:( Prehistory
After few months I decided to use my SeaUrchin again. For some reason it is not working. I tried so many times and things didn`t get any better. So I said to myself " Build another one!"
After some reading I ended with Hamlet.
One sub (because here I can`t find them) 1n5817 changed to 1n5819
I`m using TC1044SCPA
http://i608.photobucket.com/albums/tt164/kokySX/21122013242_zps986fe908.jpg
http://i608.photobucket.com/albums/tt164/kokySX/21122013243_zps81a948a3.jpg
http://i608.photobucket.com/albums/tt164/kokySX/21122013241_zpsa91a8cbf.jpg
What is the problem then?
It seams to work somehow because the status LED is working but I don`t have neither bypass or wet (IS that the right term) signal.The only thing is noise, motor-boating and iiiiiiiiiiiiiiiiiiiiiiiiii.... If I turn LEVEL trim CW or CCW it works. If I turn REPEATS pot it is getting faster or slower (that iiiiiiiiiiii is what I mean).
My DC adapter shows 10.80 v but regardless of that here are some voltage readings:
I. 1044 - I used socket and have cut pins 4 to 7 as it is mentioned in build document
1. 10.70 5. 2.72
2. 9.70 6. 9.07
3. 9.17 7. 8.60
4. 2.78 8. 10.70
I know that this IC is voltage invertor and some of these values should be negative but this is what I have
II. 78L05 IN - 10.70 GND - 9.19 ???? OUT - 9.44 ???
III. 2399
1. 9.43 16. 8.11
2. 0 15. 8.09
3. 3.07 14. 8.67
4. 2.44 13. 8.72
5. 8.72 12. 8.71
6. 8.78 11. 8.72
7. 8.78 10. 8.71
8. 8.71 9. 8.68
There's something wrong with your regulator ... actually a couple things.
First, the center pin does not appear to be connected to ground. Fix that first and see if it results in 5V output.
Actually, there's a whole host of places you should be getting ground but you don't seem to be. What are the voltages on your transistors? Did you triple check all ground points on the layout with your multimeter?
Second, there are two types of regulators, the "L" which doesn't have the heatsink and without the "L" and they have opposite pinouts. If grounding the center pin doesn't fix it, you might want to turn the regulator around.
The chip is not a voltage inverter. It's a charge pump. It boosts the voltage on the audio path to +18V.
Finally, can you snap a clear picture of the underside of the board?
EDIT: Remove the PT2399 while you're getting the regulator working. Feeding it 9V could result in a dead chip. Get the 5V working first and then you can put it back in. Have another PT2399 ready to go just in case this one fried.
Here is a better pic of bottom side
http://i608.photobucket.com/albums/tt164/kokySX/Picture_zps3fd18088.jpg
You are right center pin is not connected to ground . Rookie mistake.
Quote from: koky on December 21, 2013, 08:50:57 PMRookie mistake.
Eh, I miss stuff all the time...
Your perf work is really good. Mine rarely looks that tidy. :)
Grounding middle pin of Q3 - solved. Now I have 5 v on pin1 2399.
There is bypass and wet signal. :D
But... like always happens to me ... I don`t have spare 2399 and tomorrow is Sunday and ##*@#!*!#!# I`ll have to wait till Monday.
Bought some new IC`s today and here is what is going on after I put the new one - oscillation even with the bypass (preamp) and sound is kind of dull and distorted. Meanwhile I realized that one of the pins of Q2 is not soldered - now it is. These are the missing solder joints http://i608.photobucket.com/albums/tt164/kokySX/ad27aeb2-2b64-49b3-aa62-a2ae6714c97e_zpsf94e8e45.jpg
Then I forgot to put Q2 back and plugged the pedal again to see if this is the problem. WOW what a nice clean sound on bypass and wet ... DANG ... I saw that 2n5457 is not on its place. Put it back in and oscillation is back.
Any suggestions what to do now?
And Midwayfair thank you for kind words. It feels so good to receive approval from someone like you.
Quote from: koky on December 23, 2013, 09:54:16 PM
Bought some new IC`s today and here is what is going on after I put the new one - oscillation even with the bypass (preamp) and sound is kind of dull and distorted. Meanwhile I realized that one of the pins of Q2 is not soldered - now it is. These are the missing solder joints http://i608.photobucket.com/albums/tt164/kokySX/ad27aeb2-2b64-49b3-aa62-a2ae6714c97e_zpsf94e8e45.jpg
Then I forgot to put Q2 back and plugged the pedal again to see if this is the problem. WOW what a nice clean sound on bypass and wet ... DANG ... I saw that 2n5457 is not on its place. Put it back in and oscillation is back.
Any suggestions what to do now?
What type of oscillation? power whine (super high pitched), or the PT2399 is oscillating a lot?
What are your voltages like now?
I`m not quite sure but it sounds more like high pitch.
1. 10.50 5. 0.30
2. 4.60 6. 4.77
3. 0.00 7. 5.16
4. 0.14 8. 10.56
1. 6.07 16. 4.27
2. 3.03 15. 0.10
3. 0.01 14. 4.89
4. 0.01 13. 3.05
5. 3.52 12. 2.21
6. 3.04 11. 3.05
7. 1.86 10. 3.05
8. 3.97 9. 0.30
78L05 IN - 10.60 GND - 0.01 OUT - 6.09
bc549 LEFT - 8.50 MID - 2.54 RIGHT - 8.55 (Top view like on the build doc)
2n5457 TOP - 5.70 MID - 0.40 BOTTOM - 0.00 (Top view like on the build doc)
Is the emitter resistor on your BC549C grounded? The emitter voltage should be maybe a couple of volts at most.
Your 2N5457 should also have something more like 10V on the collector.
Your multimeter seems to be reading about 10% too high, too. Might be time to change the battery.
After you fix the emitter on Q1:
What are you powering it with? Try sticking a 100R in series with the power supply (use alligator clips or something if you have to). Does the noise get quieter?
Also, do you have any delay? Or is the chip still motorboating?
Witch one is emitter resistor of Q1? If 1K then it is grounded witch means that my trany is reversed isn`t it?
bc549 E - 8.17 B - 2.10 C - 7.09 (plugged like on build doc) C - 8.17 B - 2.10 E - 7.09 (reversed) if that makes any sense!
2n5457 Drain (E) - 7.05 Source (B) - 0.35 Gate (C) - 0.00
DMM fixed.
I`m powering it with old router power supply only reversed -/+.
Don`t have any delay and the chip is still oscillating.
Quote from: koky on December 24, 2013, 12:26:02 PM
Witch one is emitter resistor of Q1? If 1K then it is grounded witch means that my trany is reversed isn`t it?
I drew the layout for a 3904. The BC549C has a reversed pinout. The emitter of whatever transistor you use goes on the right.
If you can set up an audio probe, I need to you follow the audio through the schematic and tell me where the oscillation is introduced. Set the repeats to zero for now.
Schematic is here for reference:
https://docs.google.com/document/d/1P7uOYFRH6ZW5eGoquhAiMQMyUU76bod_gNKkiSlPNJM/edit
Shame on me but I don`t know how to follow schematics! ::) I am in process of learning all this.
But I have come to this:
1. As soon as I plug Q2 in its place and begin to turn Repeats pot oscillation occurs. Delay pot slows or fastens oscillation.
2. If Q2 is out nothing of the above mentioned is happening.
3. I think that somehow I managed to solder the switch wrong. What I mean. When switch is off (LED not light) see point 1. and when switch is ON (LED light) I THINK it activates preamp section of the pedal.
Speaking of this do you think that the problem is Q2?
After some reading I decided to sub 2n5457 for BF245A. A little step forward because when I turn R and D pots I don`t have immediate oscillation. I`ve found also that I soldered Mix pot maybe wrong because when I turn it CCW oscillates -> CW stops oscillating. Pot is B50K - how to make it B25K?
And suddenly when I was playing with trims I touched with screwdriver pin 13 (?) and I heard repeats. But not repeats of guitar but like when you short something. All pots were full CW and I started to turn them. They behaved like they should ( I have had Sea Urchin and I know what to expect)
What do you think?
Quote from: koky on December 24, 2013, 08:04:31 PM
After some reading I decided to sub 2n5457 for BF245A. A little step forward because when I turn R and D pots I don`t have immediate oscillation. I`ve found also that I soldered Mix pot maybe wrong because when I turn it CCW oscillates -> CW stops oscillating. Pot is B50K - how to make it B25K?
And suddenly when I was playing with trims I touched with screwdriver pin 13 (?) and I heard repeats. But not repeats of guitar but like when you short something. All pots were full CW and I started to turn them. They behaved like they should ( I have had Sea Urchin and I know what to expect)
What do you think?
The repeats pot is a HUGE reason you're having the oscillation issue (also, it sounds like it could be backwards ... pin 1 should be ground). Anything above 25K will oscillate at like 9:00, and it should be an audio taper for best performance. The reason it's a smaller value -- and oscillates easier -- than other PT2399 delay designs is that there is far less filtering in the delay path, so more signal is present. The smaller value on the pot help correct this without relying on extra filtering.
Here's the required reading for calculating the resistors needed to make your 50K pot a 25KA:
http://www.geofex.com/article_folders/potsecrets/potscret.htm
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
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.
One more thing if it is not too late for this. I`m using TC1044SCPA instead of MAX. Can this be the solution?
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.
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.
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.
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.
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?
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).
:-[
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.
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.
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)
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.
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.
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!
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. :)
Couple more question. Can I wire this pedal with standard MB wiring diagram (for true bypass) and is there a way to make status LED blink with repeats?
Happy New Year
Quote from: koky on January 01, 2014, 09:45:04 AM
Couple more question. Can I wire this pedal with standard MB wiring diagram (for true bypass) and is there a way to make status LED blink with repeats?
Happy New Year
To get an LED to blink in time with the PT2399, you need something that can convert a clock signal into a control voltage.
http://www.diystompboxes.com/smfforum/index.php?topic=102660.0
or you can add Tap Tempo with the Taptation, which has its own LED drivers.
For true bypass, yes, you can use the MB standard wiring diagram instead of the DPDT footswitch wiring in the build document, but you must jumper the connection to the delay line.