Completed sex kit: No sound from right channel

[mpent]

Hmmmm...I did receive the C4S upgrade but did not open it. I guess I should open it up and see if the 1270 is in there. So overall, will resoldering the pins you mentioned and putting in the proper resistor at pin 6 rectify my issue?

[mpent]

So the C4S parts pack does not have the 1.27k resistor in there and what was supposed to have been stocked in the sex kit were 2 237ohm resistors. I need to obtain these to swap them out. But Paul, the parts list for the C4s upgrade does not contain 237 ohm resistors just 499ohm and 150kohm resistors so I'm confused.

[mpent]

Ok. I'm an idiot. I have the 1.27 resistors. I put them at the wrong terminal. Instead of the 249's I got 237's but Dan says that's fine. So I have to swap places with the 1.27 and 237.

[Doc B.]

I misunderstood you on the phone. The 237 ohm resistors are very different than the 249K ohm resistors. We will send replacements for both.

[mpent]

Oh, ok. Thank you much!

[Paul Joppa]

Apologies for my confusion - too many kits and versions, so I mis-remember the values.

There is a 220 ohm grid stopper at pin 4 on the circuit, which has (I think) been replaced with the 237 since we have a large number of them on hand for many kits.

There is a 150K 2-watt resistor on pin 5; it's larger than the others.

There is a 1270 on pin 6.

The C4S kit has 499 ohm resistors and 150K 2-watt resistors - yes, a second set of the latter - it's easier than trying to re-use the old ones!

[mpent]

Ok, so I got replacement resistors coming in the mail. That being said, is it possible that once the out of spec voltages are corrected that my issue of no second channel and scratchy left channel will be resolved?

[Paul Joppa]

So far we have addressed one channel's driver, pins B4-5-6. There are probably similar problems with A4-5-6 - at least the wrong 1270 ohm resistor. I can't figure out why the plate voltage A6 is correct but the cathode A5 is not, so check and fix all those resistors and we'll see what problems remain.

[mpent]

Ok, sounds good. Thanks again!

[mpent]

Ok. Corrected placement of 1.27 resistors and installed 249ohm resistors. Went back through resistances and voltages out of spec and everything now within range. Left channel seems to be working properly. Output is clear and strong.

However, still no sound from right channel. Checked wiring at output transformers. Resoldered some connections at transformers and headphone jack but still nothing. Removed left channel from operation and turned volume all the way up and right channel has very dim, scratchy sound. Any guidance would be greatly appreciated.

Michael

[Paul Joppa]

If the voltages on the tube pins are within the normal range, then the tubes are working correctly and the problem is at either the input or the output.

With gain all the way down, listen very closely (headphones are easier to hear with if you have some; otherwise put your ear right at the speaker, in a quiet room if necessary). If both channels produce the same tiny level of hiss and hum, then the problem is probably at the input or gain control. If you can hear some left channel but the right is completely silent, then it is at the output or the output transformers.

[mpent]

Ok....slight hiss (wow this amp is quiet) in both speakers.

[Doc B.]

Check your input jacks for a solder bridge from the center post to the outer shell.

[mpent]

Yahooooooooooooo!!!!!! That did the trick!!!!!! I sured up the jacks with additional solder.  Thank you so much for all your assistance and patience!!!

[Doc B.]

Excellent! Enjoy!