rteglgaa

Hi there,

I am about to buy spare tubes for my Marshall JVM410h head, and I would like to know exactly what kind of tubes is in it from the factory?

On marshall's website I can only see what KIND of tubes is in it - not what brands.

I hope someone can help me out

/Rasmus

poeman33

Does it not say the brand on them?

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Marshall JCM2000 DSL50
Avatar Vintage 4x12 cab
Fender American Deluxe HSS Strat Ash body

MartyStrat54

A lot of OE Marshall tubes are relabeled. They could be made in Russia or China. You can buy any 12AX7 type tube as a replacement for your amp. Trust me, there are a lot better tubes out there than what is in your amp right now. I mainly use New Old Stock (NOS) tubes, but there are certain current production tubes that are pretty sweet sounding.

The only warning I can give is stay away from using short plate Tung-Sol's in your Phase Inverter slot. They have been failing in this position.

Marty

__________________
MARTY

2009 Gibson Explorer-Hell Raising Machine
1989 Fender Strat Plus USA
2008 Fender Tele USA
2004 Schecter Elite w/DiMarzio's

TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers.
TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends."
DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker.

Tubes: Let's just say they are NOS that kick ass.

MonstersOfTheMidway

Hello. From what I understand, most JVM410H amps have SED Winged C ( or sometimes written out as SED =C=, as they are referring to the same brand) EL34 tubes in the power amp section and either Chinese, aka Shuguang, aka Sino preamp tubes or Electro-Harmonix preamp tubes. *If your stock preamp tubes are labeled with white marshall logo, then you probably have the Chinese preamp tubes; if your stock preamp tubes are relabeled with a red marshall logo, then you probably have Electro-Harmonix preamp tubes. I have the Chinese preamp tubes in then and they are great! They project wonderful characteristics in a high gain amp such as the JVM. The SED winged C EL34 also sound great and are very reliable (I've owned mine for over a year now and everything on it has worked great. Whether you keep it the same, choose NOS, or whatever, the choice is entirely yours, but I'd encourage you to do two things:

1. Go to the JVM forum to learn all about what others have used in their JVM and how they feel about the change (good, bad, so-so, etc. This is one of the very best ways to learn about the characteristics of different tubes in different positions. We talk a lot about different tubes and there are useful links to sound and video clips to help you hear what we are talking about there.

2. Buy a couple of different brand and try them in various positions. Position V1 is an important position since it is used in every channel and mode.

Hope this helps.

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johnnycom

Hey Marty. I recently had some problems with my JCM900 Model 4100 Dual Reverb 100 watt head and we decided I had a bad tube. My head has Sovtec 5881 power amp tubes and I bought a matched quartet of Tung Sol 5881 tubes from Musicians Friend. They were a lot shorter than the originals but the tech thought they would be OK. He put them in and turned it on to bias them and they got real hot and now the head has no output at all. Could this have blown the PT? Are these the tubes you were referring to that we should stay away from?

Thanks.

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John

Guitars:
Rockin' 1989 Fender Strat USA
Ovation Celebrity CC44S Electric Acoustic

Amps:
Marshall JCM 900 High Gain Dual Reverb
Marshall JCM 2000 DSLMLB 100
Marshall 1960B 4X12 Cab

MartyStrat54

Well I have to say that a lot of Russian tubes are relabeled many different ways. The Sovtec's you had were probably 6L6GC tubes relabeled as 5881 and that's why they were taller. A 5881 is shorter than a 6L6, so there should be no problem with the size of the tube. What this sounds like is that your tech did not lower the bias pot before turning the amp on. When the amp was turned on, the bias value was so hot all four tubes red plated. If it took out your output tranny, that's too bad, but I guess it could. This looks like a situation where the tech needs to eat some time and parts because of his f**k up. Let me know how it turns out. BTW, the Tung-Sol tubes I was talking about up there ^^^ are preamp tubes. They have nothing to do with your problem.

__________________
MARTY

2009 Gibson Explorer-Hell Raising Machine
1989 Fender Strat Plus USA
2008 Fender Tele USA
2004 Schecter Elite w/DiMarzio's

TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers.
TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends."
DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker.

Tubes: Let's just say they are NOS that kick ass.

MartyStrat54

EDIT: I realized that I made a mistake. I meant to say keep away from using short plate Tung-Sol's in V3, Tone Stack/Cathode Follower. They have been failing in this position, not V4 (PI).

__________________
MARTY

2009 Gibson Explorer-Hell Raising Machine
1989 Fender Strat Plus USA
2008 Fender Tele USA
2004 Schecter Elite w/DiMarzio's

TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers.
TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends."
DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker.

Tubes: Let's just say they are NOS that kick ass.