What voltage do you measure before the CRC ?
I believe you have the same transformer as Nic, so I cannot quite understand why so much difference.
Patrick
I believe you have the same transformer as Nic, so I cannot quite understand why so much difference.
Patrick
>I believe you have the same transformer as Nic, so I cannot quite understand why so much difference.
The transformer(s) I have been using till now were from toroidman and according to the original specs so I think they are actually specified 1V lower than the Toroidy GB transformers. I will check once I feel like taking apart the amp again 🙂
The transformer(s) I have been using till now were from toroidman and according to the original specs so I think they are actually specified 1V lower than the Toroidy GB transformers. I will check once I feel like taking apart the amp again 🙂
>Of course soldering is the much better option.
A couple of suggestion, if I may:
1) needles to say, but test the circuit before mounting in the amp🙂
2) the relay behavior can be nicely visualized by soldering in LEDs (with series current limiting resistors) in place of the relays for testing. Probing each output with your DMM is much less enlightening and will take much more time😉
3) if you go over the information provided by Patrick and co. you will realize that you are unlikely to change jumper settings very often (if ever) so you might as well use wire rather than expensive sockets and jumpers. A bended piece of cat5 solid core is good, cheap and easy for the job.
Cheers,
Nic
A couple of suggestion, if I may:
1) needles to say, but test the circuit before mounting in the amp🙂
2) the relay behavior can be nicely visualized by soldering in LEDs (with series current limiting resistors) in place of the relays for testing. Probing each output with your DMM is much less enlightening and will take much more time😉
3) if you go over the information provided by Patrick and co. you will realize that you are unlikely to change jumper settings very often (if ever) so you might as well use wire rather than expensive sockets and jumpers. A bended piece of cat5 solid core is good, cheap and easy for the job.
Cheers,
Nic
Just touching base, I am currently in exam period, to make up for the delay, anyone who wants a corrected pcb, please email me and I will send you the number you need free of charge, but get in quick ill order them on Wednesday, if I run out you miss out.
Regards
Regards
Hi Alexis,
I have not received the non-standard part. Perhaps you could include it with the new board?
Has the previous protection PCB been scrapped?
Are we "all" to order the new PCB?
Or is this an option?
Can we use either the old (with a hardwired mod) or the new?
Re-measured
Mains = 232V
Before CRC = 21,4V
After CRC = 19,8V
Toroidy transformers
Mains = 232V
Before CRC = 21,4V
After CRC = 19,8V
Toroidy transformers
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The other protection pcb is fine if you want to do the fix mentioned above, this is also not an order, rather it is a gift. You will not be charged at all. Ever.
The only changes between the two boards are this one will have the hard wired fix backed in. And the boards will be 2mm thick rather than 1.6mm thick.
The only changes between the two boards are this one will have the hard wired fix backed in. And the boards will be 2mm thick rather than 1.6mm thick.
> Before CRC = 21,4V
That is OK.
> After CRC = 19,8V
Difference before and after CRC is 1.6V.
R in the CRC is 0.67R.
So your total bias per balanced F5X is at this moment 2.4A.
Dissipation per FET is 24W per FET, so nothing detrimental will happen.
For optimum output at 6 ohm load, total bias current per channel should be 4A when fully warmed up.
Suggest you check voltage across the 0R22 resistors on the F5X PCB.
To be on the safe side you can start with cold bias (room temperature) of 1.5A.
That means voltage across the 0R22's should be all 0.33V at start up.
And please read Dave's excellent instructions at the start of the thread.
Patrick
That is OK.
> After CRC = 19,8V
Difference before and after CRC is 1.6V.
R in the CRC is 0.67R.
So your total bias per balanced F5X is at this moment 2.4A.
Dissipation per FET is 24W per FET, so nothing detrimental will happen.
For optimum output at 6 ohm load, total bias current per channel should be 4A when fully warmed up.
Suggest you check voltage across the 0R22 resistors on the F5X PCB.
To be on the safe side you can start with cold bias (room temperature) of 1.5A.
That means voltage across the 0R22's should be all 0.33V at start up.
And please read Dave's excellent instructions at the start of the thread.
Patrick
They were already offered in January ?
http://www.diyaudio.com/forums/pass-labs/208880-f5x-euvl-approach-build-thread-8.html#post3327222
If you still want some now, you can contact WK.
But we need to add service charge for the extra time and cost to go to the Post Office just for you.
Unless you can wait till the regulator GB is finalised.
Sorry for that,
Patrick
http://www.diyaudio.com/forums/pass-labs/208880-f5x-euvl-approach-build-thread-8.html#post3327222
If you still want some now, you can contact WK.
But we need to add service charge for the extra time and cost to go to the Post Office just for you.
Unless you can wait till the regulator GB is finalised.
Sorry for that,
Patrick
I'm getting the hang of soldering tiny SMD parts. Not so bad when you have good liquid flux and some good braid! 🙂
For the red LED's on the protection board (D5_L, D5_R, D6_L, D6_R), how do I know which way the polarity is on the soldermask? Is the tapered end the negative (cathode) end? So the green marking on the underside of the diode should point toward the end with the taper (or right side when reading the soldermask label)?
For the red LED's on the protection board (D5_L, D5_R, D6_L, D6_R), how do I know which way the polarity is on the soldermask? Is the tapered end the negative (cathode) end? So the green marking on the underside of the diode should point toward the end with the taper (or right side when reading the soldermask label)?
I had the same doubt. Fact is that it does not matter as the two LEDs are antiparralel in the circuit. So just place them in opposite relative orientation🙂
Thanks Nic!
I also noticed a couple of discrepancies in the BOM of the Protection Board F5X Chapter 1 article.
1. R33L/R and R34L/R call for a 120ohm resistor under the "description" column but indicate a 300ohm resistor under the "comment" column which is what Alexis provided with his GB. What is the correct value to use here?
2. R32L/R call for a 2.0 kohm resistor under the "description" column but indicate a 2.7 kohm resistor under the "comment" column which is what Alexis provided with his GB. What is the correct value to use here?
Thanks!
I also noticed a couple of discrepancies in the BOM of the Protection Board F5X Chapter 1 article.
1. R33L/R and R34L/R call for a 120ohm resistor under the "description" column but indicate a 300ohm resistor under the "comment" column which is what Alexis provided with his GB. What is the correct value to use here?
2. R32L/R call for a 2.0 kohm resistor under the "description" column but indicate a 2.7 kohm resistor under the "comment" column which is what Alexis provided with his GB. What is the correct value to use here?
Thanks!
Those values were revised and the reason of revision is already explained in the document.
Please read it through. The new values are valid.
For the polarity of the SMD LEDs, just go to Digikey and dig out the data sheet.
This is what I do every time before I solder those things, unless I already have it on my laptop.
Patrick
Please read it through. The new values are valid.
For the polarity of the SMD LEDs, just go to Digikey and dig out the data sheet.
This is what I do every time before I solder those things, unless I already have it on my laptop.
Patrick
The markings on the LEDs are easily located/understood (even if they can only be seen before the LED is mounted😱). To me it was the non standard (to me at least) markings on the PCB that were not easily understood.
Cathode is allways pin 1, pin one is always the end with an identifying mark, I.E. the curved end.
This was just pulled out of a standard footprint library, if I were to redesign this today I would have designed my own that is more unambiguous.
This was just pulled out of a standard footprint library, if I were to redesign this today I would have designed my own that is more unambiguous.
ashaw,
Don't worry. You did the PCB the way you have been trained to do. Not all of us are EE so that is why we sometimes get into trouble when we cannot just google a question (like a silkscreen).