Gram Input

[cpvh]

Hi All,

Back in the day when I were too poor to born (I were knitted by the WRVS an d dropped throuh?t letterbox when me mam weren?t looking).

My ?HiFi? Consisted of a busted Dansette clone with no amp or transformer (we used my train set transformer and a dropper resister). A nd the Gram input of a valve radio (we had a similar setup downstairs which my father had built into an old sideboard to make a Radiogram)

Anyway, I used to play 45s and later LPs on this.

I imagine the radio was probably just post war.

Would this have had RIAA Compensation circuitry built in?

Only the records sounded fine to me, which makes me wonder if RIAA isn? ??t that important??

Or maybe it did (and 78s also used RIAA??)

TIA

Chris

[spuorgelgoog]

RIAA became standard about 1954 on LPs

Accoustic 78s were made without equalisation; electrical 78s had varying equalisation curves depending on company (and year of production)

and

RIAA seems to be about average, if you have nothing else.

"the majority of all 78 rpm records can be equalised within a 2dB of the nominal (or alleged) curves claimed, using 4 low and 5 high frequency ranges - including flat and true RIAA for both."

Multi standard equaliser circuit

Now it can be done in software

Owain

[The Natural Philosopher]

If it used s ceramic or crystal pickup voltage was proportional to deflection, not to velocity, so it would not have needed one.

No, but they still had an amplitude/deflection relationship.

[newshound]

Just what I was going to say. Will have been "crystal" in those days. I guess electromagnetic pickups might have been used in studio equipment.

[tabbypurr]

t looking).

amp or

+1. To call such kit hifi is of course fantasy. The sound quality of kit li ke that was normally hideous. 1970s lofis were a revelation, suddenly one c ould make out the words.

NT

[Brian Gaff (Sofa)]

It was a crystal pick up, Hi level and these were as far as I know almost flat.

Brian

[Brian Gaff (Sofa)]

Yes but wind up gramophones sounded quite nice the big ones anyway with bass.

There were lots of eqs about, look at Decca FFRR, which to my ears sounded screechy.

I actually think these days that some CDs seem to be being made with an odd EQ setting as well. I've heard talk of this on high end players being detected and compensated for giving some enhancement of the graininess some recordings can exhibit. Sounds a bit like Russ Andrews territory to me, I prefer the theory that the person doing the final balance was going deaf. Brian

[Brian Gaff (Sofa)]

Have you ever looked at cylinders? A lot of those used vertical modulation which made the groove shallow sometimes and they relied on the thread pitch of the screw to keep it in the right place. I did once see on the bbc stand at a show, an electrified cylinder player sporting a goldring cartridge, but according to the bloke there, the foil ones played OK, but not the pure wax ones as they were drying out and cracking and there was a project to play them all with a laser before they fell to bits. I wonder if in days to come we will start having issues with CDs and other optical media? Brian

[Brian Gaff (Sofa)]

Yes my Rogers Cadet has two plugs based on an octal system, and one is for ceramic the other magnetic which has the riaa. I used a Decca Deram. That was actually pretty amazing for a crystal pick up in its day. One thing is of course when a mixer never had enough line inputs, ceramic cart settings on a pick up input could be used if one was careful about matching and levels. Brian

[Brian Gaff (Sofa)]

Yes well, much like early guitar amps or stuff of that ilk. I have to say though that valve distortion was more tolerable than the early transistor amps with crossover distortion due to the heat affecting where the linear curve started and stopped.

About the best of the Germanium ones for sound was the z12 by Sinclair. It could sound quite good but obviously on a scope at the crossover point, though tiny, there ewes a bit of a signal there that varied with heat. Much better later on when silicon devices came along, and finally power fets. Brian

[Clive Arthur]

I used to buy crystal cartridges to provide a trigger signals for seismographs. You taped them to a sledge-hammer shaft to provide some volts when you hit your 'seismic source' target. These were many times cheaper than the seismograph manufacturer's devices which we found were the same except that they were potted in a short length of Al channel.

Indeed, a lot of them ended up almost flat.

[The Natural Philosopher]

When they first cut disks, amplitude of signal = amplitude on disk. A crystal or ceramic cartridge reproduced that with no equalisation. Whgen moving coal and moving magnet came a long, voltage was proportional to speed, so they need lots of bass boost - at 6dB per octave.For some reason they then decided to put a bit less on the disk and a bit more in the amp, and the infamous RIAA curve was borne.

[cpvh]

This ?HiFi? replaced my LoFi, an old gramophone on which th e spring had gone. I had to spin the 78s with my finger on the label.

My dad later bought a Leak Stereo 70 (which I rebuilt with Silicon transist ors after the magic smoke escaped) and a pair of Goodmans Magnum SLs.

These days I have a boat anchor Denon A/V receiver and a pair of Wharfdale Linton III XPs

[tabbypurr]

I had a Decca Deram long ago - it was magnetic.

[Chris Holford]

I don't think so; DEcca ceRAMic

[charles]

I had a Decca ffss - that was magnetic

[Dave Plowman (News)]

The Decca Deram cartridge is ceramic. Advertised as the first true Hi-Fi ceramic.

[Bob Eager]

Indeed. I used to sell them when I worked in a hi-fi shop!

[Andrew]

Bet you didn't pay £1000 for the speakers though :-)

[Max Demian]

Did anyone come in asking for a "gramophone"?