Akashic Guitar effects circuit lookup
BURNDYNAMICSTONELEVEL

1590B · 4 knobs

Tagboard Effects

Barber Small FryVerified

Based on the Barber Small Fry· 2 other boards clone it

Category
Distortion
Controls
Burn · Dynamics · Tone · Level
Build
Vero· 22×16· 21 cuts, 4 links
Layout
Verified · Tagboard Effects marks it as built and working
Tags
Barber, Distortion, Overdrive

From the post

With 4 internal trimmers this was a pain to keep 1590B friendly. As it sits it's 22 columns wide and so will just fit in if you file the sides down a bit (and insulate the side of the box next to the board with electrician tape or similar to avoid shorts). It will however fit in vertically with the components facing down without too many problems. The original was in a 1590BB size box with 4 external pots and a switch and so people may want to keep it in that size box anyway, but the option is there for 1590B if you want to cram things in.

The diode switching in this is unusual. It has 7 diodes in the feedback loop plus a germanium to ground after the output of the first opamp stage which are controlled via the switch. In one position you have 2 + 2 anti-parallel silicon diodes in the loop to give you a common symmetrical clipping that you have seen before. In the centre off position you get 4 + 3 anti-parallel silicon diodes in the feedback loop which gives you asymmetrical clipping, and in the other position you get the 4 + 3 again, plus a germanium diode to ground after the first stage.

On top of that you also have the Dynamics pot which can bring 2 more germanium diodes, 1 + 1 anti-parallel, gradually through the sweep of the pot.

Lots of clipping options there!

Burn is the drive control, the Tone control is a simple low pass filter before the second stage and you then have further Bass and Mids trimmer controls on the board. The other trimmers are for Presence and Note Shape.

Anyway, here's the interesting bits that Mr Barber writes about his original:

Three way toggle- This new control allows three distinct styles of symmetry to allow a perfect mate to your amps character.

8 knob control for tonal versatility-The Small Fry uses eight (including internal trim pots) control knobs as follows, Volume, Tone, Dynamics and Burn. Internal controls for Note shape, Bass, Midrange and presence. These controls allow the Small Fry to produce sounds ranging from sweet subtle sustain to smooth singing California amp style tones!

Unique controls- The note shape allows you to adjust your sound from tight and focused to a big round vintage tone, The dynamics control has earned a great reputation over the years for setting the transfer to smooth singing overdrive or raspy growling deep dynamics, continuously!

Barber adjustable phono style recovery stage- Most of our op-amp based overdrive pedals use a cool old style phonograph circuit to recover the frequencies lost in the overdrive stage, this worked great for vinyl and now works great for guitar overdrive!

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 33 rows

Report a wrong parse

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

RefValueNormalizedTypeNotes
Resistors 8
×310K10kread from the layout by eye
×33K3kread from the layout by eye
×2470K470kread from the layout by eye
×191R91read from the layout by eye
×1220R220read from the layout by eye
×11K1kread from the layout by eye
×147K47kread from the layout by eye
×11M1Mread from the layout by eye
Capacitors 13
×1120p120pread from the layout by eye
×1680p680pread from the layout by eye
×12n22.2nread from the layout by eye
×13n33.3nread from the layout by eye
×110n10nread from the layout by eye
×222n22nread from the layout by eye
×168n68nread from the layout by eye
×182n82nread from the layout by eye
×1100n100nread from the layout by eye
×14u74.7uelectrolytic; read from the layout by eye
×110u10uelectrolytic; read from the layout by eye
×147u47uelectrolytic; read from the layout by eye
×1100u100uelectrolytic; read from the layout by eye
Diodes 2
×71N41481N4148D1-D7; read from the layout by eye
×31N34A1N34AD8-D10; read from the layout by eye
ICs 1
ICJRC4559JRC4559read from the layout by eye
Potentiometers 4
BurnA1MA1MPotentiometerread from the layout by eye
DynamicsB5KB5kPotentiometerread from the layout by eye
ToneB50KB50kPotentiometerread from the layout by eye
LevelA50KA50kPotentiometerread from the layout by eye
Trimmers 4
VR15K5kPresence; read from the layout by eye
VR210K10kNote Shape; read from the layout by eye
VR310K10kMid; read from the layout by eye
VR450K50kBass; read from the layout by eye
Switches 1
SwitchDPDT on/off/onDPDT ON/OFF/ONtoggle; read from the layout by eye

Other boards based on the Barber Small Fry