[keyid]

I am having high voltages on -12 and +12. Everything else measures fine, dc offset is less then 2mv.

On -12 im getting -20v and at +12 im getting 15v, should I be worried?

Im planning on adding the jisbos would this be a problem with the high voltages? I also noticed the voltage jumped when I added a big heatsink on vr3, but they were always higher then 12v around 14v. I am thinking of replacing vr1 and vr2 incase they might be damaged, I do remember a spark when the heatsink on vr2 touched a jumped wire. Right now im burning in my brimar 13d5 tube and it sounds great!

 

[dBel84]

I would sort out that voltage problem before listening any further. something is not well and you may just end up damaging your precious headphones. Assuming that you are using opa 2134 - it has a max Vs of 36V ( iirc ) and you are sitting awfully close to that , on top of that it is not a balanced supply. If you are using the TO92 vregs , you may have them in the wrong way around but I wouldn't have expected any voltage at all. If you are going to add jisbos then change them with 15V TO220 regs which you can isolate and heatsink. ( it sounds like you did not isolate the previous ones - hence you are most likely using TO220 types ....doh )

..dB

 

[keyid]

I am using 2134, the voltage regulators are the default 12v LM78L12/9 in To220, not sure what you mean by isolating them.

 

[Eokboy]

ST 7912 reg needs a load to regulate. Without the opamp I'm getting -15V. 7812 does not have this anomaly though.

 

[dBel84]

yes - good point about the regulators, I recall several people having this issue in the past. By isolating them, I mean that you use a mica / silica membrane between the metal tab on the regulator and the heatsink - this isolates the heatsink electrically..dB

 

[keyid]

I took off the heatsinks on vr1 and vr2 the voltages are now 14.95v steady close to 15, but its supposed to be 12v. I should take out the heatsink on vr3 and isolate them as suggested, maybe that will take it to +/-12v. The great thing is now I can use 627 opamps and dam does it make a hudge difference, everything is so much clearer and more powerful. Reminded me of a millet max with the Brimar 3d5 tube on the soha. But now I have some hum to take care of... Its not boxed up yet any quick suggestions to rid of hum, besides wiring myself to ground?