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Bass Boost cMoy v2.02
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JDS Labs Store |
Bass Boost cMoy Revision History
| Version |
Released |
Changes |
2.02
Instructions |
12/10/2008 |
-
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
cMoyBB, 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 cMoyBB'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 omitted by default. 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.
|
2.01
Instructions |
06/05/2008 |
- 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.
|
2.00
Instructions |
11/24/2007 |
- 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 cMoyBB's.
Received
Editor's Choice Award at Onheadphones.com.
|
1.48
Instructions |
08/05/2007 |
- Changed 3.5mm input jack to Kycon STX-3100-9N
- Changed bass boost switch to PCB-mounted toggle switch between
3.5mm jacks
|
1.45
Instructions |
07/23/2007 |
- First non-prototype offering of the Bass Boost cMoy
|
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