The point I'm making is that this is all about engineering, of course using various techniques can resolve the issue ... so, if one has spent good money, a lot of money in fact(!), why aren't the components impervious to these issues?
One of the biggest headaches for me over the years, was knowing that 'good' sound could be got, and having to deal with the fact that this high SQ was a very fragile state, one little element out of kilter and the 'goodness' evaporated. The battle has been to make this state robust, getting all the factors under tight control ... and I'm still not there yet ...
One of the biggest headaches for me over the years, was knowing that 'good' sound could be got, and having to deal with the fact that this high SQ was a very fragile state, one little element out of kilter and the 'goodness' evaporated. The battle has been to make this state robust, getting all the factors under tight control ... and I'm still not there yet ...
Because this is about evolution in the broadest sense - such components have no niche to fit into, so they're not adaptively 'fit'. Components that dealers love are ones that are quirky, require high margin cables and adjuncts to get sounding good. Components which you and I would want to buy (plug and play ones so we could get on with the important business of enjoying the music) would be rejected by dealers because they in effect make the dealer redundant. The dealers are the gatekeepers.
Depends on the project budget.
If I'm pressed to keep the costs down, then yes, I do use the same +/- 15V for both, and I use just one pair of trannies, typically MPSA 56/06 or BC 639/640. Both ca disspiate about 1W in real life, both will push peaks of up to 1 Amp, and both sound rather good.
If I am free to run wild, then for the preamp output I will use an emmiter follower driver/output transistor setup, same trannies as above for drivers, BD 139/140 or even MJE 15030/15031, what the hell, if you have it, flaunt it. If I were to astound you and pump out like 10 Amps from a preamp, I'd use BD 249/250 C, which are in my view the unsung heroes of audio. 40 Amp peak output, 25 Amp continuous looks mighty good to me, as do its very short switch on, storage and switch off times.
If I'm in the all out mode and damn the cost, I use say +/- 20V rails for the trannies and a zero feedback mini regulator down to +/- 15V for the op amp. That really rocks. I did that on my mod of the Burr-Brown two op amp phono RIAA stage (author Hermann Holger, BB Germany, 1990, posted it once, but can post again). This practically eliminated the output voltage swing limitation of classic op amps and raised its overload margin by quite a bit.
If you really want the best, use a dual op amp, configured to have a nested NFB line for the second half, and driving an emitter follower discrete output stage. That is a whopper, once you get it right. Used an AD 828 dual 818 op amp, even though it was not strictly made for audio. Perhaps AD 847 would be a better choice.
I assume you use a setup connected to the ground. If so, the ground may well be to blame, because its potential is anything but constant when you use sudden large power draws.
I use a floating model which doesn't give a damn about ground potential, and is immune by design to its changes. In my view, best setup ever.
You give me too much credit, Rick, it's all far more mundane than that. My ears tell me it sounds better when you have some real muscle charging those caps in the signal and NFB paths (if you have any), and of course, possible low impedance inputs of the next stage.
Also floating, the audio unit is double insulated ... but, I have grounded the metal chassis, with some complex bypassing. This is a hairy business: do one step at a time, have an extended listening session, doing and undoing the change to confirm the effect. What makes it much worse is that many of the more subtle effects don't immediately manifest themselves, they require time to build in intensity - there is some type of charging, or discharging process taking place. Sometimes the sound will steadily improve in quality, other times it will slowly deteriorate in a slippery slide.
Indeed so.
Also, I find most important, is what your case is made of. In my experience, by far the bet material is sheet steel, way better than aluminium, and the only thing better than sheet steel is pure copper. Haven't tried pure gold or pure platinum.
I do not bypass at all, don't need to, so long as the location wall outlets are truly grounded - which is, most unfortunately, not always the case. For example, our very own Pierre (Peufeu) here reported back in 2002 that his ground in his Paris apartment (as I understood it, an old building, with ancient electrical systems by then hopelessly out of their depth) had a potential of 70V (Pierre, remember that?). So of course he had problems, and no bypassing I can ever do will solve them. The only fortunate thing was that at least with Pierre, I didn't have to worry about either safety or solving the problem.
Just one socket, anywhere in the house grid, will kill the ground dead. My filter isn't worried, but safety regulations I have to adhere to are worried.
Anyone seen 'well done' actives? I haven't yet, still looking. They'd need passive line-level XO for a start, totally separate power supplies optimized for the individual amps, amps optimized for each of the drivers' loads ...
Bingo, combining both application is still the best way ....
I don't remember this one but I've been in places with pretty old and crummy electrical installations... Actually the flat think you're talking about was in Lyon I guess, and the color of the wires was random, red, blue, or striped yellow green, any of those could be connected to live, neutral, earth, or who knows what else. Right now is much better since I rebuilt the entire thing myself in my new home...
About your case materials I've always wondered about anodized aluminum, since the oxide coating is non conductive, it doesn't make a shielded box... you'd have to scrape it off along the edges, which noone does. The RF guys like aluminium though, but not anodized, and with more screws than an aircraft wing panel...
In the next project I'm working on (but progressing veeery slowly alas) I'd like to test proper shielding for once... I'll try to make a continuously shielded box (that will need some scraping of anodization, lots of screws, and RF gaskets ) and proper RF handling of connectors & IO filtering, I wonder what the results will be...
In case you wonder it's an ESS DAC and multichannel poweramp in a box. I've only done the USB interface... and lots of thinking but nothing built yet... and the weather is so nice today, that means I'll go out stick new mud to my mountain bike :mrgreen:
About your case materials I've always wondered about anodized aluminum, since the oxide coating is non conductive, it doesn't make a shielded box... you'd have to scrape it off along the edges, which noone does. The RF guys like aluminium though, but not anodized, and with more screws than an aircraft wing panel...
In the next project I'm working on (but progressing veeery slowly alas) I'd like to test proper shielding for once... I'll try to make a continuously shielded box (that will need some scraping of anodization, lots of screws, and RF gaskets ) and proper RF handling of connectors & IO filtering, I wonder what the results will be...
In case you wonder it's an ESS DAC and multichannel poweramp in a box. I've only done the USB interface... and lots of thinking but nothing built yet... and the weather is so nice today, that means I'll go out stick new mud to my mountain bike :mrgreen:
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I have had the good fortune to run into several half- or fully active loudspeakers over time. Two I have heard have left me fond memories.
One was made by Boothroyd-Stuart Meridina. If memory serves, it was a mid range model, using two parallel mid/bass drivers and one dome tweeter. It was driven by a PS Audio 4.5 preamp, and fed the signal by a high part of product line by Sony, if memory serves 808-ES, circa 1997-1998. All very 3D, lots of air and space all around them and that wonderful feeling of effortlessness.
The other was a prodfessional product by Klein & Hummel of Germany. A big box, housing a 12 inch woofer and a mid and treble dome tweeters. Made in 1990, according to the sticker. Full fledged active system, with electronic XO and dedicated amps for each driver. Not sure, but I think the bass driver amp had 120W, the mid 80W and the treble 50W, all said to be tailor made for the drivers used (Peerless, by the looks of them). A nicely full bodied bass, but not overblown, clean and clear midrange, sweet treble. Hot heat sinks all over the speaker's back. Lots of pots to fiddle with so you can adjust it to the room. Sound to die for, price to die from. Made the case for active in my book.
The others were mostly unknown manufacturers, and most unfortunately, I never ran across an ATC active monitor. Of that lot, by far the best sounding was a Philips Motional Feedback box, at the time top of the line, also 12 inch bass, mid and treble domes - best controlled, clean and clear bass I ever heard from any dynamic loudspeaker, period.
Also worthy of mention, the Grundig Professional series, again top of the range model, using 2 8 Inch drivers, dome mid and treble - in effect, a developed, repacked and rebadged Philips product, by then Philips owned Grundig lock, stock and barrel. Locally available for funny money, around €200 (app. USD 240), as used vintage. A deal of a lifetime if you can nab it.
Put together, all that made me decide to go all active.
One was made by Boothroyd-Stuart Meridina. If memory serves, it was a mid range model, using two parallel mid/bass drivers and one dome tweeter. It was driven by a PS Audio 4.5 preamp, and fed the signal by a high part of product line by Sony, if memory serves 808-ES, circa 1997-1998. All very 3D, lots of air and space all around them and that wonderful feeling of effortlessness.
The other was a prodfessional product by Klein & Hummel of Germany. A big box, housing a 12 inch woofer and a mid and treble dome tweeters. Made in 1990, according to the sticker. Full fledged active system, with electronic XO and dedicated amps for each driver. Not sure, but I think the bass driver amp had 120W, the mid 80W and the treble 50W, all said to be tailor made for the drivers used (Peerless, by the looks of them). A nicely full bodied bass, but not overblown, clean and clear midrange, sweet treble. Hot heat sinks all over the speaker's back. Lots of pots to fiddle with so you can adjust it to the room. Sound to die for, price to die from. Made the case for active in my book.
The others were mostly unknown manufacturers, and most unfortunately, I never ran across an ATC active monitor. Of that lot, by far the best sounding was a Philips Motional Feedback box, at the time top of the line, also 12 inch bass, mid and treble domes - best controlled, clean and clear bass I ever heard from any dynamic loudspeaker, period.
Also worthy of mention, the Grundig Professional series, again top of the range model, using 2 8 Inch drivers, dome mid and treble - in effect, a developed, repacked and rebadged Philips product, by then Philips owned Grundig lock, stock and barrel. Locally available for funny money, around €200 (app. USD 240), as used vintage. A deal of a lifetime if you can nab it.
Put together, all that made me decide to go all active.
Okay, did a bit of 'snooping'
Cheers,
The only "trick" I ever used is to put two filters in parallel and call it a high power filter. First signs of saturation start to appear at around 44 Amp with 230V, which is a whopping 10 kVA.
That filter was born in 1974, when 99.9% of those selling them today didn't even exist as companies, or had never heard of them. I actually still have Grandpa, the real No.1 model, around somewhere, I keep it for the sweet memories. Of course, the current version is like the 7th ot 8th generation and barely looks like Grampdpa.
It has seen service with the local secret service to clean up bugged comms lines, military airports for comms and lines, and so forth, but currently it serves in radio stations, hospital operating rooms (although it was never offered as medical electronics, that is a whole new ball game I never dared enter), editing studios (in Holland and Germany), medical resreach labs and of course, homes, where most of them are.
Frank, I am as Old School as it gets, I believe in true quality, meaning it must work for AT LEAST 20 years before something gives way. It was designed and is built to essentially work forever, although one would be wise to change the caps (all by Wima, although I did make a few on request using Plessey caps, you guessed it, for the UK market). The key part, inductors, is custom made for me in the Czech republic, now that France's original manufacturer abandoned its manufacture and sold everything to the Czechs. No big secret, the whole trick is that the core is made of fully sintered material. Not cheap, but the best we can do, exceptionally high saturation limits, very high quality OFC wire. It can take some heavy hitting, believe me.
The paradox here is that Europe's safety regulation mandate that I must use 10A fuses max for home products. Since I don't feel like being arrested (minimum penalty is 6 months of prison and €20,000 fine), I have to put them in, but I do tell my customers that if they are willing to accept the risk, they can change the fuse rating.
The only BITCH of this business is the simple fact that many countries feel it's very patriotic to invent sockets like nobody else's. This complicates my life no end, in addition to the fact that some local laws prohibit use of universal sockets. The only unversal model I can ever have is one which uses IEC output sockets, but that's a drag from the customer's point of view, because he/she now has to redo each and every cable they own, no small matter when your cable prices run into thousands of whatever.
My best markets were Germany and Holland, year in, year out fighting hard for the No.1 spot. Much to their credit, the Dutch are especially cosmopolitan about it all, they honestly don't give a damn where it's from so long as it works as advertised, very reasonable customers, I've never had a request from Holland which was even doubtfull, let alone unreasonable. My most critical (in terms of effects) customers are probably the Canadians; they all but pick it apart, but you sure can rely on their views, which makes them invaluable to me as customer feedback. The Chinese customers (Hong Kong and Singapore) love to discuss matters the most, but are very faithfull owners, they take true pride in what they own. I don't think there's one I ever sold there which didn't reel in another customer eventually.
My very first customer ever though was from New Zeland, I like to remember that.
Okay, did a bit of 'snooping'
Cheers,
Er, Frank? What other pieces?
If you refer to the headphone amps, I make them to specific order only. But honestly, it's not a business any more, it was torpedoed by the Chinese, who have prices I can only dream about. Sure, mine are way better sounding, but these days, nobody cares any more, the whole world boils down to the price only.
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