Author Topic: Beginner Project Built...but...tone questions  (Read 12522 times)

Beginner Project Built...but...tone questions
« on: July 10, 2011, 10:05:54 PM »
I built the booster and it works as expected! However, the original circuit was extremely dark, like the tone knob on the guitar was rolled down.
I looked around this forum, and found that someone else had this problem, and fixed it by replacing the input cap.
.1uf input cap just got replaced by a .047 uf cap...the excessive bass is gone and sounds MUCH more like my normal tone, but I still have a question:

Despite the bass being decreased, (a less muddy sound than before) the pedal is still decreasing treble significantly. Is there a part substitution I can make that will definitely allow more treble through?

Thanks! This hobby has been a lot of fun getting into!

aron

Re: Beginner Project Built...but...tone questions
« Reply #1 on: July 11, 2011, 10:28:51 AM »
There's nothing in the original circuit that makes the sound more muddy that I have found. If it does sound more muddy there's probably an error somewhere.

Re: Beginner Project Built...but...tone questions
« Reply #2 on: July 11, 2011, 10:36:35 AM »
What kind of error do you think would cause this?
Where is the most likely place in the circuit/offboard for me to be bleeding high end? (sorry, thats probably a difficult question.)

For the most part, I used the components specified, except for the 47uf cap on the volume pot. I forgot to order that part (duuuhh), but I did a little research and discovered I could use a pair of 22uf caps in parallel. Is it possible that's having a negative impact on something?

Thanks for the help! great site.

aron

Re: Beginner Project Built...but...tone questions
« Reply #3 on: July 13, 2011, 07:23:39 AM »
It would be something that is bleeding the highs to ground. Hmmm maybe somewhere around the input section?

Scruffie

Re: Beginner Project Built...but...tone questions
« Reply #4 on: July 13, 2011, 07:47:22 AM »
What's your set up like, lots of long leads? Maybe you need a buffer.

Re: Beginner Project Built...but...tone questions
« Reply #5 on: July 13, 2011, 10:50:11 AM »
aron - interesting. I didn't plan the inside of my enclosure very well...basically I forgot to allow space for ummm lets see - ANYTHING X(
the result being I was in fact having some problems screwing in the back of the box - components on the board were being squished into the input jack and shorting out.
I thought I had solved that problem by smothering the inside of the box in electrical tape. (lots of electrical tape. lol)
it seemed fine, but maybe there's still something going on with that. I shall fiddle.

Scruffie - what do you mean, lots of long leads? on the circuit board? or on my setup (guitar, amp etc.) as a whole?
The bypass signal through the boost is fine, plenty of highs. It's just when the booster is engaged that it drops that high end.

Gus

Re: Beginner Project Built...but...tone questions
« Reply #6 on: July 13, 2011, 10:51:30 AM »
It should not need a buffer.

Check that the 22uf + goes to the 10k, 100k and 47k node and the 22uf - goes to the emitter.  Without the bootstrap cap it will have a low input resistance.

The circuit should be fairly clean at the min gain setting of the 5k potentiometer.   The input resistance is at it max and the gain is at min(about x2) with the gain control at min.

wavley

Re: Beginner Project Built...but...tone questions
« Reply #7 on: July 13, 2011, 11:46:54 AM »
Yeah, I still use mine and haven't had a treble problem at all.  I took mine and built it on the return of an effects loop to take care of the volume drop from my small stone and Morley PFL.
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Re: Beginner Project Built...but...tone questions
« Reply #8 on: July 14, 2011, 11:07:46 AM »
I checked the bootstrap cap, and it seems to be nicely connected to all three resistors and the transistor.
How would I diagnose where a grounding leak at the input is occuring? Is there something I should check with my multi-meter?
Also - how about fixing the problem by modifying the circuit a bit more - I did a search on this forum and found this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=82313.msg682968
So according to that last post, I could possibly turn my booster into an actual treble boost with a lower value bootstrap cap?

Thanks for putting up with yet another n000000000000bbb