Voltage check problem [solved]

[Kai]

Hello,
a couple of hours ago I completed the build, however some of the voltage reads are off. I will also post the resistance read for those that I am not certain..

Resistance:
Terminal     Should Read     Actual
12               *                      No Read on the meter
14               *                      No Read
17               *                      No Read
19               *                      ~209.1k
20               *                      ~5M to 10M
22               *                      ~208.4k
24/27/29/30 *                    No Read

I notice for any of those No Read terminals, those are not connected to another part of the system, thus I assume getting a No Read is correct?


Voltage:
Terminal                              Should Read               Actual
+275vDC on PSB                 275                            278.2/277.3
+6.3vDC on PSB                  6.3                             6.34
IA's on C4S                          275                            276.3/276
Breg Regulator                    220                            219.2/219.2
-reg Regulator                     0V                              1-5mV (very close to zero, would that be good enough?)
Kreg Regulator                    220V                          10.84(A)/10.23(B)


As you can see, the Kreg measurements are way off. I noticed that the tubes did glow, and I also went through the whole manual again, noticing, I believe, I did not make a mistake on the installtion.


Please let me know what you guys think
Thank you!

Kai

[Paul Birkeland]

That Kreg voltage is a typo, so sorry!

Your amp looks like it's most certainly ready to listen to! 

(That Kreg voltage should be somwhere betwen 4 and 15V)

[Kai]

Great news!!
Thank you!

[Kai]

Amp is working great. However, I noticed when the fine attenuator is set to -4.5dB the sound from the left ear sounds significantly louder than what you hear on the right ear. Good news is, this issue only happens when the Fine Attenuator is set to -4.5 dB, regardless of the coarse attenuator, nor any other coarse/fine settings...
The fact the balance is broken under this specific setting is "interesting", any thoughts on what might be the cause? I will look over the connections on the fine attenuator tomorrow as well as possibly reheat the solder...

As always,
thank you!

Kai

[adamct]

I think you've already identified the issue. It sure sounds like a bad solder joint. Fortunately, you don't have that many to check. If that problem only appears at one setting, you know where the culprit will be! 

[Kai]

Indeed a bad soldering joint. Problem solved, thanks guy.  =}

[Kai]

This is just a random question:
this problem got me wondering a couple minutes ago..
Was wondering for the mainline, when I want to switch impedance, input, or RTS/XLR do I need to turn off the amp and then make the switch or it doesn't matter (as for a smack, one would need to turn off the amp first before adjusting the impedance, was wondering if this was purely for safety purpose or it's better for the circuit)... If I do need to power off the amp first, should I wait the 5 min for it to discharge itself?
On the other hand, say I have the amp connected to a DAC, is there a sequence for powering up each unit and powering off each unit??

Thank yoU!
Kai

[Paul Birkeland]

This is just a random question:
this problem got me wondering a couple minutes ago..
Was wondering for the mainline, when I want to switch impedance, input, or RTS/XLR do I need to turn off the amp and then make the switch or it doesn't matter (as for a smack, one would need to turn off the amp first before adjusting the impedance, was wondering if this was purely for safety purpose or it's better for the circuit)... If I do need to power off the amp first, should I wait the 5 min for it to discharge itself?
On the other hand, say I have the amp connected to a DAC, is there a sequence for powering up each unit and powering off each unit??

Hello Kai,

Turning off the Smack was purely a safety issue, you can flip all the switches on the Mainline without a powerdown.

For powering sequences, the Mainline tubes have an unusually long warmup time, and an unusually quiet warmup in terms of making noise through the headphones.  If your sources are a little thumpy while they warm up, you can power them on first, and turn them off last.

-PB

[Spinifex]

That Kreg voltage is a typo, so sorry!

Your amp looks like it's most certainly ready to listen to! 

(That Kreg voltage should be somwhere betwen 4 and 15V)

This info should really be a sticky somewhere on this forum.

I just finished building my Mainline and I panickeda bit at first, but after a quick visual check I just plugged it in and it works very well.

[Paul Birkeland]

I flagged this for a manual correction. 

-PB

[Spinifex]

Ah, I see. I pre-ordered the kit, so I have the first version of the manual.

[dth31]

I ordered my Mainline when the most recent "special deal" was announced.  That version of the manual is correct.

Dave