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Old 2nd Nov 2021, 12:48 pm   #1
Phantomrose1999
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Join Date: Mar 2008
Location: Melbourne, Victoria, Australia
Posts: 271
Default Grundig TK27 - Low audio output

Hi All,
Got another one and someone has been in it previously.

The playback output is very low, equal to about 20% of normal at max.

It has had new filter caps installed, 47uf / 400v, x 2 (quote small compared to the original can)

Measured the DC and it was low, 220 volts, so removed the old block rectifier and made a new one using 1Kv 3A diodes as the old block rectifiers do go bad.

Put it all back together, and now the DC measures 242 !! no where near the 260-270v stated in the schematic.

Removed the EL95 and the DC came back to 265v, with all other valves in place.


So either something in the EL95 circuit is pulling way more power or the EL95 is playing up and drawing too much power and pulling down the main DC.

Any suggestions from the resident experts please ? do EL95s go leaky ?
Attached Thumbnails
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Name:	Only Magic eye installed.jpg
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Attached Files
File Type: pdf sch_1.pdf (124.9 KB, 44 views)
File Type: pdf sch_2.pdf (120.7 KB, 41 views)
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