HK matrix 100 schematic
Engineering Change Order (ECO)
for:
high
Date:
Name/Signature:
G. Degen
FM045
Page 1 / 6
Project: H&K Matrix 100
Combo HU0204 Head HU 0304
Issued by: RD Date: 13-Apr-06 ECO No.: 10
Receiver: [AXL China
[Norman Hua]
[Ningbo]
Description of affected item(s) / old denomination:
Stamer part-no:
Drawing no:
Supplier:
Reason of change(s) / new denomination:
New part
Alternative
Stamer part-no:
Drawing no:
Supplier:
End-Of-Life of currently used part
Replacement part for:
Comments / necessary changes:
SEE 3 Pages Attachment
CC: AXL USA
Kenny Kwan
External/Receiver‘s
part-no:
Supplier part-no:
Product upgrade
Other Reason: Failure Rate field too
External/Receiver‘s
part-no:
Supplier part-no:
[NO]
[NO]
[NO]
[NO]
1) Replace C64 and C65 from 220uF/25V version to 220uF/35V version
2) Replace Resistors R82, R83, R69, R70, R75 to VISHAY manufacturer AC 05 type, same value
3) Modify assembly method of resistors (see attachment), ensure mfctr. procedure prevents from
Resistor leads being bent during production process
4) Improve procedure of assembly of power transistors to heatsinks to prevent gaps resulting burnouts
5) Replace Caps C14,C48,C49 from 85 degree type to 105 degree type, same values for capacitance
and voltage
6) Replace FX modules to Chip-directly-soldered types instead of Chip-in-socket types
7) Additionally replace R105, R106 to VISHAY manufacturer AC 05 type, same value
8) Additionally correct assembly method of diodes D25,D26,D27,D29,D31 (see attachment)
Approved by:
Date: 13.04.06 Name/Signature: K. Ballhorn
QA approval (for safety relevant parts only): required
Confirmation by:
Document flow: RD (QS) QM Receiver
EngineeringChangeOrder_FM045.dot RD Revision B, 05.11.2004
Engineering Change Order (ECO)
<Inspection Conclusion and Suggestion About the Quality Problems Of
Matrix 100>
From: AXL Ninghai Factory Engineering Staff
To: Stamer Engineering Staff
Date: 04/11/2006
• Electrolytic Capacitors
1. In Matrix 100 original circuit design, the max. allowable operational
voltage is only 25V for C64 and C65, but the actually maximum voltage
applied to these to caps are +30V and –28V, which had led about 10%
machine appeared noisy. This is the major reason to causing the
humming noise. Unfortunately, our technical department didn’t catch
this small technical detail and did not do the inspection in time.
KB/BS:
FM045
Page 2 / 6
You are right. At this point a 35V type must be used. This is the first time this point came up, and so far we never had problems or any other
indication or information on this. It also did – fortunately – not cause
any additional problem. The “humming” amps, we or our partner abroad
received for repairing, could always be fixed by exchanging (mostly
damaged) C48/C49.
So we cannot understand that this the major humming problem, as you
are supposing. Please let us know how you proof this statement.
Anyway: This must be changed, we will send ECO for replacement to a
220uF, 35V type together with the other issues. Same size of cap !
2. The local supplier for capacitors C48 (4700uF/63V) and C49
(4700uF/63V) provided us with lower capacitance than standard, not
consistent characteristics, technical parameters are fuzzy. In addition,
in Matrix 100 original design, C48 and C49 actual running temperatures
were very closed to the specified maximum temperatures, which had
caused some little lower quality capacitors failed (about 1%). But if the
design had chosen 5600uF/63V 105 thermostable capacitor instead
of the 4700uF/63V, it should have been more reasonable.
EngineeringChangeOrder_FM045.dot RD Revision B, 05.11.2004
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