opa 627bp in MHZS cd33

Cat,

I'm not there to observe, but how does your player sound? I hate to sound discriminating, but your measurements make no sense if you are getting failry clean sound. The circuit incorporated here in your output stage is called a cathode follower. I can't find a scematic, but if I were to guess, only one tube is used per channel like a buffer.

Viewer's measurements are dead on.

Please look up Duncan's Amp Pages, and you can query the 5670 tube and see a visual of the pinout and figure out if you are hitting all the right point and then give us new measurements. Unless you have a resistor that has drastically changed, your plates and filament voltages should stay the same between the two tubes.

Hope this helps some,

Blair

Cat,

I think that there is some good advice coming in from other members, but lets take a few minutes and breathe. One thing I can tell you from working on tube gear all this time is that troubleshooting on the tube end is not always a good idea.

Try this. Take all associated signal wires off your new board so as the tubes are the only thing still connected. Not because you are damaging anything, but it removes several different possibilities. Now you simply have the jumper between the PS board and the audio signal board. Remove the jumper from the audio board end of the jumper and take your meter set to DC and test all the pins on the cable. Write them down in order of what you get. If the holes are too small for your meter, take a push pin and put it in there and use a alligator clip to clip your meter to the push pin. Now that you have established the voltages are good from your PS, take three different colored markers (preferably fine tipped). Begin by tracing the path of your high voltage trace all the way to the tube. Then do the same for your filament voltages. If I remember correctly, this should be around 6.3v on this tube. Note that the 6.3v should be AC, so you may need to adjust your meter to establish the correct pin for these voltages. Do not start at the tube as it is much easier to make a mistake this way because you are viewing the tube upside down when you look at it.

Now that you have your traces marked for the 6.3v and the 80-100v depending on how you modded the player, trace each path with your fingers and examine each component on the board. I know this will take time, but there is probably nothing but resistors in the voltage paths. If you are not certain about the values, remove one end of the resistor carefully as not to lift the contact pads. The value is clearly marked underneath each resistor. If you ohm the entire voltage path out and the values are all correct then you will need to either change tubes to see if they are the culprit, or begin to examine the signal path for bad components. Take your time, and have fun with this

If you are anything like me, you are about to toss the player out the window!

I hope this advice helps you to take a step back and learn instead of troubleshooting by changing parts. Not that resistors are expensive, but you can sometimes do more damage than good by swapping parts out.

Blair