Intact Audio

For the full xover (4 ways) I need in total 8 coils. Most important is the xover between upper bass and mids which will be around 500 - 1k Since I'm still playing with the xover frequency the adjustability comes in handy. For this I need a value around 100-200mHy. I need 4 of them and they should a...

i agree that a one size fits all approach isn't the best way to go, so here are a few more pictures with a few more measurements. I adjusted the perm and brought fringing flux into the math to make the lines match, then ran the numbers for two sizes smaller and the seemed to line up. I will suggest ...

here are some measurements... take them for what they are. They were made with the series connection with my B&K 885 which can measure at 100, 1000, and 10000hz and 50mv 250mv and 1V. I simply pushed the buttons and recorded the numbers. There are a few suprises, but for the most part they measu...

they say a picture is worth a thousand words.

in a perfect world, the lines would be straight and parallel (i think)

not to far off

dave

should be easy to do... the shim kits will make adjustment easy and repeatable. what voltages and frequency... keeping the AC flux down will be a concern. (max AC and min HZ) the tradeoff will be DCR vs. linearity. It looks like 2 coils on an amorphous core that measures 200mhy with a small gap will...

Thanks Johnny - I've been scratching my head wondering why there was a pronounced flabbiness in the non-inductance canceling mode...the mini-tank circuit is the answer! whoa there... can we at least wait to see some numbers before we pronounce the patient dead :-) i would love to know where the tan...

Hi Dave, I guess I would go for the sane approach here ! I don't blame you... toss out some desired numbers so we have a place to start. Are you sure that cross field thing would yield an inductance which would be halfway constant with a varying signal ? of course not... i don't have a clue but i'm...

How crazy do you want to get with this idea??? how about an inductor you can adjust vaule electrically? If we operate under the assumption that a saturated domain behaves as air, then all we need to do is introduce a cross field to locally saturate a section of the coil. if you want to remain a bit ...

this seems the perfect IT for a low level stage when the plate impedances rise and the currents are low... and most importantly, no grid current of the next stage to mess up the balance... i was referring more to its use in a plug and play system for the masses. the 2A3 It for jim is just that... a...

so.. I am thinking (and things never end up as we think) i like your thinking... but remember, staked supplies suggest a large DC voltage difference between primary and secondary. This may not make the bifilar transformer happy. Do note that given enough resources it isn;t an issue, but for now can...

Hi Dave, What kind of inductance are you getting with these? With a cap in parallel you have a "tank" circuit with a oscilation frequency of roughly the square root of 1/LC. Johnny interesting... this is a two fold problem, first I am not confidant on the inductance measurements that my m...

hey ed,

looking forward to the listening comparisons... here is the info on the small current behavior of the two beasts.

How would they differ from NIWW (non-inductive wirewound) resistors like those power resistors wound on ceramic cores? well, they are decidedly inductive, they have large capacitance, and they change value with temperature. I presume those are nicrhome wire or something with a lot less conductivity...

lets start looking at the three main issues i see with the copper resistors. Temperature co-efficient of copper: copper changes resistance with temperature. a 30 degree change in ambient temperature is roughly equal to a 5% change in resistance. Since most of these things are placed near tubes... yo...

So Jeffrey is one of the people that is going to play with the current cancel 1:1’s His initial intention is to use it to IT couple a 10 as a driver to an output tube. We decided that 350V and 30ma would be the general area where the 10 would operate. This should work well and a goal of 80 hy’s ...

The tube to be loaded is an RS241 in various positions attached below are the L vs. I graphs for three different desings on different core materials. The graphs are pretty general and widespread at this point due to the range, but can be narrowed down in the future. The basic identification is by co...

This is a little bit of pre-history on some experiences with playing with different gap sizes in a pair of output transformers. Next, I took my amp back to my place and tried the amorphous trannies as output transformers with no gap and with a gap of four post-it note thickness. In the first case, n...

This is an idea that I have been tossing around in my head for some time now and I finally found a situation that will be an appropriate test bed. First a little prehistory from the days of email. John, steve and grant have been playing with several different combinations of plate chokes and outputs...