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Hamlet build on perfboard

Started by koky, December 21, 2013, 08:06:52 PM

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midwayfair

Quote from: koky on December 25, 2013, 03:25:23 PM
Managed to make that pot 25k. Thank you for the link.
I found another mistake. I have soldered both lugs of 220nF (blah). Now it`s how it should be.
But allow me try to explain what is going on.
1. Switch OFF -> Nice warm sound and when i turn Bias CW or CCW I have respectively more or less "room". I guess this is because of increasing or decreasing voltage if I understand the purpose of this trimpot right. If I turn LEVEL pot it goes quieter or louder.
2. Switch ON -> LED`s are light -> All of the above but there is no delay only oscillation when I play with rest of  the pots. I still have guitar signal going thru only that it is NOT delaying.
Prove me wrong but I think that somehow the signal bypasses IC2.

And Merry Christmas to all of you

The footswitch disconnects the input to the delay line. The delay itself is never shut off (tails). Thus, if the repeats are set to lots of repeats, it will carry over a long time. If you turn the repeats way up (past about 2:00) when you have it bypassed, it may self-oscillate even if you haven't played any notes.

One trim pot is a low-pass filter on the delay line. That's the one closer to the PT. It will make the delay repeats sound brighter or darker.

The other trimpot sets the bias for Q2. You have to use your multimeter and adjust it until the voltage on Q2's drain pin is about 10-12V. You can do it by ear, but it's better to at least start from that point.

If the oscillation you are talking about is the high-pitched whine, that is likely still a power filtering issue, or it could be related to the MAX chip. If you are no longer hearing the high pitched whine AND the delay does not oscillate until the repeats are above ~1-2:00, then the pedal is most likely working as it should.

koky

One more thing if it is not too late for this. I`m using TC1044SCPA instead of MAX. Can this be the solution?
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

koky

I am desperate! I really want to make this delay work but for 2 days I bang my head against a wall. I know that solution is simple.
Jon, you mean that when i switch on the input line then the guitar signal must pass thru PT2399, right? Coz that is exactly what is NOT happening. Guitar signal stays dry and on the background when I turn Repeats pot, after lets say 2:00 the oscillation occurs and when I touch with something pins of IC2  :-[(don`t laugh) I hear this: Shhh....Shhh...Shhh...Shhh...Shhh
I`ve checked all solder joints, all connections everything I can think of and still have no luck to make it work.
I know that I am annoying but I really want this pedal to be part of my chain.
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

Quote from: koky on December 27, 2013, 08:45:51 PM
I am desperate! I really want to make this delay work but for 2 days I bang my head against a wall. I know that solution is simple.

It wasn't clear that you still didn't have delay.

You need to audio probe the PT2399 to find where you are losing signal. Follow the schematic, and tell me what you have at each point in the audio path -- that's the collector of Q1, the emitter of Q1, pins 11-16 of the PT2399, and lugs 2 and 3 of the repeats and feedback pots. I need to know EXACTLY where the problem is occurring. Guessing won't get us anywhere.

You should also post updated voltages and updated pictures.

koky

  IC1 TC1044SCPA 
   1. 8.82    8. 8.82
   2. 3.86    7. 4.16
   3. 0.01    6. 4.02
   4. 0.10    5. 0.28
  IC2 PT2399
   1. 5.06   16. 2.13
   2. 2.53   15. 2.53
   3. 0.01   14. 2.53
   4. 0.01   13. 2.53
   5. 2.95   12. 2.53
   6. 2.53   11. 2.53
   7. 0.19   10. 2.53
   8. 0.60     9. 2.54

78L05  IN - 8.82 GND - 0.01 OUT - 5.05
bc549 
BIAS full CCW
E - 0.01
B - 0.49
C - 0.15
BIAS full CW
E - 0.01
B - 0.50
C - 0.17
BF245A ( sub for J201)
BIAS full CCW
E - 12.09
B - 1.86
C - 0.01
BIAS full CW
E - 0.68
B - 0.50
C - 0.00
With 0.1mF cap connected to out tip and other side with DMM lead when I strum there is guitar signal. As soon as I Q1 E sound disappears. Same happens when I touch 11 to 16 pins of IC2.

I still don`t have delay and still have oscillating pitch wine.
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

Q1 isn't hooked up to the power. The collector voltage should be closer to 12V. The tiny amount of voltage you have is probably just incidental from the base voltage.

It's hard to tell from your pictures, but double check the resistor that's just above the 549C on the far right of the perfboard layout. It's supposed to be 4.7K. In your build, it looks like it might be a carbon comp resistor (the picture is super blurry so I can't read the color bands on anything). Carbon comp resistors use a different color code for the multiple. Make sure it's not 47K. Or just make sure you didn't get it mixed up with the 4M7 that's right next to it.

Make sure your BF245 is in correctly. The pinout is backwards from a J201.

koky

Checked resistors and left one is  Yellow, Purple, Red, Gold (which is 4k7) and the right one is Yellow, Purple, Green, Gold ( which is 4m7 )
BF245 is plugged backwards. Flat side facing IC2.

Q1 - checked for continuity everything seems to be ok. Power for C Q1 comes from 4k7 resistor right?
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

Quote from: koky on December 28, 2013, 08:00:06 PM
Q1 - checked for continuity everything seems to be ok. Power for C Q1 comes from 4k7 resistor right?

Yes.

Something has to be wrong with Q1. Either there's a resistor wrong, a connection isn't made, you have a solder bridge, or there's something wrong with the transistor itself. There are only 5 parts hanging off of it, and only three matter as far as getting signal with your probe at the emitter and collector (the base, emitter, and collector resistors).

koky

 :-[
There is a missing bridge between 4m7 and 4k7 resistors. But that is something I will be able to solve tomorrow.
I will keep you updated with my build. Thank you for  your time and help.
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

Quote from: koky on December 28, 2013, 09:15:14 PM
:-[
There is a missing bridge between 4m7 and 4k7 resistors. But that is something I will be able to solve tomorrow.
I will keep you updated with my build. Thank you for  your time and help.

Glad you found the mistake! It's easy to miss stuff on perfboard, but it gets MUCH easier to find them with practice. And this was a difficult perf build, and my layouts are a little ... erm ... chaotic sometimes.

The good news is that I know your delay line is working -- you touched the chip and you got a delayed shush. Let me know if you have more problems.

koky

 8)
In my case it is said "Open your eyes!" . There is nothing wrong with your pref layouts I am the one who needs new glasses and patience to go slow.
I HAVE DELAY !!!
One more thing to mention. I have only one repeat at the moment but I broke my A20K pot (of course at Sunday) and replace it with A50K and if I am not wrong that is the reason for one repeat only. Wait till tomorrow to buy new one and a B25K and I will post results.

THANK YOU for your time.

Next on the line is Cardinal Tremolo ( with LDR/LED combination because here nowhere you can find Vactrols)
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

The A50K will work; it won't cause you to have one delay. We can put a parallel resistor on it later if the repeats are out of control. Double check the connections and wire/make sure none of the wires broke. If they're all solid, pull out the probe again, and follow the schematic from C9, R14, Repeats lug 3, C13, R8, and R6 -- that's the full feedback path and covers every part between the "first" repeat and the subsequent ones.

Quote from: koky on December 29, 2013, 05:45:18 PM
Cardinal Tremolo ( with LDR/LED combination because here nowhere you can find Vactrols)

That won't work. I haven't been able to find a discrete LDR with high enough dark resistance and low enough light resistance to reliably work. You can get the right vactrols on Ebay pretty easily. Also Smallbear sells them and, so far as I know, ships worldwide.

koky

Probe results
Where C9 (47nF) connects to R14 (2k2) signal becomes quieter but there is still repeat (one)
Repeats lug3, C13 (100nF), R8 (4k7) and R6 (10k) immediately after I touch them starts oscillation. So first I play a note and quickly touch with probe and tails are presented but still loudly oscillating and when I remove probe it stops.
"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

koky

D-d-d-d-e-e-e-e-l-l-l-a-a-a-a-a-y-y-y-y-y! ::)
Today I can say I am lucky! Bought new A20K pot and because in store they haven`t got any B25K I decided to buy B20K for MIX. When I went back home I soldered new pots plugged the pedal and everything is now as it should be.
Thank you Jon for everything and especially for this wonderful pedal!

"When you want something in life, you just gotta reach out and grab it." - Christopher McCandless

midwayfair

Quote from: koky on December 30, 2013, 05:47:03 PM
D-d-d-d-e-e-e-e-l-l-l-a-a-a-a-a-y-y-y-y-y! ::)
Today I can say I am lucky! Bought new A20K pot and because in store they haven`t got any B25K I decided to buy B20K for MIX. When I went back home I soldered new pots plugged the pedal and everything is now as it should be.
Thank you Jon for everything and especially for this wonderful pedal!

Glad you got it working, and thanks for sticking with it and working through each issue in turn. Hope you enjoy the delay sounds you get out of it. :)