Choral Reef not Chorusing

[WAXOU]

Hi All,

So, this weekend I've finally built the Choral Reef, but the only sound that I can get is almost like if Flipper the Dolphin was inside and wanted to communicate ! A kind of a tiny whinning.
The bypass signal is Ok though.

i've double checked my soldering and it seems to be okay.

However they're are some voltages that  have not the value that they should have :

TLE2074		CD4047BE
PIN	V	PIN	V
1	4,64	1	7,4
2	4,64	2	0,2
3	4,41	3	5,03
4	8,42	4	7,58
5	4,62	5	7,58
6	4,63	6	7,58
7	4,63	7	0
8	7,55	8	0
9	7,07	9	0
10	6,96	10	3,77
11	0	11	3,5
12	1,3	12	0
13	4,7	13	7,39
14	4,64	14	0
MN3008		LM358N
1	7,6	1	varies
2	3,5	2	3,75
6	7,3	3	3,47
7	7,3	4	0
8	0	5	varies
9	3,77	6	1,97
13	0,18	7	varies
14	0	8	8,42
5087		5088
PIN	V	PIN	V
C	0	C	8,42
B	5,5	B	8,18
E	5,2	E	7,58

Do you have any ideas on where to start the debugging ?

Thx

(In the meantime I'm gonna start the Tractor Beam, maybe I'll be better at it )

[WAXOU]

So, I've put the board back on the workbench, but still no luck.

Voltages on Pins 8, 9, 10 and 12 of the TLE2074 seems weird.
Same on the 14 of the CD4047 and 13 of the mn3008.

The first time I've tried the board, I forgot the reverse cap on the switching board, could this have damaged something somehow ?

[Scruffie]

Pins 8, 9 & 10 of the TLE2074 are biased by the BBD output and there's a problem with the BBD's pin 13 input bias voltage (which affects its output voltage)

I would double check your reading of the 4047 pin 14, it's connected directly to the 3008 pin 1 and T1's emitter and they both look okay.

Post up some photos of your board.

[WAXOU]

Thx Scruffie for your answer.

You're right, the pin 14 on the CD4047 is at 7,65V, I must have failed the first time I mesured it.

Here are some pics.

[Scruffie]

I'm not 100% sure but is R14 a 3k3 rather than 33k? I can't see R17 in your photos but check the value of that too... and the value of R16 just to be sure.

In the mean time could you post a photo of the back of the board too please and can you also double check your 3008 pin 13 voltage.

[WAXOU]

So, I've checked for R14, R17 and R16, they have the right values.
Since I'm colorblind I had to desolder them to mesure them, so in the mean time I change the mn3008 socket to be sure.

Pin 13 of MN3008 is still at 0,19 V.

Here are the back of the board. I'm ashamed of showing this mess, with all the solder/desolder the board is quite ugly now.

[Scruffie]

Where did you source the 3008 from? And if you remove it and test pin 13 does the voltage change?

[WAXOU]

Well If I remove the Mn3008, pin 13 is at 7,5V.

So I'm guessing I've got a faulty Mn3008.
I've sourced it at banzai music in Germany, where I've purchased several mn3007 before, so I was confident.

[Scruffie]

It's certainly a possibility, unless there is a short on the board.

However I think I recall someone else getting some bad chips from Banzai so it's possible they currently have a poor source for these parts.

[WAXOU]

I will source another one and let you know if it resolves the issue.
Thanks again for your help.