John Curl's Blowtorch preamplifier part II

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Due to the odd way my brain works this has reminded me of a question I had. My sister in law has a sensible house which has structured cabling in and I was musing the best way to send audio between rooms. It's 100 Ohm twisted pair at the end of the day so a balanced signal at pro levels should happily pootle between floors? Seems on inspection a few boards using the whitlock THAT chips and jobs a goodun?

I am glad I didnt go your route and there exists PLC; It's PnP.

What between floors? If you have it, use it I suppose. For me, it is either wireless or PLC.


-RM
 
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I had the experience in ~2008 of having participated in the development of a fairly decent home theater system for Epson, thought of as a vehicle to help Epson sell more projectors. Virtually everyone who saw and listened to the system thought it was a great deal at about 6k USD. It included a motorized screen with L-C-R loudspeakers, rear channels with the ceiling mounted projector, a decent subwoofer with all the amplification/equalization, and a DVD preamp for a rapid out-of-box experience. And a universal remote. And the sound kicked butt.

But then the DVD/A-V "preamp", a custom purchased component, had horrible initial reliability (I had been warned about the supplier in confidence), and the initial failure rate was about 40%. But this was as nothing compared to the economic crash. My analysis of the situation was, suddenly either you had money for a complete home theater system and dedicated room, or you had money for a little Visio flat screen with built-in sound system, say a hundred bucks or so. Banks stopped lending to the less-than-well-heeled, period. 6k was suddenly entirely out of reach for the target market.

The timing could not have been worse.
 
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Maybe far in the future there will be a chidren's book "Where the Better Things are". Bizarre that anyone would think the average folks at any class at any time would buy power conditioners for their TV's and stereos.
Whitlock has opined that the great advantage of power conditioners comes from people plugging equipment with safety grounds into the same box.
 
Whitlock has opined that the great advantage of power conditioners comes from people plugging equipment with safety grounds into the same box.

Circuit City never tried to sell me a power conditioner, they were mostly interested in the ridiculous extended warranties. And anyway this business has all gone on line why would the potential market have vanished?
 
Better things ....

The term "dirty power" would invoke thoughts for some kind of electron
"soap" in most people. :D

Those same consumers would plug several dollar store mobile chargers into
the same power strip as their audio. But , their audio is a Walmart RCA rt2781be
(which also does not use a PFC IC).

If they did care a little about their Hi-Fi , I see pricier units like the HK990
or even some of the cheap analog Sherwood amps will include a common mode
CLC AC filter. The HK actually has CM and DM.
The good CD player (below) , also has one.
I suppose they do expect a mix of cheap imports on the same strip.

OS
 

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I had the experience in ~2008 of having participated in the development of a fairly decent home theater system

But this was as nothing compared to the economic crash. My analysis of the situation was, suddenly either you had money for a complete home theater system and dedicated room, or you had money for a little Visio flat screen with built-in sound system, say a hundred bucks or so. Banks stopped lending to the less-than-well-heeled, period. 6k was suddenly entirely out of reach for the target market.

The timing could not have been worse.

Sounds like a very familiar situation to me.

-RM
 
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Correlation is not causality. They still sell a lot of power products. Only monster know the truth but I bet Dr Dre had a hand in the decision to cull some low turnover parts when they started making millions of headphones and then lost the farm.

i was there on the inside when all this happened at Monster. No guessing being done over here regarding power protection/filter sales $$. Let Scott and others do the speculating.

Anyway, the MOV + GDT app I suggested works very well. As does isolation transformers and isolating filters. And maybe an explanation why JC didnt like the MOV ..... its capacitance can cause noise issues when connected to ground side.

Can we stay focused on these things rather than the debating just for points all over the place? This subject came up because JC said he didnt like using MOV's. I just expanded on it a little bit and offered another way to do the protection.

The only question for SY and Scott is -- besides protection, did it ever make a difference to sound or picture? Ask them. But I know what the store managers, buyers and sales people and customers said for those years before The Crash.


.
THx-RNMarsh
 
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Balanced interconnects. You know it makes sense :)

It's got to get past the thiele/zobel networks to cause mischief. Is this a real bogeyman in a well implemented power amp?

I would argue a toroid with an electrostatic shield is not exotic, just a correctly specified toroid.

Assuming you do have said shield then you have maybe 4" of input cable, which should be twisted together from which the radiation can emerge. I don't see that as an issue, but I would also think nothing of spending £6 on a shaffner filtered IEC connector for belt and braces.

Is anything more complex than that actually needed? Wanted is of course a completely different thing :D

I'm talking about HF RF - the stuff balanced interconnects and Zobels can't stop. Electrostatic shield is always a recommendation and can help. But if you have RF in the housing' it won't help - my PLC problem blasted through everything.
 
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I'm talking about HF RF - the stuff balanced interconnects and Zobels can't stop. Electrostatic shield is always a recommendation and can help. But if you have RF in the housing' it won't help - my PLC problem blasted through everything.

Following the std best practice for EMC on connectors should attenuate at line levels well enough? Or for the lazy the neutrik EMC series. Am interested in how much gets past that.

This is why I like structured cabling in a house. Worrying about noisy mains then adding an unregulated source of it doesn't seem like the optimal solution IF you happen to be building/re-wiring a listening room (big if).

Single mode fibre round the house is possibly a little extreme!
 
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Anyway, the MOV + GDT app I suggested works very well. As does isolation transformers and isolating filters. And maybe an explanation why JC didnt like the MOV ..... its capacitance can cause noise issues when connected to ground side.

I must be being thick ( as usual) as having them in series does really seem to be leveraging the worst of both, so you have the slow response of the GDT and the low power handling of the MOV combined, rather than using the positives.
 
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