So the Marshall is back home

[Securb]

A couple of weeks ago, I had a couple of volume drops with the Marshall. I thought it could have been the voltage in the space. We draw a lot of current. Last week the drops became more frequent and dramatic. I will play it at home for a while to see if the behavior duplicates itself. If so, I will drag it into Boston to my tech.

In the meantime, I am playing the JC 120 and loving it. There have been no similar drops but solid-state is a different animal.

The amp has a relatively fresh set of Mullards in it, so I do not think it is the tubes. Let me know if there is anything else you think I should check before dragging it into Boston.

 

[LLL]

Power supply electrolytic caps may need replacing.

 

[LLL]

If they do, may as well replace the preamp electrolytics as well.

These are the big can caps on top of chassis (older amps sometimes had the preamp caps inside).

Tube amp electrolytics typically last 15-20 years.

 

[Securb]

I played it all afternoon and had no problems. However, I was not playing it at live/rehearsal volumes. Playing it that loud in a small room would blow my ears out.

I think one of my Furman Power Conditioners has a voltage meter on it. I need to dig it out. If so am going to drag it to practice to see if it is a voltage issue with the building.

 

[Bogner]

Wall voltage can definitely cause issues. Regarding tubes, no guarantee on them being good or lasting a certain amount of time. Some tubes also don't hold up as well as others in high plate voltage situations. I am not sure what your amps plate voltage but it is always something to be mindful of and to consider when buying new tubes. If you do indeed need caps, get everything done at once so you have a clean slate going forward.

 

[JMP/HBE]

Volume drop sounds like a bad preamp tube.
If you had a power tube problem you'd know it.

 

[Securb]

If you had a power tube problem you'd know it.

Agreed.

 

[NegativeEase]

Since you are not using it in the band and have some time -I'd swap the 12AX7s out one at a time and if the power tubes are young -just check the plate voltage bias it like a regular service.

Then if no love, change the big Paper Filter Caps and Electrolytics out.

 

[JMP/HBE]

That amp should not need a cap job.
90% of tube amp problems are tube related.

 

[Securb]

Since you are not using it in the band and have some time -I'd swap the 12AX7s out one at a time and if the power tubes are young -just check the plate voltage bias it like a regular service.

Then if no love, change the big Paper Filter Caps and Electrolytics out.

I did not change the preamp tubes when I did the Mullards. If the behavior comes back I might do this. I played the amp for a while this morning and it still seems fine.

 

[Securb]

Mystery solved. I have been using the JC 120 at practice with no problems. The Marshall has been operating perfectly at home. Last night my bass player was experiencing the same issue with volume drops. We plugged him into a different outlet across the room and the problem was solved. We were drawing too much power from the same leg of the electrical panel.

I am going to stay with the JC 120 moving forward, it just sounds soo damn good.

 

[GuitarStv]

Hah! I was wondering if it would be something like that. A couple big tube amps draw more power than you would expect . . . I once plugged my guitar amp into a place with crap wiring, turned it up, hit a loud chord and had all the light bulbs in the place burn out at the same time.

 

[JMP/HBE]

Mystery solved. I have been using the JC 120 at practice with no problems. The Marshall has been operating perfectly at home. Last night my bass player was experiencing the same issue with volume drops. We plugged him into a different outlet across the room and the problem was solved. We were drawing too much power from the same leg of the electrical panel.

I am going to stay with the JC 120 moving forward, it just sounds soo damn good.

Standard house 115VAC wiring should easily handle 2 [Amplifiers] on the same outlet as they AMPLIFY.
If you have a current draw issue there is something wonky with your house wiring cuz those 2 amps couldn't draw more than 10 amps.
Any USA house outlet up to code should easily supply 15 amps per outlet. 90 amps for the house altogether.
A Marshall with bad tubes would draw more current than its suppose to.
A house with bad wiring and excessive current draw is un-safe and could cause a fire.

 

[Securb]

Standard house 115VAC wiring should easily handle 2 [Amplifiers] on the same outlet as they AMPLIFY.
.

It isn't in a house where we had problems, this happened in our rehearsal space. The Marshall, Bassman and the PA rack were all on the circuit. The PA rack alone has a poweramp, mixer, power conditioner, delay, 31-band EQ, and a monitor mixer. We moved the Bassman to a different circuit and as I said everything seems okay.

At home, I have no problems whatsoever.

 

[JMP/HBE]

It isn't in a house where we had problems, this happened in our rehearsal space. The Marshall, Bassman and the PA rack were all on the circuit. The PA rack alone has a poweramp, mixer, power conditioner, delay, 31-band EQ, and a monitor mixer. We moved the Bassman to a different circuit and as I said everything seems okay.

At home, I have no problems whatsoever.

Sounds like your PA is eating up all the Watts.

 

[Securb]

Sounds like your PA is eating up all the Watts.

Yep, there is a lot of gear in there plus a board and a wireless monitor system.

 

[Aceman]

So - your Marshall vs the Carvin?

 

[Securb]

So - your Marshall vs the Carvin?

Too soon to tell but if I were to make a knee jerk decision I would say the Carvin. There is more flexibility with the tone. However, that could be because the Carvin is new and shiny, the flavor of the month. I need more time with the amp