Which LM4780 Kit ?

[DaveSail]

I have an empty case from a HAFLER SE120 Amp . Nice , big heat - sinks , all required plugs / switches / fuses / wires , etc.

I want to build a pair of LM4780 Kits . I have found two on the web .
One by " AudioSector " for $ 79 , plus shipping from Canada . And ,
another shown on " Chipamp.Com " with no price . The latter seems from the picture to have four discrete diodes included . I had wanted to build my own bridge using the " Semi - Famous " MUR860s .

Not counting the bridge , and saying I use a Plitron 33 or 35 VAC XFMR ,
which would produce the best sound through a " Neutral " loudspeaker ?

TIA , David V. Webber

[ianpengelly]

The chipamp kits use the MUR860s. Not wanting to be biased, but the Peter Daniels kits are very good value for money and will be made to an excellent standard, so you can't go far wrong with those. I am not sure there will be much difference in sound from the two as the component types are pretty similar on both kits.

[AndrewT]

Do not use a 33+33Vac transformer with National's chipamps.
The highest voltage they are guaranteed for is 92Vdc(+-46Vdc) when no signal is present and 84Vdc (+-42Vdc) when signal is present.
A 35+35Vac transformer will typically give a "normal" voltage of 100Vdc (+-50Vdc) and worst case could be as high as 120Vdc (+-60Vdc).

It is usual to use ~25+25Vac for an 8ohm speaker and ~18+18Vac for a 4ohm speaker.

[DaveSail]

My bad ! Just was looking at the AFTER BRIDGE column on NUUK's
Power Supply help for Dummies . [ He has LM4870 , but I GUESS he
means LM4780 ! ]

Are there Circuit Boards or " Kits " available for the proper bridges
for a 60 Watt / Channel Chip Amp ?

My Hafler case is just 3" deep . Will either or both of the above two
kits fit in that depth ? If not , would " Low Profile " Caps be able
to be used on the supplied circuit boards?

David V. Webber

[ianpengelly]

I have the 3886 kits and if I recall correctly the caps with the chipamp kits are low profile, so would fit in a 1U case.

I'm not sure I understand your question about the proper bridges? Both kits mentioned come with full bridge rectifiers more than suitable for the task, in fact the ones that came with my kit are going to be driving 4 x 150W boards for a while whilst I figure out what I want to do.

[DaveSail]

I guess I should have said " correct " . Sufficient for the 60 Watts
per channel of the LM4780s . And , whatever , price - no - object
" Quality " .

P.S. :

Since this is the second 120 Hafler that died here , I now have
another unit for free . However , on the earlier oine , the XFMR was
good , and that is what the guy wanted . ( He did ask for all the
" guts " for the parts ) . On this one I know the XFMR is bad. But
the case could be used for a Chip Amp . Has massive Heatsinks,
all the normal plugs on the back , fuse and holder , lighted power
switch on front, the , ( damaged ), circuit boards and the MOSFETS
or whatever on the Heatsinks . Anyone who would like it need only
pay the shipping .

David V. Webber

[katana2112]

YGM

[DaveSail]

What does YGM mean ? Also , I deleted the link of the guy who wanted the
" dead " Hafler . He was in California . I don't need money in advance ; just an address . I'll know what it costs to ship after it has been shipped . Then , he can send me that amount .
David V. Webber

[DaveSail]

Now the note from the second guy wanting the Hafler is gone ! Is there
a " Page Two " I am missing ??? David V. Webber

[katana2112]

It means "You got mail"!