[BUILD] 1176 Rev F/G - new board, new transformer!

[germoju]

thanksa lot
and can you tell me where can I attach the other end of the shielded wire coming from the attack pot CW lug to the main PCB - shield to ground and the inner conductor to pad 7 ? where is the "ground" ?

:'(

Have a look at the schematic and the board itself. Notice that the "F" has a different meter circuit than previous models.

is the answer : attach the other end of the wire coming from the attack pot CW lug to the main PCB - the inner conductor to pad 7, they is no shield ?

OR ? I put the shield wire in pad 28 ?

 

[germoju]

thanksa lot
and can you tell me where can I attach the other end of the shielded wire coming from the attack pot CW lug to the main PCB - shield to ground and the inner conductor to pad 7 ? where is the "ground" ?

:'(

Have a look at the schematic and the board itself. Notice that the "F" has a different meter circuit than previous models.

I just follow "the Wiring the Rev A/D/F with a Hairball Case" but it's not indicated. I'm looking at the shematics and compare the Rev A and F but... I'm really not sure of me Maybe can you help me for that please ?

 

[germoju]

As I was desperate I decided to plug my rev F without shield from the wire of the attack pot connected to main board pad 7. I try to power it and it works, first victory... but tests points indicate +21,8V (too low !) and the other -9,6V (good I think).
Nothing's burning or too hot...
I try to send some sound and sound's good... so I calibrated it and it worked perfectly !
So I got a rev F with good sound, good calibration, good compression but with only +21,8V at test point => ??

please where can I find a shematic with typical voltage ?


_IGP6004 par vocanovap, sur Flickr

_IGP6005 par vocanovap, sur Flickr

 

[buildafriend]

Hm, if I remember right you should be getting 30 volts.

 

[germoju]

Hm, if I remember right you should be getting 30 volts.

Yes ! That's a problem !

 

[Brizco]

im building bluestripes and have following problem: at Calibrating the Discrete Meter Circuit , shown here: http://www.youtube.com/watch?v=at82NxrPQzI&feature=relmfu

- i cant zero the gain reduction meter, any changes on the trimmer doesnt affect the meter...
- changes on r75 wont change any voltage on r74...

thanks for any hint or help
(i already changed fet's and trimmers, (are on sockets now))

 

[mnats]

im building bluestripes and have following problem: at Calibrating the Discrete Meter Circuit , shown here: http://www.youtube.com/watch?v=at82NxrPQzI&feature=relmfu

- i cant zero the gain reduction meter, any changes on the trimmer doesnt affect the meter...
- changes on r75 wont change any voltage on r74...

thanks for any hint or help
(i already changed fet's and trimmers, (are on sockets now))

This is the wrong topic for the bluestripe, but how many things have you checked so far in the link provided in the first line of the first post of this thread? Are the voltages in the meter circuit correct?

 

[moybm]

Hi, I was recived these board and I'm soldering components but observe the condenser polarity C26 in the photo if the first page it's ¿wrong? Thanks.

 

[mnats]

Hi, I was recived these board and I'm soldering components but observe the condenser polarity C26 in the photo if the first page it's ¿wrong? Thanks.

Don't use pictures to stuff the board. Refer to the original schematic.

 

[moybm]

Hi, I was recived these board and I'm soldering components but observe the condenser polarity C26 in the photo if the first page it's ¿wrong? Thanks.

Don't use pictures to stuff the board. Refer to the original schematic.

Ahhm, ok. then follow the scheme, because the plate is a component different from the scheme. The resistor R59 is 3.9k in the plate but in the scheme indicates that k is 3.6k, then the R59 is 3.6 k right?

Thanks!

 

[Echo North]

Refer to the original schematic.

http://www.waltzingbear.com/Schematics/Urei.html

 

[mnats]

Ahhm, ok. then follow the scheme, because the plate is a component different from the scheme. The resistor R59 is 3.9k in the plate but in the scheme indicates that k is 3.6k, then the R59 is 3.6 k right?

In this case you would never notice the difference. Once calibrated, the meter would display the correct reading regardless of the slight difference in value of the resistor.

 

[moybm]

In this case you would never notice the difference. Once calibrated, the meter would display the correct reading regardless of the slight difference in value of the resistor.

Excelent, you help me. THANKS!

 

[sktellis]

I just finished my Rev F build. I am working on the Q Bias calibration but nothing happens when I turn the Q Bias. When it is set to GR the meter goes to zero just fine, however when it is set to +4 and I turn up the Input the meter is very jumpy. I have triple checked everything and will check again, but thought some of you might know exactly what it is.

Thank in advance!

 

[moybm]

Well if you screw mounted potentiometer then you have to give many turns to start answering you. For "Q bias" everything revolves clockwise, put a sign 1Khz 0dB and comrueba that reaches the transformer, then you put the attack to "off", then the VU to +4, the output volume to 3/4 input volume and climb ... should run you ...

test if you have the correct voltages on the board.

 

[moybm]

Hi, I think have a problem with my ref F and there is a transistor bad. I have the schematic from the rev J with voltajes but the schematic from rev F it´s different in Q5 (for example).

Where can I know the correct voltajes values?
How can I Know if any transistor it´s bad?

 

[sktellis]

Well if you screw mounted potentiometer then you have to give many turns to start answering you. For "Q bias" everything revolves clockwise, put a sign 1Khz 0dB and comrueba that reaches the transformer, then you put the attack to "off", then the VU to +4, the output volume to 3/4 input volume and climb ... should run you ...

test if you have the correct voltages on the board.

This is exactly what I have been doing.. Is there a reference to what voltages I should be getting at what points anywhere? I have been looking for that, but so far the only ones I know for sure are the +30 and -10 in the power section.

 

[Echo North]

Well if you screw mounted potentiometer then you have to give many turns to start answering you. For "Q bias" everything revolves clockwise, put a sign 1Khz 0dB and comrueba that reaches the transformer, then you put the attack to "off", then the VU to +4, the output volume to 3/4 input volume and climb ... should run you ...

test if you have the correct voltages on the board.

This is exactly what I have been doing.. Is there a reference to what voltages I should be getting at what points anywhere? I have been looking for that, but so far the only ones I know for sure are the +30 and -10 in the power section.

Qbias is present at the gate of Q1.  Something between 0-3VDC as you turn the trimmer.  The voltage travels through the release pot, make sure that wired right.  Look at the schematic, it's super simple to see if you have an issue there.  There is the -10VDC rail and a R82/R83 are a simple voltage divider that connects to the Q trimmer that feeds the Q1 gate by way of the release pot.

 

[Echo North]

Hi, I think have a problem with my ref F and there is a transistor bad. I have the schematic from the rev J with voltajes but the schematic from rev F it´s different in Q5 (for example).

Where can I know the correct voltajes values?
How can I Know if any transistor it´s bad?

May not be the transistor, might be the resistors around the transistor (wrong value).

 

[moybm]

This is exactly what I have been doing.. Is there a reference to what voltages I should be getting at what points anywhere? I have been looking for that, but so far the only ones I know for sure are the +30 and -10 in the power section.

Here you are the voltajes from J rev.