newbie need help
hello.
my name daniel, i am newbie.
after i read this thread, i want to build this F5. it seem litle bit simple than
the other f series.
but there's some question about F5 i want to ask?
1. is there any difference sound quality if i change ztx550 to bc560 and ztx450 to bc550.
(because it's difficult to find ztx type in my country, indonesia)
2. when i read f5 pdf files, they write about adjusting P1 and P2. i don't understand this one.
please2 someone tell me, how to adjusting P1 and P2 using digital avo meter.
i only have Digital AVO Meter (not good avo meter but cheap digital avo meter).
i really2 don't know about this P1 & P2 adjusting.
it would be nice if someone can show me with the picture?
3. PSU sector. can i change the toroid tranformer with EI type?
is there any difference sound quality if i change toroid to EI type.
4. in my country if we buy toroid or EI tranformer, they always ask
the VOLTAGE (V) and AMPERE (A) type, not VA type.
ex:- EI trans, single tap 12V and 2A ( 12v/1A )
- Toroid trans, double tap 18v and 3A ( 18v-0-18v/3A)
i know the PSU using tranformer 18V double tap (18v-0-18v).
but how much AMPERE (A) do i need?
Thank you
PS: i am sory if my english not good
hello.
my name daniel, i am newbie.
after i read this thread, i want to build this F5. it seem litle bit simple than
the other f series.
but there's some question about F5 i want to ask?
1. is there any difference sound quality if i change ztx550 to bc560 and ztx450 to bc550.
(because it's difficult to find ztx type in my country, indonesia)
2. when i read f5 pdf files, they write about adjusting P1 and P2. i don't understand this one.
please2 someone tell me, how to adjusting P1 and P2 using digital avo meter.
i only have Digital AVO Meter (not good avo meter but cheap digital avo meter).
i really2 don't know about this P1 & P2 adjusting.
it would be nice if someone can show me with the picture?
3. PSU sector. can i change the toroid tranformer with EI type?
is there any difference sound quality if i change toroid to EI type.
4. in my country if we buy toroid or EI tranformer, they always ask
the VOLTAGE (V) and AMPERE (A) type, not VA type.
ex:- EI trans, single tap 12V and 2A ( 12v/1A )
- Toroid trans, double tap 18v and 3A ( 18v-0-18v/3A)
i know the PSU using tranformer 18V double tap (18v-0-18v).
but how much AMPERE (A) do i need?
Thank you
PS: i am sory if my english not good
Hi,
let's start with the last question.
Suppose you are looking for a 300VA transformer (EI or toroid).
Take the VA and divide by the total output voltage. If you require 18-0-18Vac centre tapped, then the total is 36Vac
The output current is 300 / 36 = 8.3Aac
Ask for centre tapped 18-0-18Vac 8Aac or 8.5Aac
or
ask for dual secondary 0-18, 0-18Vac 8Aac per winding or 8.5Aac per winding.
let's start with the last question.
Suppose you are looking for a 300VA transformer (EI or toroid).
Take the VA and divide by the total output voltage. If you require 18-0-18Vac centre tapped, then the total is 36Vac
The output current is 300 / 36 = 8.3Aac
Ask for centre tapped 18-0-18Vac 8Aac or 8.5Aac
or
ask for dual secondary 0-18, 0-18Vac 8Aac per winding or 8.5Aac per winding.
Re: newbie need help
1. you can use these BC types ;
2. when you are ready with all parts , ask again ; in meantime - read again and again all Papa's pdfs ......
3. you can use EI without any harm ........ maybe you just need to use slightly powerful one (comparing to toroid ) because EI have slightly worse power regulation
4. so - you need at least 350VA (VA=W ) EI xformer ; that's 2x18Vac and ~10A
your english is good enough
meemee said:
1. you can use these BC types ;
2. when you are ready with all parts , ask again ; in meantime - read again and again all Papa's pdfs ......
3. you can use EI without any harm ........ maybe you just need to use slightly powerful one (comparing to toroid ) because EI have slightly worse power regulation
4. so - you need at least 350VA (VA=W ) EI xformer ; that's 2x18Vac and ~10A
your english is good enough
Re: newbie need help
The va of the transfomer is just the V(voltage) x A (current) ie 18v x 8.33 amps = 150 va per winding for 300 va total.
I haven't listened to the Zetex parts vs the other ones. I plan on using the Zetex parts. I'm not sure if there's a difference in sound since the transistors are used for overcurrent protection. I don't think it's part of the audio signal path. Though some people think the amp sounds better with the parts completely removed.
P1 and P2 are used to adjust the bias (operating point) of the output stage. Initially they are set at their minimum so they measure zero ohms then slowly turn them up until you measure .59 volts across R11 and R12.
meemee said:
The va of the transfomer is just the V(voltage) x A (current) ie 18v x 8.33 amps = 150 va per winding for 300 va total.
I haven't listened to the Zetex parts vs the other ones. I plan on using the Zetex parts. I'm not sure if there's a difference in sound since the transistors are used for overcurrent protection. I don't think it's part of the audio signal path. Though some people think the amp sounds better with the parts completely removed.
P1 and P2 are used to adjust the bias (operating point) of the output stage. Initially they are set at their minimum so they measure zero ohms then slowly turn them up until you measure .59 volts across R11 and R12.
Copper + aluminium for a heatsink
Hello.
I am new, my name Christian. I plan to construct an F5, beginning by heatsinks. I put one heatsink per channel, composed of two pieces: one of red copper sheet, coming from an old big calculator, with dimensions 400 X 160 X 8 mm, weight 4.5 kg. This sheet is already black mate painted. The second part is an aluminium oxyded heatsink, dimensions 300 X 100 mm, with fins 40 mm.
My intention is to screw the two pieces so that the fins are vertical.
Then mount the mosfets on the copper side, about 40 % from the bottom, spaced 20 cm.
I dont know if this kind of gathering will be sufficient for one channel.
There is another question : what about the contact surfaces of the two metals? Specially, the black paint can remain on the copper or no? I think to put thermal grease at the contact.
Someone can tell me the right method to do?
Thanks
Hello.
I am new, my name Christian. I plan to construct an F5, beginning by heatsinks. I put one heatsink per channel, composed of two pieces: one of red copper sheet, coming from an old big calculator, with dimensions 400 X 160 X 8 mm, weight 4.5 kg. This sheet is already black mate painted. The second part is an aluminium oxyded heatsink, dimensions 300 X 100 mm, with fins 40 mm.
My intention is to screw the two pieces so that the fins are vertical.
Then mount the mosfets on the copper side, about 40 % from the bottom, spaced 20 cm.
I dont know if this kind of gathering will be sufficient for one channel.
There is another question : what about the contact surfaces of the two metals? Specially, the black paint can remain on the copper or no? I think to put thermal grease at the contact.
Someone can tell me the right method to do?
Thanks
Is that solid copper or is it copper laid on top of something else?
I would remove the paint from at least the side that will contact the heatsink. Polished is the best option but the thermal paste will be helpful. Paint must be removed from where the mosfet will go. It is a really good idea to polish the area where the mosfet will be. Also use paste or a pad at that junction.
The heatsink will probably be fine for one channel. Not stereo, although no reason not to try it with that big slab of copper mounted to the back of it. You will be very evenly spreading the heat with that monster piece of copper so perhaps it will work. Doubtful but it is worth trying. Make sure you can measure the heat around the sink and the mosfets.
Uriah
I would remove the paint from at least the side that will contact the heatsink. Polished is the best option but the thermal paste will be helpful. Paint must be removed from where the mosfet will go. It is a really good idea to polish the area where the mosfet will be. Also use paste or a pad at that junction.
The heatsink will probably be fine for one channel. Not stereo, although no reason not to try it with that big slab of copper mounted to the back of it. You will be very evenly spreading the heat with that monster piece of copper so perhaps it will work. Doubtful but it is worth trying. Make sure you can measure the heat around the sink and the mosfets.
Uriah
Re: Re: newbie need help
waaahhhh... thank you very much for the fast answer....
about P1 and P2, first set to 0 ohm then slow turn until 0.59v across R11 and R12...thank you...
so, the toroid transformer between 8A and 10A. ooooohh......it will cost lot of my money.....
once again thank you very much........
to buy this toroid transformer.
AndrewT said:
Zen Mod said:
1. you can use these BC types ;
2. when you are ready with all parts , ask again ; in meantime - read again and again all Papa's pdfs ......
3. you can use EI without any harm ........ maybe you just need to use slightly powerful one (comparing to toroid ) because EI have slightly worse power regulation
4. so - you need at least 350VA (VA=W ) EI xformer ; that's 2x18Vac and ~10A
your english is good enough
labjr said:
waaahhhh... thank you very much for the fast answer....
about P1 and P2, first set to 0 ohm then slow turn until 0.59v across R11 and R12...thank you...
so, the toroid transformer between 8A and 10A. ooooohh......it will cost lot of my money.....
once again thank you very much........
to buy this toroid transformer.
Thanks for the quick reply, Uriah.
. The copper is solid copper, red dark color.
. I shal try to remove the paint on the contact's surface of the spreader, but I will not probably do it on the alu heatsink, because it is oxyded black.
. OK for polishing the mosfet's places.
. One copper plaque for one channel, of course.
. It will be possible to measure heat around the sink, there is place.
Regards
. The copper is solid copper, red dark color.
. I shal try to remove the paint on the contact's surface of the spreader, but I will not probably do it on the alu heatsink, because it is oxyded black.
. OK for polishing the mosfet's places.
. One copper plaque for one channel, of course.
. It will be possible to measure heat around the sink, there is place.
Regards
Re: Re: newbie need help
sory re post, wrong word.
waaahhhh... thank you very much for the fast answer....
about P1 and P2, first set to 0 ohm then slow turn until 0.59v across R11 and R12...thank you...
so, the transformer between 8A and 10A. ooooohh......it will cost lot of my money to buy this toroid transformer
once again thank you very much........
AndrewT said:
Zen Mod said:
1. you can use these BC types ;
2. when you are ready with all parts , ask again ; in meantime - read again and again all Papa's pdfs ......
3. you can use EI without any harm ........ maybe you just need to use slightly powerful one (comparing to toroid ) because EI have slightly worse power regulation
4. so - you need at least 350VA (VA=W ) EI xformer ; that's 2x18Vac and ~10A
your english is good enough
labjr said:
sory re post, wrong word.
waaahhhh... thank you very much for the fast answer....
about P1 and P2, first set to 0 ohm then slow turn until 0.59v across R11 and R12...thank you...
so, the transformer between 8A and 10A. ooooohh......it will cost lot of my money to buy this toroid transformer
once again thank you very much........
Yes just on the spreader. You could also do so on the aluminum but I dont think the black is actually a coating. I dont really know how they get the different colors. I am aware of the practice but not sure if its an actually coating. In any case with that large spreader you will be fine getting all the heat from the mosfet to the sink efficiently.Chgill said:
Using such a large spreader you will want to find some way to make sure that it indeed makes good contact with the heatsink rather than having a slight warp in it that would cause an airspace.
Uriah
A while back I mentioned how I mounted the heatsinks slightly off the sides of the case to help try and get some of the heat out of the casework. Heres a rather poor pic that might show what I mean:
And heres how the rest of it turned out:
Very happy now with this amp. Sounds great.
Fran
An externally hosted image should be here but it was not working when we last tested it.
And heres how the rest of it turned out:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Very happy now with this amp. Sounds great.
Fran
.25" copper plate for heat spreaders
I found a source: www.smallparts.com It is not cheap, but lower than most other sources including eBay. A 3" x 6" piece is ~ $ 20.00. This is an interesting website - lot's of odds and ends for small projects.
I found a source: www.smallparts.com It is not cheap, but lower than most other sources including eBay. A 3" x 6" piece is ~ $ 20.00. This is an interesting website - lot's of odds and ends for small projects.
