Vibrational effects on vintage hifi components

[dave cox]

I do wonder if the 'unrecoverable' error rate of a CD drive increases with a realistic vibration level ?

I know from experience with audio CD’s, using multiple different computer CD / DVD drives, the unrecoverable read error rate is distinctly non-zero but this occurs without vibration and, typically, the drives are trying to read at a much higher speed. Mostly, re-reading multiple times (eg cd-paranoia) can get uncorrupted data off the disk but the drive itself certainly won’t be doing that by itself and I assume a simple CD player built on such technology won’t be doing it either …

dc

[G8HQP Dave]

Yes, I knew you (Radio Wrangler) know how it works but there will those reading who might think your thought experiment involving a massive mechanical PLL could be taken seriously. That is the problem with the internet: it can be impossible to tell the difference between a joke and nonsense unless you know where the author is coming from.

[Radio Wrangler]

Aye, that's the problem with hifi. There will be people somewhere who would take anything seriously. I remember someone in the US going round saying he'd suggested the green-pen treatment of CDs as a joke and was bursting a gut trying to get people to believe it was only a joke. But was he real?

At least I held off short of suggesting the all-valve CD player (rather than one token one at the end of the audio chain...)

David

[Craig Sawyers]

You could really go steam punk and have a fluidic triode based CD player

[G8HQP Dave]

I'm sure I saw somewhere someone asking about a valve based CD player. Presumably someone who thought that 16-bit audio data comes straight off the disc, and hasn't really thought about how to make a 16-bit DAC using valves.

[stevehertz]

I think there was one in the dim and distant past. But as has been said, it was probably just a single double triode proudly mounted 'above decks' and just acting as an amplifier, and there only to appease the audiophool 'valve man'.

[GrimJosef]

Originally Posted by stevehertz

... it was probably just a single double triode proudly mounted 'above decks' and just acting as an amplifier ...

Perhaps not even an amplifier. I'd wager a small sum that it was there just as a cathode-follower near unity gain buffer (I suppose we could call that a current amplifier).

Cheers,

GJ

[Radio Wrangler]

And running below the 50v SELV limit...

David

And running below the 50v SELV limit...

Probably not, here in Maidenhead there is a 'high end' amplifier shop the amplifiers have output valves exposed and the sockets are at full HT. I don't know how they get away with selling such stuff these days.

One day I will pop in and ask why they are "so good" and revel in the bull excreta delivered.

Mind you they are very pretty and expensive!

[GrimJosef]

Originally Posted by merlinmaxwell

... the amplifiers have output valves exposed and the sockets are at full HT. I don't know how they get away with selling such stuff these days ...

Probably by saying nothing and just pointing at the nearest desk lamp. Some of these have BC sockets whose spring-loaded pins disconnect the supply when the bulb is removed. But some don't and in any case a toddler could easily push the pin into contact.

Cheers,

GJ

[Herald1360]

Originally Posted by Craig Sawyers

You could really go steam punk and have a fluidic triode based CD player

Errr, what is the Ft of a fluidic triode?

[Craig Sawyers]

Back in the day, output valves were very often exposed, and run very hot. The main risk was thought to be voltage, so the Radford STA25 had a cage over the transformers but the valves were exposed to all and sundry. Quad also had the valves in air, but had transformers that had the terminals coming out the bottom - so were below chassis.

Nowadays, there seems to be a mix of completely enclosed with ventilation perhaps with fan cooling, exposed but with a vestigial cage over the output valves, and totally exposed.

I have no idea how they get around regulations. Looks like the maximum temperature for exposed and touchable glass and ceramics is 80C, set by IEC regs. Since the envelope temperature of an EL34 (and other power valves like the KT88/6550) is 250C I'd say that an audio amplifier with exposed power valves would have a hard time getting through CE testing!

Craig

[Craig Sawyers]

Originally Posted by Herald1360

Errr, what is the Ft of a fluidic triode?

About 20 minutes per pint

[GrimJosef]

Quad's modern valve amps come with valve cages https://www.audioemotion.co.uk/ekmps...1;3]-802-p.jpg. They also come with a long screwdriver to remove the cage, as you need to to replace a valve. If you then choose to run the amp without the cage, well, that's up to you.

Cheers,

GJ

[Radio Wrangler]

I keep suggesting the 3-500z triode as a wonderful audio valve. It ticks all the boxes:

Gorgeous looks
Triode
Glass
Lights up
Directly heated.
Plenty of power
Wimps need not apply
Reassuringly expensive even before the audio brigade move in

But my ulterior motive is that with about 2kV on the top cap, they might thin the ranks of the audiophiles and lessen the price pressure on simple receiving valves.

David

[GrimJosef]

The slightly smaller 304TL, also by Eimac, is quite often used to make audio amps. Here is one of the more ambitious designs built around it http://www.amberwaveaudio.com/design-specifications.htm. It weighs 200lbs, and you'll need two of them since they're only mono.

Cheers,

GJ

[Craig Sawyers]

Want to see some exposed audio valves?

http://www.electronluv.com/

Craig

[rontech]

Try purchasing four packets of lemon jelly, remove from the cardboard outer but leave them in the transparent water proof shrink wrap.

You then stand each support pad of the hifi unit under test on one of the packets.

If it makes no improvement then you can eat the jellies, or maybe try different flavours.

Bit early for April 1st I suppose.

[mark2collection]

The only valve CD Player (output stage only, by the looks of it) that springs to mind is the Jolida JD100 ... An internet search shows reviews & all sorts ...

The metal chassis may provide a rigid base to reduce vibration, not sure the standard looking mech has anything to offer in this regard.

Just imagine an all valve CD player though, the sheer size of it

Mark

[Refugee]

Just imagine an all valve CD player though, the sheer size of it

I think you had better rent an air craft hanger before you even think of such a thing