Need help with .50 Cal +

[markblasco]

I purchased a .50 Cal + from guitar center yesterday, and I have a week to decide if I am going to keep it or not. I need some help with the following issues:

1. The clean channel has a sort of crackle and pop sound in the background. It seems to get quieter if I turn the gain all the way up. This sound happens even if I don't have anything plugged into the amp. I haven't noticed it on the lead channel.

2. When I switch from the lead channel back to the clean channel it gets really loud for about 1/10 of a second. I don't notice this when switching back to the lead channel. This happens with the footswitch and with the pull out control.

3. The presence control does not seem to do anything.

4. The sound seems quite "buzzy" when distorted. I don't know if this is how it is supposed to sound or if there is something wrong with it.


I am new to tube amps, and would love to know if I just need to put new tubes into the amp to fix these problems. Any advice would be greatly appreciated.

 

[jukesgtr]

I purchased a .50 Cal + from guitar center yesterday, and I have a week to decide if I am going to keep it or not. I need some help with the following issues:

1. The clean channel has a sort of crackle and pop sound in the background. It seems to get quieter if I turn the gain all the way up. This sound happens even if I don't have anything plugged into the amp. I haven't noticed it on the lead channel.

2. When I switch from the lead channel back to the clean channel it gets really loud for about 1/10 of a second. I don't notice this when switching back to the lead channel. This happens with the footswitch and with the pull out control.

3. The presence control does not seem to do anything.

4. The sound seems quite "buzzy" when distorted. I don't know if this is how it is supposed to sound or if there is something wrong with it.


I am new to tube amps, and would love to know if I just need to put new tubes into the amp to fix these problems. Any advice would be greatly appreciated.

If this is a new amp I would take it back for warranty service or exchange.

 

[markblasco]

The amp is old. I think they stopped making them in the early 90's. I just don't know enough about tube amps to know if these are all signs of the tubes needing to be replaced, or something else that would require repair.

 

[jukesgtr]

I am new to Mesas too so I don't really know which models are discontinued etc.

This may be preamp tubes or other components in the preamp area if the lead channel does not do that crackling. Tap the small (preamp tubes) with a pencil, is there more crackling noise? Tap also the bigger power tubes, you may find bad one(s).

Does the lead channel sound good and not "buzzy"?

That 1/10 sec loud is not a "pop" but the channel volume just increases when you play and switch to clean channel?

Thew presence pot probably is broken. I may sound silly (again) but you might want to spray all pots and tube sockets with a contact cleaner just to eliminate some potential problem sources.

 

[LHanson]

.50 cals are famous for having weird volume problems, and most are tracable to the effects loop. No kidding. The jacks for the loop get corroded, and cause intermittent problems. Try plugging a patch cord across the effects loop and see if the problem goes away.

As far as the presence knob goes, mine works okay. could be a loose wire, etc.

Search this board for .50 cal, there are a few owners here.

 

[Satchie]

2. When I switch from the lead channel back to the clean channel it gets really loud for about 1/10 of a second. I don't notice this when switching back to the lead channel. This happens with the footswitch and with the pull out control.

Same problem with my caliber 50. In your place I would take it back. The biggest minus with caliber 50 to me is that clean and lead channel have the same controls. So, if you have a great clean, you have bad distortion and vice versa. This is not a problem with Dual Caliber series, since there are sepperate controls for each channel.