amp project query
 

Hi all,

At page 48 of the Glass Audio '17 Vacuum Tube Designs' edition (Aug, 2002), you'll see plans for a "Hybrid Tube Radio." The plans include a simple but complete 2A3 circuit. I'm assuming that I can just use two of these to make a simple pair of monoblocks, but perhaps there are experts out there who would know whether there's something wrong with that.

I could imagine, for example, that since the input is from the headphone out of the CD-ROM player, that I might need to fiddle with the input portion of the circuit to accept higher input voltages. But being an armchair hobbyist, I wouldn't be able to tell just from the values of components near the RCA input.

Thanks in advance.

Jay

Is it possible for you to post the schem? This would provide sagnificant help to those not in possesion of 17 Vacuum Tube Designs. From what you already said though you shouldnt have to modify the curcuit, because I am guessing the CD-ROM has a volume adjustment pot, and the tube amp should have one also. In addition, why build a radio, when you can just do a straight out amp? Hows this a hybrid? A schem would really help...

the original design
 

Attached is the schematic.

The article was about making a little table-top CD player with tube amplification. That's why it's kind of unusual. But the amp circuit was intriguingly simply, and the article included a parts list (though I got better output transformers).

seems easy enough, a little bit unusual but easy. might want to replace R1 with a pot if you need a volume control.