Akashic Guitar effects circuit lookup
VOLUME

1590A · 1 knob

Tagboard Effects

DAM Meathead with switchable capsVerified

Based on the D*A*M Meathead· 7 other boards clone it

Category
Fuzz
Controls
Volume
Build
Vero
Layout
Verified · Tagboard Effects marks it as built and working
Tags
DAM, Fuzz

From the post

This was a request from one of our members. I wondered what the best method would be to do this, maybe using a 3 position 4 pole rotary switch, but I think this method by far gives you the most versatility.

With both 3 position switches in the centre off position, the Meathead stock values (10n & 22n) will be in circuit. When selections are made, the selected cap value is summed with the stock value to give a wide variety of stock up to Meathead Dark tones. You will have 10n, 22n or 43n for the input switch, and 22n, 69n or 122n for the output switch. Swap the caps to suit your own tastes if you like things a bit more or a bit less dark. It may be worth building the board and then breadboarding the cap selection part to make it ideal for you.

With the board only being 10 columns wide this is totally do-able in a 1590A. Let's see who's brave enough! :o)

After a conversation below it and doing a few calculations, it seems that the change of output cap for the Meathead Dark was irrelevant as the frequency cut by the standard 22n output cap was already lower than the lowest frequency on the guitar. With that in mind, this version may be more useful offering a post gain bass cut. In the centre position with just the 220p in circuit it will be a very lo-fi effect because much of the mids and all the bass will be cut. In the 22n position you will get a full bass output, and in the 1n position there will be some bass cut which may be useful for cleaning things up a bit.

Schematic

This is a board layout, a drawing of where each part goes, and the post may link the schematic it was drawn from. Open the layout at Tagboard Effects. No KiCad fragment has been drawn for this circuit yet.

Parts list 13 rows

Report a wrong parse

Got parts in a drawer? See what you can build with them.

Check before you build · 5 values the reader of this layout was not sure of
  • All 6 board resistors: values illegible in the thumbnail
  • Both board electrolytics (top right, bottom left): values illegible
  • The two small caps on the board: read as 10n and 22n only from the note 'Meathead stock values (10n & 22n)' and the 10n / 22n labels at the switch commons, not from the parts themselves
  • Transistor labels 2N3904 (left) and BC182L (right) are blurred; best reading
  • Pot name is not printed; it is wired to Output
RefValueNormalizedTypeNotes
Resistors 1
×6??value unreadable in thumbnail; read from the layout by eye
Capacitors 7
×2??electrolytic; value unreadable in thumbnail; read from the layout by eye
×110n10nstock input cap, per the note; read from the layout by eye
×122n22nstock output cap, per the note; read from the layout by eye
×112n12non the input cap switch; read from the layout by eye
×133n33non the input cap switch; read from the layout by eye
×147n47non the output cap switch; read from the layout by eye
×1100n100non the output cap switch; read from the layout by eye
Transistors 2
×12N39042N3904left transistor; read from the layout by eye
×1BC182LBC182Lright transistor; read from the layout by eye
Potentiometers 1
VolumeB500KB500kPotentiometerprinted '500K LIN'; knob name not printed; read from the layout by eye
Switches 2
Input capsDPDT on/off/onDPDT ON/OFF/ONtoggle; read from the layout by eye
Output capsDPDT on/off/onDPDT ON/OFF/ONtoggle; read from the layout by eye

Other boards based on the D*A*M Meathead