You are right again, I consulted Wikipedia.
It’s indeed based on a side looking radar forming an immense virtual antenna made of many individual images.
Impressive.
Hans
It’s indeed based on a side looking radar forming an immense virtual antenna made of many individual images.
Impressive.
Hans
For Scott Wurcer, and all who knew Tim,
https://www.diyaudio.com/forums/tubes-valves/364729-tim-de-paravicini-rip.html#post6455018
https://www.diyaudio.com/forums/tubes-valves/364729-tim-de-paravicini-rip.html#post6455018
Aw man... 
I had a few chats with him, he was quick to fill in details of circuit topology benefits, even with someone like me who he hardly knew...I know he was a polarizing personality, but I still stand by the SQ and performance of the circuitry he designed for Luxman in the 1970s. I still have a few pieces of that lovely stuff and enjoy them...RIP Tim, you left us with some wonderful creations!
Howie
I had a few chats with him, he was quick to fill in details of circuit topology benefits, even with someone like me who he hardly knew...I know he was a polarizing personality, but I still stand by the SQ and performance of the circuitry he designed for Luxman in the 1970s. I still have a few pieces of that lovely stuff and enjoy them...RIP Tim, you left us with some wonderful creations!
Howie
RIP an audio legend.
A good friend had one of his Musical Fidelity tubed/valved designs, and a superb sounding beast it was, played through a pair of Martin Logan speakers, it was musical and spookily realistic.
Craig
A good friend had one of his Musical Fidelity tubed/valved designs, and a superb sounding beast it was, played through a pair of Martin Logan speakers, it was musical and spookily realistic.
Craig
Behind the scenes, we had a discussion on ETF Facebook page (only via invitation) and some of us were at the EFT06 and on December 2nd, we saw Tim's lecture. I sat up a Sony HDV Camera and matching Bluetooth Microphone and sat right in front and recorded it. The others asked me if I could share, I joined up the files into a single 1hr 45min long. I sent it to Emile Sprenger (you will see him introducing Tim at the beginning) who reduced the file size down from 8GB and posted it on his YouTube channel.
Here is the YouTube link:
"MyFi not HiFi Lecture" By Tim de Paravicini
Tim had other interests. If you had trouble to get him talking, bring up general aviation (I believe he flew his own plane across the channel to get there) and vintage cars, especially motors. Then he would get into his stride.
It's also interesting to hear the voices, a few who are no longer with us. I particularly heard Allen Wright and we travelled together from Switzerland to attend. Maybe some of you can pick some of the voices (mine included)? That would be interesting.
Sit back and take it in...
Here is the YouTube link:
"MyFi not HiFi Lecture" By Tim de Paravicini
Tim had other interests. If you had trouble to get him talking, bring up general aviation (I believe he flew his own plane across the channel to get there) and vintage cars, especially motors. Then he would get into his stride.
It's also interesting to hear the voices, a few who are no longer with us. I particularly heard Allen Wright and we travelled together from Switzerland to attend. Maybe some of you can pick some of the voices (mine included)? That would be interesting.
Sit back and take it in...
Attachments
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Thanks for the post Joe! I really enjoyed hearing Tim discuss the fine points of tube topology!
Cheers!
Howie
Cheers!
Howie
Howie,
This should make you cringe! Locally WESA had a transmitter shack roof leak! Right into the (15 KW) main carrier transmitter. All nine output modules and ten power supply modules got wet. The logic card probably will be destroyed as it had backup batteries, that from my experience guarantee that any wet PCB copper will be dissolved.
The backup is now running but at much lower power. Last I knew they were trying to get in a new backup unit at 2.5 KW.
The tower is on top of about the highest bluff in the area and it is an old AT&T transcontinental relay tower. Ginormous!
This should make you cringe! Locally WESA had a transmitter shack roof leak! Right into the (15 KW) main carrier transmitter. All nine output modules and ten power supply modules got wet. The logic card probably will be destroyed as it had backup batteries, that from my experience guarantee that any wet PCB copper will be dissolved.
The backup is now running but at much lower power. Last I knew they were trying to get in a new backup unit at 2.5 KW.
The tower is on top of about the highest bluff in the area and it is an old AT&T transcontinental relay tower. Ginormous!
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Denon Lemon
As I know Howie is lurking at the moment...
In my wider family we've used Denon mini systems for years. Cheap, dependable, sound good for the money and keep working, at least until the damping jelly gets in the volume pot. I've had an 18 year old changer setup in the kitchen for the last 8 years but, when my 4th attempt at fixing the CD swapper resulted in the ping of death as a plastic bit snapped I agreed to get SWMBO a new setup. We listen to more music in the kitchen than anywhere else so, rather than the modern replacement for our dead one I thought I'd get the DCD-50 and PMA30 combo. The amplifier is pretty good and based on a TI class D reference design but the CD player has left me having gone off Denon for cheap and reliable.
The first one we had worked fine, but would not play about 30% of the CDs we tried in it. TOC would get read, but hit play and after 30 seconds of baleful whirring would say 'unsupported'. I figured that this was a factory alignment problem so asked for it to be fixed. It was duly sent to the UK Denon repair centre. Four months later they admitted they had lost it. So I picked up a brand new one on saturday. This one is better, but still refusing to play certain CDs that play fine in the car, the blue ray player, the bedroom B&O and the kids cheap portable. And it's variable. Of 5 CDs that didn't play yesterday, 3 are playing today with two steadfastly refusing. Oddly one of these is disc 3 of a 3 CD set and discs 1 and 2 are fine.
Wife is now obviously pissed off and wants shot of it, but I am pondering what the issue is and if it's fixable. I am guessing that the mechanisms are bought in apparantly pre-aligned and just slammed in the box in the factory with minimal checking and adjustment and this is just on the edge so it mostly works. But are modern cheap laser mechs service adjustable anymore? If I can send this back, get it aligned without being lost and then it'll just work I might be able to swing the wife around, especially as options for half width CD transports or players are very limited.
As I know Howie is lurking at the moment...
In my wider family we've used Denon mini systems for years. Cheap, dependable, sound good for the money and keep working, at least until the damping jelly gets in the volume pot. I've had an 18 year old changer setup in the kitchen for the last 8 years but, when my 4th attempt at fixing the CD swapper resulted in the ping of death as a plastic bit snapped I agreed to get SWMBO a new setup. We listen to more music in the kitchen than anywhere else so, rather than the modern replacement for our dead one I thought I'd get the DCD-50 and PMA30 combo. The amplifier is pretty good and based on a TI class D reference design but the CD player has left me having gone off Denon for cheap and reliable.
The first one we had worked fine, but would not play about 30% of the CDs we tried in it. TOC would get read, but hit play and after 30 seconds of baleful whirring would say 'unsupported'. I figured that this was a factory alignment problem so asked for it to be fixed. It was duly sent to the UK Denon repair centre. Four months later they admitted they had lost it. So I picked up a brand new one on saturday. This one is better, but still refusing to play certain CDs that play fine in the car, the blue ray player, the bedroom B&O and the kids cheap portable. And it's variable. Of 5 CDs that didn't play yesterday, 3 are playing today with two steadfastly refusing. Oddly one of these is disc 3 of a 3 CD set and discs 1 and 2 are fine.
Wife is now obviously pissed off and wants shot of it, but I am pondering what the issue is and if it's fixable. I am guessing that the mechanisms are bought in apparantly pre-aligned and just slammed in the box in the factory with minimal checking and adjustment and this is just on the edge so it mostly works. But are modern cheap laser mechs service adjustable anymore? If I can send this back, get it aligned without being lost and then it'll just work I might be able to swing the wife around, especially as options for half width CD transports or players are very limited.
Hey Ed, and YIKES!
You are right! Transmission equipment really needs to be kept in server-class clean rooms, but radio being the poor stepchild it is, this is often not the case. A college station I have just started reworking had a similar situation due to neglect:
Fortunately it was not right over the transmitter, but it did drown some fiber to Ethernet transceivers. The exhaust louvers had stuck partly open for...god knows how long, and the rest of the RF plant showed the same attention to detail and maintenance.
In stark contrast, the audio plant is state-of-the-art Wheatstone consoles and Wheatnet, a real showpiece...but that is where the parents tour so it is where the school puts its money.
Twas ever thus...
Holiday Cheers to everyone, I look forward to more audio circuitry fun in 2021!
Howie
You are right! Transmission equipment really needs to be kept in server-class clean rooms, but radio being the poor stepchild it is, this is often not the case. A college station I have just started reworking had a similar situation due to neglect:
Fortunately it was not right over the transmitter, but it did drown some fiber to Ethernet transceivers. The exhaust louvers had stuck partly open for...god knows how long, and the rest of the RF plant showed the same attention to detail and maintenance.
In stark contrast, the audio plant is state-of-the-art Wheatstone consoles and Wheatnet, a real showpiece...but that is where the parents tour so it is where the school puts its money.
Twas ever thus...
Holiday Cheers to everyone, I look forward to more audio circuitry fun in 2021!
Howie
Easy: get yourself a media server.
I've got a Proliant MicroServer N40L, curtesy of HP, but, really, any old PC will do. Mine runs on an antique AMD Turion CPU you normally wouldn't even want to do word processing with, but it handles multiple streams of HiRes audio & video with ease.
Pro:
- Central repository: no more shuffling of physical supports around the house
- Play lists, shuffling
- Accessible via Ethernet, WiFi or even Bluetooth if you're ready to give up on quality
- Accessible anytime, anywhere from any device, even a telephone
- Modern HiRes audio are delivered through download, no way around it
- Repurpose any old, retired PC instead of bringing them to a charity, or, worse, to a dump.
- Some investment in time to rip all your physical media
- What to do with all those media after they're ripped?
I'd probably do something similar to what Zung suggests also and rip your entire collection. Then you have a lot of options, none of which may be perfect. You could play it back from an embedded PC and control it via DLNA or similar. Or, you could do the reverse and put your entire collection on an iPad or Android tablet / phone and run something like AirServer or an open source alternative on a Raspberry Pi or Linux PC. Some AV receivers support DLNA also, not sure how well it works in practice. Older Apple TVs had TOSLINK outputs and could receive AirPlay streams. There are also a whole host of streaming focused devices at various price points that I don't know a lot about.
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I've got a media server, but there are always strays that haven't been ripped or new CDS that we have bought. CD capability in the kitchen is a must. SWMBO insists!
Where to start...playability of a CD or by contrast (pun intended) CD-Rs is dependent on so many factors, so for this issue I assume we are talking about molded factory CDs. It is possible the CDs may have inferior pit characteristics causing poor playability, but in general they should be easily playable, especially if they are <74 minutes CDs.
Assuming a good disc, CD playability comes down to two factors: the Airy pattern of the player lens system and internal alignment of the photodiode quad after the beam splitter. The original CD system called for a fixed track pitch which made setting the player Airy pattern trivial. Once extended play CDs became prevalent with tighter track pitches, everything went to hell in a handbasket. An Airy pattern designed for the middle of the spec will deliver high crosstalk and reduced EFM s/n with these CDs. Also, for a three-beam system relative beam alignment is critical.
One of the most common factors in current consumer CD player problems is the cheap optical path. I would bet the optical sled costs the manufacturer as much as the entire rest of the electronics, which pressures them to reduce cost as much as possible. Once upon a time the final objective lens was achromatically coated glass. This quickly changed to nicely molded, coated plastic lenses which offered comparable performance. As early as the mid 2000s we began to see uncoated, poorly molded plastic objectives, some with bubbles in the plastic!! Needless to say the Airy pattern of these lenses produced high crosstalk and poor EFM s/n.
None of this is fixable in the field, necessitating optical sled, or more frequently entire transport replacement.
The last few consumer CD players I opened had zero electrical adjustments. The broadcast players are different, and do have some adjustments possible, if only to set the laser diode current. Many pro players drive the laser hard to get a better signal from crappy CD-Rs (and most are) and I see as little as a year of 24/7 usage from these lasers before the output drops and they begin showing playabilty issues.
Contrary to common audiophile nonsense, the best optical pickups these days are often found in the high-end computer drives, Pioneer being among the best. The reason is: they are designed to have the lightest weight, fastest responding optical heads due to the disc spinning at 24x-52x, up to 12k rpm in some cases. The heads have to (try to) maintain both track and focus on the constantly wobbling disc track, so when spinning at 1x they can track extremely well. I have had CDs fail in my Oppo player at 1x, but then transfer in my PC at 8x using EAC with ZERO C3 errors. We utilized this procedure at AMI to rescue many, many customer titles from poorly recorded CD-Rs.
Getting back to your player, it is always worthwhile to try cleaning the objective, as debris or a film may be obscuring it's performance. A quick swipe with a fluffed-up cotton bud wetted with the least isopropanol you can leave on it should do a good job. Other than that, I would return it ASAP...
Good luck & Happy Holidays!
Howie