Lost volume on ch 1 of 3 ch DR

[enuenu]

I have just noticed that I can get hardly any volume out of channel 1. Something is seriously wrong. It gets to bedroom volume and still sounds OK, but that is it. Channel 2 and 3 are fine. I also notice that when using channel 1 as loud as I can get it, the sustain of notes is choked off in a weird way. They sort of crumble away quickly.

I have just stopped playing and will check tubes when it cools down. I have no idea about the tech stuff so all I really know is to look at the tubes and see if they are burnt out.

Any hints appreciated.

 

[mikey383]

Swap out the 12AX7 in V1. Most likely, the half of that tube that controls the clean channel has gone bad. Half of that tube is the input stage which controls all channels, the other half is the clean channel stage.

If you don't use the effects loop at all (or the solo function) swap V1 with V4.

It's always best to keep a few spare preamp tubes on hand.

 

[enuenu]

Swap out the 12AX7 in V1. Most likely, the half of that tube that controls the clean channel has gone bad. Half of that tube is the input stage which controls all channels, the other half is the clean channel stage.

If you don't use the effects loop at all (or the solo function) swap V1 with V4.

It's always best to keep a few spare preamp tubes on hand.

Thanks, I will give it a try. Would the problem with the 12AX7 in V1 you speak of be apparent by looking at the tube?

 

[mikey383]

Nope. The only way you can visually tell a tube is bad is if the silver coating has turned chalky white. That means air has gotten into the tube and it needs replaced.

Other than that, the only way to know it's bad is to swap it out with a good one, or test it with a tube tester.

 

[enuenu]

Thanks. The Mesa Website says the SPAX7-A is better than a regular 12AX7 so I might give one a try.

 

[enuenu]

Thanks for the advice mikey383, you saved me much hassle. It was V1. I swapped it with V4 and it all worked. No visible signs of damage to the tube were apparent as you predicted.

As an aside, I have never been able to get a loud clean out of ch 1. Any real volume and you are into breakup regardless of using silicone diodes and bold power. Is this normal? Not a hassle as I bought the amp for doom tones, but am surprised at the low volume at which the clean channel begins to break up. I know little about amps so this may be the way it is. Maybe the SPAX7-A tubes improve cleans?

 

[mikey383]

Good to hear

From what I remember of having a 3 channel Triple Rec, the clean channel was low in volume compared to the other channels. It's just the nature of the beast. Swapping tubes won't help.

There is a thread though, where a guy modded his footswitch so that the solo function is on whenever channel 1 is being used (so that the clean channel volume is increased), but off on the other 2 channels, and can be switched in on those channels as well. I wish I had bookmarked that thread just for this very purpose.

 

[enuenu]

Thanks. I will have a look for the thread. However the problem I was pondering was not the fact that channel 1 is not loud enough, it is that it breaks up at quite a low volume. It doesn't stay clean much beyond a low volume regardless of settings.

I realize this is probably just how the amp is. However I was just surprised that such a powerful rig can't create a clean unbroken tone beyond such a low volume.

 

[b0nkersx]

The easy way to get a loud clean out of a DR is to hardbypass the loop so you can control the power amp volume per channel. That way you can run the gain down and turn the master knob up high on channel 1 without having to fiddle with the output knob and the masters on the other two channels.

 

[enuenu]

The easy way to get a loud clean out of a DR is to hardbypass the loop so you can control the power amp volume per channel. That way you can run the gain down and turn the master knob up high on channel 1 without having to fiddle with the output knob and the masters on the other two channels.

I take it that's a mod requiring soldering and stuff. In other words, a job for an expert.

 

[fluff191]

The easy way to get a loud clean out of a DR is to hardbypass the loop so you can control the power amp volume per channel. That way you can run the gain down and turn the master knob up high on channel 1 without having to fiddle with the output knob and the masters on the other two channels.

I take it that's a mod requiring soldering and stuff. In other words, a job for an expert.

No dude. Just turn the loop OFF in the back above where the footswitch plugs in.

 

[enuenu]

Cheers, I will read that manual again as well!