Author Topic: Clipper Ship Question - SOLVED  (Read 333 times)

cajone5

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Clipper Ship Question - SOLVED
« on: December 27, 2017, 10:07:25 AM »
I put together a clipper ship using a PCB kindly gifted to me by a madbeaner over the holiday break and, unfortunately, only had a moment to test it and it didn't go so well, so I have some debugging to do, however, I am curious of something for anyone familiar with the circuit...

My build has uses...

R3 - socketed (7.5k was used to test)
Q1 -
Q2/Q3 - 2N5457
D1 - 1N5817
D2 - omitted
D3/D4 - on a switch with diodes ranging from 0.27v to 0.75v forward voltage

I don't have many NPN Ge transistors, unfortunately, but I was testing it with a spam can GE 2N1101 transistor with hFe (on my Peak meter) of 45 with a leakage of about 0.08uA or mA (whatever the standard output is for that... this is from memory).  Bypass was good but the with the pedal on, I get decent volume when engaged that quickly drops off (fraction of a second basically) and the sound is then well below unity gain.  I hear distortion so it's clipping, but for some reason, even with max volume, I'm getting less than unity gain.  I'll poke around and check values but was curious if what I was finding could be caused by the low hFe on the transistor or something similar.

Thanks for any help!  Will update and provide photos once I get a chance to go over it and verify everything again...

Build doc used provided below for reference...
« Last Edit: December 28, 2017, 09:00:09 AM by cajone5 »

midwayfair

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Re: Clipper Ship Question
« Reply #1 on: December 27, 2017, 10:58:56 AM »
Take voltages for me on all the transistor pins and find a Datasheet for the ge transistor you used.

Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

cajone5

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Re: Clipper Ship Question
« Reply #2 on: December 27, 2017, 11:32:50 AM »
Voltages coming later...

I think I got them from eBay but they look just like this...
http://www.smallbear-electronics.mybigcommerce.com/2n1101-house-number/

Can't seem to find a full datasheet, but found this...
https://alltransistors.com/transistor.php?transistor=402
http://www.datasheets360.com/pdf/-1082953503728154001

Voltages and photos coming soon.

cajone5

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Re: Clipper Ship Question
« Reply #3 on: December 28, 2017, 08:59:47 AM »
SMH... I have made the simplest mistakes on my past few builds.  I guess this is what happens when you build in short sprints with long gaps between... lack of continuity from start to finish and limited time means stupid mistakes.  And this is a new one, I haven't seen before...

Forgot the CLR and the power supply limited the current to a degree where the LED hung on.  When I went to check voltages, I pulled out my one-spot and boom, bright flash on the LED and then nothing.  Then I realized there was no CLR... smh.  Once I replaced the LED and added a CLR, everything worked just fine.  I guess the LED was pulling all the current and the low output was due to not having enough current to drive the thing.  Crazy.  Sounds good at very low volume this morning.  Now that it's working, I'll clean it up, solder in my working 2N1101 (hfe = 45) and maybe play with R3 a bit to make sure I'm going to be getting a good range of gain and output without ending up with settings where I can't bring things back to unity.

Oh, and I'll see if adding D2 matters.  Does this diode do anything tonally?  Any forward voltage range to stick with?  The build doc says to use Ge there with a Ge transistor, but that's it.  Suggestions are appreciated.  Thanks!

warriorpoet

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Re: Clipper Ship Question
« Reply #4 on: December 28, 2017, 09:21:16 AM »
SMH... I have made the simplest mistakes on my past few builds.  I guess this is what happens when you build in short sprints with long gaps between... lack of continuity from start to finish and limited time means stupid mistakes.  And this is a new one, I haven't seen before...

Forgot the CLR and the power supply limited the current to a degree where the LED hung on.  When I went to check voltages, I pulled out my one-spot and boom, bright flash on the LED and then nothing.  Then I realized there was no CLR... smh.  Once I replaced the LED and added a CLR, everything worked just fine.  I guess the LED was pulling all the current and the low output was due to not having enough current to drive the thing.  Crazy.  Sounds good at very low volume this morning.  Now that it's working, I'll clean it up, solder in my working 2N1101 (hfe = 45) and maybe play with R3 a bit to make sure I'm going to be getting a good range of gain and output without ending up with settings where I can't bring things back to unity.

Oh, and I'll see if adding D2 matters.  Does this diode do anything tonally?  Any forward voltage range to stick with?  The build doc says to use Ge there with a Ge transistor, but that's it.  Suggestions are appreciated.  Thanks!

D2 keeps Q1 temperature stable, nothing more. fV shouldn't matter as ong as its germ.
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