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cMoyBB Revision History

Version Changes


Bass Boost cMoy v2.03R Instructions Guide
• Added integrated NiMH recharging circuit
• Replaced protection diode "D2" with charging LED, "D2"

Remarks: Version 2.03R merges the cMoyBB v2.03 PCB and NiMH Charging Module onto a single board. Versions 2.03 and 2.03R are otherwise identical.



Bass Boost cMoy v2.03 Instructions Guide
• Changed DC jack for better power adapter compatibility
• Added U3, for optional dual TLE2426 chips
• Changed bypass capacitors to accommodate dual TLE2426 IC's
• Added pads for optional dual 9V battery connectors (18V)
• Changed pad size of J5 for easier fit
• Changed default resistors to 1/8W in Bill of Materials

Remarks: Version 2.03 brings greater modification flexibility and power adapter support to the cMoyBB, while deviating negligibly from the cMoyBB's sonic signature. U3 provides higher current handling for stronger output when driving low impedance headphones. The DC jack, J5, has been replaced with a more common barrel type jack to minimize user mistakes and improve power adapter availability.

v2.02 [Discontinued]


Bass Boost cMoy v2.02 Instructions Guide

DIY Mods
• Volume potentiometer repositioned from center of audio jacks to far left
• Bass boost pads moved to accept an internal toggle switch [i]
• Added decoupling capacitors to all IC power pins, C3+/- and C4+/-
• Added optional over-voltage protection diode, D2 [ii]
• Changed order of power switches and capacitor C1 for reduced shut-off noise
• Improved hole diameters for DC jack, audio jacks, and C2/CB capacitors
• Ground plane moved to top layer; trace widths and routing re-optimized
• Improved silkscreen notes for DIY builders [iii]
• Default gain changed from 7.25 to 6 (unless customized)

Remarks: Version 2.02 is a complete redesign of the Bass Boost cMoy, based on occasional e-mail requests for an internal bass boost toggle switch. The improved power circuitry seems to have widened the cMoyBB's soundstage and improved the clarity of high volume output.

[i] The new internal bass boost switch's pads still accept case mounted bass boost switches as used in earlier Bass Boost cMoy's, as well as bass boost potentiometers. However, these modifications are left up to DIY builders. All cMoyBB v2.02 amplifiers assembled by JDS Labs will ship with an internal toggle switch.
[ii] Diode D2 is optional. A small number of customers have damaged their amplifiers with improper DC adapters. A 24V Zener Diode can prevent overvoltage and certain instances of TLE2426 damage. Due to the exceptional rarity of such failures, it is most economical to omit D2.
[iii] The v2.02 silkscreen was updated January 17, 2009 to reflect changes made to the Assembly FAQ. Boards with this cosmetic update are marked 2009 JDS Labs. The PCB is otherwise unchanged. Due to a software glitch, the first batch of 2009 boards are missing the small headphone logo printed on the bottom left corner of the board.

v2.01 [Discontinued]


Bass Boost cMoy v2.01 Instructions Guide
• Removed a redundant trace and extended the ground plane
• Added "A", "B", "C", "D" labels to the silkscreen to correspond to the Assembly FAQ

Remarks: No major changes from v2.00; audibly identical.
v2.00 [Discontinued]


Bass Boost cMoy v2.00 Instructions Guide
• Added Alps RK097 volume potentiometer
• Added a ground plane
• Swapped input/output jacks (auto on implemented with headphone jack)
• Replaced bass boost switch with wire pads & side-mounted switch due to fit constraints
• Bare printed circuit boards made available for sale at JDSLabs.com

Remarks: Significant upgrade over v1.xx Bass Boost cMoy's. Received Editor's Choice Award at Onheadphones.com.
v1.48 [Discontinued]


Bass Boost cMoy v1.48 Instructions Guide
• Changed 3.5mm input jack to Kycon STX-3100-9N
• Changed bass boost switch to PCB-mounted toggle switch between 3.5mm jacks
v1.45 [Discontinued]


cMoyBB v1.45 Instructions Guide
• First non-prototype offering of the Bass Boost cMoy