Okay, this is ridiculous

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Julia

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Okay, new production tubes suck. We know that. We're stuck with them unless we're rich, right?

i can't play so today I thought "you know I could reamp this part." So I got set up to reamp. I plug direct for a sound check and strum a couple chords. This real enemic sound comes out. but then there's a pop and I get full sound, but the full sound is real distorted. I look around the backside of the amp and I see one tube failure light on and one tube on the same side is right on the verge of redplating.

Simple right. Replace the fuse and bad tubes. Wrong. The bad fuse actually shattered inside the enclosure. I can't get part of it out. There's small glass shards everywhere and I can see the other part of the fuse jammed into the back of the slot. Which means me with my bad hands has to remove this amp from the chassis to get that piece out or pay some amp tech to do it. Any suggestions here would be welcome.

I am getting real tired of tube amps. They may sound good but they are expensive to maintain. My Marshall JVM ate power tubes for its mid-morning snack -- it went through 5 sets in 5 months. That's right folks, 5 matched quads. The first set lasted 92 days -- just enough to go out of factory warranty on the tubes.

Last week my Hot Rod Deville ate a pair, but at least the 6L6s had lasted a year, but I think one tube took out something else since a simple replacement didn't fix it -- no drive channel, not that I ever use it, but it should work. I'll check the preamp tubes.

Today, the Lynch Box ate the EL34Ls. 14 weeks. 14 weeks on a set of tubes.

I'm wondering if I should see if I can find a variac and drop my line voltage to the amps by about 5 to 10 volts. It measures 122 V.

I am seriously disgusted.

Do you know how much money this has been? And now I'm going to have to cover out of pocket expenses for hand surgery???

I'm going to try and run it at 50W with the two remaining tubes in the center slots. I'll bias dead cold say around 33 to 35 mV for the EL34L. but I need to know where to set the speaker impedence for a single 212 8 ohm cab.

Remind me to go solid state or the AXE next time with a SS PA monitor.
 
wow that sucks .

.FWIW .I do believe that the EL34's are very bad right now .

Jeff from Egnater recently posted on here about tube failure and further damages caused to the amps .. He said that almost every single failure was caused by 34's in the power section .

you may want to consider Kt77 ,6l6 ,5881 ..I know I love the 34's but they seem more trouble than they are worth at the moment
 
Kevin O'Connor was bitching about EL34s in his books, written in the 90s. It seems that EL34s aren't the most stable tubes in the world anyways.

I had one blow in my roadster and take out a grid resistor a few months ago. Thank god it was last song of the night. If the Roadster had the MTS fuse setup I wouldn't have had to drop the freakin' chassis to replace the resistor either.
 
Make sure you bias correctly per the manual. Bias to hot and the tube life will be very short.
 
Nobody would happen to know what the most reliable companies to get EL34s from are, would they? I intend to get some from Tung Sol pretty soon, or maybe EHX.
 
Shinozoku said:
Nobody would happen to know what the most reliable companies to get EL34s from are, would they? I intend to get some from Tung Sol pretty soon, or maybe EHX.
http://www.tubedepot.com/
 
Bronco said:
Shinozoku said:
Nobody would happen to know what the most reliable companies to get EL34s from are, would they? I intend to get some from Tung Sol pretty soon, or maybe EHX.
http://www.tubedepot.com/
I was referring to makers, not sellers :p
 
Shinozoku said:
Bronco said:
Shinozoku said:
Nobody would happen to know what the most reliable companies to get EL34s from are, would they? I intend to get some from Tung Sol pretty soon, or maybe EHX.
http://www.tubedepot.com/
I was referring to makers, not sellers :p
Uh huh...and I was suggesting you ask them... :shock:
 
ned said:
Make sure you bias correctly per the manual. Bias to hot and the tube life will be very short.

5881s take 28 mV to 35 mV according to the manual.

I'm intending around 27.5 to 28.5 mV or as some people call it "dead cold".

I'll see what Guitar Center has in stock locally. I know like Ruby Tubes or Groove Tubes have a warranty on them. Ruby's 6 months. They cost more but....
 
I picked up the Tung Sol small bottle 5881s...people said I was mad when I preferred 'em at 26-28mV....but hotter not so much...30 was OK...32 (traditional 6L6 setting)..the sound got less focussed..
 
cowardm said:
what's wrong with your hand?

DeQuervain's syndrome and Ulnar Tunnel Syndrome on my left hand. I've got an appointment to see a surgeon on Thursday.

I have small wrists. The cubital tunnel (thumb) is too small and it causes pain when stressed. The carpal tunnel (fingers 1&2) is affected but not as bad. The ulnar tunnel (fingers 3&4) is in sad shape.

I decided I want this surgically repaired. The tunnels need to be enlarged or cut open. Physical/hand therapy does nothing but cost money.
 
JKD said:
I picked up the Tung Sol small bottle 5881s...people said I was mad when I preferred 'em at 26-28mV....but hotter not so much...30 was OK...32 (traditional 6L6 setting)..the sound got less focused..

People say a lot of things. It seems to be in vogue to bias way too hot these days anyway. I'm biasing on the cold side like around the minimum range for the tubes from here on.
 
Okay I got lucky. It doesn't appear like anything went inside the amp.

* I couldn't find any 400 mA fast blo fuses in that size.... anywhere. so I stuck a 500 mA fast blo in

* I have three used SED =C= EL34s from my JVM I put them the two slots that had the bad tubes.

* I turned the amp on and watched it for 15 minutes. No problems.

* I swapped the outer EL34L with the inner EL34 so that I had a pair of EL34Ls working together and a set of EL34s working together.

* I adjusted the bias:

PT1 (EL34) 33.1 mV; PT4 (EL34) 33.1 mV; PT2 (EL34L) 33.2 mV; and PT3 (EL34L) 33.2 mV.

* I let this sit for about 10 minutes and rechecked for drift.

* now to play my first chords on it. Wish me luck.

UPDATE: sounds okay. I like the sound of the EL34Ls all the wy around better, but... right now I'm content it's working.
 
Bronco said:
Shinozoku said:
Bronco said:
Shinozoku said:
Nobody would happen to know what the most reliable companies to get EL34s from are, would they? I intend to get some from Tung Sol pretty soon, or maybe EHX.
http://www.tubedepot.com/
I was referring to makers, not sellers :p
Uh huh...and I was suggesting you ask them... :shock:
Oh! Okay xD Thanks :)
 
It's simple: Ruby sells JJ, Shuguang, SED, Sovtek, Svetlana, Electro Harmonix, and Tung Sols. They're re-labeled Ruby after testing and selecting. Ruby gives a 6 month warranty on their re-labeled tubes. They cost a bit more, but if they're going to last 4 months? You get free replacement tubes. With my luck, this is my choice.

Now trying to find a local dealer that sells them is another story.

Doug's tubes does sell them. Save your sales invoice.

And for general information.... here's what my bad tubes looked like:

TubeFail2.jpg


TubeFail1.jpg


These are EL34Ls and were biased at 37 mV per the manual.
 
Biasing cold (towards the low end) isn't going to hurt your amp, will make the tubes last longer and may get you closer to some amp tones like Mesa Boogies - they have ALWAYS been biased cold.

The toughest tubes I can think of offhand are Sovtek 5881WXTs. I contacted Bill Sundt at Soldano regarding what to retube my '95 SLO with - he recommended the Sovteks. They sound fine and should last forever and a day. Plus they cut power a bit, so you can crank your amp a little more and get your power tubes cooking a bit.

EL34s are just not super reliable. O'Connor shows in one of his books that the Traynor way of using EL34s made them last much longer than the Marshall way... I'll have to dig up my book one of these days and compare/contrast to the Randall stuff. Might be interesting, if the power section is more 'Marshall' styled, then converting might make the El34s last longer.

Pete
 
Julia said:
Today, the Lynch Box ate the EL34Ls. 14 weeks. 14 weeks on a set of tubes.

I'm wondering if I should see if I can find a variac and drop my line voltage to the amps by about 5 to 10 volts. It measures 122 V.

I am seriously disgusted.

I realize I'm a bit late in this thread, but are you using any power conditioner, Furman, Monster, etc?

Have you tried testing the line voltage with your rig turned on while playing? Brown outs can be just as damaging as spikes. A refrigerator, air conditioner etc on the same circuit can play havoc on your equipment.

You've probably already considered these things but I'd be remised not to point them out...

Jimmie
 
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