High voltages in 66 Ampeg B15nf

[mosrite1]

So I have a 66 Ampeg B15nf, I just replaced all of the electrolytics and tubes ( except the rectifier), I am getting 516vdc on the plates ! 510vdc on pin 4 and -57vdc on pin 5. all of the voltages before the output section is fine, a little higher than the schematic due to the 123.5ac from the wall 
The bias seems fine, and it sounds good, I am just worried about that 516vdc plate voltage eating up tubes

here is the schematic
http://www.kbapps.com/audio/schematics/tubeamps/ampeg/b12nfb15nf.html

any help would be much appreciated

thanks

[Maschinenmann]

I've seen this on a few vintage amps using new production glass; the voltage drops are not the same as the originals due to material and coating differences. As long as you aren't exceeding the cap ratings and you bias it properly, you should be ok. A better solution would be to build a voltage "browner" to get the input voltage down to '60's era 115-117 VAC.  


http://geofex.com/Article_Folders/vintvolt/vintac.gif

[Geezer]

Yep, you need to build a "Vintage Voltage Adaptor" (MM's link above). I built one & they work great!

I worked on a friends B15 a few years ago & the voltages were almost exactly what you got, maybe even higher.

G

[PRR]

> 516vdc on the plates !

On 6L6GC? Or any modern "6L6"?

Forget about it. That won't hurt these tubes. The "450V" rating was ultra-conservative for marketing reasons.