highway 89 question

[Andy73]

I just built this pedal based on the vero layout here

http://www.aronnelson.com/gallery/main.php/v/ulysses/ulysses_layouts/ulysses_dh_hwy_89/dh_hwy89_vero_ulysses_1_1.gif.html?g2_imageViewsIndex=1

It is working except the gain knob has no effect on the sound and there is very little gain.  The only thing I differently was put some resistors in series and caps in parallel to get the desired values.

Has anyone run into this issue before?  Am I missing something dumb?

Thanks!

[96ecss]

Hi,

The HWY 89 has alot of gain so something is wrong with yours. Please follow these instructions and someone will be able to help you http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Dave

[Andy73]

Thanks 96ecss!  Thats the swift kick in the behind I needed.  (no sarcasm intended here) Pedal is working now.  I'll post my process for finding the problem below and maybe be able to help some other newb out.


With a battery attached to the pedal and no cables plugged in I checked each leg of each transistor.  I found that Q1 was reading .607 on the center and 0 on the other two.  This was significantly different than the other two, that had to be my problem.  After looking and re-looking multiple times I finally found that I had cut a strip in the wrong spot.  I soldered up a jumper and drilled the strip in the correct location.

Now the pedal did not work at all.  The only clue I had was the battery was getting warm.  I believe it was on a discussion on this site that I read a warm battery means you have a short.  So I looked to make sure all my grounds and powers were secure and where they were supposed to be.  I then went back to the area where I had fixed the previous problem.  I measured Q1 again and found one of the legs giving me irratic values.  I followed the schematic in front and behind that location and found another strip cut in the wrong spot.

I fixed that problem and it worked!

So the moral here.....  Measure values as you begin debugging instead of just re-looking at your layout.  It may point you in a specific direction.

[96ecss]

Hi Andy,

My post wasn't meant as a kick in the behind, it's just that the info in the debugging thread really is the best way to find a problem. There have been many times I've built a pedal and had a problem then solved the problem myself just by going through the debugging process. Being able to find and fix a problem gave me a great sense of accomplishment when I was just starting out.

Well I'm glad you got it working. How do you like it? I've built so many overdrives that I barely use my HWY 89 anymore.

Dave

[Andy73]

So far its pretty good.  A lot more gain than I would ever use.  I may try to substitute a smaller value pot in there to be able to fine tune in the range I want it.  It does seem to exude good harmonics and sustain from my amp/guitar.  I like being able to dial in more bass for a bigger thicker sound without taking out top end.  I don't think this will be the last overdrive I build.....

[96ecss]

You can NEVER have too many overdrives. 

Dave

[mdh]

So far its pretty good.  A lot more gain than I would ever use.  I may try to substitute a smaller value pot in there to be able to fine tune in the range I want it.  It does seem to exude good harmonics and sustain from my amp/guitar.  I like being able to dial in more bass for a bigger thicker sound without taking out top end.  I don't think this will be the last overdrive I build.....

The Highway 89 excels in low gain territory if you just back off your guitar volume.  I still need to box mine up, but I think it's my favorite among the distortions I've built.

[DougH]

Check my gallery folder: http://www.aronnelson.com/gallery/main.php/v/DougH/

There's a soundclip of it there through a clean SS amp, humbucker bridge, S/C neck. That should provide a reference for what it should sound like.

[Andy73]

I definitely need to spend more time with it before I go and change anything for my needs.  I am playing through a tube amp at levels that will allow distotion with just the amp, so that may be part of the over the top distortion I am getting.  I also have not experimented much with rolling volume off the guitar yet.  Even with all that said I did get compliments on my tone this weekend.  Definitely headed the right direction.  If I remember correctly I was getting somewhere close to the sound in the clip with my guitar volume all the way up, SC neck pickup in my strat, and about 8 or 9 o'clock on the gain knob.

[m-theory]

I am playing through a tube amp at levels that will allow distotion with just the amp, so that may be part of the over the top distortion I am getting.

Freakish coincidence.  Same here, and I too just built this circuit and took it for a stage spin this past weekend as well.  For me, the amount of gain when it's dimed and the guitar is dimed is spot on, but the tone changes pretty dramatically from having the guitar volume anywhere below 8 to having it pegged.  Below 8, it's got this beautiful, crisp, articulate tone with wonderful note separation and clarity.  With guitar volume pegged, it compresses a bit and seems to turn into a fuzz, and that beautiful, rich clarity seems to get washed out.  And, this appears to be the case either through a clean or dirty amp, from what I've heard.  You can really notice it if you're playing through a really low volume, clean amp. 

I'm going to do some tinkering with this also...lower the output pot for sure, and experiment with the gain pot and transistors as well.  This circuit has got "the tone," without question, but I would love to get that throughout the guitar volume range.  If I can dial that in, this one is definitely going to find a happy place on my board.