[reggie]

Hello,

I just finished putting a G9 together. Then I powered up for the first time, the tubes heat up, the light comes on and everything seems to work. But when I hook up a microphone and turn up the gain and output, the output seems to work reverse turning and when I turn up gain beyond 5 or so I hear a horrible high squealing noise. Other than that there is only a (very faint) signal coming through. I already checked about the output pot wiring, that should be ok.

Now I suspect that maybe I made a mistake hooking up the two 10-pin wiring connectors from the main pcb to the control pcb´s.
On the schematic the main pcb connector says (from right to left) : To Outamp / Trafo - / Trafo + / Out - / Out + and so on ..
On the control pcb is written (from right to left): To Outamp / OUT - /OUT + /Trafo - /Trafo + / and so on ...
So the Trafo -+ and the Out -+ should be twisted? But I just wasn´t sure about this and hooked them up straight. So can it be that I made the big mistake there? I´d like to ask before I take it all apart again, as I said I was really not sure about this when I put it together.

Once I get it working and my knobs arrive I will post pictures soon.

thanks for any help,
reggie

[Emperor Tomato Ketchup]

Reggie,

It sounds like you might have the 10 pin connectors reversed (pin 1 plugged to 10, pin 2 plugged to 9, etc.).  Did you try plugging into the instrument in jack?  That seems to work somewhat even if the 10 pin connectors are backwards.  You might want to check those connections again.  I had mine reversed at first and had the exact symptoms you are describing.

-Chris

[reggie]

hi Emperor-TK,

I just checked the instrument in jack (which I hadn´t done the first time, I guess the disappointment was too big  :oops:   ) and it works, even though the output pot behaves the same as before.

I assume those little signs (stars) that are written on the pcbs next to the connectors on the left, mark which side is left /pin 1. That´s how I connected them. But as I said, maybe pins 6+7 which is out +/- from the main pcb),  ought to be connected to pins 8+9 at the control pcb ( and the same with the Trafo +- )I did not do that, instead I went "straight" through. So I just want to make sure this is wrong, before I change it.

Reggie

[Emperor Tomato Ketchup]

Hi Reggie,

The wires should not be crossed.  You are correct about the asterisks lining up with each other.  After that, no pins should be crossed.  6 and 7 should go to 6 and 7, etc.  Did you buy boards that had the legends printed on them?  The reason that I ask is that it can get confusing as to which way is up/down or front/back otherwise.  If you are looking at a finished unit from the front, the wire with the star (NC) should be on the left of the bundle on the control PCB, as well as on the main PCB.  If you were using a ribbon cable, that cable would not rotate from control PCB to main PCB.

Does this make sense?

[reggie]

so it looks like I did not do anything wrong there  :sad:
When I´m looking at the G9 from the front, the main pcb connector pin 1 (on the leftmost side where the asterisk is) goes to pin 1 (asterisk, left side) on the control pcb. I did not cross any wires (though I thought that I should have, since the writing differs on those 2 pcbs). I have the pcb from Gustav with the legends printed.

I hope I didn´t solder those rotary switches in the wrong way somehow ...

reggie

[reggie]

today I solved the problem and the G9 works great!

I had made a mistake hooking up the switching jacks, I wasn´t really sure how they are supposed to work. After taking a long look at the schematic I found the right way to connect the cables and all worked well.

I´m very impressed with the sound. I couldn´t stop playing my old Telecaster, it sounds amazing.

thanks for the help,
Reggie

[Emperor Tomato Ketchup]

:thumb:

Great news.  Rock on!

BTW, I have two G9's and my dog is named Telecaster.

-Chris

[Brizco]

hello

i have no clue how to connect the instrument in jacks!!

can someone help me?
thanxs!

[gyraf]

Briz,

Look at the schematic - it's simple enough:

The signal from the input transformer goes to the switching part of the input jack - so it is wsitched out whenever a jack is inserted. If no jack is inserted, it reaches the gain stages...

Jakob E.

[dukasound]

Hello,
On the schematic the main pcb connector says (from right to left) : To Outamp / Trafo - / Trafo + / Out - / Out + and so on ..
On the control pcb is written (from right to left): To Outamp / OUT - /OUT + /Trafo - /Trafo + / and so on ...
So the Trafo -+ and the Out -+ should be twisted?

It seems to be exchange place of flat cable on trafo and out connections between main and control board?
Duka

[Brizco]

thanks jakob!

i only had to look on the schematic! and it was onviously easy to stop my confusion!  :idea:

thanks for reminding me to read the schemo!  :green:

and now i have a fully working G9!!! Incredible!!


thank you very much!

[Hulk]

I'm almost done with my G9 - all I need to do is connect the two toroids to the PCB and I'm finished  :guinness:

My question is:

When I connect the two sec. from toroid nr. 1 and one sec. from toroid 2 to the PCB is it important that the 2x3 wires are connected in a certain order at the 15VAC point on the PCB??
With that I mean, can I just place 3 random wires to one side and another 3 wires to the other side at the 15VAC??

Toroid 1 (RKT)       sec.: red-yellow/blue-green

Toroid 2 (Talema)  sec.: green-red/brown-blue

One sec. from toroid 2 goes to 15VAC/1A next to the 78S12 - could I send the green-red from the Talema there?? and just randomly mix the 3 left of the sec. to the other 15VAC?

I don't know if you understand this   :green:

[gyraf]

Hi Hulk,

Take another look at the schematic - that should show you what to do.

If you're asking if phasing of the transformers is important, then yes - on the second transformer, generating the high HT voltage, you need to parallel the two secondary windings IN-PHASE, start to start and end to end. Otherwize they'll short out.

The first transformer dosen't care about phasing of the windings.

Jakob E.

[Hulk]

Thanks Jakob

I think my problem is that I'm not shure how to interpret the sec. color codes on the toroids!

Toroid 1 (RKT) sec.: red-yellow/blue-green

Toroid 2 (Talema) sec.: green-red/brown-blue

E.g. on toroid 1 is red-yellow 15V-0V or 15V-15V???

[gyraf]

From what you specify:

Toroid 1 (RKT) sec.: red-yellow/blue-green
Meaning: red=0 yel=15 -- blu=0 grn=15

Toroid 2 (Talema) sec.: green-red/brown-blue
Meaning: grn=0 red=15 -- brn=0 blu=15

connect grn+brn and red+blu on trafo2, Talema. This gives 1x15V:220V

[Hulk]

Thanks Jakob!!

I'm going to fire it up within an hour or so, so Jakob if you look south you might see a big puff of smoke :shock:  :green:

[mathflan]

jacob,

I have an 30 VA 2*150 volt RKT transformer

15 volt : Red - Yellow

15 volt : Blue - Green

I solder RED and BLUE together to have 30 volt but When I measure Between  
YELLOW Pin and GREEN pin , I have 0 Volt on AC ...
its strange

RED = 0
YELLOW = 15
BLUE = 0
GREEN = 15

SO  i have to connect RED and BLUE together to have 30 volt, no??

I have 16.7 volt between YELLOW and BLUE+RED and 16.7 volt between  GREEN and BLUE+RED.

So why I don't arrive to have 2*16.7 volt = 33,4Bolt between YELLOW and GREEN

[gyraf]

connect y and b in stead...

[mathflan]

Ok  :oops:

It works

sorry, I could find this alone but, Afraid to do bad connections...

[mathflan]

I connected the transformer  as the diagram :

http://www.cmaudio.de/img/groupdiy/g9-4.JPG

But I don't arrive to have 220 V

I check the Transfo color code, it's OK, I solder the three 0Volt Lugs of the transformer together and did the same for the three 15 volt.

Is there a thing that I missed on the schems?

thanks

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