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hackernap advice thread

Got me, the data sheet don't explain, I have a couple of 47uF MMK's coming from the Captain soon to match a pair I already have so maybe try this out this weekend;)
Geoff
 
hacker said:
With regard to decoupling the output stage using smaller film caps instead of 470uF electrolytics, I came across this interesting beast:

http://www.mouser.com/ProductDetail...GAEpiMZZMv1cc3ydrPrFzL0jc63JHNRend5ujH6%2bqI=

22uF/700V polypropylene 4-lead caps. Sounds good... how does one hook up a 4-lead cap? Are there input and output terminals?
Click to expand...

Data sheet doesn't say so I guess its mechanical only. There are four terminal caps with input and output, DNM make some see:

http://www.dnm.co.uk/capacitors.html#tnetwork

I use them in my power amps and can recommend them.
 
no but I just removed the 8 inductors from the hackercap6 output modules and wow what a difference in Low frequency clout, but not only that it has cleaned up all the frequencies particularly during busy parts of the music it seems to be less muddled and cymbals and hi hats seem cleaner more prominent?.
I did also by pass each cap with a 100n wima as well:), I know shouldn't do 2 changes at the same time but getting these modules out and back in without shorting or getting the wiring screwed up isn't a simple job so I didn't want to do it twice.
http://www.flickr.com/photos/69508926@N05/8644047742/in/photostream
http://www.flickr.com/photos/69508926@N05/8644029270/in/photostream
Back together
http://www.flickr.com/photos/69508926@N05/8642933225/in/photostream
Alan
 
Glad I wasn't just hearing things, have some 47uF films to replace the 450uF electros just need some time to fit.
 
Well I'm just building mine and I've not fitted the inductors so seems like that's a good decision. Think I'll try the film caps but I've only got 10uFs so I'll use two in parallel. Hope that's enough.
Tim
 
337alant said:
no but I just removed the 8 inductors from the hackercap6 output modules and wow what a difference in Low frequency clout, but not only that it has cleaned up all the frequencies particularly during busy parts of the music it seems to be less muddled and cymbals and hi hats seem cleaner more prominent?.
I did also by pass each cap with a 100n wima as well:), I know shouldn't do 2 changes at the same time but getting these modules out and back in without shorting or getting the wiring screwed up isn't a simple job so I didn't want to do it twice.
http://www.flickr.com/photos/69508926@N05/8644047742/in/photostream
http://www.flickr.com/photos/69508926@N05/8644029270/in/photostream
Back together
http://www.flickr.com/photos/69508926@N05/8642933225/in/photostream
Alan
Click to expand...

Alan , did you just use a wire link instead of the inductor.

Keith
 
Building my first HN - following the 1.7 BOM. But I've just discovered that C5-8 in the BOM (http://www.mouser.com/ProductDetail...GAEpiMZZMtOnGahBoN8MAnoGu1BVM7m2grBX%2bna1yw=) aren't polarised, but the PCB (and build manual) expect polarised caps. Is the fact that the ones I've got aren't polarised a problem?

Also, R30 & R34 say 2M, but the link in the BOM (http://mouser.com/ProductDetail/KOA...=sGAEpiMZZMtMTfExsNintYz3yNn09AgQJ/t04ChqpHI=) are actually 1M (I didn't check this when ordering, so I have 1M's). Would it be ok to use the 1M value, or should I get some 2M's?

Thanks all
David
 
Lokidtc99 said:
Building my first HN - following the 1.7 BOM. But I've just discovered that C5-8 in the BOM (http://www.mouser.com/ProductDetail...GAEpiMZZMtOnGahBoN8MAnoGu1BVM7m2grBX%2bna1yw=) aren't polarised, but the PCB (and build manual) expect polarised caps. Is the fact that the ones I've got aren't polarised a problem?

Also, R30 & R34 say 2M, but the link in the BOM (http://mouser.com/ProductDetail/KOA...=sGAEpiMZZMtMTfExsNintYz3yNn09AgQJ/t04ChqpHI=) are actually 1M (I didn't check this when ordering, so I have 1M's). Would it be ok to use the 1M value, or should I get some 2M's?

Thanks all
David
Click to expand...

C5-8 in the new BOM are film-caps, so you can ignore polarity.

1M for R30/34 are ok. You can use higher values up to 2M. This reduces the voltage drop over the gyrator (and increases FE output voltage) Rule of thump for my setup: 1M = 8V drop ; 2M = 4V drop....
 
cubeasic said:
C5-8 in the new BOM are film-caps, so you can ignore polarity.

1M for R30/34 are ok. You can use higher values up to 2M. This reduces the voltage drop over the gyrator (and increases FE output voltage) Rule of thump for my setup: 1M = 8V drop ; 2M = 4V drop....
Click to expand...

Great, thanks for this. Forgive the ignoramus question, but what dictates how much I'd want to reduce the voltage drop over the gyrator?
 
keithsnaim said:
Alan , did you just use a wire link instead of the inductor.

Keith
Click to expand...

Keith yes just stripped some stranded silver plated copper wire, twisted it tight and tinned it then just bent it into U shaped links.
I inserted them from the bottom to get maximum contact with the circuit board.

Alan
 
Lokidtc99 said:
Great, thanks for this. Forgive the ignoramus question, but what dictates how much I'd want to reduce the voltage drop over the gyrator?
Click to expand...

Ideally, you want to have a FE-voltage after the gyrator that is slightly higher than your output voltage. This increases the maximum power output.

If you use 35V secondaries for output and 42V for frontend, everything should be fine with 1M.

EDIT:
I just came across your other thread, where you said you use 40V secondaries for FE.
In this case, 1M is still fine, but your FE voltage should be slightly lower than the output voltage.
Maybe 1.5M or 1.8M would be more ideal, to lift the FE-voltage a little bit.

You know more when you have the HN running....
 
cubeasic said:
Ideally, you want to have a FE-voltage after the gyrator that is slightly higher than your output voltage. This increases the maximum power output.

If you use 35V secondaries for output and 42V for frontend, everything should be fine with 1M.

EDIT:
I just came across your other thread, where you said you use 40V secondaries for FE.
In this case, 1M is still fine, but your FE voltage should be slightly lower than the output voltage.
Maybe 1.5M or 1.8M would be more ideal, to lift the FE-voltage a little bit.

You know more when you have the HN running....
Click to expand...

At the other end of the scale the restriction is the upper operating voltage of the Front End transistors, which is 65 volts, collector to emitter of the input transistor pair of BC546's at Tr1,2.
 
Hi,

I have used 2sc2547 in mine, mostly because I reused my 135 clone tranys and had to get some 44V input transformers for the front end.

Pete
 
I'm nearly there with my four HackerNaps (apart from the traffos - waiting for some bloke to get on with the group buy). I've read about changing the final cap on the output stage to 10,000uF and it just so happens that I have some Elna Cerafine 10,000uF 63v caps I took from my NAP135 clones about 5 yrs ago. Question is should I reform them as per technique in reference area.

Some pics...




for scale...

 
timH said:
I'm nearly there with my four HackerNaps (apart from the traffos - waiting for some bloke to get on with the group buy). I've read about changing the final cap on the output stage to 10,000uF and it just so happens that I have some Elna Cerafine 10,000uF 63v caps I took from my NAP135 clones about 5 yrs ago. Question is should I reform them as per technique in reference area.


If you remove the inductors between the caps you will have a 20000uF cap per side so no need for the 10k it will do no harm reforming them though if you keep the inductors.
Click to expand...
 
Just starting the front end of the nap boards. I have some 1.5uf 5mm pitch poly/film caps. Can i use these instead of the 2.2uf from the BOM. Rs are out of stock until August for the2.2uf caps.

Regards Keith
 
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