Fender 6g8 filter pack layout

[uki]

Hey folks!

This is the filter pack for Fender model 6G8 , I'm not sure if this is correct  , some help is very much appreciated, this also can help others since there is no layout for filter packs in those Fender layouts.


Thanks

[sluckey]

Here's a pic of the real cap board in a 6G8. The first two caps on right don't follow the original schematic...

[uki]

Here's a pic of the real cap board in a 6G8. The first two caps on right don't follow the original schematic...

I read somewhere they did that to fix the problem with the 50hz electricity in Germany. Those amps were originaly made to handle 60hz.

Oh here it is:

I did not do the filter caps. Actually they have two 100Uf/350 in series for a total of 50uf, a bit more than the original 40uf with two in parallel. Each cap has a 220K in parallel, as per the 1970 Twin amps.

http://bb.steelguitarforum.com/viewtopic.php?p=1617132&sid=5420d6b04e9931161d4f19148e406c46

What you are seeing in the filter input caps is a mod I devised to make my brand new Fender Twin work in Germany. While we all used transformers to reduce the 220/230 household voltage to 110/120, we could not change the line frequency which was 50Hz instead of the 60Hz the filter was designed for. The difference in the duty cycle between the two power frequencies is what was blowing the input caps.

After it blew up the first time I used it, I took the first two caps and wired them in series to double the voltage rating. I think Fender used that and maybe the resistor for export models but that was almost fifty years ago. 1965 or 1966.
http://bb.steelguitarforum.com/viewtopic.php?t=184940&postdays=0&postorder=asc&start=25

[DummyLoad]

Here's a pic of the real cap board in a 6G8. The first two caps on right don't follow the original schematic...

perhaps that's a hack? doesn't look original.


--pete 

[sluckey]

The caps have definitely been replaced, but I think the board is original. The two parallel 20µF@600V caps have been replaced with two series connected 100µF@350V with equalizer resistors, probably due to cost, size, and availability of the 20µF@600V. This modified replacement would require a slight rewiring for the first two caps.

Here's the discussion where I found that pic...

     http://bb.steelguitarforum.com/viewtopic.php?t=184940&postdays=0&postorder=asc&start=0

[DummyLoad]

they probably thought an extra 10uF of filter would work out better. 


MIEC sells 600V parts so vishay-sprague ATOMs aren't the only game in town anymore. 


http://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=1586


http://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=1738


the dimensions of the board are not known... the wiring is correct as per the 6G8 schematic, so this attached layout is more for reference than anything else. parts shown are vishay sprauge ATOMs and dimensions are 1" x 3.63"  if i were building or repairing, i'd probably use MIEC parts with 2 x 30uF for the main filter, 1 x 30uF for the screens, and the remaining four as 22uF 600V parts. i used 1W CC for all resistors.


--pete


--pete

[uki]

the dimensions of the board are not known... the wiring is correct as per the 6G8 schematic, so this attached layout is more for reference than anything else. parts shown are vishay sprauge ATOMs and dimensions are 1" x 3.63"  if i were building or repairing, i'd probably use MIEC parts with 2 x 30uF for the main filter, 1 x 30uF for the screens, and the remaining four as 22uF 600V parts. i used 1W CC for all resistors.
--pete

Hey thanks Pete 

I found the filter caps at Ted Weber web site. http://www.tedweber.com/ec206-600 ,
some usefull dimensions here: http://tubeamplifierparts.com/watts-store/audio-transformers.html#!/Twin-6G8-power-supply-board/p/45432796
and did my own boards, the power supply with 6x3 inches.
Here it is:

[uki]

I have found a good picture of an original filter pack here:


From this site: https://reverb.com/item/346782-fender-twin-amp-1962-white