Anyone recorded their voltages at the pins on their DC30 that they can share??... I have some Funky volt readings... I think what I suspected that my EF86 is bad is looking true.. But other voltages have me confused.. and would like to know what healthy voltages are???

 
"ps. what was going on with mine was that the heating wire was only putting out about 5.8 volts instead of the 6.3 it should have, and the mains to the power amp section were hotplating the tubes once off standby. the wire change solved the mains and brought the heaters up to 6.15 which is still lower than should have been, but most likely the tollerance on the tranny was low, or there was a miniscule solder error."

How and where are you measuring the heater volts at??? I have my meter set to DC volts and checked at the 5&6 pins.... I get a reading of 2.8v ? confused even further now...


[/quote]

heres the picture of how i rewired the amp, i'm pretty sure the bottom pin is going to the caps from what i remember, i didnt look carefully, but you can probably tell from the pic.

yeah, i was a little confused by the buss bar as well, but on the bottom of the board theres a wire running from the bottom of the buss to the pin that it goes to on the layout to make up for it. and yes! this amp is very loud, i was kind of nervous at first thinking that it wont be able to stay clean with a heavy handed drummer, but even with active pickups it has great headroom.

dont be dissapointed if it doesnt sound magical at first, it wasnt untill about 5 hours of time on the amp that the tone really sunk in and made me wanna cry.

Heater wiring is AC Voltage

I checked my heater volt readings on all 4-5 and 9 pins and get 2.9v added together It gives me the 5.8v within the 10% +/- tolerance . I would like to know what is causing this and the comment's here make me think it is a universal issue... maybe nik will chime in.. As far as the fix I see in the pic shouldn't the standby switch be grounded??? Also, I just added  four 1n4007 diodes to the recto sockets as it shows on the new layout revision.. I guess it helps tame the current in-rush when switching standby to operate.. nik said they were having issues with the jj gz34's arching..

Heres what nic responded:

nik,  In this image you can see where the buss bar comes up short... it doesn't match the layout position? but we have it fixed and it made a huge difference. What value are the diodes on the new dc30 revision??

Thanks

On Jul 27, 2009, Nik S Azam <nik@ceriatone.com> wrote:

    
    Greg
     
    Thats great!
     
    As for the buss bar, I see. Is that to the last 25uf? Or maybe the way it is bent?
     
    Thats great then, glad you sorted it out.
     
    As for the diodes, 1N4007 would be good.
     
    I am afraid that the current JJ GZ34s are prone to arcing due to inrush current. Having this helps a bit.
     
    Standby switch for tube rectified amp isnt necessary, and in fact, hurts the amp, esp the tube recto itself.
     
    In turn, other things can be hurt like the PT etc if the tube recto fails, or if the surge gets too big on standby switch toggling.
     
    We will be updating the layout again, this time with more ways to help protect the amp.
     
    Other than diodes, a cap can be put on the plates of the GZ34 (0.01uf 3kV)
     
    Then, a resistor, say 100K, can be put across the standby switch pins, along with a cap, 0.047uf or 0.1uf, 630V.
     
    Then, a bleeder resistor from 1st filter cap to ground can be added as well.
     
    If you want to go the full shebang, a 100R 10W or 15W resistor can be put in line on each HT before recto tube socket, to provide some resistance which helps protect further. This is not necessary with the above, it's a way to over engineer it.
     
    Thanks!
    Nik