Balanced F5 question - Page 58

_henry_ · 17th November 2010, 03:56 AM

i dont like to buy copies also. i bought the boards from cviller and parts from tech diy.

just saying in general.

alot of agressiveness here

cheers
henry

Horio · 17th November 2010, 04:00 AM

The coefficient of thermal expansion for aluminum is 12.3 x 10^-6 inches per degree Fahrenheit. So if you have a difference of 20 to 65 Celsius, thats roughly a difference of 70 degrees Fahrenheit. Over a PCB that is say 6 inches long, that means the aluminum would expand roughly 0.005 inches (assuming I didn't mess up on the crappy windows calculator).

I wouldn't think that's going to pose any problems.

EUVL · 17th November 2010, 04:40 AM

There is enough flexibility in the bended legs of the MOSFET to allow for such differential expansions, something that is more difficult with SMD components.

Patrick

EUVL · 17th November 2010, 05:08 AM

> alot of agressiveness here

Was not intending to be. My apologies.

If you know manufacturing in China, then you know that you can get from junk to top quality, with vastly different prices.

Just take the front panel. You can use US imported 6061, or Chinese 6061.
If you black anodise, then you would probably not notice any difference.
If you do matt silver anodise, you can tell which is which immediately.
And we have thrown away a thousand USD's worth of front panels (for our own use) just for that reason.

Patrick

Luke · 17th November 2010, 07:20 AM

Quote:

Originally Posted by EUVL

> alot of agressiveness here

Was not intending to be. My apologies.

If you know manufacturing in China, then you know that you can get from junk to top quality, with vastly different prices.

Just take the front panel. You can use US imported 6061, or Chinese 6061.
If you black anodise, then you would probably not notice any difference.
If you do matt silver anodise, you can tell which is which immediately.
And we have thrown away a thousand USD's worth of front panels (for our own use) just for that reason.

Patrick

Perhaps next time you might consider offering them for sale here on DIYA.

_henry_ · 17th November 2010, 07:36 AM

hi patrick,

im kind of curious what would be the difference is? the chassis i bought wast machine milled from a alum profiles extrusions.

i dont know for sure the grades they are using, but it does look less pleasing as PASS XA AMPS.

cheers
henry

EUVL · 18th November 2010, 02:42 PM

Another update :

Variac is now up to speed and we had our first team meeting by email.

I received the draft of 3 of the PCBs today and shall check them in the next day or so.

We agreed who would be doing the prototype builds, etc., and we also agreed that all PCBs will be prototyped and tested first before volume production.

We also had the first discussion with the case production people.
Apart from a few things that need finalising, we think we'll be able to keep to the promised production costs.

So things are moving at pace, at last.

Patrick

_henry_ · 19th November 2010, 12:02 AM

great news

EUVL · 19th November 2010, 05:11 PM

The prototype team might be ordering transformers in the next couple of weeks.

Details see -- Balanced F5 question

With electrostatic shield. No encapsulation in a can.

Anyone else interested ?

Patrick

AndrewT · 19th November 2010, 05:48 PM

Could put me in provisionally for two transformers.
I'll confirm when prices & postage are firmed up.

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17th November 2010, 03:56 AM	#571
_henry_ diyAudio Member Join Date: Jun 2002 Location: Australia	i dont like to buy copies also. i bought the boards from cviller and parts from tech diy. just saying in general. alot of agressiveness here cheers henry

17th November 2010, 04:00 AM	#572
Horio Newbie diyAudio Member Join Date: Mar 2010 Location: San Francisco	The coefficient of thermal expansion for aluminum is 12.3 x 10^-6 inches per degree Fahrenheit. So if you have a difference of 20 to 65 Celsius, thats roughly a difference of 70 degrees Fahrenheit. Over a PCB that is say 6 inches long, that means the aluminum would expand roughly 0.005 inches (assuming I didn't mess up on the crappy windows calculator). I wouldn't think that's going to pose any problems.

17th November 2010, 04:40 AM	#573
EUVL diyAudio Member Join Date: Oct 2003	There is enough flexibility in the bended legs of the MOSFET to allow for such differential expansions, something that is more difficult with SMD components. Patrick

17th November 2010, 05:08 AM	#574
EUVL diyAudio Member Join Date: Oct 2003	> alot of agressiveness here Was not intending to be. My apologies. If you know manufacturing in China, then you know that you can get from junk to top quality, with vastly different prices. Just take the front panel. You can use US imported 6061, or Chinese 6061. If you black anodise, then you would probably not notice any difference. If you do matt silver anodise, you can tell which is which immediately. And we have thrown away a thousand USD's worth of front panels (for our own use) just for that reason. Patrick

17th November 2010, 07:36 AM	#576
_henry_ diyAudio Member Join Date: Jun 2002 Location: Australia	hi patrick, im kind of curious what would be the difference is? the chassis i bought wast machine milled from a alum profiles extrusions. i dont know for sure the grades they are using, but it does look less pleasing as PASS XA AMPS. cheers henry

18th November 2010, 02:42 PM	#577
EUVL diyAudio Member Join Date: Oct 2003	Another update : Variac is now up to speed and we had our first team meeting by email. I received the draft of 3 of the PCBs today and shall check them in the next day or so. We agreed who would be doing the prototype builds, etc., and we also agreed that all PCBs will be prototyped and tested first before volume production. We also had the first discussion with the case production people. Apart from a few things that need finalising, we think we'll be able to keep to the promised production costs. So things are moving at pace, at last. Patrick

19th November 2010, 12:02 AM	#578
_henry_ diyAudio Member Join Date: Jun 2002 Location: Australia	great news

19th November 2010, 05:11 PM	#579
EUVL diyAudio Member Join Date: Oct 2003	The prototype team might be ordering transformers in the next couple of weeks. Details see -- Balanced F5 question With electrostatic shield. No encapsulation in a can. Anyone else interested ? Patrick

19th November 2010, 05:48 PM	#580
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Could put me in provisionally for two transformers. I'll confirm when prices & postage are firmed up.