merlin2069er said:
Let's assume that you haven't mis-wired anything on the the left, as you are getting legitimate numbers. It still won't hurt to look, however!
On the left channel, what is the max bias can you attain with zero offset?
ok, this is what I've attempted...
I've adjusted my left channel to ~ .004v dc offset after an initial few minutes of tweaking.
I had to adjust the voltages @ 1.284 v dc & -1.279v dc (across the .47ohm 3 watt resistors)
It definitely heats up quicker... I'll check it again at 30 minutes and 1hr.
That's more that 2x the .59v dc the service manual suggest to bias the amp at.
Any suggestions, or is this fine?
-----
I've checked it at ~ 30 minutes, and the heatsink is quite hot. I can leave my hand on it for 5 seconds or so.
It's 2x as hot as the other heatsink...
-----
I've turned it off just after ~ 40 minutes...
I've adjusted my left channel to ~ .004v dc offset after an initial few minutes of tweaking.
I had to adjust the voltages @ 1.284 v dc & -1.279v dc (across the .47ohm 3 watt resistors)
It definitely heats up quicker... I'll check it again at 30 minutes and 1hr.
That's more that 2x the .59v dc the service manual suggest to bias the amp at.
Any suggestions, or is this fine?
-----
I've checked it at ~ 30 minutes, and the heatsink is quite hot. I can leave my hand on it for 5 seconds or so.
It's 2x as hot as the other heatsink...
-----
I've turned it off just after ~ 40 minutes...
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Huh...
Turn your pots all the way down and try it again. Can you, for instance, bias to .2v with zero offset? If so, then try for .3, and then .4, each time attempting to keep the offset to zero.
Turn your pots all the way down and try it again. Can you, for instance, bias to .2v with zero offset? If so, then try for .3, and then .4, each time attempting to keep the offset to zero.
ok, I'll turn the pots all the way counter clockwise until they click and try again tomorrow.
I might have adjusted the pots too quickly to begin with...
I might have adjusted the pots too quickly to begin with...
If everything is wired up correctly and you got that much bias, there is no doubt that you are well, well past the rated dissipation of the output devices. You have the 4U x 400mm heatsinks, right? You should be able to leave your hand on them indefinitely. It is more than enough heatsink. The fact that you could only do 5 sec means that something is wrong. Hopefully it's only a wrong bias adjustment.
Turn the pots all the way down until they click and start over.
Turn the pots all the way down until they click and start over.
ok, got it!
I reset the pots to 0hms, and powered it up.
adjusted each pot and looked at the offset. As you adjust one pot, the offset grows larger, by adjusting the other it takes it back down to ~ 0v.
So after a few minutes I got ~ -.005 v dc
.536 v dc & -.537 v dc.
I'll leave it on for another .5 hr before I get to bed...
🙄 I melted my a pair probes on one of the resistors... at the higher bias.
I reset the pots to 0hms, and powered it up.
adjusted each pot and looked at the offset. As you adjust one pot, the offset grows larger, by adjusting the other it takes it back down to ~ 0v.
So after a few minutes I got ~ -.005 v dc
.536 v dc & -.537 v dc.
I'll leave it on for another .5 hr before I get to bed...
🙄 I melted my a pair probes on one of the resistors... at the higher bias.
recommendations?
I just have to finalize a few things...
Can anyone recommend speaker binding posts for the F5?
I'm going to have to pick up some speaker wire too, maybe 10 feet.
I just have to finalize a few things...
Can anyone recommend speaker binding posts for the F5?
I'm going to have to pick up some speaker wire too, maybe 10 feet.
Awesome!!!
I especially like the thick faceplate. And that we have the same DMM - the fluke in the center.
Can you post some pics here?
I especially like the thick faceplate. And that we have the same DMM - the fluke in the center.
Can you post some pics here?
Sure, I got to get around to taking some more photos and adding some text to that video.
Those dmm readings were initial start up left side, ~ 1hr left side, right side 1hr, right side a bit of adjustment.
Those dmm readings were initial start up left side, ~ 1hr left side, right side 1hr, right side a bit of adjustment.
two leds in parallel
Hi friends,
I'm building an F5 and I'm using parts methacrylate. I'm using the plates cviller 1.1. The PCB has holes to solder LEDs with cable or mounted on the plate.
I can use this pair of holes to mount two LEDs in parallel with its corresponding resistance? Will it affect the sound charge led PSU with a more?.
The LEDs are blue.
Thanks for your reply. Excuse my English.
Hi friends,
I'm building an F5 and I'm using parts methacrylate. I'm using the plates cviller 1.1. The PCB has holes to solder LEDs with cable or mounted on the plate.
I can use this pair of holes to mount two LEDs in parallel with its corresponding resistance? Will it affect the sound charge led PSU with a more?.
The LEDs are blue.
Thanks for your reply. Excuse my English.
The LED's will have to be matched if they are in parallel, you would be better off with the LED's in series.
Is anybody else currently building an F5? Please post anything relevant, especially pictures, in this thread.
I finished with my binding posts, and moved it into the bottom shelf of my rack.
It's huge, I've got about 1" of clearance at the top of the unit. Hopefully it will stay cool enough.
It's huge, I've got about 1" of clearance at the top of the unit. Hopefully it will stay cool enough.
If you have decent room around the sides of the heatsink, that will help.
Be glad that you bought the enormous chassis - the heatsink size will help counteract that poor ventilation you have.
Be glad that you bought the enormous chassis - the heatsink size will help counteract that poor ventilation you have.
Quote >Is anybody else currently building an F5? Please post anything relevant, especially pictures, in this thread.
Are you really sure about it?😀😀😀
😀😀😀
Funny Joke about wheater in Uk>Quote
reminds me of an experience I had last time I visited England...
After two weeks of rain in july I asked a young boy passing by :
- Don't you ever have nice weather here? ...
He said :
- How could I know, I am only 16 ...
Is it funny ?
Manu
Still got the giggles and as sunny today 3 bottles of Sol with lime to many sizling in the garden so no much work.
definetly back to 18 C and dull tomorw
So have a pre view.
New 2 transistors on off and soft start
Mounted on aux supply
In new PSU case with DC filter and shafner EMF duda
Big box today she saying what the Fluff is in that?
Usual answer>they blipping got not a clue about global warming such a big box and is full of packing paper. And a few new Caps.
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
Are you really sure about it?😀😀😀
😀😀😀Funny Joke about wheater in Uk>Quote
reminds me of an experience I had last time I visited England...
After two weeks of rain in july I asked a young boy passing by :
- Don't you ever have nice weather here? ...
He said :
- How could I know, I am only 16 ...
Is it funny ?
Manu
Still got the giggles and as sunny today 3 bottles of Sol with lime to many sizling in the garden so no much work.
definetly back to 18 C and dull tomorw
So have a pre view.
New 2 transistors on off and soft start
Mounted on aux supply
In new PSU case with DC filter and shafner EMF duda
Big box today she saying what the Fluff is in that?
Usual answer>they blipping got not a clue about global warming such a big box and is full of packing paper. And a few new Caps.
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
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