NOAD, and a few questions.

[gottalovethe80s]

So last week I got a great deal on this neat little amp: A 1980s guyatone H&M 30 celestion, for like 85$ shipped. The amp is loaded with a 12ax7 tube and a celestion G8L-35. After a whole week of waiting for the delivery guy, the amp finally arrived and I was eager to plug it in. I was glad to find that the amp is in good shape, all the functions work properly, but the sound was really muddy. Considering how I bought it from a guy who bulk-imports used amps from Japan and how old this amp is, I suspected a bad tube to be the cause of the problem. The 12ax7 that came with the amp had no marking on it to indicate the brand and barely even lit up when I turn the amp on. There is no local shop that sells tubes where I live so I temporarily swapped out the nameless tube for an old mesa 12ax7 my friend had lying arround. Now the amp sounds better, the clean channel is gorgeous but on the dirty channel the gain is fizzy and not pronounced, like the amp was being covered with the blanket.

I'm going to order a new tube to replace the old mesa 12ax7, will this solve my problem? and what 12ax7 tube would you guys recommend for a crunchy 80s hardrock sound?
Also the seller added a little transformer as the voltage here in Vietnam is different to Japan's, will the transformer affect how the amp sounds?

 

[Edgecrusher]

Re: NOAD, and a few questions.

The transformer shouldnt be a huge issue as long as everything matches. I know japan is 100 volts and depending on east or west either 50 or 60hz. As for the tube curing your issue... no idea as the amp might just sound like that.. another possibility is that the amp is old enough that the caps arent pulling their weight anymore and making it muddier. The only way to know for sure would be to have a tech bench it.

Different tube brands wont make like worlds of difference, there is no "80's" sound tube. Some are a bit brighter some are bassier. What you describe I would be tempted to use a 5751 for a touch less gain to see if you can clear up some of the mud but its not a guarantee it depends on whats causing it.

 

[zzmoore]

Re: NOAD, and a few questions.

Pretty solid advice above ^^^^^^^
I can see where the OD Channel would be "fizzy"...that is a common complaint. But not so with it sounding like it has a blanket over the speaker.
You may want to play with the knobs when the OD is engaged. Especially make sure the treble boost is not engaged while the OD is.
Does this amp have a Solid State power amp.?
It could be 100 different things.....including a Bad/Drifted component that is causing attenuation when the OD is pulled.
good luck