[tubesforever]

I am wondering why the comparitor circuit resistors fried?  I wonder just how much current was going through these to burn them to a brown color? 

Do you have a variac?  If so you can use this to bring up the ac gradually and check the voltages at the B+ and the H+ before other things blow.  Do you have the rectifier socket soldered in with the locating tab in the right location?   Looking at the socket from the top of the board where the tubes mount, the locating tab should be approximately 7 pm on an analog clock dial.  On the 12au and 12ax tubes the gap between the pins should be at 5pm.

Check this before powering up again after you change out the burned up resistors.  Something is wrong and we need to hunt this down and stomp on it. 

[jameshuls]

I will check into that when I get home. I did not use the sockets from the parts list - instead I used the teflon ones with the gold-plated copper contacts from parts connexion, so maybe they are misaligned? I did have a short when I was checking voltages a few weeks ago, - the iec plug touched the RCA when I was moving it around. This is may be when the resistors in 104-8 got zapped by a spike.

[ronpod]

Oooo, I hate it when that happens. I agree with Tubes regarding chasing down the cause. But if the momentary short was the cause, there might not be a problem other than the fried components. You know the old saying, "measure twice, replace once" or something like that.

[hagtech]

It is common mistake to use 1.8k ohm for the 5W heater resistor.  Should be 1.8 ohms.  Sorry for the late response, I been out.

jh

[jameshuls]

Yep - I put in a 1.8K resistor. Damn!

[tubesforever]

James,

Do you have an update for us on your Clarinet?  I am hopeful the piece is sounding pretty and playing nice with the other gear now.

[jameshuls]

Parts connexion is out of 6K8 Kiwames, so there is a bit of a delay while I order some from Michael Percy Audio. It has taken 3 weeks and 3 attempts to get a reply to my request for a quote from him. It did give me a break from DIY madness over Christmas though - it turns out I have a family to spend time with My wife was getting a little disgusted I think but my 3 year old son can now point out caps, resistors and tubes with ease, and he is very interested in the soldering station ! Meanwhile, I am also fixing a bent spindle on my drill press so I can finish the custom chassis...

[Bill Epstein]

Good manners forbids me from asking how the spindle got bent

If yer stuck for the 6k8s, I have some. Just PM me with yer address.

[jameshuls]

Thanks Bill, but I picked up some generic 6k8's whilst I await my order from MPA.