Jen (Gretsch Playboy) - Harmon Booster  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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azrael
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Post by azrael »

I looked up the BC318C, it's PNP? Do you just build it with a modern transistor that's NPN?

mmolteratx
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Post by mmolteratx »

Just cracked mine open and it matches Sonic VI's schem. Will post pics in a bit.

sinner
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Post by sinner »

Run through it again and seems to be fine.

I've changed trimmer size, added wiring, LED, and corrected pot tapers

Wiring is for NPN. I don't give a damn to source PNP silicons, dealing with PITA powering and stuff. NPN's won't explode :twisted:

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Post by sonicvi »

The BC318Cs I bought from Mouser were NPN. You want NPN, Not PNP. I didn't worry about gain values. I think the 318s were in the 400-500 range. They're discontinued by Fairchild now. I'm sure anything similar will be fine.

http://www.mouser.com/Search/ProductDet ... 512-BC318C

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Post by sonicvi »

Looks like Mouser has plenty in stock still.

bandus
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Post by bandus »

hi guys!

i have a jen harmon booster and i want to know when was it made.

http://timemachinery.tumblr.com/post/16 ... on-booster here are some pictures. i heard that they was made from the late 60s. but my frien told me this one made round the 80s. are they made differently or did any circuit modification?

thanks!

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Post by sonicvi »

They were made in the late 70's.

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azrael
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Post by azrael »

Any idea what kind of voltages are the transistors operating at?

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chicago_mike
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Post by chicago_mike »

this sounds so good on bass!!
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sinner
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Post by sinner »

chicago_mike wrote:this sounds so good on bass!!

Who's layout did you used? Is that mean mine is confirmed? :)

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chicago_mike
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Post by chicago_mike »

Reviving old thread!!

My buddy has one that his dad bought long ago! Sounds amazing on bass and I need to clone this!!
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Post by MGaburriJazzDude »

I build it with BC549's and a 22K resistor instead of the trimpot; and it sounds AMAZING!

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Post by johnk »

i love mine too. i used BC318C's in it.
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