Search found 20 matches

by KMN
Sat Jul 21, 2018 10:36 pm
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

Hmm, or maybe I should say humm... I hadn't thought of that. I don't know how I'd stop myself from trying it now. Great idea!
by KMN
Sat Jul 21, 2018 1:10 am
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

It'd be somewhere around a mH. In order to get the best emi immunity, wire gauge should be as small as possible to enable optimal constructions of a smaller loop area. Up to maybe ten ohms or so series coil R is acceptable. Multilayer is fine. What I've seen, off the shelf looks nowhere close to opt...
by KMN
Fri Jul 20, 2018 9:47 pm
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

good point, and it will be differential noise too. Not to mention the coil would need to be very near to other circuitry it could easily interfere with. That is definitely on my mind. I'd be looking for a low loop area coil and possibly try and come up with some kind of small, grounded steel shield ...
by KMN
Thu Jul 19, 2018 11:19 pm
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

I believe it is pretty much as you described. We have a nice impedance analyzer at work where I can frequncy sweep various parameters . The high ripple current output filter ael caps drying out is essentially what determines our product lifespan. I have been able to catch snapshots at varying stages...
by KMN
Thu Jul 19, 2018 1:11 am
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

^^^^ oh yeah. Sorry if this is the wrong place for this.
by KMN
Wed Jul 18, 2018 11:57 pm
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

The love of those big, well built, coincidentally low DA, audiophile caps probably isn't completely irrational. Would the magnetic complement to dielectric absorption be core material hysteresis? If high levels of filter energy storage element linearity is the goal then why wouldn't air core inducto...
by KMN
Wed Jul 18, 2018 8:43 am
Forum: Test, Measurement and Repair
Topic: Classic Bead Tantalum Capacitor Failure
Replies: 5
Views: 1127

Re: Classic Bead Tantalum Capacitor Failure

If the fuses stop the explosions, it might convince me to consider straying from the flock. Hard to deal with, expensive parts that fail safe are better than not shipping due to long lead part sourcing problems. I've also experienced the cratering. Often the collateral damage seeming much more drama...
by KMN
Tue Jul 17, 2018 8:56 pm
Forum: Test, Measurement and Repair
Topic: Classic Bead Tantalum Capacitor Failure
Replies: 5
Views: 1127

Re: Classic Bead Tantalum Capacitor Failure

Tantalums are pretty well against my religion... I got tired of trying to figure out how to keep them happy in high current ripple applications. Though I hear the tantalum polymers are quite a bit more tolerant high ripple current...the little beasts are way to rich for my blood. Then there is the p...
by KMN
Thu Jul 12, 2018 10:01 pm
Forum: Pro Audio Design
Topic: ZTX851 Low Noise, Low rbb Transistor Vbe Matching and Noise Comparison
Replies: 2
Views: 1231

Re: ZTX851 Low Noise, Low rbb Transistor Vbe Matching

Zetex has their own spice models for many of their parts and they seem pretty decent. What fun it is to sit around and do some transistor noise drag racing in my favorite low noise design simulations!! :lol: So far my favorites are ZTX1051A - NPN ZTX1147A - PNP Just a tiny tad of a smidge quieter th...
by KMN
Thu Apr 05, 2018 2:24 pm
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 48
Views: 15326

Re: Dielectric Absorption

Trying to get the models perfect in the simulations is a big topic of discussion where I work, ie power conversion, not audio. Though even the grizzled old engineers, aware of the effect, haven't made much of a fuss about it. When I've noticed the effect in the lab, hv dc power supply filter caps, t...