Bottlehead Forum
General Category => General Discussion => Topic started by: korneluk on March 03, 2023, 06:43:48 AM
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Folks,
I bought an experimental (butchered by previous owner) Stereomour 45 online, and noticed there are no bypass caps on the 1.6K cathode resistors of the 45 tube.
Question: did the previous owner remove them (if so, what was the value) or they were never part of the original design?
TYVM,
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The power supply PC board holds the cathode bypass capacitors. These are the K connections on that board.
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Paul,
TYVM for the quick reply. Where can I find the full instructions for converting the Stereomour 2A3 to the 45 version? Besides the power supply resistors (values for each tube) are there any other changes?
Like I mentioned, just want to make sure the previous owner did not butcher the mods - this is strictly for personal use + you can PM me the details if you'd like.
thanks a bunch,
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For 45 operation, the blue plate choke wires go to the tube plates and the red plate choke wires go to the power supply. The black wires get capped off with heatshrink and aren't used. The 360 ohm power supply resistors are clipped out, as are the 4.7K cathode resistors that flank each 1.6K 10W wirewound resistor. Lastly the parallel feed caps should be bumped up from 3.3uF to 5.6uF. You may find it easier to just parallel and extra 2.2uF across what's already there if they are 3.3uF.
The manual originally had a mistake with how the plate choke would be connected for #45 operation.
-PB
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If ordered today would the manual for the Stereomour II include updated assembly instructions for one using 45 tubes? Thanks.
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https://forum.bottlehead.com/index.php?topic=11138.0 (https://forum.bottlehead.com/index.php?topic=11138.0)