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I assume I can pull the 4 front screws to do that?
Speaking of contrarians. Mk VII owners; can you try something for me? Power tubes problem?
- Thread starter JT
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Yep
TSJMajesty
Rock Star
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Oh, so you "can" get them out, but it's not as easy to see what you're doing when aligning the key of the tubes, putting them back in?
Why not stick your phone in there, and take a pic, so you can see where that tab/key is located, then when you reinstall the tubes, you can hold that key in the right position. Just trying to think of a way you can keep that chassis in there, so you can swap tubes, and fire it up right away to see if it solves the issue.
Why not stick your phone in there, and take a pic, so you can see where that tab/key is located, then when you reinstall the tubes, you can hold that key in the right position. Just trying to think of a way you can keep that chassis in there, so you can swap tubes, and fire it up right away to see if it solves the issue.
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TSJMajesty
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You'll be fine. Something tells me this ain't your first rodeo.Thanks!
Got the 2 center tubes out now. We'll see how it goes
Pre amp is quieter on 3, poweramp louder….I’d navigate on the assumption it’s “as designed…and I’ll eat my shoe if there’s some sort of issue causing this.
Desertdweller
Roadie
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I haven't checked but you might be able to get to the 12ax7 you need through the front.
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I think you are 100% on the money. I went through each preamp tube. No matter what; it worked that way.
The only way to test this as an owner would be using the FX send to something else and tap it there. My issues with the stomp volumes on channel 3 appeared at the send out on the Stomp which would be that send tap from the amp itself. It has got be designed this way. If you put something in the loop of the VII and go from that multifx/whatever back to the VII's return; the channel volumes are as they should be. It's only if you tap channel 3 at the amps send that you get that volume discrepancy. What an odd design choice.
James Freeman
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Why pull tubes before understanding how the loop works?
The Master on each channel work as either Send or Return volume controls, they are either before or after the loop.
The JP2C had an official FX Loop revision where they moved only Channel 1 Master after the fx loop.
This could be different on the VII.
You want to check if the Master volumes on each channel are before or after the Loop,
Plug your guitar into the FX Retrun and check if the Master of each channel controls the volume after the loop.
This is suggested in the link below by MESA.
*Start with all master volumes on 0 to not blow anything.
Official loop update info:
The Master on each channel work as either Send or Return volume controls, they are either before or after the loop.
The JP2C had an official FX Loop revision where they moved only Channel 1 Master after the fx loop.
This could be different on the VII.
You want to check if the Master volumes on each channel are before or after the Loop,
Plug your guitar into the FX Retrun and check if the Master of each channel controls the volume after the loop.
This is suggested in the link below by MESA.
*Start with all master volumes on 0 to not blow anything.
Source
Official loop update info:
Yeah…seems to me no problem as long as you don’t insert other amplification methods in the loop. Adding a 2nd amp for a stereo setup would come with some complications to tackle.
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PBGas
Roadie
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Just tried. Ran mine into the H90 and out to the KSRPA50 to cab.
They are pretty close as it not that much change in volume that I could detect. Very slight if anything.
Now as far as changing tubes goes....this is why I bought the rack versions for both amps. 4 screws, slide the chassis out and off you go!
They are pretty close as it not that much change in volume that I could detect. Very slight if anything.
Now as far as changing tubes goes....this is why I bought the rack versions for both amps. 4 screws, slide the chassis out and off you go!
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Thanks for checking! There's a very noticeable dip in mine. I'm not planning on running it in this manner so I'll probably just deal with it as is
One of the few things in life we can 100% rely onIf there's a complication; I'll certainly find it
Did you try the amp upside down yet?
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Message Mesa at least.Thanks for checking! There's a very noticeable dip in mine. I'm not planning on running it in this manner so I'll probably just deal with it as is
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I will next week.
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This is (as I expected) how it works. Straight in to fx return and channel master is volume control. And doesn't explain why the preamp volumes are so different. Contacting my sales rep tomorrow.
la szum
Goatlord
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Other than times like this; I like the small headshell. I might be able to get the power tubes out as the cage has just enough clearance. I don't trust the ability to dig around on the preamp tubes side though and then get the pins back in correctly with that limited visibility and space to move. Reading the tube layout isn't really any clearer than talking it out here either
Holy 20 pounds of shit in a 10 pound sack!!
MCII KT150
Groupie
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Didn't think they could cram much more in after the MKIV.
Don't care for the ribbon cables in the JP2C. But more MFr's seem to be using them.
I'll post gut shots of my MKV, MKVII, MKI, MKIIC+ if I ever get them uploaded.
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The TA-30 is similarly quirky, in that channel 1 has Master Volume post-FX loop and channel 2 has Master volume pre-FX loop. Meaning, if you're running 4cm on channel 2 and you accidentally pull the Mesa preamp out of the equation, you're (very suddenly) getting the entire power amp blowing your hair back. (In my case, all that's required is for my HX Stomp to run out of battery power.
)If you're dealing with a similar issue, then diming the Master Volumes on the MkVII should (approximately) normalize the preamp outputs across all three channels.
