Pieter, please, I am serious. I live in THE PEOPLE'S REPUBLIC OF BERKELEY' so your political affiliation is of little consequence, BUT I need INFO!
Because he makes TOROID core transformers, John, NOT laminated core transformers.
*sigh*
se
Yes, I (try to) select the best core material for a given application.
In practice this means nanocrystalline amorphous or cobalt amorphous material for small signals (up to line level), and "standard" amorphous or high quality grain oriented silicon steel material for line opt's up to output transformers.
Steve, the small signal transformers are toroids, the large signal transformers c-cores. Unlike iron powder cores for instance, these transformers (toroids and c-cores) are all "strip wound", so "laminated".
Let us talk laminations, Pieter. That is the hot topic here at the moment. Then we can go to nanocrystalline amorphous and its advantages. The BIG problem I have with amorphous is LOW FREQUENCY distortion. However, that can wait. First, eddy current losses due to lamination thickness, etc. Please remember, it was you who introduced yourself with 1 mil lams. just this morning.
John, apart from my MC step-up transformers and inductive volume control, all transformers are custom made to order for DIY'ers; there is no catalogue.
By the way, I was in the SF bay area last summer but I did not feel like being in a socialist environment 😉
You're welcome. I should have known there was nothing to be learned from an article about limited quality input stages.
True.
But still lots of people here would like to expand their knowledge beyond what's easily available on the net and on mass-market books.
And being no professionals, some of the prices charged by the AES are not justified by their scope.
They're not laminations, John. They're ribbons. They're not stacked, they're wound into coils.
se
No actually a transformer can be designed to improve the SNR of any JFET input stage. Do I have to post the .06nV article (Simple K170 diff-pair input) again? Or for that matter the Jensen app note., 1.23dB noise figure from 10 Ohms considerably better than a BT.
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'POWER TO THE PEOPLE!' We hide our socialist tendencies in an exterior of normalcy. Just ask anyone in Texas about Berkeley or the SF Bay Area, or even the Swiss!
Once in Switzerland, I visited a hardware store to buy some tools. I introduced my associate and myself as from San Francisco. I got a note of disapproval from mentioning that. '-)
Once in Switzerland, I visited a hardware store to buy some tools. I introduced my associate and myself as from San Francisco. I got a note of disapproval from mentioning that. '-)
You'd find that Austin is identical to Berkeley except for the higher heat and more live music. As a von Hayek kind of guy, I tend to say very little when the discussions turn political since everyone here carries guns as well.
Yes, Scott, presuming the transformer is IDEAL! However, there are differences between transformers, and I seek to find these differences. Then I can chose between them.
It is POINTLESS for me to put in a less than optimum transformer. I am willing to go as high as 200 Euros / transformer, in limited quantity, 100 or so. Pieter, can you work in this range?
It is POINTLESS for me to put in a less than optimum transformer. I am willing to go as high as 200 Euros / transformer, in limited quantity, 100 or so. Pieter, can you work in this range?
First of all I am curious what causes your problem with amorphous and low frequency distortion. Low frequency distortion points in the direction of core saturation. Standard amorphous cores which I use for line outputs, interstage and output transformers have a lower saturation treshold (1.56T) than for instance HiB (it's already in the name) silicon steel cores (over 2T). However with a well calculated amorphous core transformer low frequency reproduction should be no problem.
Direct measurement comparison between the mumetal and amorphous transformers: LL1931, and LL1933, show a VERY large difference in distortion at 10Hz.
My apologies. He's also using C cores (I'd just looked at the volume control previously). However these also use ribbons which are wound and then cut (producing two C's).
se
se
John,
I just pop into this huge thread, and you can't blame me for not reading all in order to see what is going on.
What is the application of your transformer?
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