Bottlehead Forum
Bottlehead Kits => Eros Phono => Topic started by: Anton on June 30, 2010, 01:11:52 PM
-
Hello,
I am building Eros phono pre-amp. Really enjoying building it but faced a little problem...
I was doing shunt regulator voltage test today (as described at page 58 of Eros manual). When I powered up pre-amp - only three out of four LEDs on shunt regulator PC board did light up. The one in D1 slot at the A-side of the board didn't light up. What is the reason could be? I checked orientation of the LED - it is correct (silver end in the squared solder pad).
What should I do now? Try to re-solder this LED or replace it? Or may be the problem is in something else? I would appreciate your advise.
And another question: manual says voltage should stabilize at 225V. In my case when I connected to D1 tube socket terminal - voltage was 240 V (+6.6% difference), and when connected to D6 terminal - 221 V (-1.8% difference). Are these ranges considered to be acceptable?
Thank you very much!!!
-
Re-wetting the solder joints on the LED is the first step.
The voltage might be better if the LED is functioning properly.
-
Hello Grainger,
Thank you. I just tried to re-solder the LED and it fell apart. I guess I damaged it somehow while soldering first time - may be applied too high temperature.
Now I need a replacement LED....
-
Contact the Queen and she will send you one out. The contacts are on this page:
http://www.bottlehead.com/contu/cntu.html
-
Thanks Grainger - I sent her e-mail yesterday.
-
I shouldn't have spoken for Bottlehead, I don't work for them. Past experience has shown that they are good guys, and a gal, and send parts that are damaged. But "It's not for me to say." (that is the name of a song from my teen aged years)
-
Granger,
I received LED replacement in the mail this weekend. Re-solder that one LED - now it works fine. All four LEDs lighting up now.
Voltage is 221.5 and 224.6 - very good.
Thank you for help.
And thank to Eileen for sending me extra LED.
Support is really superb.
Anton
-
Anton,
Give it a little time, 100 hours, to break in. The tubes break in fine with no music going through them but the capacitors need an audio signal to break in.
I bought a reverse (inverse) RIAA device for breaking in a phono stage. I think it was from MCM Electronics but I can't find it today. Hagerman sells one for $50, $30 for the half kit but then you need to order parts (12 resistors & 6 capacitors). Both are completely passive, the accuracy is irrelevant and it allows you to feed it with a CD player on repeat and do a burn in. Nothing but your CD player and Phono stage needs to be turned on.
Pretty neat. But who builds a bunch of phono stages, except one poster I won't point fingers at. He loves all of his.