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ADA MP2 No Cleans from Stage Output B

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Hanneman213:
I don't have engineering skills or fixing experiences, I just plug, set and play. I realized that no clean tones coming from Output B, Just Crunches. And another issue that sometimes a radio-frequency search sound (I didn't know,else how to describe it) comes, the sound Increases a few seconds, becoming bright and later decreases.
Do they Seem like tube problem ? It has Marshalls on it, when I bought it from someone 3 years ago. And I dont know its replacing date. It's obvious that to try with different tubes but that means buying it 2 times expensive than european prices in my country.

rnolan:
Hey Hanneman213, did you ever get your wah/comp issues sorted ? IIRC that was back in 2015.

Just to confirm I understand correctly, it doesn't matter what patch voice etc you select, stage output B just has crunch like sounds, no proper signal ?  What happens with the B cab sim out ?, does it work or make the same sound.  Fx loop B send should also have decent signal (level will be affected by level buttons setting) but loop A and B sends should both sound similar (clean "signal" tone).  So you can test those 2 outputs.  I don't think this issue is tube related as the tube/gain stage is before the signal is split into A & B.  Have a look in the front of the MP2 manual (page 4), the schematic there is reasonably easy to understand and you can see where the signal splits (after eq & noise gate).  The signal splits into (pseudo) stereo at the chorus (whether it's on/in or off/out), basically the B signal is the A signal inverted.  So the first place the B signal is available is at Fx loop B send jack (which should have signal regardless if the loop is on or off). But with chorus out/off, the B signal is still made by the chorus (the chorus circuit/chip inverts the A signal).

When the radio tune noise comes and then decreases, does it go away after a little time ?  This is sounding like a capacitor dying, my guess, getting better as it warms up ??.  But could be tube related.

The tubes probably need changing regardless and "may" fix the radio tune noise  :dunno: .  But changing them won't hurt anything and will make your MP2 sound better.  The Marshall tubes are re-badged/branded, they don't make their own.  I think they use Chinese tubes and paint their logo on them.
What county are you in ? can you buy tubes online from the US or Australia (or do you have import tax/restrictions) ?  Also European tube prices seem to be higher than US and Australia from what I've seen.  If you can buy tubes online, then I'd buy a pair of New Sensor 12AX7 Long Plate Mullard re-issues from Dougs Tubes.  These are the tubes I use in all 4 of my MP2s because they work so well in MP2.  Also if you buy them from Dougs, they test all their tubes thoroughly so the chances of a dud tube (and it does happen) are highly unlikely. (http://www.dougstubes.com/mullard-12ax7.html), there's even a review by me on there if you scroll down. And $20 USD per tube is about as good as it gets price wise.

Hanneman213:
Hello, Unfortunately I couldn't find the specific op-amp. Instead I have bought a cry baby.
And Yes, I've changed the connection from parallel to serial of My Tc Gmajor2 sometime ago, I'd forgotten to shutdown effects loop option. After I shut down it. Clean channel came back.
Baby is serene and There's no radio tune noise today :)
I have also The Ampulator.I adjusted the drive level in minimum.and tried some different Amp settings. The sound is very beautiful now.
I am from Turkey, I was thinking Mullard or Tung-sol too from the posts here. But, We have Mesa,EH,Grove, Sovtek and Tung-sol in the market. I will go for Tung-Sol I think.
I'm regretful for not buying these tubes when I saw at Guitar Center in LA, instead I gave this money to Parking Area in Universal Studios.

rnolan:
Well bummer about the op-amp but good to here the rest is working now  :thumb-up: .
Of the tubes you have easily available the only one I'd consider for MP2 is the Tung-Sol (http://www.dougstubes.com/brands/tung-sol-tubes/tung-sol-12ax7-re-issue.html), it's made by the same people as the Mullards so if you can get the Tung-Sols, they (the shop) should be able to order the Mullards.  But you should be able to just order from Dougs Tubes ??.

The Messa tubes (JJs) aren't great in MP2, I've tried them and I wasn't impressed.  I also had a MP2 come with EH tubes, worst tubes in MP2 I've heard do far.

Hanneman213:
Yes. I can order from Dougs but shipment+time+taxes will be more expensive for me. I asked any of my friends travelling to USA but non of them have on their schedule nowadays. Nevertheless I think Tung-sol will make an improvement. Next time I'll go for Mullards.
Thank You very much.

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