Early Electronics

[Crossy]

24 minutes ago, Muhendis said:

There used to be a factory in Bedminster, Brislol called Will's which made Will's Woodbine cigarettes.

 

It was being given a Woodbine by the big-boys behind the bike sheds (yes really) at Hindley and Abram Grammar School that put me off smoking forever.

 

Drinking yes, women yes, smoking never again ????

 

[Tippaporn]

11 minutes ago, Crossy said:

 

Was that The Analog Shop? Not sure if it's still there, but there's certainly a place in Zeer doing the same type of kit. If you have to ask the price - you can't afford it ???? 

 

There are many explanations for the "valve sound", they certainly sound different.

 

They "clip" gently and the distortion is second-harmonic which is less grating than the third-harmonic that bipolar transistors produce. FETs are similar to valves in producing second-harmonic distortion but they still clip hard.

 

All very subjective.

 

The Analog Shop.  Yes, that rings a bell.  And I agree hi fidelity is definitely subjective.  I visited a high end audio boutique once and it was a very interesting and unique experience.  Upon entering one had to sign their name in a register.  The store had two sound rooms - one for the "affordable" components and one for the "in your dreams" components (a speaker set at USD 30k, for instance - and that was mid-nineties).  The reason for signing in was due their practice of serving only a single customer at a time in a given sound room.  And this is how it worked:

In the lobby was a rack of CDs which the customer could choose from when testing out equipment.  Alternatively, you could bring your own favourite music.  The room was rather expansive but the entire range of audio components was all displayed on shelving a single wall only.  From amps to pre-amps to CD players to tape decks, turn tables, etc.  The rest of the room was flush with speakers and a strategically placed sofa with coffee table.

No audio brand company had their entire line available.  The idea being that every audio manufacturer excels in one or perhaps two areas but not all areas.  So the available selection of components was based on the best of the best in category.

 

Now none of the audio components had price tags.  And the idea wasn't to prevent sticker shock.  Their idea was that since everyone has a slightly different range of frequencies they're able to discern then the lack of price tags was to prevent those with deep pockets from basing their purchase solely on the highest priced component.  They encouraged the customer to purchase based only on the quality factor of what they were able to hear.  If a set of speakers costing $8,000 sounded no different than a set costing $2,000 then you've just wasted $6,000 thinking that higher price equated to better sound.  True and not true.  It's a relative truth which depends on what you're able to hear.

And so the salesperson would first ask you what your budget was.  From there he would offer selections based on that budget.

Also, if you were to bring a friend or two along with you the salesperson would strongly advise your friends to refrain from providing any  of their own input.  They discouraged any outside influence to the purchaser.

The most amazing discovery in audio quality for me was listening to three different CD players.  The price range was $350, $450 and $700.  In my particular instance all three CD players were produced by the same brand (which I can't recall).  Upon listening to the $450 model I was most definitely struck by the difference to that of the $350 model.  It was unmistakable.  My budget at the time would have accommodated the $450 player.  But when I heard the $700 CD player the difference in the audio quality was magnitudes greater than the difference between the $350 and $450 players.  So much so that I would have blown my budget without another thought because I would never have be able to forget the difference had a purchased the lower priced players and thus would have never been able to enjoy them fully.

Ever since I've always wanted to compare the sound between the usual componentry to that of tube componentry.  Ah well, I doubt there's opportunity to do that in Thailand.

Thanks for the explanation, Crossy. 

[Muhendis]

Anyone remember the live chassis radios?

 

It got rid of the mains transformer and also the ground wire in the power plug.

 

One of the deadliest innovations ever. 

 

Modify one of those at your peril.

 

My electrician father did exactly that by adding a ¼" coax plug for an extension speaker. He connected the screen to the chassis.

Nobody noticed anything until one day the plug accidentally contacted a water pipe. My concerned mother made certain that radio went off air 'till the mod. was removed.

[Crossy]

3 hours ago, Muhendis said:

Anyone remember the live chassis radios?

 

Yup, chassis connected (hopefully) to the neutral side of the mains.

 

I worked on some Pye/Philips TVs (CT200 Chelsea) which, whilst not live-chassis, did rectify the mains with a bridge and then made the -ve of the bridge "0V". All fine and dandy until some innocent tech connected a grounded scope probe to the "0V".

 

 

Bottom of the sheet, centre is the offending bridge.

 

 

[Muhendis]

11 minutes ago, Crossy said:

Yup, chassis connected (hopefully) to the neutral side of the mains.

Or not.

Those were the days of two pin, five amp mains plugs and sockets so there was a 50:50 chance of the chassis being very live. Or in my case more like 95:5.

[bluejets]

For around 10 years or more it became manditory to run an earth from the main switchboard to the antenna because of these puppies.

So no longer was it sufficient for a tv tech to install the tv (as they did back then) but also a qualified lecky had to attend as well.

Meant costs doubled, but had to be done as some internal TV fault livened up the antenna and a few people were booted.

Probably not so much the boot but the fall off the ladder that brought about the changes.

TV techs were issued with a "restricted ticket" but this was limited to mostly fitting a plug on a tv/radio.