Print Page - Bumblebee Q4 Emitter voltage

Title: Bumblebee Q4 Emitter voltage
Post by: Chrisx5x5 on May 30, 2020, 08:18:10 PM

I am getting good signal and gain throughout, but no swell effect. Checking the voltages everything is OK except for the 3904 in the lower right of the voltage chart; I believe that's Q4. There I get a reading of 5.9V at the emitter instead of zero.
I've socketed that location and swapped out the transistor; no change.
I don't understand that part of the circuit well enough to know what to try next. Can someone please help?
Thanks,
Chris

Title: Re: Bumblebee Q4 Emitter voltage
Post by: jimilee on May 30, 2020, 09:17:04 PM

There's a post somewhere that's says that's right, the zero was a mistake.

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Title: Re: Bumblebee Q4 Emitter voltage
Post by: jimilee on May 30, 2020, 09:22:48 PM

Quote from: jimilee on May 30, 2020, 09:17:04 PM
There's a post somewhere that's says that's right, the zero was a mistake.

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I guess I should have pointed out that the 5457 hfe definitely has to be around 1.7. I'm still troubleshooting mine.

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Title: Re: Bumblebee Q4 Emitter voltage
Post by: benny_profane on May 30, 2020, 09:43:27 PM

https://www.madbeanpedals.com/forum/index.php?topic=30283.0

Title: Re: Bumblebee Q4 Emitter voltage
Post by: Chrisx5x5 on May 31, 2020, 12:23:31 AM

Got it. Thanks.

madbeanpedals::forum

Projects => VFE Projects => Topic started by: Chrisx5x5 on May 30, 2020, 08:18:10 PM