So magnetic field interference isn't any big deal?
Ok.
But why go out of your way and intentionally create larger loop areas and spend more money on switches that you don't need to? We're you just spending as much money as you could simply to increase the price for marketing purposes?
se
See Steve, that's your blind spot. The point is that it can be seen, so the money is well spend
jan
One more thoughts for future audio components...
current status is that we have no common standards for signal transmissions. I think we should use a standard for input sensitivity & input- / output impedances of our components.
Some examples:
output impedances min. 600R or lower, input impedance min. 10K or higher
signal output for sources (CDP, DA-converters, Phono Stages) 1.55Vrms
signal input sensitivity for power amplifiers of -6dB / 775mV (Full output).
This means we can use easely a passive attenuator as volume control with 600R...
current status is that we have no common standards for signal transmissions. I think we should use a standard for input sensitivity & input- / output impedances of our components.
Some examples:
output impedances min. 600R or lower, input impedance min. 10K or higher
signal output for sources (CDP, DA-converters, Phono Stages) 1.55Vrms
signal input sensitivity for power amplifiers of -6dB / 775mV (Full output).
This means we can use easely a passive attenuator as volume control with 600R...
john curl said:
Steve Eddy, you're very shortsighted.
Just think for a minute about the following factors from the equipment manufacturer perspective:
1. Parts availability (in stock/custom order/lead times)
2. Price break (1/10/25 pcs.)
3. All possible combinations that you might need to cover requirements of your potential customers.
4. If you decide to go with two slightly different parts, but do not know how many units will be built with one part and how many with the other, how many of each part do you stock? If you buy both parts in enough quantity, you end up spending more money, not less.
And so on.
P.S. Actually, I'm wondering how many of the posters here do really make their living by serving the so called "High-End" customers.
Actually, Steve Eddy is a manufacturer and purveyor of "high end" audio cables.
Oddly enough he chooses some of the materials used in his products on the basis of "it smells nice and sounds good to me", then criticizes other people's choice of materials or components if they can't (according to him) be justified on the basis of cost vs performance (in the strictly EE sense).
As a chef, or a perfume manufacturer ?
Normal conversation would be for someone to bring up a question, followed by a plausible answer.
Short answer in this case would have been to just mention the cost of 50 open-frame 4-deck switches, or 25.
1st thing I learned at engineering-u was : what, what for, why, how, by which means, at which cost.
Why is separating shields good?..the design shows zero EMC engineering.
That always depends on how one measure success. I recall someone mentioning driving a "bentley" as a measure of success..
Me personally, I am where I want to be, doing what I want to do, and am with someone I want to be with.. I am successful.
Loop area??...what's that??
And it gets worse...the passive preamp displayed brings the externally coupled ground currents INTO the chassis, all the way to the selector switch. In other words, coupling to input wires for ground loop currents has been MAXIMIZED BY DESIGN.
The least they could have done is connect all the grounds at the back panel, tie it to the case there, and run the shields to the front as electrostatic shields to avoid crosstalk. If you really need to have a separate ground referenced at the front of the chassis, run all the shielded cables through a 3/4 or 1 inch ID copper or brass pipe polished to within an inch of it's life with diamantine or some red rouge. Reference the control ground to the copper, keep the copper isolated from ground, use some pretty insulators.
Note: when current flows along a hollow cylindrical conductor, there is NO internal magnetic field.
Actually, he states up front when he chooses materials based on it smells nice and sounds good, and also when there is an engineering justification. I've not seen him make up pseudoscience to claim why the materials work good.
jn
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See Steve, that's your blind spot. The point is that it can be seen, so the money is well spend
Point taken.
se
Truer words never spoken. I can look at myself in the bathroom mirror every morning and be satisfied that my work is solid, honest, interesting, and useful to society, and that I'm training the next generation of scientists who will take up where I left off. Looking to the left side, I see the woman I love. Looking to the right side, I see a lovely lake and forest. Walking downstairs, I turn on my stereo and hear beautiful sounds.
My guitar playing still sucks, though.
I'm shortsighted?
No no, you have it backwards.
With the bizarre and inexplicable "need" for the balanced configuration to have a single deck dedicated to each of the inverting and non-inverting leads (apparently it has something to do with lunch meat), CTC had to keep FOUR different switches on hand, depending on whether it was to be used for balanced or unbalanced switching.
Without this bizarre and inexplicable "need," it would only require TWO different switches, each a two pole, two deck, using one pole when switching unbalanced leads and both poles when switching balanced leads.
So now which makes more sense to you from the "manufacturer's perspective" you list above? Having to stock four parts or having to stock two parts?
se
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But that would violate your standard that input impedances be 10k or higher.
se
OK, this WAS the situation 15 years ago: My now deceased friend and CTC business partner, Bob Crump did the design of the box and the selection of the passive parts for the CTC Blowtorch.
He introduced me to the Shallco switches: Before this, I had used RELAYS, dedicated cmos selector switches, selected CMOS individual switches, and Elna rotary switches (much more compact).
As I was most familiar with RELAYS, this is what I would have chosen at first, and I think that it is a pretty good solution for most, as it was for the Parasound preamp products that I had made before and after the Blowtorch. AND what I am using for Constellation designs that I am currently working on.
However, these relays are not quite as good a solution for OUR personal needs, when we strove to make the BEST product possible, rather than a practical product. And to this day, I stand behind this 'solution', although it is difficult to recommend it to anyone else.
For the record, the only promotion for the CTC Blowtorch was a review in 'Ultimate Audio' based on my own personal unit, in 2001. The only interior pictures were taken by Bob Crump about 10 years ago, AND I have never seen the interior of MY personal CTC Blowtorch, although I would presume that it looks similar to the one put up here, years ago (not first by me) since I have the same configuration. We did NOT display the interior of the CTC, so I don't think that the 'customers' for the CTC bought the unit from what it looks like. In fact, it is difficult to open the box and display the interior.
While I must admit that Bob's selection of a 4 section switch seems 'extreme', it is actually consistent with his switch and pot layout philosophy.
That is: All switches and pots are firmly mounted to the FRONT face of the enclosure. No false front panels, no extra supports necessary for mounting the switches, the pots and selector switch mounted in the same plane for easier connection. The rest grew from there, backward, leaving room to GROW, if balanced input was necessary.
We never advertised, personally, although they may have advertised in Japan, where most of the units were sold. We never opened the box, as for as I remember to anyone, except to repair a unit, if necessary. So, I would say 'boloney' to SE and SY's allegations. '-)
He introduced me to the Shallco switches: Before this, I had used RELAYS, dedicated cmos selector switches, selected CMOS individual switches, and Elna rotary switches (much more compact).
As I was most familiar with RELAYS, this is what I would have chosen at first, and I think that it is a pretty good solution for most, as it was for the Parasound preamp products that I had made before and after the Blowtorch. AND what I am using for Constellation designs that I am currently working on.
However, these relays are not quite as good a solution for OUR personal needs, when we strove to make the BEST product possible, rather than a practical product. And to this day, I stand behind this 'solution', although it is difficult to recommend it to anyone else.
For the record, the only promotion for the CTC Blowtorch was a review in 'Ultimate Audio' based on my own personal unit, in 2001. The only interior pictures were taken by Bob Crump about 10 years ago, AND I have never seen the interior of MY personal CTC Blowtorch, although I would presume that it looks similar to the one put up here, years ago (not first by me) since I have the same configuration. We did NOT display the interior of the CTC, so I don't think that the 'customers' for the CTC bought the unit from what it looks like. In fact, it is difficult to open the box and display the interior.
While I must admit that Bob's selection of a 4 section switch seems 'extreme', it is actually consistent with his switch and pot layout philosophy.
That is: All switches and pots are firmly mounted to the FRONT face of the enclosure. No false front panels, no extra supports necessary for mounting the switches, the pots and selector switch mounted in the same plane for easier connection. The rest grew from there, backward, leaving room to GROW, if balanced input was necessary.
We never advertised, personally, although they may have advertised in Japan, where most of the units were sold. We never opened the box, as for as I remember to anyone, except to repair a unit, if necessary. So, I would say 'boloney' to SE and SY's allegations. '-)
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