Original Website © Amplabs 2009 This new site created February 2024
LEAK Stereo Twenty Full Service and Modification
Amplabs
Our full service and Modification includes:
Safety check, cut out and fit a fused/switched mains EC block, fit a 250mAF HT fuse, perform fault diagnosis and replace all the
out of tolerance and physically damaged resistors with modern high tolerance types. We also replace all out of tolerance small
signal electrolytic capacitors and dual smoothing blocks, replace the full set of original paper coupling and decoupling capacitors
(if they are still insitu) with HV polypropylene capacitors and Check valve biasing and recommend what valves, if any, need
replacing. Faulty valves will be replaced at cost if requested. We run a full performance check and adjustment and 24 hour soak
test/retest. If the output or mains transformers are faulty we can replace them at cost plus fitting charge. We will also blank off the
old mains outlets.
The images above show a typical full service and safety
modification. The images upper left and middle left, show the rear of
the Stereo 20 with the modified connectors. In place of the round
pin Bulgin connector a switched/fused IEC block is fitted. The upper
left image has professional speaker terminal posts, twin IEC outlets
and an internal HT fuse fitted. On the lower right image the HT fuse
is external and fitted just above the switch cable. The fuse is
315mA medium blow type.
The schematic bottom left, shows the position of the HT fuse and
GZ34 rectifier valve 'protection' diode mods. (Shown by red dots).
The diodes help preserve the life of the GZ34 particularly if it is a
modern reproduction type.
For ure listening pleasure
