Problems And Solutions - SPHINX Project Two MKII Service Manual

SPHINX Project Two Mk2

9. PROBLEMS AND SOLUTIONS

At the moment of writing the Project Two Mk2 has
two known specific problems.
If in the future you encounter any problem(s) you
may enter the info in this table. This table can then
be used for future reference.
Problem
Volume potmeter has not
enough gain range
Oscillation problem at balanced
output
Cause
Overall Gain of pre-amp is too
high
Not enough frequency
compensation across U2 and U3
Service Manual
Please also send (by fax or e-mail) the specific
information to the Sphinx International Service
Department (see page 3): this info can then be
added to the general database to aid others.
Solution
Change R76 (left channel)
and R85 (right channel) from
3k33 to 1k8.
Install a ceramic condenser
(56 pF / 50 V) between pin 2
and pin 6 of U2 and U3
Refer to
page/file
Pj2Adjust.PDF
Pj2Adjust.PDF
11