Yaqin MC-10L Heater Voltage

[JayDCason]

Hello all, first post. According to a previous thread on this site:

Yaqin mc10L


"Best to check the heater volts if you can, two yellow twisted wires around V2 on the pre-amp board at the top edge of board. This of course is AC volts and expected to be approximately 6.3V."

Just replaced all EL34 with matched quad set after V3 fizzled out two weeks ago and I set the bias to .35vdc. Yesterday the stereo started sounding garbled when I turned the volume up. So I shut it down and removed the cover. Checked my bias voltages and they were all about half of what they should be. Turned off the stereo set up my test leads to check another voltage turned stereo on and it sounds good and voltages where they should be then once I turn it up it gets garbled again. Checked the voltage on one of the heater wires (yellow twisted pair labeled heater supply in aforementioned thread) and I get 3.2vac to ground.

Am I measuring this correctly? I shouldn't measure the voltage drop between the twisted pair to get the 6.3v?

[piero7]

No. Test points are pin 2 and 7 of EL34.

[tyu]

I did mine, came out at 6.5 v so only just over, near enough for me,
I say Not for Good tone!
An yes you have 3.2 on EAch wire to ground, 6.4 i have been doing work on High Heaters an Sweet tone,an have found lower is better for Better tone, An the maines change from day to night, at night the heaters can go to 6.9-7 sucks the life out of the sound, i am Working on a way to lower, a EZE way, There is a Big diff. in high too low, I think tube Heater Have, What I call Heater Headroom, High an the Xfourmer run Hoter,lower cooler. Run the input tube any higher than 6.3 an sound is glassy an hard,an when the maines change you will have 6.5-7, Amps preamps well sound Good sometime an Bad at others, i here this all the time.After All the one thing all the Tubes have Amp or Preamp is one Heater!
It got to be Right or all is lost.

[JayDCason]

Thanks for the answers guys.