Announcement

Collapse
No announcement yet.

New amp/old topic - still voltages

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • New amp/old topic - still voltages

    Hi all,

    Hi, I've built a 5E3 clone, a mojotone kit, with TAD cabinet and a P12Q Jensen Speaker. It sound beautifull. The grounding scheme worked very well and even with single coils, no hummm.

    I know that voltages is an old topic and there is plenty of info. However, to be honest, after reading a coupleof dozens of post, I've still confused what is the proper values for the 5E3 voltages.

    I have the current voltage reading:

    Pin 8 from 5Y3: 400 V (Just before the 4.7Kohm and fist cap resistance)

    Pin 8 and 3 from 12AX7: 2V

    Pin 8 from 6V6: 23V

    Does there voltages seem ok? The 400V and the 2V seems a little high.

    I'm in europe, were the public power network is suppose to be 220V. However, recurent measurements at home show 235V. So, I've decided to use PT primary 240v options. Any comments on this decision?

    Thanks in advance guys.

    Regards,

    Marco

    P.S a couple of pictures of the wiring job and the amp

    Click image for larger version

Name:	_MG_1596.jpg
Views:	1
Size:	260.6 KB
ID:	863636 Click image for larger version

Name:	_MG_1740.jpg
Views:	1
Size:	279.8 KB
ID:	863637

  • #2
    Some voltages that I noted for the 5E3, not sure where they came from:
    6V6 anodes (Pin 3) 380 VDC
    6V6 screen (Pin 4) 339 VDC
    6V6 cathode (Pin 8) 21.7 VDC

    V2 12AX7
    Pin 1 167 VDC
    Pin 3 1.1 VDC
    Pin 6 175 VDC
    Pin 8 70.5 VDC

    V1 12AY7
    Pin 1 120.4 VDC
    Pin 6 122.8 VDC
    Pin 3 & 8 2.0 VDC

    Rectifier 5Y3 pin 8 390 VDC

    Personally I like for the 6V6 anodes to be right at 360 VDC.

    Remember that Fender's noted voltages on their schematics are +/- 20%.
    Hope this helps.

    Comment


    • #3
      Great! So it is a match.

      400 VCD out of the rectifier are within the 20% (only 2,5% above). Probably it will depend on the 5Y3 used.

      Thank you!

      Originally posted by mac dillard View Post
      Some voltages that I noted for the 5E3, not sure where they came from:
      6V6 anodes (Pin 3) 380 VDC
      6V6 screen (Pin 4) 339 VDC
      6V6 cathode (Pin 8) 21.7 VDC

      V2 12AX7
      Pin 1 167 VDC
      Pin 3 1.1 VDC
      Pin 6 175 VDC
      Pin 8 70.5 VDC

      V1 12AY7
      Pin 1 120.4 VDC
      Pin 6 122.8 VDC
      Pin 3 & 8 2.0 VDC

      Rectifier 5Y3 pin 8 390 VDC

      Personally I like for the 6V6 anodes to be right at 360 VDC.

      Remember that Fender's noted voltages on their schematics are +/- 20%.
      Hope this helps.

      Comment


      • #4
        Nice wiring! The JJ's you have in there will cope with the high voltage and dissipation, but if you wanted the amp to run in the "zone" Leo intended, I'd wire up the 240V primary and look into a real 5Y3.

        - Scott

        Comment

        Working...
        X