John Curl's Blowtorch preamplifier part II

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I've been asked to choose a good pair of speakers for around $200. Can you guys offer suggestions for that price range? I don't have the experience or tools to put together boxes although I can of course handle basic assembly.

JBL has some high value, low dollar tower 3-way speakers in that range. Dual 6.5" woofers. Also, Emotiva Audio Corp's Pro Airmotiv 4s for slightly more.... but is self powered.


THx-RNMarsh
 
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Reliability is getting awfully good, especially if you're a bleeding edge kind of guy that will likely be relegating older toys to lesser-used systems on a decent schedule.

The SSD Endurance Experiment: They're all dead - The Tech Report - Page 1

I have a portable i7 with all SSD and I have a 5 year old converted to SSD (Samsung). I have never had a problem with either and am not surprised the author damaged his SSD as what he did is expressly told Not to do. My 5 year old has been on most of the day and evening for these years. very reliable and very fast if you use them properly.

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Dont know about that one but the new price of a pr LOF T50 is good bang for the dollar IMO. The port tuning seems to be tuned for broken-in bass drivers as it gets 'right' after being used awhile. Its a tower floor standing speaker.

I bought a pair for the pool table area and paid 150 dollars/pr new in the box. Free shipping.

But Now I see that our Best Buy retailer is trying to get $999.90 a pair!

??


THx-RNMarsh
 
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That's not what he said then. He just proffered master gain which could be assumed to be a +/- some small number of dBs. If he wanted to say that a 16 bit by 16bit DSP MAC can result in a 32 bit intermediate he should have said so? He doesn't name names but I surely no professional workstation software would get the maths that wrong in this day and age? User error of course will always screw up the result...


Quote:
Inside a digital mixing console (or workstation), the mix buss must be much longer than 16 bits, because adding two (or more) 16-bit samples together and *multiplying* by a coefficient (the level of the master fader is one such coefficient) can result in a 32-bit (or larger) sample, with every little bit significant.

Read the sentence closely...
 
Amusing you went from this



to this



in successive posts, ;) ...

And, what's your point, the supplies are still SMPS's for the heavy current work, and the boards are still supplied by a master voltage from an SMPS. Maybe you should trot off and learn about all the different voltages that are found on todays digital designs. You haven't a clue what I am saying in my second quote just your normal dilly rambling on trying to prove some point, usually that all engineers and engineering is bad.....
Further if you did some studying of noise where high speed digital switching is involved you would again understand what I was saying... The posts do not disagree on their points, so instead of trying to score cheep points and prove some point try and learn, I have provided information in the past regarding noise in digital systems, EMC testing and engineering, static build up on circuits, all problems I have to deal with in real life... Yet like many you look at SMPS's as being bad, linear is good.
 
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Oh dear, it's a wrong side of the bed day ... :)

Edit: Well, perhaps not so poorly after all ... SMPS is not "bad", just that the engineering has to be more stringent if they're in close neighbourhood with some circuit aiming for well over 100dB S/N ratios.
 
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Yes but is that not a multiplication with some number?

Jan

If your master gain is +/-15 bits yes. Otherwise its an intermediate result. If each processing phase added 16 bits as he suggests then you would end up with a 700bit output. Clearly this doesn't happen as people who code DSP stuff know about this a keep the bit depth under control.
 
I have a portable i7 with all SSD and I have a 5 year old converted to SSD (Samsung)...very reliable and very fast if you use them properly.
Yes, unless using them for the logs of a web server, we can write more datas than we'll never need, and anyway, a predictable wear is better than an all of a sudden failure that can happen (too often) with some HDDs.
 
And, what's your point, the supplies are still SMPS's for the heavy current work, and the boards are still supplied by a master voltage from an SMPS. Yet like many you look at SMPS's as being bad, linear is good.

It might be useful to point out that a modern CPU will have 1 or more main supplies at near 1V or slightly higher at 100A or more. These will waste large amounts of power generated by conventional linear techniques.
 
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Oh dear, it's a wrong side of the bed day ... :)

Edit: Well, perhaps not so poorly after all ... SMPS is not "bad", just that the engineering has to be more stringent if they're in close neighbourhood with some circuit aiming for well over 100dB S/N ratios.

You already have sound cards that deliver -130 dB noise levels ref 1V and I have seen better. - Pavel has shown some plots here. As Scott has just pointed out, modern PC CPU require 100 A. They are fed from a buck converter usually running at c. 300 KHz with the mosfet switches transitioning in a few ns.

Noise? What noise?

;)
 
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It might be useful to point out that a modern CPU will have 1 or more main supplies at near 1V or slightly higher at 100A or more. These will waste large amounts of power generated by conventional linear techniques.

Yep and separate IO voltage, then memory, in fact for many years motherboards have had on board power supplies for the various voltages, so even when using a battery there are still SMPS's working, of course simultaneous switching noise is totally disregarded and all the noise is the fault of the SMPS....
100A hence good decoupling practice, once had a guy want 4oz copper for power planes under a BGA so it could handle the current!!!!!!!!! and even this he thought was a compromise, couldn't do it though as the features could not be etched from such thick copper.....
 
Marce, in light of your last post, do you think it is time for an additive process to produce PCB's in stead of the present subtractive process?

With 3D printing, you might even create different thicknesses for different traces on the same board, and stack different layers on the same substrate by printing an isolating layer where needed...just waisting this perfect Monday afternoon with some pie in the sky thinking.
 
Marce, in light of your last post, do you think it is time for an additive process to produce PCB's in stead of the present subtractive process?

That's been around for a while and the old problems (conductivity, solderability) seem to have been greatly educed in recent years. The issue at this point is economics, but with the advent of high speed electronics printing and the required inks, this may change soon.
 
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