Pass Labs F4
- IslandPink
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#31
Info ?
http://www.diyaudio.com/forums/pass-labs/
More discussion and build info than you could shake a stick at .
http://www.diyaudio.com/forums/pass-labs/
More discussion and build info than you could shake a stick at .
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#32 Nearly finished
As expected, there was no whirlwind of activity on this, however, see attached - one channel finished . Second one will only be a few days behind .
"Once you find out ... the Circumstances ; then you can go out"
- pre65
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#33
I spy star earth tags, where did you get them Mark ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- IslandPink
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#34 Star
No Phil, honestly, it's just a little propeller used to move air around the inside...
( actually I got it from the little box upstairs in my electronics stash ... but I'm not telling anyone what my postcode is )
( actually I got it from the little box upstairs in my electronics stash ... but I'm not telling anyone what my postcode is )
"Once you find out ... the Circumstances ; then you can go out"
- Mike H
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#35
lol, 'course you can make a star earth tag by putting a few "ornary" tag washers on one screw
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
#36
Hi Mark
I've just seen you're pics of the F4 progress...I might be a bit late here but one problem I had with both my first watts was the pesky rf from the toroids. There is a good chance of rf probs if you mount your transformers at the rear of the box, anywhere near the i/p circuit.
I did loads of measurements and scope pics, and after some dialogue with Nelson he said my interference problems were down to mounting the transformers at the rear, close to i/p wiring etc.
He mounts his at the front.
I had to insert steel sheets to block rf in the F2, it was easier than re-doing the whole layout.
If you do have zzz/hum probs then I found that rotating the toroids can have an effect, but it wasn't the whole answer.
just a thought, or two.
I've just seen you're pics of the F4 progress...I might be a bit late here but one problem I had with both my first watts was the pesky rf from the toroids. There is a good chance of rf probs if you mount your transformers at the rear of the box, anywhere near the i/p circuit.
I did loads of measurements and scope pics, and after some dialogue with Nelson he said my interference problems were down to mounting the transformers at the rear, close to i/p wiring etc.
He mounts his at the front.
I had to insert steel sheets to block rf in the F2, it was easier than re-doing the whole layout.
If you do have zzz/hum probs then I found that rotating the toroids can have an effect, but it wasn't the whole answer.
just a thought, or two.
There's nowhere you can be that isn't where you're meant to be
#37
Yep, but it has to be said Ed that your F2 board layout does cover a fair amount of space.ed wrote:Hi Mark
I've just seen you're pics of the F4 progress...I might be a bit late here but one problem I had with both my first watts was the pesky rf from the toroids. There is a good chance of rf probs if you mount your transformers at the rear of the box, anywhere near the i/p circuit.
I did loads of measurements and scope pics, and after some dialogue with Nelson he said my interference problems were down to mounting the transformers at the rear, close to i/p wiring etc.
He mounts his at the front.
I had to insert steel sheets to block rf in the F2, it was easier than re-doing the whole layout.
If you do have zzz/hum probs then I found that rotating the toroids can have an effect, but it wasn't the whole answer.
just a thought, or two.
And remember the F4 has no gain.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#38
doesn't alter the fact that if you put the transformers at the front there is little risk of rf interference......
and..and .. and
Mark's transformers are a lot closer to the i/p circuit and wires than mine are on the F4....but I appreciate he's got less chance of nasties being dual mono.
and..and .. and
Mark's transformers are a lot closer to the i/p circuit and wires than mine are on the F4....but I appreciate he's got less chance of nasties being dual mono.
There's nowhere you can be that isn't where you're meant to be
- IslandPink
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#39
Mmmm..too late !
Well, I shall just have to see how it goes.
I'm using shielded input wires ( the old WAD grey stuff actually ) and will run the wires around the inside of the upper chassis lip as much as possible . As Nick says, it's coming in at a considerably higher signal level with the F4, so hopefully that will keep things acceptable . I do have some mu-metal upstairs for the LCR phono ( one day ) so should have some left over if needed for later tweeks .
Just been doing a bit more on the amp this evening . I'm about 1 or 2 hours work away from being finished now . Will try to get my friend Len over for the set-up and adjustments, with his trusty Variac .
Cheers
MJ
Well, I shall just have to see how it goes.
I'm using shielded input wires ( the old WAD grey stuff actually ) and will run the wires around the inside of the upper chassis lip as much as possible . As Nick says, it's coming in at a considerably higher signal level with the F4, so hopefully that will keep things acceptable . I do have some mu-metal upstairs for the LCR phono ( one day ) so should have some left over if needed for later tweeks .
Just been doing a bit more on the amp this evening . I'm about 1 or 2 hours work away from being finished now . Will try to get my friend Len over for the set-up and adjustments, with his trusty Variac .
Cheers
MJ
"Once you find out ... the Circumstances ; then you can go out"
#40
Surely that's not good. On just about every WAD kit the considered general opinion was replace that horrible boot lace with something better at the earliest opportunity! Most of us did. It's your turn now, Mark!IslandPink wrote:I'm using shielded input wires ( the old WAD grey stuff actually ) MJ
#42
Without being biased, can I put in a vote for the pink "Silver Plated Copper Screened wire" that HiFi collective sells.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#43
paradox?Nick wrote:Without being biased, can I put in a vote for the pink "Silver Plated Copper Screened wire" that HiFi collective sells.
There's nowhere you can be that isn't where you're meant to be