GGG ITS8 help

[iainpunk]

I was thinking since I have them in a socket now,  I  could pull them and see if there is any difference in sound.

try 4148's in those sockets, it should sound the same as the other 4148's, if not, there is a problem with the tracks or the switch.

cheers, Iain

[Phoenix60]

Fixed!  I put the diodes in the LED sockets and it sounded same as the other diodes. I put new LEDs back in and I can hear a difference, although it's not profound. 

This is my first build and if there is one thing I wish I would have known before I started it is to use sockets for the LEDS and diodes.  That would've saved me some serious debugging time.

Thanks to all for the help and patience.

Ed

[EBK]

Fixed!  I put the diodes in the LED sockets and it sounded same as the other diodes. I put new LEDs back in and I can hear a difference, although it's not profound. 

I've got my rebuild on the correct side of the enclosure face now, but I have a few wires to hook up.

After I get it wired, I may record a quick demo for you to compare what you are hearing to what mine sounds like.  The differences in the toggle settings should be very noticeable.  Perhaps your gain is too low?

[Phoenix60]

That would be great thanks

[EBK]

So, I attempted to record a demo with not-so-great audio quality, and I discovered something interesting. While videoing this, the three modes (Si, followed by LED, followed by Open) sounded distinctly different, especially in volume.  Upon playback, the differences were less pronounced.  I believe it is because I used my phone, which compressed the audio.  If your amplifier compresses a lot, then the LED clipping will probably sound similar to the Open mode.  Just another guess.  I didn't have time to explore it more fully.

The LEDs definitely glow when they clip, by the way, but you have to dim the room lights to see them.

[willienillie]

Dean?

[EBK]

Dean?

Yep.  It's my flea market amp that I've mentioned a couple times. I use it for all my testing. I know it is weird to test an overdrive this way, but I'm ok with it. 

Edit: Better angle.

[willienillie]

Roger that.  I was just trying to figure out the logo.

[Phoenix60]

Thanks EBK, I would say mine sounds very similar to the video recording.  Lifted position is louder than LED but not drastically so, and they both sound nearly the same in tone
to my ear.  I'll check again to see if they glow.  The silicone diode position sounds drastically different in volume and tone.

[Phoenix60]

Well I guess it's not fixed    LEDS are not glowing.  I know the LEDS are good, and I measure voltage there.  Is it a switch issue?

[EBK]

Is it a switch issue?

That would be a good place to check.  Test for continuity at the board pads for each switch position (with the power disconnected).  Or, you could reflow the joints and try it again. 

[bluebunny]

LEDS are not glowing.

Are you testing in the dark as Eric suggested?

[Phoenix60]

Yes I am testing in the dark.  Here's a pic of the wiring diagram:


As you're looking at the underside of the switch, I have the left lug wired to C3, middle lug to C2 and right lug to C1.  So if you numbered the lugs, left to right 3, 2, 1 this is what I get while checking for continuity:

C-continuity
NC - np continuity
D3, D4 - these diodes light up

Mid switch position        Lug 3     Lug 2     Lug 1
C2                                 NC         C            NC
C3                                 C           D4          D4
C1                                 D3         NC          C

Right switch position        Lug 3     Lug 2     Lug 1  I think this is SI position
C2                                 D3         C            C
C3                                 C           D4          D4
C1                                 D3         C          C

Left switch position        Lug 3     Lug 2     Lug 1  I think this is LED position
C2                                 C         C            D4
C3                                 C         C            D4
C1                                 NC        NC          C

Apologies if this is overkill, and for my lack of understanding.  I really appreciate the help!

Ed

[EBK]

I have a massive amount of pandemic-avoidance fatigue that is preventing me from deciphering that due to the line wrapping skewing it all.  Sorry.   

When your switch is in the LED position, do you have continuity between pads C2 and C3 on the board?

[Phoenix60]

No problem!  Yes I have continuity between pads C2 and C3 in the LED position.

[Phoenix60]

Just to wrap this up, I put silicone diodes in place of the LEDs as Iainpunk suggested, and I forgot to do.  The sound was exactly like the other silicone diodes in the board.  So I replace the LEDS and it sounds the same as the lift position, and for the life of me I can't see them light up.  I put in different LEDS and those didn't light up either.

I'm sure I'm wearing on everyone's patience, but is there anything else i can check?

Thanks,
Ed

[EBK]

Assuming your LEDs are good, then it seems like your signal isn't reaching the clipping threshold of those LEDs.  I'm going to peek back at some of your previous data/pics to see if I spot anything.

Could you double check that you have the correct potentiometer values in the correct spots (especially the drive pot)?

[Phoenix60]

Thanks, I double checked and I have the potentiometers wired according to the diagram and the drive pot is 500k, tone is 20k and volume is 100k

[EBK]

And, the LEDs won't light up even when your drive pot is turned the whole way up?

[Phoenix60]

No   I've got the drive all the way up and I'm strumming hard.