Millwood, different views are certainly tolerated. You won't find two people with more different views than Peter and me, yet we're starting what will probably be a most interesting collaboration. And we've had (and have) strong differences of opinion, yet our interaction has always remained cordial and respectful. As has yours and mine.
Let's keep all this on topic, OK?
Let's keep all this on topic, OK?
Pink Microdots
What characteristic do they have ? - spongy and lossy etc ?.
Anybody else have experience of these ?.
Eric.
Microdots Of The Sixties
Fred, do you know what these tuning dots are made of ?.
What characteristic do they have ? - spongy and lossy etc ?.
Anybody else have experience of these ?.
Eric.
Microdots Of The Sixties
janneman said:
Such capacitive leakage to the chassis earthed heatsink might introduce high frequency earth loops - how much effect this might have is open.
I agree that the mechanical resonance characteristics of the heatsink is one factor, but ime/imo the actual material imparts a character also, along the lines of silver wire sounding different to copper wires.
Eddy currents induced into the heatsink material may be a loading influence here.
The alumina pads that Peter uses are quite thick and physically seperate the device from the heatsink and thereby reduce any such eddy currents.
Eric.
SY said:
I am not mad at the whole thing, or Peter's sometimes less-than-desirable behavior in this discussion - I am sure I could be viewed the same at times.
However, I approached the discussion with the sincere goal of understanding Peter's claim, which can potentially have profound impact not only on DIY audio but also physics and electronics at large.
I thought I tried my best to be honest, respectful, civil, and even-headed, in spite of low shots, multiple of them, fired at me, and being called BS a couple of times as well.
All this did to me was planet10's coming out calling me a bully. This is what Webster has to say about "bully":
so, planet10, would you mind telling me which of the following is true?
1. Peter is weaker? (His arguments are pretty weak, I will grand you that);
2) am I habitually cruel to others? and how/where/when?
3) am I self-assertive? where and when?
4) did I ever make swaggering threats? where and when?
5) did I intimidate others? where and when?
6) did I make arrogant speech? where and when?
a few data points for you as well planet10:
1) who revoked qualification in this discussion?
2) who said that he presumed others to be less qualified and dumb in a discussion? that post, for your information, had been revised by its author to take out this particular part;
3) who asked how many amps I have built?
4) who asked me to build an amp of my own before I can speak on a subject?
to list a few.
Persistent I am, bullying I am not.
and if you cannot see that, planet10, I don't know how you can be possibly fair and balanced as a moderator needs to be.
Again, to SY's point, I don't want to continue this discussion with you if you cannot be fair. Enough said.
Crossed Currents.
The correct reading is currents in the collector tab inducing currents into the heatsink.
Extra spacing of the thick alumina pads would exponentially reduce this.
Eric.
You two are as silly as each other.SY said:Don't feel bad, Jan. I'm mystified as well
The correct reading is currents in the collector tab inducing currents into the heatsink.
Extra spacing of the thick alumina pads would exponentially reduce this.
Eric.
Err, AFAIK it is pretty much universal that the collector connection is the heatsink area of transistor devices.SY said:
In the GC chips, the HS tab is the -VE connection.
Both of these will be carrying speaker current plus quiescent current.
The speaker curent is of course quite large in magnitude.
At least part of the cause of heatsinks 'singing' in sympathy with the audio I expect is induced eddy currents.
Eric.
As Jan already said, the heatsink and the collector plate might be a few p size of capacitor formed together with the pads. This means the part of the heatsink under the collector plate might alter few +/- charges. Could it be a real concern for the amp sound or stability? Probably the same effect like 10ppm water drop into 1 liter of wine?
of course.......
"Fred, do you know what these tuning dots are made of ?"
Yes. They are a several layers of different
lossy materials. They don't work by adding mass but by converting vibration energy to heat. the different sizes and different materials degrees of damping and different mechanical impedances. Before all the whining starts again I should probably mention that Rod is a Mechanical Engineer and reccomend that one read the websites for the 3M and EAR
materials. I will let everybody get back to arguing instead of trying to learn anything about the subject.
"Fred, do you know what these tuning dots are made of ?"
Yes. They are a several layers of different
lossy materials. They don't work by adding mass but by converting vibration energy to heat. the different sizes and different materials degrees of damping and different mechanical impedances. Before all the whining starts again I should probably mention that Rod is a Mechanical Engineer and reccomend that one read the websites for the 3M and EAR
materials. I will let everybody get back to arguing instead of trying to learn anything about the subject.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.