table radio w/ tube amp...in the designing process...anyone do this?

[ambience exists]

I am hoping to design and build a table radio with some rad mono tube sonics. I am thinking of having a fostex driver for a full range sensitive setup. The amp electronics I am thinking of are either that of an s-5 electronics kit bridged into mono for 16 watts or a single ended el84. Since budget is an issue I am thinking that the s-5 is more economical since I already have iron- but something intrigues me to try a simple mono point to point...

Peace!

[DigitalJunkie]

There are a few simple single-ended schematics floating around on the forum here.. You might want to look into "spud" amps.

Here's a couple links:
Spud anyone?

http://www.tubeaudio.8m.com/RH84/rh84.html

http://www.pmillett.com/midget.htm

[ambience exists]

I guess an important question I left out is that I am planning on using an FM radio kit like this one: http://www.ramseyelectronics.com/cgi...ction&key=FR1C

It says it has 250mw audio output- could I just tie that output from the board into a tube amplifier and retain the boards volume control? Could it maybe even be used as a preamp stage for an el84?

Thanks

[bigwill]

Originally posted by ambience exists


It says it has 250mw audio output- could I just tie that output from the board into a tube amplifier and retain the boards volume control? Could it maybe even be used as a preamp stage for an el84?

Thanks

The volume control certainly can be used, but as for driving an el84 directly, it probably doesn't have enough voltage swing (not that the el84 needs much, but it needs at least about 12v peak to peak

[Arnulf]

It says it has 250mw audio output- could I just tie that output from the board into a tube amplifier and retain the boards volume control?

Yes.

Could it maybe even be used as a preamp stage for an el84?

How much power do you want to get out of it ? This board probably has output in the range of 1V p-t-p or less. This is not enough to drive EL84 to any reasonable level.

[Geek]

Originally posted by Arnulf
This board probably has output in the range of 1V p-t-p or less. This is not enough to drive EL84 to any reasonable level.

But it's perfect for a 6FD7 spud or something

I am thinking of having a fostex driver for a full range sensitive setup.

Well, a 6FD7 with a 2.5W out with a 1V input will "blow your ears off" for a table radio setup.


Cheers!

[Arnulf]

Indeed, and any triode-pentode combos such as ECL/PCL series tubes (especially E/PCL82 or E/PCL86) would be a good choice as well for a single envelope amplification up to very decent listening volume level. There are plenty of schematics floating around for these tubes.

[ambience exists]

I like the idea of the spud amp in here- I am feeling the tubelab spud would do well here, or I could point to point it. I am thinking of using some more budget orientated iron to keep costs down and also to save space in the wooden enclosure I am planning.

Although el84's seem to be everywhere and I could probably cram a driver stage in the box... I have heard only good things about the el84. Any favorite simple designs you would recommend to a novice point to pointer?

[wa2ise]

I did this, adding a tube output stage, in a solid state radio, sounds nice.
See, at the bottom of my page, at
http://pw2.netcom.com/~wa2ise/radios/feedback.html

[ambience exists]

awesome work man! ...but I don't think that I have the experience to make that happen.

I am kind of thinking about the beauty of the radio, the medium of music transfer, and how much it frees you into music by you just tuning into a list of songs chosen by a DJ- rather than the force within you to pick your own. Although forced to one other persons playlist, we are all forced and that is what is- and so we learn to treat music as not a list of wants and wants but the true-ness of just what is.

So I guess I should build this radio then....


peace