Help required: Missing 0.1 ohm resistor. Can I use jumper cable?

Zimmer64 · 3421

0 Members and 1 Guest are viewing this topic.

Offline Zimmer64

  • Full Member
  • ***
    • Posts: 210
    • Blog
Hi there,

I am assembling my kit and am missing the 0.1 ohm 5w resistor that is used in den DC heater supply. What does this resistor do? Can I use a jumper wire until I have bought a replacement? All shops are closed in Switzerland until the 3rd.....

Thanks for your advice and happy New Year!

Michael
« Last Edit: January 01, 2014, 09:32:33 AM by Zimmer64 »

Nelson Pass F5 Turbo V2, Quickie (mod), S.E.X. 2.1, Tubes4hifi SP14, Dynaco VTA ST 70, Tubelab SSE, Vroemen Diva Superiore ER4, Jordan JX92S VTL, 47 labs 0647 CD, Aqvox DAC, Rowen Absolute pre / psu / power amps, BG Neo3 / Betsy / Eminence A15 open baffles


Offline mcandmar

  • Hero Member
  • *****
    • Posts: 1599
  • Not all engineers are civil
I assume you know if you contact [email protected] or phone Eileen they will send you a replacement.  If you want one quickly and cant source them locally then PM your address and i'll send you one as i have a few Dale .1ohm resistors here. Post from Ireland -> Switzerland should only take a day or two.

I'm not really sure as to its purpose but i think its more to limit startup current rather then smoothing the supply so i don't think it would be a good idea to bypass it with a jumper.

M.McCandless


Offline Zimmer64

  • Full Member
  • ***
    • Posts: 210
    • Blog
Thank you for the kind offer. I will try to get this resistor locally tomorrow. Finished the build this morning. Installed impedance switch and C4S. Resistance checks all ok. Just can't fire it up just yet  :'(

Cheers

Michael

Nelson Pass F5 Turbo V2, Quickie (mod), S.E.X. 2.1, Tubes4hifi SP14, Dynaco VTA ST 70, Tubelab SSE, Vroemen Diva Superiore ER4, Jordan JX92S VTL, 47 labs 0647 CD, Aqvox DAC, Rowen Absolute pre / psu / power amps, BG Neo3 / Betsy / Eminence A15 open baffles


Offline howardnair

  • Sr. Member
  • ****
    • Posts: 329
what zimmer was asking was of course can he use a jumper--why a jumper-- well!!!  a jumper could have .1ohm resistance--zimmer measure a jumper and see



Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 5846
The added resistance adjusts the DC voltage to the heaters. (It has other benefits, not easy to summarize in a line or two.) The adjustment is small less than a half volt, so it won't damage the tubes to use a jumper for a few hundred hours. But don't leave it out for too long.

Paul Joppa


Offline Zimmer64

  • Full Member
  • ***
    • Posts: 210
    • Blog
Thank you all. I can source this resistor locally.

Michael

Nelson Pass F5 Turbo V2, Quickie (mod), S.E.X. 2.1, Tubes4hifi SP14, Dynaco VTA ST 70, Tubelab SSE, Vroemen Diva Superiore ER4, Jordan JX92S VTL, 47 labs 0647 CD, Aqvox DAC, Rowen Absolute pre / psu / power amps, BG Neo3 / Betsy / Eminence A15 open baffles


Offline Zimmer64

  • Full Member
  • ***
    • Posts: 210
    • Blog
Got one today, put it in and fired it up. No smoke, no hum, no hiss, just great music!

Michael

Nelson Pass F5 Turbo V2, Quickie (mod), S.E.X. 2.1, Tubes4hifi SP14, Dynaco VTA ST 70, Tubelab SSE, Vroemen Diva Superiore ER4, Jordan JX92S VTL, 47 labs 0647 CD, Aqvox DAC, Rowen Absolute pre / psu / power amps, BG Neo3 / Betsy / Eminence A15 open baffles


Offline Grainger49

  • Hero Member
  • *****
    • Posts: 7175
Michael,

I love to hear those stories.  Too often we only see problems on the board.  I believe the vast majority fire up first time and work as intended.



Offline Zimmer64

  • Full Member
  • ***
    • Posts: 210
    • Blog
Yeah. I just took it slowly. Read a step in manual, attached the parts as instructed, checked against the photos in the manual and only then soldered if so instructed. After each section I took high resolution photos and checked the solder joints on my iPad (magnified). That process really minimizes the chance of errors, plus gives you a nice documentation of your work.

Michael

Nelson Pass F5 Turbo V2, Quickie (mod), S.E.X. 2.1, Tubes4hifi SP14, Dynaco VTA ST 70, Tubelab SSE, Vroemen Diva Superiore ER4, Jordan JX92S VTL, 47 labs 0647 CD, Aqvox DAC, Rowen Absolute pre / psu / power amps, BG Neo3 / Betsy / Eminence A15 open baffles


Offline Grainger49

  • Hero Member
  • *****
    • Posts: 7175
(http://i244.photobucket.com/albums/gg7/Grainger49/Smiles/thumbsup_zps4d4312f2.gif)

Slow and meticulous beats fast and sloppy any day.  I wouldn't expect you to be sloppy either.

But so many first kit builders are in a hurry and have no idea how to make a good, solid solder joint.