Probably won't try that method this time around, but I like that guy's thinking with hand tightening the chuck. I might test it on a scrap piece of aluminium, just for fun.
I'll most likely stick to the character building method for this job. Hahaha
Bloody holes
I'll most likely stick to the character building method for this job. Hahaha
Bloody holes
This short video shows four hole tapped with a hand drill in 30 seconds so you could tap all your holes in just 20 minutes using this method.
https://www.youtube.com/watch?v=OmBrfO_hZW4
https://www.youtube.com/watch?v=OmBrfO_hZW4
Yeah that is what I already do.
Tapping is actually the easiest part, it's the precision drilling which is the more annoying part. Very little margin for error.
Tapping is actually the easiest part, it's the precision drilling which is the more annoying part. Very little margin for error.
Yeah I agree Lynn. M3 taps are extremely delicate/susceptible to breaking.
I recently purchased a battery operated portable hand drill (been living in the stone age), and if you set the clutch on the lowest torque setting it is effectively less than finger tight so impossible to break the tap. Saves me a lot of time and haven't broken an m3 tap with it.
Always use a cutting lubricant. Basically anything.
I recently purchased a battery operated portable hand drill (been living in the stone age), and if you set the clutch on the lowest torque setting it is effectively less than finger tight so impossible to break the tap. Saves me a lot of time and haven't broken an m3 tap with it.
Always use a cutting lubricant. Basically anything.
Lynn, the guy in the video said you can't use just any tap it needs to be a spiral tip and machine steel, not carbon steel. normally I would tap by hand but with 160 holes I would see if it worked. The guy said number 4 is as small as he would go, but I would have to agree that that does seem too small to tap a hole this way.
I appreciated the video Rob.
The thought had crossed my mind before but hadn't considered hand tightening the chuck to protect against breakage.
I'll give it a go on a piece of scrap just for fun.
The thought had crossed my mind before but hadn't considered hand tightening the chuck to protect against breakage.
I'll give it a go on a piece of scrap just for fun.
Interesting discovery today. My front-end circuit has DC degeneration of the Toshiba MOSFETs, consisting of a 47R resistor in parallel with a 3300uF electrolytic capacitor connected between the source terminal and the rail. The discovery was that the second harmonic (H2) is very sensitive to the ESR of the electrolytic caps. Just few milliohms more or less ESR can result in 20dB or more difference in the H2 level. If you are using similar DC degeneration you can see the behavior by setting the Rser parameter of the capacitors to different values any observing the change in the FFT. This might be a good argument to not use DC degeneration.
We had this effect in Spice with the optocoupler version some days ago too. No source resistors for the Toshibas k3 dominant, with more or less source resistors k2 dominant.
Inserting the 47R and parallel 1000uF you could think the k2 should go away, no it stays.
PR wrote some thoughts about this, but I still have to read it.
Today three Jazz lovers all about 70 like me were in my house for eating and hearing music
And the good news they liked the sound of the beast very much!
They said I should stop at this point!
That is encouraging isn't it!
Oh I have to add, I would prefer the non degeneration version with k3 dominance and add the needed k2 from this "neutral" point with cascode feedback.
Inserting the 47R and parallel 1000uF you could think the k2 should go away, no it stays.
PR wrote some thoughts about this, but I still have to read it.
Today three Jazz lovers all about 70 like me were in my house for eating and hearing music
And the good news they liked the sound of the beast very much!
They said I should stop at this point!
That is encouraging isn't it!
Oh I have to add, I would prefer the non degeneration version with k3 dominance and add the needed k2 from this "neutral" point with cascode feedback.
Not all of us. I have been pursuing a simple way to stabilize the DC offset of the FE output. I have not found anything as simple as DC degeneration. The optocoupler approach has different problems. Totally eliminating all degeneration of the FE outputs has bias and offset issues, as well as a reduction of possible open-loop gain. I haven't figured out Nelson's trick(s).
I never left. You can see the basic topology of my amp in the first post.
Having said that, there is no right or wrong, just build it anyway that interests you.
I have no interest in cloning at all.
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Carry on.
I'm in my own world most of the time and forget what you guys are doing.
I always stick with the brute force, caveman, dumb as a door nail method. I only deviate away from that if adding complexity adds a real benefit that personally interests me.
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The first post shows the Toshibas without any degeneration. Is that the way you are building it, or is the first post just the rough topology?
No degeneration anywhere in circuit
I'm purely relying on increased bias of the Toshibas to take care of thermal drift
I'm purely relying on increased bias of the Toshibas to take care of thermal drift
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Is a combination of PRs optocoupler solution to make the Toshibas stable with the thermistor stabilized IXYS outputstage possible?
Just a thought!
Just a thought!
Most likely yes.
I was able to bias the hockey pucks without any fancy techniques but it took over an hour for it to stabilise. I felt that wasn't really practical when you want to just turn on the amp and listen so decided to add the thermistor but it certainly wasn't necessary.
I was able to bias the hockey pucks without any fancy techniques but it took over an hour for it to stabilise. I felt that wasn't really practical when you want to just turn on the amp and listen so decided to add the thermistor but it certainly wasn't necessary.
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I had the same experience Jeff! I had to wait too long, was no pleasure.
And yesterday with my Jazz fellows after four hours I had a moment of panic feeling the heatsinks, but there were only 48 degrees Celsius.
So I can again say that the stabilization of the IXYS current with the thermistors works really fine!