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2 layers90.2 × 128.5 mmBBO&VCA v1.0, the printed circuit board in 3D

BBO&VCA v1.0

StudioKAT/BBO-VCA6

In this oscillator, increasing the Bounce raises the frequency. Narrowing the Bounds further increases the frequency but reduces the amplitude.

Size
90.2 × 128.5 mm
Copper layers
2
Thickness
1.6 mm
Parts
124
Nets
91
Pads
350
Tracks, vias
597, 156
Pours
22
Routed
Yes
KiCad
KiCad 9.0 (file 20241229)
Created
16 Jul 2025
Updated
19 Jul 2025

Overview

BBO&VCA v1.0 is an open-source printed circuit board by StudioKAT, from the StudioKAT/BBO-VCA repository on GitHub. It is a 2-layer board of 90.2 × 128.5 mm with 124 parts on 91 nets, routed with 597 tracks and 156 vias.

It is built around the LM13700M, BCM857BS and 1N4148WS, with the 1N5819WS and MMBT3906 among its other parts. Its parts include 54 resistors, 19 capacitors, 9 connectors, 6 diodes and 6 transistors.

Main components

5

README

README.md

BBO&VCA

BBO&VCA_Front

概要 / Overview

BBO&VCA は、Ieaskul F. Mobenthey の Denum と crucFX Utility BBO にインスパイアされた「バウンズ・バウンス・オシレーター(Bounds Bounce Oscillator)」です。
この回路は、「バウンス(Bounce)」と「バウンズ(Bounds)」という、2つの概念を軸に動作します。
ボールが2つの壁の間を行き来して跳ねている様子をイメージしてください。バウンスはボールのスピード、バウンズはその2つの壁の距離です。
このオシレーターでは、バウンスを大きくすると周波数が上がり、バウンズを狭めると振幅が下がる代わりに周波数はさらに上がります。つまり、壁を近づけると、ボール(信号)の移動が速くなるという構造です。
BBO&VCA は、バウンスとバウンズをそれぞれ独立して調整・変調でき、主出力からは常に三角波が出力されます。また、もう1つの出力からは矩形波が得られます。
さらに、レンジスイッチにより3つの動作範囲を選択できます:

  • 標準オーディオレート
  • 低オーディオレート
  • LFOレート

出力される三角波と矩形波は、それぞれ専用のリニアVCAを通して出力されており、外部CVやノブで音量(振幅)をコントロールできます。

※ 1V/oct の標準CVピッチ制御には対応していません。

BBO&VCA is a "Bounds Bounce Oscillator" inspired by Ieaskul F. Mobenthey's Denum and the crucFX Utility BBO.
This circuit operates based on two key concepts: Bounce and Bounds.
Imagine a ball bouncing back and forth between two walls. The Bounce represents the speed of the ball, and the Bounds represent the distance between the two walls.

In this oscillator, increasing the Bounce raises the frequency. Narrowing the Bounds further increases the frequency but reduces the amplitude.
In other words, when the walls are brought closer together, the ball (i.e., the signal) travels faster, resulting in a higher pitch.

BBO&VCA allows independent control and modulation of both Bounce and Bounds.
The main output always produces a triangle wave, while the secondary output provides a square wave.

A range switch allows you to select from three operating ranges:

  • Standard audio rate
  • Low audio rate
  • LFO rate

Both the triangle and square waves are routed through dedicated linear VCAs, allowing you to control their amplitude (volume) via knobs or external CV.

Note: This module does not support standard 1V/oct pitch tracking.

仕様 / Spec

  • Format: Eurorack
  • Function: Oscillator / LFO
  • Current needs: +12V: 30mA, -12V: 30mA
  • Width: 8 HP
  • Depth: 25mm (including power connector)

販売 / Sales

StudioKATオフィシャルショップで販売しています。(日本国内限定)
https://www.studiokat.jp/items/113562094

ライセンス / License

この作品は Creative Commons 表示 - 継承 4.0 国際 (CC BY-SA 4.0) の下でライセンスされています。
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

クレジット / Credits

更新履歴 / Changelog

  • 2025-07-17 Released version 1.0

Parts

124
QtyValueFootprintReferences
10100nFCapacitor_SMD:C_0603_1608MetricC3, C4, C5, C6, C7, C8, C9, C10, C11, C12
910KResistor_SMD:R_0402_1005MetricR11, R12, R20, R22, R26, R29, R30, R49, R50
8PH_Audiokat_eurorack:PH_AudioJack_3.5mm_PadH11, H12, H13, H14, H15, H16, H17, H18
6100KResistor_SMD:R_0402_1005MetricR6, R8, R9, R10, R19, R21
64.7KResistor_SMD:R_0402_1005MetricR13, R14, R15, R16, R51, R53
410MResistor_SMD:R_0402_1005MetricR1, R2, R3, R4
41KResistor_SMD:R_0402_1005MetricR39, R40, R52, R54
422KResistor_SMD:R_0402_1005MetricR5, R7, R27, R28
447KResistor_SMD:R_0402_1005MetricR17, R18, R24, R25
4680RResistor_SMD:R_0402_1005MetricR43, R44, R45, R46
4B50Kkat_eurorack:Potentiometer_RV09RV1, RV2, RV3, RV4
4BCM857BSPackage_TO_SOT_SMD:SOT-363_SC-70-6Q1, Q2, Q3, Q4
4PH_Potkat_eurorack:PH_RK097_15mmKnob_PadH5, H6, H9, H10
3TL074Package_SO:SOIC-14_3.9x8.7mm_P1.27mmU3, U4, U5
215KResistor_SMD:R_0603_1608MetricR31, R32
218KResistor_SMD:R_0402_1005MetricR47, R48
21N4148WSDiode_SMD:D_SOD-323D3, D4
21N5819WSDiode_SMD:D_SOD-323D1, D2
222uFCapacitor_SMD:C_0805_2012MetricC1, C2
2330KResistor_SMD:R_0402_1005MetricR33, R34
2330pFCapacitor_SMD:C_0402_1005MetricC16, C17
233KResistor_SMD:R_0402_1005MetricR35, R36
247pFCapacitor_SMD:C_0402_1005MetricC18, C19
26.8KResistor_SMD:R_0402_1005MetricR37, R38
2B100Kkat_eurorack:Potentiometer_RV09RV5, RV6
2LED_Dual_BidirectionalLED_THT:LED_D3.0mmD5, D6
2LM13700Package_SO:SOIC-16_3.9x9.9mm_P1.27mmU1, U2
2MMBT3906Package_TO_SOT_SMD:SOT-23Q5, Q6
2PH_LEDkat_eurorack:PH_LED_3.0mm_PadH3, H4
2PH_Potkat_eurorack:PH_RK097_15mmKnob_Uni_PadH7, H8
11nFCapacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolderC13
11uFCapacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolderC14
1240KResistor_SMD:R_0603_1608MetricR41
1360KResistor_SMD:R_0603_1608MetricR42
1470KResistor_SMD:R_0402_1005MetricR23
147nFkat_eurorack:C_1913_4833MetricC15
1Bounce_CVkat_eurorack:AudioJack_PJ301M-12J3
1Bounce_Linkat_eurorack:AudioJack_PJ301M-12J2
1Bounds_CVkat_eurorack:AudioJack_PJ301M-12J5
1Bounds_Linkat_eurorack:AudioJack_PJ301M-12J4
1PH_SWkat_eurorack:PH_ToggleSwitch_5.1mm_PadH2
1POWERkat_eurorack:BoxHeader_2x05_2.54mm_Europower_2J1
1Panelkat_eurorack:Panel_8HPH1
1SW_SPDT_MSMkat_eurorack:ToggleSwitch_2MS1-T2-B4-M2-Q-E-SSW1
1Square_OUTkat_eurorack:AudioJack_PJ301M-12J9
1Triangle_OUTkat_eurorack:AudioJack_PJ301M-12J8
1VCA_CV_Squarekat_eurorack:AudioJack_PJ301M-12J7
1VCA_CV_Trianglekat_eurorack:AudioJack_PJ301M-12J6

Questions

How big is the BBO&VCA v1.0 PCB?

It measures 90.2 × 128.5 mm and has 2 copper layers, 1.6 mm thick.

What parts does the BBO&VCA v1.0 use?

124 parts, built around the LM13700M, BCM857BS, 1N4148WS and 1N5819WS. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the BBO&VCA v1.0 KiCad files?

From the StudioKAT/BBO-VCA repository on GitHub, at the commit this page was made from: the board is v1.0/KiCAD/BBO&VCA_v1.0/BBO&VCA_v1.0.kicad_pcb and its schematic v1.0/KiCAD/BBO&VCA_v1.0/BBO&VCA_v1.0.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the BBO&VCA v1.0 design in my own project?

Its repository states no licence, so its author keeps all rights: ask StudioKAT before reusing the design.

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