor is specified for the two power supply capacitors. In many applications this is necessary because the power supply voltage can go over 450 volts. This is especially important with solid state rectifiers since the B+ voltage comes on instantly and there is no load on the power supply until the output tubes warm up. If you are ABSOLUTELY SURE that your B+ will never go this high, a lower voltage capacitor can be used. A 6V6 ( or other low voltage application) amplifier with a 550 volt CT transformer can use a 400 volt capacitor. The B+ in this case is 300 to 350 volts. These capacitors are often found surplus from SMPS applications. The value is not critical (at least 100 uF for C2 and 22 to 47 uF for C1). A 450 volt capacitor can be used with a 600 VCT transformer, and some 650 VCT applications. These are often easier to find that 500 volt capacitors. A capacitor rated for 105 degree centigrade operation is required for C1 and C2 if the ventilation is poor, and is recommended in all cases if new parts are being purchased. A 105 C cap should be used for C12 and C22 due to the close proximity of the output tubes.