Bogen CH18 Schematic & Mods

[DummyLoad]

A friend acquired a Bogen CH18 and he was wanting to improve his schematic reading and drawing skills, so he drew a schema, and gave the amp to me to do same to compare to his afterwards. Attached is a schematic that I drafted.

The amp was acquired by my friend with modifications already in place for use with guitar. Looking at the schematic of a similar model, the Bogen 618 which adds an integrated record player, it seems that modifications made were minimal, however, the tone selector switching is iffy in that regard, as most other Bogens that I've run across use a 2 pole 4 throw selector switch, this one has a single pole 4 throw selector. Pics in link, more notes in the schematic.

Link to pics.

Doug, add the schema to the Bogen archive if you wish. Not much out there on the CH18 model.

--Pete

[SEL49]

Here's another reverse engineered schematic. No guarantees on accuracy but may be worth adding to your collection.

[DummyLoad]

Thanks for sharing. I saw that but had a concern after viewing. See attached. Circled part seems redundant.

--Pete