New build 6080 red plating (false alarm)

[grosen]

Hi all.  My new C2A has been up and running without a hitch for about a week.  Just now I noticed that the 6080 seems to be red plating. Haven't put the amp back on the bench yet, but thought I'd ask where the problem is likely to be.  Thanks in advance.

 

[Doc B]

First step is to check your voltages. Watch that tube when you do, don't run it for more than a minute or so.

 

[grosen]

Thanks, Doc.  The voltages look fine, except that

          KregB on the Low Current board is 6.3V, when it should be between 3V and 6V, and
          OB on the High Current boards is 88V on one; 82.5 V on the other, when it should be between 90 and 110V.

Here's the complete set of readings. 

Low current

        Spec      Measured

IA      150          148
OA      60-90      70.6
KregA  3-6            4.5
bRegA  150        148

IB        150        148
OB      60-90      67.1
KregB  3-6        6.3
bRegB  150        147


High Current        D          B

IA          190        186      188
OA        150        147      149
bA            0          .3mV    .5mV

IB              0            .3mV    .6mV
OB          90-110    82.5      88
bB          150          149      149

 

[Paul Birkeland]

Can you post a picture of the red plating?

 

[grosen]

Not sure how to post a pic.  Let's see if this works.

https://postimg.cc/7J405T1j

 

[Paul Birkeland]

I don't see any red plating.  I do see a nice hot cathode sleeve, but that's totally normal.

 

[grosen]

That’s great. Thanks. I wasn’t sure, but it looked unfamiliar to me, and like some of the pics of red plating on the web. Good to know it’s normal.

 

[grosen]

Bonus pic of amp.  All stock with eccentric paint job and ambrosia maple case.  Thanks to Paul for chiming in so quickly.

 

[Deke609]

Very nice! Painting the stock knobs is a really cool touch. I don't recall seeing that before. What kind of paint did you use? 

cheers, Derek

 

[grosen]

Thanks.  The knobs and transformer edges are Rustoleum Gloss Enamel red.  The plate and the transformer cover are Rustoleum Oil Rubbed Bronze metallic.

 

[johnsonad]

That's a nice looking build! 

 

[Paul Birkeland]

I like the maple a lot.