Signal level to hot for flanger?- weird noises now

Started by Thump-Lump, July 30, 2011, 04:04:06 PM

Previous topic - Next topic

Thump-Lump

Someday, I will learn not to do dumb things but...........  So I read where sometimes a BMP will sometimes sound better with a hotter signal.  So I plug in a cheap ART TubeMP pre between the guitar and the BMP.  I also had the BYOC Flanger after the BMP and then to the amp.  OK.....Experiment done (not impressed with any change) and now, while the BMP is fine, I am getting some noises out of the flanger.  Electronically speaking, I'm as dumb as a box of rocks and have NO idea where to even start looking as to what may be the cause.  Below is a link to the schematic as well and a recording of the noise posted to YouTube and recorded on the clean channel with the gain all the way up to get a good recording level.  And of course, I would like to THANK ALL that are willing to help me sort this out.

http://buildyourownclone.com/flangerscheme.pdf




LP Hovercraft

So the dirty record sound goes away as soon as you turn down the BMP volume control?  If so, I'd speculate that you may have a poor solder point somewhere in your flanger.  It may not even to be serious enough to be audible until you have fed it that boosted signal coming out of your BMP.  Also, in my experience with flangers that are designed for low level signals that they will prefer a smaller signal coming into it for maximum richness of effect.  I had an Ultra-Flanger that would get more subtle the more signal I fed it.  Also, are you saying that your BMP sounds best when fed a hot signal?  That can be attenuated by the BMP's output volume control.  If you are talking about feeding a loud and fuzzy signal into the input of a tube amp for extra richness, one could also go BMP>Flanger>Clean Booster (LPB-1, MOSFET Boost etc..)>Amp.  Hope that helps!

LP Hovercraft

The last chain described is a BMP whose volume is set for around unity gain into the flanger, then all is boosted into the amp input.

Thump-Lump

I'm sorry, I should have clarified.  Like I said,  I'm not the smartest rock in the box!   ;D  The recording is just the flanger into the amp.  Nothing plugged into the "input" side of the flange. This was to eliminate the normally small amount of noise the BMP generates.  The BMP is fine.  I believe that I just fed the flanger to hot of a signal and cooked something.

Since my first post, I have been going through all the resistors to see if any are fried.  As of right now, I am mostly through all of them.  I will post what I find as some don't measure correctly.  Though, that may be because they are still in the circuit.  But, my guess is IC1b, the RC4558 but, I haven't a clue how to check it.

John Lyons

It's not really possible to fry something from a pedal being too loud into another pedal.
Plugging your amp's output in to a pedal will...you know but what you describe
does not sound like the culprit.
Basic Audio Pedals
www.basicaudio.net/

Thump-Lump

Got all the resistors checked and will post what I found tomorrow.  Must......Go.......To.......Sleep........Now.   :icon_rolleyes:

Thump-Lump

So I went and re-read the debugging sticky post and made a rig to eliminate the PSU running the BYOC flanger (No room inside for a battery) and plugged in a new 9vdc battery to eliminate the possibility that it was the PSU.  Powered it up, flanger out to the amp and no other connections, and no change.  It still sounds like the YouTube audio clip I post earlier.

My thinking is that the hot signal from the ART pre-amp passed through the BMP and didn't damage anything but when that hot signal got to the BYOC flanger, it cooked an IC.  But, I really don't know.  That is just a guess.

I went ahead and checked what I know how to do and checked all 58 resistors.  These where ALL checked in the circuit and I THINK that is why I am getting weird readings on a few of them.  On the ones that I got readings that where off, I doubled checked the bands to confirm that they were what they are suppose to be.  All the bands read what was suppose to be there.  All the resistors that read weird where in groups which makes me think that because they were checked in the circuit is the reason for the readings being off.

They are....

R36 - 68k......Read 42.5k
R37 - 150k.....Read 42.5k
R38 - 470k.....Read 44.7k

R44 - 10k......Read 5.6k
R45 - 10k......Read 5.6k
R46 - 220k.....Slowly climbs to 151k
R47 - 470k.....Slowly climbs to 155k

R53 - 10k......Slowly climbs to 7.5k
R54 - 10k......Slowly climbs to 7.5k
R55 - 10k......Slowly climbs to 7.5k
R56 - 10k......Slowly climbs to 7.5k

It took about 2 hours to get all these readings and make sure they were as accurate as possible.

Anyone that can tell me what to check next to isolate the problem, please help.  I refuse to accept that I have a few month old, $120.00+  door stop that has worked fine until now.  :icon_lol: