• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

My Simple P-P Build

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
Einric

Einric

Member
Joined 2011
Paid Member
OK, So I have removed the brown wire from the RCA to Earth and I connected the top plate to Earth.
Now it is motorboating, UGH, So it appears with any number of connection variations I can make this thing Scream, Motorboat or Humm.

I'm gonna take a break for the night, Thank You All.
 
R

ronaldw441

Member
Joined 2008
Have you checked all the voltages? In late July I sent you a bunch of SPP stuff including a spreadsheet that has every voltage you can measure on a SPP when using a 600VCT Edcor. Your voltages will be higher with the Hammond but should be close.

I don't know if you received this information or not since you didn't reply.
 
C

cjkpkg

Member
Joined 2008
Here is how I managed a hum free SSE.

Move the input RCA's as far away from the pt as possible. Now as for grounding what I ended up doing after numerous configurations was to do the following.
1. Power inlet earth to chassis point
2. On the PC board I ran a wire from the terminal for the xformer CT which is also the ground connection for an aux capacitor to the star ground point.
3. All rca connections are very short twisted pair from the rca to the board...that's it.

You may want to test a setup like this with your RCA's with short leads coming out the front of the amp underneath just to see. I don't like the long run you have going across the chassis.

And I assume you are testing with the inputs shorted?
 
Last edited:
C

cjkpkg

Member
Joined 2008
My see is very loud with an open input.

Also...be careful connecting a device on checkout...I lost an iPod by accidentally sending 40vdc to the headphone jack through a the cable adapter.

I now always short the inputs with alligator cables

And if you use that ground scheme make sure there are no other ground points to earth or you will have a loop.
 
Last edited:
S

Sprags

Member
Joined 2013
I know it's been a while since anyone has posted a reply to this but...
Can you recommend an Edcor transformer that is equivalent to the Hammond power transformer? Or if that isn't the way to interpret this can someone tell me which Edcor transformer would work? I read the TubeLab pages and I just don't get it. I'm new to trying to learn electronics...been a Mechanical Engineer all my life. Sorry for the trouble.
 
Last edited:
Z

zman01

Member
Joined 2011
Sprags,

This is for a Tubelab SPP build?

2 options I found from Edcor:

https://edcorusa.com/xpwr172

https://edcorusa.com/xpwr131

The Edcor XPWR172 has a lower voltage rating (your B+ likely to be slightly lower), but is rated for 200mA vs minimum George's minimum recommendation of 175mA.

The Edcor XPWR131 has voltage rating of 660v which is slightly higher than 650v mentioned by George, and the current rating is on par at 175mA.

6.3v and 5v rails are adequate for both of the transformers.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom