F5 power amplifier

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#10,241
bear said:
The difference is in Damping Factor!!
Click to expand...
Damping Factor is a measure of the output impedance of an amplifier.
Source impedance does affect the speaker Q and this results in a different bass response.
Please show us the explanation of how and why DF gives the apparent bass report that was posted earlier.
Both explanations could be valid, one may be more plausible than the other.
That is no reason for expressing "Bah"
 
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#10,242
Nikon1975 said:
Ok guys, I have a moment of insanity. Here is my offer: I volunteer to document some variation of the circuit, to be published after the review of an expert member, in the most appropiate format (post, article, wiki, whatsoever). The goal is to relief the expert member from recurring questions and give info without the need of reading 10000 posts.

Davide
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One of the clevest things I've heard around this thread. Would be nice to make a Wiki, so everyone can add things :Pumpkin:
 
#10,247
Trying to get to the bottom of my biasing problem I disconnected everything and discovered that I had inadvertently fitted npn's in Q5:blush:
I have managed to change it on one pcb but managed to damage the second board; good job I bought spares. Is there anything other than Q5 which might need changing? TIA.
As a matter of interest is there anything other/better than a solder sucker to use when changing components?
 
#10,252
if components are going to be dumped/changed, cut the legs first
then remove the pieces, one by one
and then begin to clean the board and holes with solder sucking braid

some times holes can be tricky
then I have inserted a sewing needle into the melted solder
or used compressed air

but be careful
solder braid need lots of heat
some components might not like it
 
#10,253
#10,254
Remote power trigger circuit: In the amp?

While I'm waiting for my heatsinks, a thought came to me about my build plan I wanted to run by you all...

I have a 12v trigger from my head unit that I planned to utilize to turn on my 2 F5 stereo amps. I had a simple relay circuit planned...

But now I'm wondering if it might be a bad idea from a noise perspective to house it in the amp itself. Maybe building a power strip with the circuit built into that would be the better choice.

Do you guys think a trigger circuit might insert noise in the amp?

How would you mitigate that possibility?
 
#10,255
udailey said:
Nikon
WOW.
Great offer. Very friendly offer.
I hope you go ahead and do so.
Uriah
Click to expand...

So my plan is the following:

1) I will make a draft table of content and post it for comments.
2) When this is almost accepted I will start putting the beef inside and chapter by chapter send it for revision.

I really wanted to contribute in some way, as I do not have the knowledge to produce brilliant circuits, at least I can let people that have this knowledge have more time to do it, instead to answer always the same questions.

As a general approach, I am not aiming to make a bible: if explanations or options are disputed I will just write the various possibilities, and "let people chose their own poison" (quot. ZenMod)

As NP says "This is the entertainment business, and I hope everybody is having fun"

Davide
 
#10,256
AndrewT said:
Damping Factor is a measure of the output impedance of an amplifier.
Source impedance does affect the speaker Q and this results in a different bass response.
Please show us the explanation of how and why DF gives the apparent bass report that was posted earlier.
Both explanations could be valid, one may be more plausible than the other.
That is no reason for expressing "Bah"
Click to expand...

Andrew, my friend from the British Isles, Scotland is it?

Anyhow, it sure as heck ain't the difference in frequency response below 5Hz. is it?
I didn't look at the Hafler spec, but it's likely down around 1Hz...
So, 1Hz. vs DC that's the cause??

Higher DF usually gives the report of "tighter" or "thinner" bass, while lower DF usually gives the report of "looser" or "fatter" bass - of course depending on the Qt of the speaker system, and the room response.

Since we don't know the poster's set up, we can speculate. But you can explain to us how sub-sub-sub bass frequency response is going to make a difference in the report of the bass?

Perhaps you are right! 😀

_-_-bear
 
#10,257
Thanks for the responses. I originally used solder braid then switched to a solder sucker but never quite seem to be able to suck all the solder out on boards with vias.I'll start and use both from now on.I'm well on the way to stuffing the spare pcb so hopefully be able to set it up this weekend; just hope this time I can set the bias correctly.
 
#10,258
solder braid need lots of heat
some components might not like it
Click to expand...

Not so amusingly the usual cheap solder suckers are not temperature regulated or whatever at all. They cook happily and also need care to use them. Can destroy pads in seconds 😉

Personally I always use desolder braid for anything smaller than, say, TO-247. The cooker takes care of the big ones.

Hannes
 
#10,259
Personally, i continue to use the old solder containing lead, it melts at lower temperature.
One thing i do not understand is why DIYers prefer double layers PCBs for simple amps, which makes unsoldering unpleasant and tricky. Simple layer and larger PCBs makes life easy when you have to troubleshoot.
 
#10,260
bobodioulasso said:
Personally, i continue to use the old solder containing lead, it melts at lower temperature.
One thing i do not understand is why DIYers prefer double layers PCBs for simple amps, which makes unsoldering unpleasant and tricky. Simple layer and larger PCBs makes life easy when you have to troubleshoot.
Click to expand...

I whole heartedly agree this is the first time I think I have ever lifted a trace like I did with this one. Never had a problem with single sided boards.
Please do not take this as a criticism of cvillers pcb's which are of excellent quality this problem was down to my hamfistedness🙄
 
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