All tube DAC? Could you?

madmax

I wonder if someone were to develop a dac using all tubes how big it would be and how many tubes it would take?
madmax

Early B.

Max -- I thought you stopped smoking pot...

rskarvan

I remember the little tid-bit from Engineering school that one OP-AMP has the equivalent of 648 transistors. Now, considering a single transistor acts like a tube.... I'm thinking that you would need one hell of a power supply.

Now, the D to A conversion is a heck of a lot more complicated than a single OP-AMP.

While your request is not completely idiotic... its probably along the same lines as building a bridge to Hawaii. Just not practical.

madmax

Oh yea, not practical at all, just wondering. Anyone know how many transistors in the typical dac?
madmax

Systems

Well You can use as little a single dual triode at the output of a Digital to Analog converter IC which itself(the IC) is not possible to do with tubes.

madmax

Anything is possible.

Systems

madmax wrote: »

Anything is possible.

Then some tube crazy audio engineer would have tried it

steveinaz

madmax wrote: »

Oh yea, not practical at all, just wondering. Anyone know how many transistors in the typical dac?
madmax

I think it's a bagillion.

madmax

I'm guessing it would be the size of an industrial building. Well, not everything is possible. Could be you couldn't reach the speeds necessary. And the connections could be troublesome. OK, guess I'll just have to stay with vinyl.
madmax

rskarvan

I once used a mostly-tube calculator. Don't think it had an IC in it.
It couldn't do anything above +, -, x & /. The display was a set of "stacked" lights that illuminated the proper output number. It was about the size of a type-writer. And, it had a bagillion tubes in it.

rskarvan

The world's first electronic digital computer was developed by Army Ordnance to compute World War II ballistic firing tables.

The original agreement between the United States of America and the trustees of the University of Pennsylvania, dated June 5, 1943, called for six months of "research and development of an electronic numerical integrator and computer and delivery of a report thereon." This initial contract committed $61,700 in U.S. Army Ordnance funds.

Nine supplements to this contract extended the work to 1946, increased the amount ultimately to a total of $486,804.22, assigned technical supervision to the Ballistic Research Laboratories, and called for the delivery of a working "pilot model," first to be operable at the University of Pennsylvania and then to be delivered to the Ballistic Research Laboratories at the Aberdeen Proving Ground.

From this point forward, the research staff and faculty of the Moore School under Dr. Pender undertook rigorous prosecution of the development pursuant to the terms of the Ordnance contract. The project was placed under the supervision of Professor Brainerd, with Mr. Eckert as chief engineer and Dr. Mauchly, who provided the original outline for this development, as principal consultant. Captain Goldstine, the resident supervisor for the Ordnance Department, not only exercised extraordinarily detailed and highly competent supervision for the Government but also contributed greatly to the mathematical side of this undertaking. As in all important undertakings which achieve important results, this was the work of many individuals.

The ENIAC was placed in operation at the Moore School, component by component, beginning with the cycling unit and an accumulator in June 1944. This was followed in rapid succession by the initiating unit and function tables in September 1945 and the divider and square-root unit in October 1945. Final assembly took place during the fall of 1945.

By today's standards for electronic computers the ENIAC was a grotesque monster. Its thirty separate units, plus power supply and forced-air cooling, weighed over thirty tons. Its 19,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors, and inductors consumed almost 200 kilowatts of electrical power.

But ENIAC was the prototype from which most other modern computers evolved. It embodied almost all the components and concepts of today's high- speed, electronic digital computers. Its designers conceived what has now become standard circuitry such as the gate (logical "and" element), buffer (logical "or" element) and used a modified Eccles-Jordan flip-flop as a logical, high-speed storage-and-control device. The machine's counters and accumulators, with more sophisticated innovations, were made up of combinations of these basic elements.

ENIAC could discriminate the sign of a number, compare quantities for equality, add, subtract, multiply, divide, and extract square roots. ENIAC stored a maximum of twenty 10-digit decimal numbers. Its accumulators combined the functions of an adding machine and storage unit. No central memory unit existed, per se. Storage was localized within the functioning units of the computer.

The primary aim of the designers was to achieve speed by making ENIAC as all-electronic as possible. The only mechanical elements in the final product were actually external to the calculator itself. These were an IBM card reader for input, a card punch for output, and the 1,500 associated relays.

Bill Ayotte

You would have to refinance your house to re-tube that thing.....Leave it to the Army....

RuSsMaN

rskarvan wrote: »

It couldn't do anything above +, -, x & /.

Your computer today can't do much more either. It can just do it a LOT faster.