Next build suggestions please.

[yorgle]

In my Drawer of Accumulation, I have a bunch of parts that seem usable for a guitar amp:  a ancient PT w/approx. 275-0-275, 6.3 secondaries; a 5y4GT rectifier; one of those little square SS rectifiers; a 6sj7GT; a pair of 6bq5's; a couple of 6eu7's; a whole bunch of 12a_7's; two pp output transformers; and an assortment of octal, 7, and 9 pin sockets.  Paging through the zillion or so schematics here, I don't see any using a 5y4- is there a reason for that?  What would you guys suggest building from this stash? 

Another question:  the primary side of the PT has 2 thin black wires in addition to the 2 mains wires.  One of the black  wires still has a bolt lug at the end suggesting it was originally connected to ground.  There is continuity between the two black wires, but not between either black wire and the transformer itself or any of the other wires.  The transformer seems to test fine with the black wires not connected to anything.  Should I just ignore them?

[PRR]

5Y4 is 5Y3 with a different pinout. The 5Y3 eventually became far more popular.

[sluckey]

Plug it in to the wall. Do you measure any voltage between the two thin black wires?

Your DOA has the beginnings of a neat 20 watt amp. Look around this site for some nice projects. Lot's of junk box stuff on my site.     Even if you don't find anything interesting, you may pick up some ideas that will guide you as you search for your perfect DOA amp.

http://sluckeyamps.com/index.htm

[kagliostro]

May be your choiche is one other

You say you have a pair of PP OT, assuming they can be used with a pair of your power tubes

I would like this

http://sluckeyamps.com/dual_lite/dual_lite.pdf



Use 6EU7 as 12ax7 -- 6SJ7GT as EF86 -- 6BQ5 obviously are EL84

Franco

[yorgle]

Well, the good news is I powered up the PT last night and tested all of the wires with my good digital multimeter and the its actually 345-0-345vac; 5vac; and the two black leads are actually secondaries (not ground)and measure 12vac. 

The bad news is that while testing the PT, I knocked one of the 6bq5's off my bench and it shattered. 

Kagliostro:  That Dual-Lite looks interesting.  Thanks.

[sluckey]

its actually 345-0-345vac; 5vac; and the two black leads are actually secondaries (not ground)and measure 12vac.

So, no 6.3VAC?  345-0-345 is too high for a 6BQ5 amp.

[yorgle]

its actually 345-0-345vac; 5vac; and the two black leads are actually secondaries (not ground)and measure 12vac.

So, no 6.3VAC?  345-0-345 is too high for a 6BQ5 amp.

Apparently not.  I assume the 5vac is for the rectifier and whatever the PT came out of must have had a bunch of 12v tubes.  What about using a couple of 6v6's as a PP?  Is this PT too big for those as well?