TG1 - advice from any one who has built it...

[trampo]

All of the documentation is here.

http://twin-x.com/groupdiy/index.php?cat=10333

Trampo

 

[Bonsaimaster]

Looked thru those documents can find the input and output transformer specs but not the power transformer.

 

[peskado]

2x25v 50va

 

[drask]

Hi Guys,

What do I have to check if R84 on the main PCB is burning when I turn on the uni?

Thanks

 

[bruno2000]

C7,C121
Best,
Bruno2000

 

[drask]

C7,C121
Best,
Bruno2000

Thanks
And in the case they're good?
Could it be VT26 or 25?

 

[bruno2000]

C7,C121
Best,
Bruno2000

Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000

 

[drask]

C7,C121
Best,
Bruno2000

Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000

Problem Solved Thanks.
You were right. C7 was reversed

 

[bruno2000]

C7,C121
Best,
Bruno2000

Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000

Problem Solved Thanks.
You were right. C7 was reversed

Congrats!  Happy to help.
Best,
Bruno2000

 

[bruno2000]

Ever wonder why the 40 Hz and 80 Hz settings on the HPF sounded the same?  It's because C110 and C108 are swapped (mis-labeled) on the switch board, that's why.
Best,
Bruno200

 

[Biasrocks]

Ever wonder why the 40 Hz and 80 Hz settings on the HPF sounded the same?  It's because C110 and C108 are swapped (mis-labeled) on the switch board, that's why.
Best,
Bruno200

Thanks for that Bruno. I rarely use that feature but it gives me something to do when I have it on the bench next time.

Mark

 

[late]

I have working unit in dual mode but stereo link is problem. When switch stereo link on right channel drops 2db. What can do this?

 

[trampo]

I had a similar problem, and although I could not get the unit spot on I did manage to get it within 1/2 a dB.

I found that carefully matching the diodes and the threshold between the 2 channels got the unit closer.

Whilst in dual mono compression mode, try inserting a low level sine wave into both channels (this level needs to start below the threshold), then increase the level of the sine wave until compression starts and check that both channels start compressing at the same level. If not adjust the AOT3 and 4 resistors until they match. Do the same in limit mode and adjust AOT 5 and 6.

I found it easier to replace the AOT resistors with trimpots .

Good luck

Trampo

 

[Bonsaimaster]

Ok I am setting off to start this project. Have the major parts together. Some questions. I will break it up in sections.

Bypass -  I am using 1:1 input and 1:1 output transformers (I have the Black boards Version 2)
1. C31-C38 are labelled .1uf on the boards. In the BOM that I have they are required to be 47nf-0.33uf. Which one is correct?
2. I see that there are C2 anc C3 but no mention on the BOM. Do I used them on the board? Values?
3. Are both 1N4004's installed or just one? One is unlabelled. Or do I just populate was is in the pic? 
4. Do my connections look ok? Pic included.
5. What do I use in CZ and DZ and RZ?
6. There is a unlabelled capacitor next to the unlabelled diode. Do I populate? Value?

 

[Bonsaimaster]

Motherboard

1. There are two unlabeled parts one resistor and one capacitor near the power connectors. What are these values?
2. Do I populate R47 with a 82K resistor?
3. Values for AOT?
A.O.T. 8 = not used
A.O.T. 10 = 10R
aot1 = 330R
aot2 = not used
aot3 = 47k
aot4 = not used
aot5 = 3k
aot6 = not used
aot 7  = 3.3k
aot 9 = 68k

Where are the meters connected to the board via CV?


LORLIN Switches should they be shorting or non-shorting?

Switches
BYPASS is a SPDT ON-OFF-ON?
FAST/SLOW is a SPDT ON-ON?

LIN/COMP is a DPDT ON-ON?
LIN/THD is a DPDT ON-ON?

I have the original HS2051 diodes.

I will have extra diodes after my build that I will sell if anyone is interested.

 

[Rob Flinn]

Does anyone have the threshold fix details ready to hand.  I'm searching back through the thread & links seem to be broken.

 

[Rob Flinn]

1. There are two unlabeled parts one resistor and one capacitor near the power connectors. What are these values?
2. Do I populate R47 with a 82K resistor?
3. Values for AOT?
A.O.T. 8 = not used
A.O.T. 10 = 10R
aot1 = 330R
aot2 = not used
aot3 = 47k
aot4 = not used
aot5 = 3k
aot6 = not used
aot 7  = 3.3k
aot 9 = 68k

this is detailed further back

Where are the meters connected to the board via CV?

Yes

LORLIN Switches should they be shorting or non-shorting?

Not sure it makes much of a difference.  Would probably use a shorting for the gain make up.

Switches
BYPASS is a SPDT ON-OFF-ON?
FAST/SLOW is a SPDT ON-ON?

LIN/COMP is a DPDT ON-ON?
LIN/THD is a DPDT ON-ON?

Yes

 

[Bonsaimaster]

Thanks for the answers. A couple of more then I will be able to wire it up. I am using the LL1540 transformers and there is some suggestion to use 12K resistors for asymmetric input amplifier. Not sure if I understand this. Has anyone else use these transformers and can suggest wiring? Also would like to know the values used in CZ and RZ. Second, I am luck enough to get the Fester PSU board with the kit. I understand the connections from it to the motherboard. It has a couple of labels I don't understand if anyone can help.

G1
G2
G3
~G
~25
~1

I am using an Antek AS0528 with to 28V and not sure how to connect.

Thanks again in advance.

Bonsaimaster

 

[Rob Flinn]

Thanks for the answers. A couple of more then I will be able to wire it up. I am using the LL1540 transformers and there is some suggestion to use 12K resistors for asymmetric input amplifier. Not sure if I understand this. Has anyone else use these transformers and can suggest wiring? Also would like to know the values used in CZ and RZ.

I have no idea about your transformers because I've not used those specific ones.  CZ & RZ form a zobel network, which damps down ringing from the transformer.  These values are specific to the particular transformer used.  You will need to find them yourself.  If you inject a square wave & look the secondary of the transformer you quite often see overshoot on the leading edge.  CZ & RZ kill this.  I think if you search on the forum you will find how to determine values, if not Google will have the answers.

I am luck enough to get the Fester PSU board with the kit. I understand the connections from it to the motherboard. It has a couple of labels I don't understand if anyone can help.

G1
G2
G3
~G
~25
~1

I can't remember what these points do.  However I would guess that the G1, G2 etc are grounds.  Maybe you could buzz these points out with a meter.  See if they are connected to ground.  I think the points with ~ in front of them are likely to be a.c points where you might connect the mans transformer.  Again a meter can determine if the connect to the diodes that form the bridge rectifier.

I am using an Antek AS0528 with to 28V and not sure how to connect. .

I ASSume that the AS0528 is your mains transformer.  Does it have dual secondaries  or a single centre tapped secondary ?

 

[Bonsaimaster]

Dual secondaries.