Seems you make great progress, Whitigir. Already one amp working, then one is almost home.

Made some more work on the Carbon. Managed to keep it within 4.5 x 2.4 inches. Three layers – will try to do this in kitchen…..
For some unknown reason the software flips the to-126 in 3D view.

Below: inner layer,

and bottom.

Wow. 

Thanks Joa, I will need to check again and again tomorrow to see if it was perhap,caused by the faulty bipolar trans that fried that line.  What else could cause the PZTA56 to get fried if not faulty from the Source as DOA ? Any ideas 

 

also joa, you are making SMD style ? Will there be spare boards ?

Nice!  Is it running yet 

10 hours ago, Whitigir said:

So I fired it up, everything works, but one of my amp board is not working as only 1 led is on, the second led on the HV is not on :(.  Anyone has any clues ? I think I smell something and...50k resistor is burned out

 

10 hours ago, Whitigir said:

Both PZTA 56 is also not working >_<

 

8 hours ago, Whitigir said:

Thanks Joa, I will need to check again and again tomorrow to see if it was perhap,caused by the faulty bipolar trans that fried that line.  What else could cause the PZTA56 to get fried if not faulty from the Source as DOA ? Any ideas 

 

also joa, you are making SMD style ? Will there be spare boards ?

Check that you have

- used the right transistors/ resistor values
- have the right voltages from the PSU at the PSU connector
- wired everything correctly. and check the voltages at the amp board as well
- no shorts and/or blobs...if you have used too much solder it might hide a bad joint ...clean up with some wick and re-do with extra flux

If the above doesn't make things work, post a close up picture of your board top and bottom.
 

Edited March 15, 20179 yr by sorenb

HV is running 457 each side and LV 14.96 each side

11 minutes ago, Whitigir said:

HV is running 457 each side and LV 14.96 each side

... in context of your questions/information so far, I dare to ask, do you by any chance wired the Split PSU so you really have 457 and 14.96 on both positive and the terminal supposed to be negative?

13 minutes ago, sorenb said:

... in context of your questions/information so far, I dare to ask, do you by any chance wired the Split PSU so you really have 457 and 14.96 on both positive and the terminal supposed to be negative?

Yes sir, I did wired the 400+ to positive and 400- to negative, and the same as 15+ to positive and 15- to negative 

i replaced the 50k ohm resistor but have not yet to fire this board up as I know the problem has not been found.  

Pzta56 and stn9360 are in OL but resistance from B to C is fine reading.  My guess is that something just doesn't open up this drive circuit at these guys

 

https://imageshack.com/i/pmescTwGj

https://imageshack.com/i/pmyzg54jj

 

this 50K in the middle row and above pzta56 is the one that got shot.  It burned so ever slightly that it only get slightly browned out, the resistance still measured up...the LED is not on.  My other board is on just fine

Measured the Voltage at O- and O+ To ground and each of them was 430+ or something when I did not realize it was being burned....measured both O- to O+ and it was almost 830+V across.

https://imageshack.com/i/pmqtbe95j

Just now, Whitigir said:

Yes sir, I did wired the 400+ to positive and 400- to negative, and the same as 15+ to positive and 15- to negative 

Not what I am asking. If you use the SPLIT PSU boards, and have two identical HV boards ....and wire GND to Ground, you'll have +457 on both PSU's ...

Same goes for the GRLV split boards 

So, try to be more specific and give more information if you want help ... there are lots of skilled people here that might give you help or a hint to what is wrong, but they need a bit more than: "it not work, what is wrong?"

5 minutes ago, sorenb said:

Not what I am asking. If you use the SPLIT PSU boards, and have two identical HV boards ....and wire GND to Ground, you'll have +457 on both PSU's ...

Same goes for the GRLV split boards 

So, try to be more specific and give more information if you want help ... there are lots of skilled people here that might give you help or a hint to what is wrong, but they need a bit more than: "it not work, what is wrong?"

Yes, all boards GRD are into 1 star ground, or did I do it wrong ? Split PsU on both negative and positive

6 minutes ago, Whitigir said:

Yes, all boards are into 1 star ground, or did I do it wrong ?

Well, Sherlock, is it working? if not, you did some thingS wrong 

I still don't know what caused this 50k to burn-out  don't want to fire it up again. 

 

i have all negative and positive reading as -457 and +457 then -14.96 and +14.96.  There is nothing wrong with pSU.  Bias testpoint runs 576V.

 

More finding:  after leaving everything overnight, the working Amp board has these transistors measured very similar to the none working one.  All diodes are in checks, resistors on the non working one is a bit out of place such as 200kohm = 194 Kohm instead and while the working board has 199.8 k-Ohm measured.  Should I replace this R too ? Or what am I missing ? Voltage drops across the bipolar transistors and diodes are similar on both boards, however >_<.

The 50k Resistor was burned out slowly, so there was some overloaded current somewhere ? LED on pZTA56 did not light up

On the second photo of the board, the solder joint of the tab of the PZTA06 between the offset trim pot and the 0.1uf bypass capacitor looks suspicious to me. May want to re-flow it.

7 hours ago, mwl168 said:

On the second photo of the board, the solder joint of the tab of the PZTA06 between the offset trim pot and the 0.1uf bypass capacitor looks suspicious to me. May want to re-flow it.

Finally ! She is up. Sir ! You have hit the jackpot!!!! I went through all bipolar trans and reflow it to just immediately realized that the PTZA06 was a bit floating on the solder.  This explained why the R50K was being overloaded and the rest of it didn't click  phewww....I thank you so much ! Now onto the trimming and current offset, balances

Great, well done!

Have drilled and cut out  boards for the three layer Carbon.  A bit smaller than the T2.

Is there a way to tell if 10m90s is bad ? Q26.  I burned the 1k R, now the Q26 measure different than The rest

Good one on a little transistor tester on my desk reads 4.4mA current and 3.1 gate voltage. Other good ones are within a little bit of that 4.6mA, 3.2V etc.

Just now, Tinkerer said:

Good one on a little transistor tester on my desk reads 4.4mA current and 3.1 gate voltage. Other good ones are within a little bit of that 4.6mA, 3.2V etc.

The problem is that reading off board is different than on board :(.  I tried measure the 1k R and it also measure 140ohm, the exact amount of the G/S

Well yeah, you gotta desolder things to check them properly.

22 minutes ago, Whitigir said:

The problem is that reading off board is different than on board :(.  I tried measure the 1k R and it also measure 140ohm, the exact amount of the G/S

de-attach the high voltage from the board.

put the LV+ to the HV+ ...put the LV- to a DMM common, and put the probe from the DMM at the tail ...if you get steady current it probably works

3 hours ago, sorenb said:

de-attach the high voltage from the board.

put the LV+ to the HV+ ...put the LV- to a DMM common, and put the probe from the DMM at the tail ...if you get steady current it probably works

Got 22.6-22.7 mA ? That means it probably is working like you said.  Now 10007 to the 100R voltage is 1.5V.  This is probably why the G R and V is measured different.  The other board has 0.6 in the similar place.  There is something to hang the 10007 this way >.<

Edited March 17, 20179 yr by Whitigir

2 hours ago, Whitigir said:

Got 22.6-22.7 mA ? That means it probably is working like you said. 

Yes, meaning you have adjusted the output stage for 22.6mA 

2 hours ago, Whitigir said:

Now 10007 to the 100R voltage is 1.5V.  This is probably why the G R and V is measured different.  The other board has 0.6 in the similar place.  There is something to hang the 10007 this way >.<

Not sure what you are trying to express?

On 3/17/2017 at 4:29 PM, sorenb said:

Yes, meaning you have adjusted the output stage for 22.6mA 

Not sure what you are trying to express?

I see, so this is one way to help more securely tuning the current down / up as well.  Another lesson updated.  Thank you so much sir.

 

the above scenario was my finding that either 10007 was being hung weirdly...or my 10m90s is fried. 

 

 after tracing and making sure the relative components values to 10007 were all up to task, so 10007 is ok.  So I tried to adjust again but nothing moved compare to my working board.  This can only means 10m90s is fried.  Waiting on new part to replace it

 

i can confirm that if it is on amp board and measured below 0.2... or less than 400 Ohms in the board then it is dead.  Removed it and it still measure 0.1 something

 

*update* if the 10m90s is at 0.25 V measured on the board, it still kicking.  But it is half dead.  After I replaced the non working board, now it read 0.53V.  I replaced the other one as well.

 

now my balance is 330mv and offset is 18V.  Will drop in opto Servo and check again tomorrow before test listening

Edited March 18, 20179 yr by Whitigir

Yay! I got music ! I retuned the amp after 30-40 min where the offset drift back and forth instead of cold start.  

Bias 585V

offset 15.75

Balance 200-300 mV

current is around 17-18mA ! Playing it safe

i only need to wait for all my sockets and clean up this wires otherwise it is healthy and pumpy

 

thank you Kevin, John, Manuel, Soren, and all who have helped me to make this happen ! Love, joy and cheer!

I can not appreciate Kevin enough for sharing this wonderful build which makes my dream of an endgame rig happened!

Edited March 19, 20179 yr by Whitigir