Thanks Nuuk. I have read that several times. 🙂 Very useful thanks!
But I cannot find anything about using seperate transformers for each rail. This may be my oversite, but I did not see it. 🙁 In any case I have my answer now. Thanks.
Steen, I meant by the above that your post #219 had given me the answer. 🙂 Thanks so much, especially for not flaming me. 😀 This is great news for me by the way since I have a few small toroids which I now know I can use for my preamp as well! 😀
Carlos,
i would be interested in hearing from you the motivation for adding the extra snubber as well as the reasons for value choices. also, which values are critical and which arent? or what ranges of values can be used?
i would be interested in hearing from you the motivation for adding the extra snubber as well as the reasons for value choices. also, which values are critical and which arent? or what ranges of values can be used?
Nuuk said:
Sorry for the delay, uncle Nick.
Too much work... at work.😀
Nuuk said:
Well, the big caps do benefit being snubbed right on their pins.
The smaller the distances, the better.
But the chip also benefits, and the big caps, as close as you mount them, will never be near the chip's PSU pins.
They are big, not much you can do.
Nuuk said:
Hey, I don't use wirewound resistors, and I don't recommend them for the snubber(s)
I used 0.47R 3W carbon resistors.
3W because it was what I had at hand, but 2W should be fine.
And yes, paralleling two 1R resistors is OK.
Nuuk said:
For me, polyester (MKT) are just fine for this.
You want small film caps, low inductance.
I would surely not recommend an MKP cap if it is at a much bigger voltage rating and consequently much bigger in size.
If they are around the same size, OK.
But if they are much more expensive, I would not consider them, as I really see no advantage on this application.
Free yourselves from fancy components, just use the right ones for the right job.😎
peranders said:... no, no, it's just a coincidence.
P-A,
A member reported on another thread that in his case he tested the snubber near the chip and he liked it better than on the big PSU caps.
Don't make me search, I have no time now.
I have been thinking about this since then and I opted to use on both places, but with different values.
For me, it's the best approach.
Sorry, but I can't consider your oppinions because of your behaviour since I opened this thread.
I didn't even bothered to post on your thread, because I can't loose my precious time with someone who has many theories, many doubts, and until today didn't have the honesty to say if the snubber is an improvement to the amp or not.
So, either subjectively or objectively, you didn't contribute at all.
What you did contribute was to put more wood in the fire, generate big discussions and bring your friends to the spanking.
Don't worry, I'm still laughing.😎
Russ, that is what this forum is all about🙂 No need to say Thank you, but you are so welcome🙂
Steen.
Thanks for the explanations Carlos.
Sorry to hear that you were so busy today, but good to know that the Portuguese economy is in good hands! 😉
Well I've got the polyester 0.1uF caps and the PPS types (both the same size) so if I can muster enough enthusiasm I may try both!
I'll use two 1R resistors as Farnells only do the 0R47's in wirewound.
I need to build another (snubbered) 3886 amp for my active speakers! 😎
Sorry to hear that you were so busy today, but good to know that the Portuguese economy is in good hands! 😉
Well I've got the polyester 0.1uF caps and the PPS types (both the same size) so if I can muster enough enthusiasm I may try both!
I'll use two 1R resistors as Farnells only do the 0R47's in wirewound.
I need to build another (snubbered) 3886 amp for my active speakers! 😎
Nuuk said:
Well... converting a big software application from Oracle database to SQL Server is more like a long project.🙂
Nuuk said:
Don't make the LM3886 amp now.
Can you wait a few days?
I'm cookin' something.
Besides the PSU, there's still more to improve.😉
carlosfm said:
it just never ends....
well i guess one has to stop waiting and build at one point, and then build again later on when your first project becomes obsolete....
homer09 said:
Waiting?
In my life I'm not used to wait for anything or anyone.
Just build it, man.😎
Don't worry, you can improve later.
Or do you wait forever the fastest PC?😀
Two months later there's a faster one.
homer09 said:
To wait till you can build the ultimate one implies that you will only be building one. And that it turns out is a really bad assumption. 🙂
Two reasons to build now:
1) The journey is part of the enjoyment even if the destination is the prize.
and
2) The current designs sound great even (as we hope) there is something even better over the hill.
I'd like to report the results from my GC being snubberized.
Doubling the PS caps improved the LF allot.
I have 2000uF/rail/channel. It's a common transformer and bridge rectifier for both channels. The PS caps are located close to the chips. I did connect the snubbers across the PS pins of the chip. I don't have the extra 100n bypass caps. Big dif. in the HF (much clearer and refined). I found that the best value for my setup was 100n+(2 to 2.7 ohms). 1 ohm resistor didn't have as much effect as the 2.4 ohms. It could be the type and amount of PS caps and the wiring in my setup.
I'm planing to add more PS caps and I'll report the results.
Greg
Doubling the PS caps improved the LF allot.
I have 2000uF/rail/channel. It's a common transformer and bridge rectifier for both channels. The PS caps are located close to the chips. I did connect the snubbers across the PS pins of the chip. I don't have the extra 100n bypass caps. Big dif. in the HF (much clearer and refined). I found that the best value for my setup was 100n+(2 to 2.7 ohms). 1 ohm resistor didn't have as much effect as the 2.4 ohms. It could be the type and amount of PS caps and the wiring in my setup.
I'm planing to add more PS caps and I'll report the results.
Greg
Oh yes I can Uncle C! I have the crossovers to finish and the speaker cabs to refurbish so I can delay the amp for a few days. 😉
Patience is a virtue but a stitch in time saves nine and he who hessitates is lost. Look before you leap but don't put off until tomorrow what you can do today.
For it isn't important who brought up the idea. The important thing is that it is on the agenda if you know what I mean.carlosfm said:
Since Mr. Ottala had this snubber in the 70's I'll regard it pretty serious but I don't value it. Later I'll maybe be able to do that. It surely is a technical micro detail and it has a proven technical purpose.
TO RUSS WHITE:
See image from post#201. There are two single secondary transformers as you have. Yes, it will work. If not - replace pins on any secondary.
See image from post#201. There are two single secondary transformers as you have. Yes, it will work. If not - replace pins on any secondary.
percy said:
LOL, that's right!😀
percy said:(i do Oracle pl/sql programming)
Me too.
Including some massive Bulk Collect routines, sometimes.🙂
percy said:
why did you downgrade ?? 😉😀
(i do Oracle pl/sql programming
I'm a SQL Server DBA and even I wouldn't do that!
Nuuk said:Look before you leap but don't put off until tomorrow what you can do today.
It's just that I'm still testing and I have to design the schematic.😀
I don't like to report anything until I have the final values and design.
Just make a small break a go see a Chelsea match, ok?😛
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