Raspy sounds etc

[chrisspencer]

Well I finished my Mission 5e3 and all seemed to be going well until tonight...
When I plugged in tonight the tone sounded very harsh, and quite hard to get a bright cleanish sound...
chords sound raspy/hard, bass distorted...if I play an open E hard the sound appears to fade in and out very slightly, and very little "nice sustain" so guess its the meter and soldering iron out for the weekend.
I guess what i'm looking for are some pointers, does this sound like a dry joint/loose joint, the voltage did seem a little on the high side, but a zenner in the B+ sorted them out.
I havent re checked them yet, but will do that before I start poking about :-)
and it sounded sooooo good before this...
Actually I did recall that the volume seemed to fade a little when I first turned it on....ho-hum

[daz]

I'm no expert to say the least, but I would definatly bypass that zeener before i looked at anything else. You seemed to suggest it was after that went in that it started this, and it does sound like it could cause what you described.

[Jag]

It could be that signal isn't getting to one of the two output tubes. If the amp sounds good at low to mid volume and starts to get ugly when you start to wind it out, look for a tube not seated properly, or loose connections on the socket or bad connection feeding to/from it.

[chrisspencer]

I added the zener a few days back, and it hass been ok until tonight.
Tried removing it, but makes no difference...here are the voltages with the zener in place

EH6V6 GT's...
Plates are both 364V, grid is 319V & cathode is 20V

V1 EH 12AY7
1=121V
3=1.90V
6=122V

V2 12AX7
1=154 V
3=1.2 V
6=194V
8=44V


Rectifier NOS 5y3gt Pin 8
367v
checked for bad joints...prodded about with the "chopstick" seems ok,
One thing I noticed, and this might be a regular thing is if I try to wiggle the 12AY7 it crackles a little bit...the 12AX7 does not.

the sound is deffo not right, if I have Volume 1 about 11, Volume 2 about 8, tone 7-8 if I "pluck a bass note, the sound seems to compress/distort before coming back up...and thats with a strat, single coil, volume 5-7...
certainly sounded better yesterday....

[chrisspencer]

thanks Jag...but it's at all volumes
if I tap pin 2 V1 with a chopstick it crackles, will re-do the joint...

[chrisspencer]

Looks like my weber 12s Alnico is U/S
Tried a celestion and althought I dont like the tone, the distortion/rasp has gone
Tried the weber in a champ, and its still there...