hifi williamson circuit.triode electrnics opt...ps questions

[shabtek]

I just built a williamson stereo amp and was initially pleased ...i used a PT salvaged from an OLD tv set which gives me 390V rectified and has 3 6.3v taps and a 5v rectifier fil tap...the tv had 2 5au4 rectifiers.

I used triode electronics tf110 25w ul opt and the russian 5881 style tubes that are on sale for 10.95 a pair...so 100$us max is invested in this...it is plenty loud and sounds terrific...swweps into the scope look really good across the spectrum. I recommend this xfmr when it gets back in stock...so ok th pt was getting really hot...so I added a RadShat 12.6-0-12.6 for the power tube fil.s...this new xfmr gets really hot too and the original pt gets pretty hot....


i dont have the fils referenced to anything as of yet so I'm Wondering if that is necessary and will that reduce the thermal problem...without reference can excess current be drawn? hum and noise is nearly inaudible in the inefficient speakers I'm using.

the tubes and xfmrs are good deals if you can use them...I was going to get a dynaco clone xfmr from triode and would like to for comparison...but will put it off cause these 25w numbers do the trick

 

[WJS]

not refenceing the heaters shouldn't draw current. aslong as they are within range you should be fine. If something happened (ie cathode-heater arcing) you'd notice as your transformers/psu would not like it.

I'd guess that your pt should be able to handle everything just fine, guessing that the tv used more power than your setup.

I've used radioshack tranies for a lot of heaters and they are usually very quiet. But they do get rather warm sometimes. The first time I build a tube preamp a few years back that used two, one wired normaly and the second wired backwards (secondaries connected to the secondaries of the 1st, using the primaries for ~120vac). A few months ago i was using the preamp and noticed the current ratings on the tranies; the first one was definatly over worked. The preamp still works fine, hour after hour of being on (does get hot though).
good luck!

 

[shabtek]

I got the pt to run cool without an additional tranny!... I was shooting for dc on the small tubes heaters but have gone to the 4 12au7 tubes running ac from the rectifier fil. tap and i paralleled the 3 6.3v taps to the 4 5881s. I think hum is less... runs warm for the last 2 hours but not hot. I have not got the neg. feedback stable yet, but it sounds good without through zenith allegro 4000 crap inneficient speakers...I am out of shape when it comes to critical listening since all my free time is spent with these projects...this is probably not the forum for hifi stereo gear but it is diy with a buget --to the brewery i go