Components, Bill of Materials

A project log for The Muffsy BSTRD - Class A Valve Preamp

An open source Class-A valve preamplifier and regulated PSU, complete with Eagle project files and detailed Bill of Materials

skrodahlskrodahl 12/01/2016 at 08:483 Comments

Here's the bill of materials for both the BSTRD Tube Pre and the Power Supply.

It contains part numbers from Mouser, and other sources where Mouser can't provide the parts. It's recommended that you buy more than the specified component quantities, especially for cheaper parts like resistors.

These are just suggestions, there are a lot of cheaper, more expensive, better, worse and higher or lower quality components available. There are also a lot of other places to get components, like,, to mention a few.

Mouser Shopping Cart

All components below except LED resistor, transformers, tube sockets and tubes have been placed in this Mouser shopping cart:

The BOM and shopping cart were last updated 2019-04-03, ensuring that everything is in stock.

Note that the 470uF/160V electrolytic capacitor has been replaced with a 200V version, and that the 100V ceramic capacitors have been replaced with 200V models.

The BSTRD Tube Pre:

Quantity Component Value Mouser Part #, or other source
2 Resistor, 0.6W 1k ohms 279-LR1F1K0
2 Resistor, 0.6W 22k ohms 603-MF0207FTE52-22K
2 Resistor, 1/4W 100k ohms 603-MFR-25FRF52100K
2 Resistor, 1/4W 330k ohms 603-MFR-25FBF52-330K
2 Resistor, 1/4W 1M ohms 603-MFR-25FRF521M
2 Electrolytic capacitors, 25V (≤10mm width, 5mm pin spacing) 47 uF 647-UKZ1E470MPM
2 Film capacitors (7.5mm pin spacing), ≥ 100V 1 uF 505-MKS41.0/100/10
2 Ceramic capacitors 0.1 uF 80-C320C104K1R
1 Stereo Potentiometer, logarithmic, 16 mm 100k ohms 652-PDB182-K430K104A
2 Sockets, for tube 8 pins Search for "octal socket pcb" on eBay, Amazon etc.
2 Tubes, valves 6J5 or equivalent Available from various sources, such as eBay and other online stores.
3 Screw terminals 3 ports 651-1705469

Alternative tubes that can be used with this preamp are:

The BSTRD Power Supply:

Quantity Component Value Mouser Part #, or other source
10 Diode 1N4004 821-1N4004
1 Resistor, 2W 180 or 200 ohms 71-CPF2200R00FKE14
1 Resistor, 1/4W 100 ohms 603-MFR-25FRF52100R
1 Resistor, 1/4W 820 ohms 603-MFR-25FTE52-820R
1 Resistor, 1/4W 3k3 ohms 603-MFR-25FRF52-3K3
1 Resistor, 1/4W 6k2 ohms 603-MFR-25FRF52-6K2
1 Resistor, 1/4W Suitable for LED @6.3V Calculate here
4 Electrolytic capacitor, 100V (≤13mm width, 5mm pin spacing) 390 uF 661-EKZN101E391MK35S
1 Electrolytic capacitor, 100V (≤13mm width, 5mm pin spacing) 47 uF 647-UHE2A470MPD
1 Electrolytic capacitor, 200V (≤18mm width, 7.5mm pin spacing) 470 uF 647-UCY2D471MHD
4 Electrolytic capacitor, 25V (≤13mm width, 5mm pin spacing) 3300 to 3900 uF 661-EKYB250E392MK40S
1 Electrolytic capacitor, 16V (≤5mm with, 2.5mm pin spacing) 47 uF UKZ1E470MPM1TD
4 Ceramic capacitor 0.1 uF 80-C320C104K1R
1 Voltage regulator, TO-220 TL783 595-TL783CKCSE3
1 Voltage regulator, TO-220 LT1086 (or LM317) 512-LM317T
2 Heat sink SK104 567-637-20ABPE
2 Heat sink mounting kit TO-220 532-4880SG
3 Screw terminal, 5 or 5.08 mm pin spacing 2 ports 651-1711725
1 Screw terminal, 5 or 5.08 mm pin spacing 3 ports 651-1705469
1 Transformer, ≥ 15VA 6 V AC (or up to 12V) The print on the PCB
says 9-12V. but 6-9V is
better suited.
1 Transformer, ≥ 10VA 18 V AC (or up to 24V) The print on the PCB
says 21-24V, but 18-21V is
better suited.

Transformer options are not given in the shopping cart, as there is too many choices depending on input voltage and designs. However, this one should work for 115-230V AC input and both 9V (parallel) and 18V (serial) AC output:

Also note, it's better to get transformers with lower output than stated on the PCB. The reason for this is that many transformers output a higher voltage than stated due to higher than nominal mains voltage.


bfd wrote 01/07/2020 at 02:30 point

are you saying use the same transformer twice (buy 2); for the 15va and 10va?

  Are you sure? yes | no

skrodahl wrote 01/07/2020 at 08:29 point

Yes, you need two transformers. The one I linked to has two 9V secondary outputs, you can connect the secondaries in parallel for 9V and series for 18V:

  Are you sure? yes | no

jan bentum wrote 09/30/2018 at 15:58 point

Please check the 3 ports screw terminals when ordering, because all I received were the 2 ports terminals! I could use them after modification, but still….

  Are you sure? yes | no