Author Topic: Aron, someone anyone, I NEED HELP  (Read 9503 times)

boedonaldson

Aron, someone anyone, I NEED HELP
« on: December 04, 2005, 06:54:25 PM »
This is never ending, ive checked the circuit and everything is fine, perfect, the grounding point are all connected to either a ground point on my jack ground points or at a common point so its not a grounding problem. Im using a BC549 tranny 5089 or88 equivalent) and the voltages are as follows
Battery; 8.27V
C-7.36V
B-7.48V
E-8.20V
I have been at this project for months and i cannot seem to get it, ive got some more bass added to my signal due to teh input cap (0.12uf) so i know something is workin, but no actual boost at all. When there is distortion or overdrive running through the unit it also buzzes a heap nearly to a volume that matches the signal. At least i got a signal through the thing this time. Some help on the subject please, or would you recommend a even easier project (not a True Bypass Box, i can do switches fine)

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #1 on: December 04, 2005, 11:59:28 PM »
There's a miswire in there. Look at the base, emitter values - way too high. If you can post a picture, that will help us figure out what's going on.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #2 on: December 05, 2005, 02:26:49 AM »
By The way the voltages are the same with teh tranny in or out of the ocket. Quick question, how do i post pictures or get them displayed

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #3 on: December 05, 2005, 03:08:09 AM »
Yeah, a miswire. Look in the about this forum.... thread in the main forum. The last post in that thread tells you how to upload it to the gallery.

http://www.diystompboxes.com/smfforum/index.php?topic=21.0

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #4 on: December 05, 2005, 03:43:28 AM »
Sorry bout the picture quality but its the best i can do
In the picture of the solder joints underneath the circuit has basically been flipped with the 10uf cap at hole 55F (positive side hope this helps but i cant fault my build maybe you can Aron



boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #5 on: December 05, 2005, 03:46:18 AM »
By the way it is not wired with a switch and teh 5k pot has two sets of lugs and the lug that has two ground wires from it, i have put one on the corresponding lug (pot can be used for controlling two things?)

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #6 on: December 05, 2005, 12:54:02 PM »
Take the 9V black and attach it directly to ground (green wire strip). Now measure the values.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #7 on: December 05, 2005, 04:28:54 PM »
Aron tried that, It works, in my mind it does, has a fuzzy sound when turned up all the way?
Here are the voltages now
Bat-8.24V
C-8.16V
B-7.5V
E-7.22V

I decided to ground all my ground points to that strip also. I must point out that the 10k resistors are actually like 12k, does this matter at all? And what type of tranny should i use to get a cleaner sounding boost. Also what input cap should i use for a more treble/midrange boost.
My test setup follows: Gibson Les Paul Standard->Boost->Marshall 100HDFX Head and Cab (solidstate device) (would it work better with a tube type amp?

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #8 on: December 05, 2005, 05:32:38 PM »
When you are doing the measurements, do you have the black probe on the ground (green wire strip) and the red on the test points?

The base and emitter values are just too weird.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #9 on: December 05, 2005, 05:47:40 PM »
I have the ground point on the ground of the battery and probe with teh red (the + terminal is plugged in), its really fuzzy though, Im a noobie but maybe a bias problem?

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #10 on: December 05, 2005, 06:50:00 PM »
Put connect the battery black (ground) to the stripe where the green wire connects to. Also connect the black probe to that strip as well when measuring. See if the measurements change.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #11 on: December 05, 2005, 08:25:24 PM »
Ok heres the readings with the probe on the black strip
Bat-8.28V
B-2.63V
C-2.42V
E-1.94V

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #12 on: December 05, 2005, 08:33:54 PM »
So the battery is directly connected (both wires) to the board?

The collector is way too low. Is this with the transistor removed? If so, you have a miswiring from the red battery strip to the collector strip somehow.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #13 on: December 05, 2005, 08:50:44 PM »
Yeah the battery is connected directly to the board, its strange eh. This is like my 8th attempt. At least i got some kinda boost though. The reading was with the tranny in so i dont know what the prob is (tranny BC549) Would you like me to post some more close up pics. Its hard to keep in touch being in different time zones to as im from Aus so sorry if it takes a while for me to reply or i reply at like 2.00am in the mornin. Just one more thing could it be because the electro caps have stuffed up due to to much heat during soldering (just a thought) or any components?

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #14 on: December 05, 2005, 09:03:28 PM »
OK, pull the transistor and test the collector voltage.

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #15 on: December 05, 2005, 11:38:23 PM »
Collector ended up with 8.09V without the tranny in it

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #16 on: December 06, 2005, 11:39:21 AM »
That is too weird. Can you try with a typical transistor: 2n2222, 2N3904??? Oh, please give me the voltages without the transistor on all 3 "pins".

boedonaldson

Re: Aron, someone anyone, I NEED HELP
« Reply #17 on: December 06, 2005, 03:32:21 PM »
Bat- 8.26V
C- 8.10V
B- 2.52V
E- 0.00V
Without tranny in.
what would be a 2n2222, 2N3904 euicvalent in the BC series of trannies?. Also another quickie. Would could be used to substitute the BS170 MOSFET in the AMZ Mosfet Boost?

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #18 on: December 06, 2005, 06:16:12 PM »
BC108???

I'm guessing it's the transistor at this point. Those voltages look much better.

aron

Re: Aron, someone anyone, I NEED HELP
« Reply #19 on: December 06, 2005, 06:17:54 PM »
Yes, BC108 - I found this great page:

http://www.kpsec.freeuk.com/components/tran.htm