Build Your Own Clone Message Board

It is currently Fri Jun 21, 2024 4:00 am

All times are UTC - 6 hours




Post new topic Reply to topic  [ 50 posts ]  Go to page Previous  1, 2
Author Message
PostPosted: Tue Apr 18, 2023 6:49 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Here's the latest. This time I didn't use a battery, and used an adapter.. (see pics)

So... basically, readings are:

C = 45ish
B = 160-ish
E = 45-ish

...no idea.


Attachments:
IMG_7544.jpg
IMG_7544.jpg [ 143.82 KiB | Viewed 2887 times ]
IMG_7543.jpg
IMG_7543.jpg [ 190.72 KiB | Viewed 2887 times ]
IMG_7540.jpg
IMG_7540.jpg [ 43.76 KiB | Viewed 2887 times ]
Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 1:57 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
I'm still trying to figure out what the numbers that you're reporting could mean. They certainly don't reflect what I'd expect to see on the legs of the Q2 transistor.

It would be very helpful to establish that you're getting the required power into the pedal. Could you please take these two measurements:

  1. Plug that AC/DC adapter into the wall and then stick the red probe tip into the center of the plug and touch the outer sleeve of the plug with the black probe. This should read the voltage output of your P/S. See example photo below that I took using an inexpensive Electro Harmonix P/S that I often use to test pedals--it puts out slightly over 10VDC. Please post a similar photo here. (EDIT: That should have been "BLACK probe tip into the center of the plug and touch the outer sleeve of the plug with the RED probe.")
  2. Plug the P/S into your pedal, along with an instrument cable into the input jack, and test the DC voltage level at the + eyelet at the top of the board; black probe on the input jack sleeve tab, as before. See second photo below. Please post a photo for that test result, as well.

Attachment:
PS_voltage_check.jpg
PS_voltage_check.jpg [ 103.11 KiB | Viewed 2881 times ]


Attachment:
CF_power_in_test.jpg
CF_power_in_test.jpg [ 48.34 KiB | Viewed 2881 times ]

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 3:24 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
You aren’t going to like this, lol…

I also added a video of this, here… https://photos.app.goo.gl/wadjEND3ksmbouib6


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 3:26 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
oops.. forgot pic


Attachments:
IMG_7548.jpg
IMG_7548.jpg [ 163.78 KiB | Viewed 2880 times ]
Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 5:14 pm 
Offline

Joined: Mon Nov 23, 2020 1:39 pm
Posts: 188
Location: Vermont
hekkmart wrote:
You aren’t going to like this, lol…


It's very strange indeed. Have you tried measuring, with that multimeter, any voltages for which the correct answer is confidently known, such as a fresh 9 V battery, or a fresh 1.5 V or 1.2 V or 3 V cell? I would find the results you've reported so far almost plausible if each were divided by two (apart from the fact that the BIAS knob seems not to change the results). I'm never sure what to make of a multimeter that uses the same terminal for mA that it does for V or ohms.


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 6:28 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Yeah, on a brand new 9v battery I’m getting “1735”…. https://photos.app.goo.gl/wadjEND3ksmbouib6


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 7:29 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
Bad battery in the meter--that's what the symbol in the upper left of the display means. Replace and let's try this all again!

BTW, sorry for giving you the wrong directions on which probe went where on the P/S plug test; that's why you saw a negative voltage. My bad.... :roll: :oops:

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 7:40 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Lol. You’re right! I swapped it out, and the old battery reads 5.45. ..looks right!
I’ll have some new readings for you tomorrow. I appreciate it!


Top
 Profile  
 
PostPosted: Tue Apr 18, 2023 8:18 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Actually tried it again just now…

Still not great…

I’m not seeing a difference turning the bias knob

it’s staying consistent with…

C = .27
B = .92
E = .26

…regardless of bias knob position


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 10:22 am 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
OK, let's get a series of DC voltage measurements between the incoming power connection and the Q2 collector. Please take a voltage measurement at each of the five test points I've marked on the PCB diagram below:

  1. Incoming power @ + eyelet
  2. Left lead of 47R resistor
  3. Left lead of 330R resistor
  4. Middle lug of Bias pot
  5. Top lug of 4.7K resistor

As before, cable in the input, black probe on ground/sleeve of input jack, red probe on test point. Report your results here.

Attachment:
CF_VDC_test_points.jpg
CF_VDC_test_points.jpg [ 58.73 KiB | Viewed 2865 times ]

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 11:15 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Ok, I'm on it. (I'm not doing anything with the bias knob this time, am I?)


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 11:22 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
ok, here are the results...

1 = 9.49
2 = 9.47
3 = 9.47
4 = 9.47
5 = .27

so... that #5 is looking suspicious...


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 11:44 am 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
Yes, very. How did you have the Bias pot set? Try it set to full CW, if that's not where you had it. Does that voltage change at all when varying the pot setting? Also measure on the left-most pot lug, directly above the 4.7K resistor.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 11:55 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Both read at .26 - .27 ..regardless of where bias is set (referring to 4.7k resistor and the left-most pot lug)


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 12:08 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
OK, that appears to be a defective/damaged B10K pot. Contact sales@buildyourownclone.com and request a replacement (unless you happen to have one on hand!).

When you remove the existing pot, it's important to do it correctly to avoid damaging the PCB eyelets and making things worse. I strongly advise using the combination of a "solder sucker" and good quality desoldering braid:

https://www.amazon.com/TBBSC-Desolderin ... B08XQF9WYV

https://www.amazon.com/gp/product/B008O9VLA2/

Remove as much solder as possible from each joint with the sucker, then clean up the residual with the braid. Done correctly, the pot should literally fall out of the PCB once all the solder is removed. Do NOT try to force removal if even one leg is still stuck in the eyelet. Patience is key! You may need to desolder on both sides of the PCB if you can't get it all out from the top.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 12:14 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Ok! Thanks! ...I just sent them an email.

Really appreciate your help.

I already have that solder sucker thing, but I'll order the braid you recommended.

Do you know of a YouTube video that shows how to best do this? If not, no worries.

Thanks again!


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 12:16 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
BTW, anything else I should check? Or are we pretty sure that's "the" problem? Thanks!


Top
 Profile  
 
PostPosted: Wed Apr 19, 2023 3:14 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
hekkmart wrote:
BTW, anything else I should check? Or are we pretty sure that's "the" problem?

That's by far the most likely cause, but you might want to just check the resistance across the 4.7K resistor, and make sure that the left lug of the Bias pot doesn't have continuity to ground.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Thu Apr 20, 2023 6:00 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Great. The new pot is in the mail, as well as that braid.

..Can you be more specific on how to "check resistance" on that 4.7k resistor, and the "left-lug continuity to ground" ? ..Not sure how to check that. Sorry.

Thanks!


Top
 Profile  
 
PostPosted: Thu Apr 20, 2023 9:37 am 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
hekkmart wrote:
..Can you be more specific on how to "check resistance" on that 4.7k resistor, and the "left-lug continuity to ground" ? ..Not sure how to check that.

No problem.

Continuity Check: Two points in a circuit have continuity when they are directly connected with no significant source of resistance between them. In this case, we want to make sure that the left lug of the Bias pot doesn't have a direct or very low resistance connection to ground--if it does, your voltage will flow to ground rather than on through the 4.7K resistor to the Q2 collector. To check, disconnect power from the pedal and turn your multimeter to the continuity setting--it's at the low end of the resistance settings at the bottom of the dial, next to the "hFE" setting, and its icon looks like sound waves emanating from a point source. Now you just need to place one probe (doesn't matter which) on each test point, so one on the left lug of the pot and the other on ground (I'd stick with the sleeve of the input jack that you've been using). If there is continuity between them, the meter should give an audible "beep" sound; you can confirm this capability of the meter by just touching the probe tips together before you test on the pedal. If it's a non-beeping meter, just report the readout value you get.

Resistor Check: As I've thought about this, I've realized that a bad resistor in the R6 spot couldn't cause what you're seeing, so no need to do this. Still, it's a good thing to know how to do, so here's how. Leave the power disconnected from the pedal. Set the meter on the resistance setting that's the next higher value than your expected result--in this case, measuring a resistor of 4.7 Kohm nominal value, you'd set the meter to 20K. Then just touch the probes (again, it doesn't matter which) to the leads of the resistor and wait for the reading to stabilize. IMPORTANT: This method is often NOT reliable for resistors that are installed in a circuit! That's because of the very common occurrence of parallel circuit paths between the two points, which will lead to erroneously low resistance results. In this case, it works, but I don't recommend using the method generally, unless you have a very clear understanding of the circuit schematic you're working with. What this method is VERY useful for is verifying resistor values before they're installed in a circuit.

BTW, I have the R6 resistor spot socketed in my own Classic Fuzz, so I pulled out the resistor to simulate no voltage coming through to the Q2 collector from the Bias pot. I then tested the voltage levels on the Q2 legs:

C = .27
B = .93
E = .27

Essentially identical to what you've reported!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Thu Apr 20, 2023 11:24 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
Perfect. Thanks!


Top
 Profile  
 
PostPosted: Thu Apr 20, 2023 11:43 am 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
FYI, I did the continuity check, and no beeps or numbers, so I think that's all set.

I'll report back after desoldering and then installing the new pot. Thanks!


Top
 Profile  
 
PostPosted: Thu Apr 20, 2023 12:08 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
Sounds good. Once the pedal is working, if you find that you have to run the Bias control at or near full CW to get the sound you like, it's easy to adjust that by changing the R6 value to something lower. I actually have it jumpered (i.e. zero resistance between the Bias pot and the Q2 collector) on my own CF, but different transistors will react differently to that R6 resistance value, so see what you think when you get yours running.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
PostPosted: Mon Apr 24, 2023 7:58 pm 
Offline

Joined: Wed Jan 26, 2022 10:10 am
Posts: 38
It works! :o

First of all, Thank you so much for the thoughtful, detailed help. Very much appreciated!

I broke off a tab on the AC Adapter while doing all the re-work. But, managed to do a half-assed solder job just enough to make a connection. That got the bulb lighting up again…

But, I think I’ll order another AC adapter part and re-wire that. Right now it works, but it’s pretty fragile. But the proof of concept is that it works!

I’ll check out the bias adjustment option you mentioned later.

Thanks again!


Top
 Profile  
 
PostPosted: Mon Apr 24, 2023 8:10 pm 
Offline
Moderator
User avatar

Joined: Tue Jan 02, 2007 1:24 pm
Posts: 16252
Location: Albany, NY
hekkmart wrote:
It works! :o

Excellent news! 8)

hekkmart wrote:
First of all, Thank you so much for the thoughtful, detailed help. Very much appreciated!

You're most welcome--that's why we're here. :mrgreen:

hekkmart wrote:
I think I’ll order another AC adapter part and re-wire that. Right now it works, but it’s pretty fragile.

Good idea--replace it before it becomes a problem.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 50 posts ]  Go to page Previous  1, 2

All times are UTC - 6 hours


Who is online

Users browsing this forum: No registered users and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group