Search found 1603 matches

by dave slagle
Mon Feb 28, 2005 4:40 pm
Forum: Inductors
Topic: nickel in PS chokes, plate chokes, and output trannies?
Replies: 9
Views: 14662

hey len, i shrunk the jpegs and added a full res pdf for those that want to print... hope you don't mind... the horizontal scroll is a pain and i'm on dialup at home :-( All in all, the pre is working but with a few problems. Firstly, upon replacing out the last 380 uF electrolytic cap in the HT PS ...
by dave slagle
Wed Feb 23, 2005 4:39 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

some pictures....

here are two series of measurements of restel's first revision. stacked 1X1 i measure 40hy's of inductance. DCR of each winding is around 70 ohms. i am really surprised that the 1:2 worked as smoothly as it does given the bifilar wind. (I am also equally surprised that the phase inverting hookup mak...
by dave slagle
Tue Feb 22, 2005 5:02 am
Forum: Transformers
Topic: Using Bifilar Wire
Replies: 20
Views: 17620

I also take my wire off the top of the spool and then pass it through a felt guide and a wheel. I also have to hold it between thumb and fingers to better tension it. the fingers are the key part, they will feel the kinks The bonded bifilar wire that I bought isn't neatly layed on the reel, it's tw...
by dave slagle
Tue Feb 22, 2005 4:32 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

Re: Transformer output from a SACD player

Dave Cigna said that the outputs are differential. If that is the case, Kevin Carter explained to me that it could be wired up with the + and - leads wired up to opposite ends of the primaries of the transformer, with the center leads of the primaries wired to ground. ahhh...now the light goes on.....
by dave slagle
Mon Feb 21, 2005 3:49 am
Forum: Transformers
Topic: Using Bifilar Wire
Replies: 20
Views: 17620

Re: Using Bifilar Wire

I just bought some bifilar wire 0.1 mm with the intention of winding a 1:1 interstage for 6 ma. This is the first time I've tried anything bifilar. Bifilar wire (two individual wires bonded together) can be very tricky. read the bits about keeping constant tension. for your use, i suspect too much ...
by dave slagle
Sat Feb 19, 2005 1:57 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

Re: Transformer output for a SACD player

Thanks Dave! It seems that you did all these measurements on the bench. Did you load the secondary with your no gap autoformers? It would seem important to provide the same load. no i did not, i am working through an easy way to quickly measure a lot of different situations. i would only expect the...
by dave slagle
Thu Feb 17, 2005 4:32 am
Forum: Your name here.
Topic: Hello to everybody!
Replies: 4
Views: 7818

so put up some pictures of your system and give us something to talk about...


dave
by dave slagle
Thu Feb 17, 2005 4:27 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

Re: Transformer output for a SACD player

Based on the roughly 10 ohm output impedance, is a 1K/1K transformer the most ideal? 1K is such an arbitrary number in this situation. I'll put a lot of faith into what allen suggested... and it just happens that i think i can get 6hy's (1K @ 20hz)pretty easily with a butt gap for a first attempt. ...
by dave slagle
Wed Feb 16, 2005 7:59 pm
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

so we are back to the trifilar transformer... and 1K is a breeze. I just happen to have some trifilar #33 wire with no real use :-)

actually I think the quad 36 litz i have would do better, just parallel the appropriate wires for the secondary.

dave
by dave slagle
Wed Feb 16, 2005 1:50 am
Forum: Attenuators
Topic: First look at making a passive pre where do I start
Replies: 11
Views: 10865

The $200 autoformers would be a nice start :-)

read through the FAQ and associated links, then searching the various other forums will give you more background and theory.

dave
by dave slagle
Sun Feb 13, 2005 2:29 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

maybe a known choke in series with the resistors might also help the situation??? measurements at two different frequencies should allow someone to extrapolate the Z-out. I have been meaning to ask, what is the frequency of that 1V signal, and what meter are you using to measure it? just curious. dave
by dave slagle
Fri Feb 11, 2005 1:59 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

what is the cause of the actual problem here??? if, as allen suggested the squealing was a loading issue and not a coupling one, you have been barking up the wrong tree with how the primaries couple to each other. i understand the (possible) need for some sort of filter, but have we determined the n...
by dave slagle
Thu Feb 10, 2005 4:57 pm
Forum: Transformers
Topic: 1:1 bifilar output to remove the parafeed coupling cap.
Replies: 31
Views: 37034

we don't know how they sound yet... when i said by the weekend, i didn't specify which weekend. :-) i got around to doing the measurements and a frequency response plot when used as a 1:1, i chose a GM-70 at the source since its Rp was closer to the 75TL. the graphs should tell it all, the excel doc...
by dave slagle
Thu Feb 10, 2005 4:52 pm
Forum: Transformers
Topic: 1:1 bifilar output to remove the parafeed coupling cap.
Replies: 31
Views: 37034

we don't know how they sound yet :-) i got around to doing the measurements and a frequency response plot when used as a 1:1, i chose a GM-70 at the source since its Rp was closer to the 75TL. the graphs should tell it all, the excel doc will let you manipulate the info and see the frequency respons...
by dave slagle
Wed Feb 09, 2005 9:46 pm
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

Re: Transformer output for a Sony 90000es SACD player

I will wire with the primaries in parallel and the secondaries in series to derive a 1:2 stepup. I am looking at the following manufacturers: Tribute, Electraprint, Jensen and Stevens and Billington. Do you have any experience with the transformers from these various manufacturers to say what might...
by dave slagle
Wed Feb 09, 2005 5:02 pm
Forum: Inductors
Topic: Three different "80 hy 25ma" plate chokes
Replies: 34
Views: 39081

i updated the images above to show what they are gapped at. I gapped the 80% nickel at .025 so there will be slightly less inductance than the .024 line on the graph. the gap on the graph is double the actual spacer, so the 49% nickel chokes have a .025 gap which is 1 piece of "black" shim...
by dave slagle
Sun Feb 06, 2005 12:24 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

are the outputs isolated form each other and floating??? can they be put in series connect A- to B+ and take a single winding from A+ and B- ? thye would need isolated grounds to do this, but the goal would be ot get a floating ballanced output. maybe witha little circuit work??? damn where did i pu...
by dave slagle
Fri Feb 04, 2005 5:56 pm
Forum: Resistors
Topic: R(k) listening report
Replies: 13
Views: 20123

How much variance will there be? Meaning, if the resistor is 260 ohms at 90 degrees F, what will it be at 120 degrees F? [Or vice-versa?] a resistor wound to be 248 ohms at room temp (68 degrees) will be 260 ohms ay 90 degrees and 277 ohms at 120 degrees. I think once the amp stabilizes, the temp i...
by dave slagle
Fri Feb 04, 2005 4:08 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

You can't tie the outputs together because they might (probably) have slightly different offsets, so they end up fighting with each other. gotcha... still might be worth a try for lester since he has the parts on hand... that is if it won't cook something :-) here is a crazy thought... place whatev...
by dave slagle
Thu Feb 03, 2005 7:59 pm
Forum: Transformers
Topic: 1:1 bifilar output to remove the parafeed coupling cap.
Replies: 31
Views: 37034

funny you should mention it, i just wound them today and am waiting for the cores ot dry as we speak. DCR is 200 ohms as a transformer and 100 ohms as a plate choke. I just need to run the inductance vs. airgap plots and do an in circuit frequency sweep and they are ready to go. hopefully a big box ...
by dave slagle
Thu Feb 03, 2005 4:22 pm
Forum: Resistors
Topic: R(k) listening report
Replies: 13
Views: 20123

so i'll do them to be 260 ohms at 90 degrees with 25ma of current.

but i honestly think it will be warmer than 90 degrees, ambient temp with the amps off can be that in the summer without AC. maybe 120 degrees is a better target temperature for the 260 ohms???

let me know.

dave
by dave slagle
Thu Feb 03, 2005 5:46 am
Forum: Resistors
Topic: R(k) listening report
Replies: 13
Views: 20123

hey jim, had a chance to play with your resistors tonight... trying to get heating (both ambient and copper loss) under control... or at least predictable. i played with the 260 ohm ones you requested, but i need to know two things... what is the current through them, and where will it ultimately be...
by dave slagle
Thu Feb 03, 2005 1:21 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

the lack of data on the chip makes me ask these questions... what does the chip actually do??? i know it has a voltage out, but google suggested it was a filter chip. I did try this and it had its benefits and also introduced some different problems. As you noted below this chip outputs pulsestream ...
by dave slagle
Wed Feb 02, 2005 10:53 pm
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

It sounds like a dual primary transformer might be a really slick solution. Simple low-pass filtering gives you analog. (though he might try to talk you into 1:1 :wink: ) Dave it would definitely be 1:1 if i do it. small stepups and stepdowns just don't work for me :-) the problem i run into is usi...
by dave slagle
Wed Feb 02, 2005 1:16 am
Forum: Transformers
Topic: Ideal transformer for an output for a SACD player
Replies: 86
Views: 74142

it seems dave is on top of it, is there a link to the application sheet of the chip?

dave
by dave slagle
Wed Feb 02, 2005 12:39 am
Forum: Playing With Airgaps
Topic: Adjustable inductors
Replies: 15
Views: 22219

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...
by dave slagle
Mon Jan 31, 2005 8:26 pm
Forum: Playing With Airgaps
Topic: Adjustable inductors
Replies: 15
Views: 22219

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 ...
by dave slagle
Mon Jan 31, 2005 2:48 am
Forum: Playing With Airgaps
Topic: Adjustable inductors
Replies: 15
Views: 22219

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...
by dave slagle
Sun Jan 30, 2005 4:59 am
Forum: Playing With Airgaps
Topic: Adjustable inductors
Replies: 15
Views: 22219

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
by dave slagle
Sat Jan 29, 2005 4:47 pm
Forum: Playing With Airgaps
Topic: Adjustable inductors
Replies: 15
Views: 22219

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...