EVH 5150 50w el34, help not sure if it's me or issue with amp.

[chillytouch]

Hi,

Sorry this may be a dumb question but I am right at the 30 day period so I'm getting a little nervous.

I bought this amp used from my local shop. It's in very good shape. It was manufactured beginning of this year based on SN.

Anyway, I noticed that on the blue channel which is the medium gain/rhythm channel, the sound fades quite fast. For instance if I tap a harmonic on my guitar, the sound rings, then just fades out super fast. I have a reverb pedal on and the red channel isnt like this at all. It sounds off and sustains.

But on the blue my guitar and tone knobs are at 10, and regardless of the amp knobs, it just fades out super fast.

It basically sounds like I have a noise gate in front of the amp and the decay is super fast.

Is this possibly an issue with the amp or just kinda normal for a crunch channel?

[JMP/HBE]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

I wouldn't expect perfection from a mass produced amp from Mexico or wherever they're made this month.

Might try swapping some preamps tubes with known good tubes.

[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

From my experience, sound fading out has been mainly caused by tube issues. I would look to see which pre Amp tube is assigned to the channel you're having issues with and swap that one out. If you have an extra good tube, you can start placing it in different positions and seeing if it makes a difference.

Do you know how old the tubes are?

I've also had to fix cold and/or cracked solder joints on the tube sockets on 2 different amps. It was by far the worst with EL84's (those suckers are HOT) but had it on an EL34 Amp as well.

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[jeremy]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

did you get it from a local shop? id bring em in and have them give it a once over

[Van Noord]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Locate the tube schematic and isolate Channel 2 preamp tube designations, then start swapping with a known good preamp tube.

[chillytouch]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Locate the tube schematic and isolate Channel 2 preamp tube designations, then start swapping with a known good preamp tube.

So a couple things. First, I don't know how to do the maintenace myself (like swapping and stuff) I dont want to electricute myself lol.

Also,

I just had an instance where I was using the red channel (channel 3) and the volume dropped for like 2 minutes. I thought it was my hearing going bad but then 2 minutes later the volume just blasted back up.

Should I just retube everything?

The biggest problem is, this seems to be intermittent, so if I bring it to the shop it's gonna suck cause they aren't going to be able to reproduce it then i'm screwed lol.

Since I bought it used I honestly have no problem spending the $$ on all new tubes if it will fix it, I'm just not 100% sure which ones to get/how many.

[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Here's a chart of the tubes. Since it's happening with more than one channel now, you might look at power tubes and phase inverter first.

When you bought it, did they tell you how old the tubes were? You may be able to get the shop to throw in some new tubes. They would probably look at the tubes first anyways. It might not hurt to talk to them about it.

Every amp has a different design, so tubes react differently in different designs. I had a preamp tube that caused no sound in a Jet City and volume changes and popping noises in a Laney.

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[Lake Placid Blues]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

To test for a bad preamp tube you only need one additional 12AX7-as long as it's a known good tube. You then swap it in place of the other preamp tubes one at a time. If the amp sounds right after swapping out a particular tube then you have found the bad tube. It's unlikely that there will be more than one faulty tube in an amp at any given time. This is relatively easy and safe to do.

[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

In looking at the tube diagram, V1 could be a good place to start. It is 1/2 Ch. 1, all channel 2, and 1/2 channel 3. This could explain why Channel 2 is worst and now it's affecting Channel 3. Channel 1 may not be affected as much due to less gain on that channel. Just a theory based on my logic/my 2 cents.

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[Lake Placid Blues]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Unless this is the only 5153 around locally why mess around with a particular amp that may not be working properly? Have them get you one that does work properly. If possible compare it to another 5153.

[chillytouch]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Unless this is the only 5153 around locally why mess around with a particular amp that may not be working properly? Have them get you one that does work properly. If possible compare it to another 5153.

It's because I bought it used and I just went past the 30 day warranty they give you on used gear. Also, if I bring it to them and they test it and the problem doesnt replicate itself when they test it for like 2 minutes, it's not gonna matter. I will call them tomorrow though and explain the situation.

Can I just tell them hey I'll pay can you just please replace the preamp tubes?

[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Don't pay anyone to put tubes in. They just press into a socket. It's as easy as changing a light bulb...instead of screwing them in, you just pull the old ones out and press the new ones in.

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[chillytouch]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

Don't pay anyone to put tubes in. They just press into a socket. It's as easy as changing a light bulb...instead of screwing them in, you just pull the old ones out and press the new ones in.

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So theres no chance I can electrocute myself if its unplugged? Forgive my ignorance I just read a lot of stuff on the web about how they hold charges and people have died from it even unplugged.

If that's the case I'll just get a full tube replacement set and do it myself. Cant hurt to make everything fresh right?

Only problem is I cant find the set for the el34s, only the 6l6s

[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

The risk is if you are working on the internal components and a capacitor inside holds a charge, the charge can be released and is dangerous.

You are not handling capacitors or internal components. Tube changes are normal and expected of owners of tube amps. In fact, tube amp manufacturers have instructions to change them whereas they do not have the same instructions for working on the internals.

Bottom line, turn off the amp and you'll be fine. BTW, turning off the amp to change tubes is probably more for the safety of the amp rather than for you.

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[aiaosu]

Re: EVH 5150 50w el34, help not sure if it's me or issue with amp.

https://www.eurotubes.com/store/pc/Fender-EVH-5150-III-50W-Stealth-EL34-Standard-Retube-Kit-p2873.htm

https://reverb.com/item/24811252-jj-electronic-evh-5150iii-50w-head-new-premium-jj-electronic-full-tube-replace-set?gclid=Cj0KCQiAq97uBRCwARIsADTziyZ1XL50bJjXnp4ZEqqMxkuOnRVEergmvIBPFMtg7xHIaWiVMzw6SPoaAt3LEALw_wcB&merchant_id=136124659&pla=1&utm_campaign=2068628530&utm_medium=cpc&utm_source=google

Or, you can just order the tubes you need on Amazon. You can order a set of 12ax7s and the EL34's separately.

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