Burned up my first set of tubes yesterday

pjdami

I was messing around yesterday in the living room listening to different gear and after a while I noticed the distortion levels going up on the LSi 15s. I was like "great what now?" My first guess was that it sounded like the cd player, which is a Jolida tube output cdp. Fortunately, I had a pair of spare SED 12AX7s laying around and after I swapped them out all is good again. I asked the dealer if leaving the unit in "standby" would burn up the tubes and he said no. Well, I started to put the finger to the calculator and the tubes had roughly 5,000 hrs on them. Perhaps a bad batch? or perhaps that was just their useful life?

Everybody's talking about these EH 12AX7 tubes now. Might put in an order for them.

And no more standby mode for me either!

Paul

mantis

12ax7 tubes are common used preamp tubes.

When I used to play guitar,all my Fender amps used them.

they don't last that long.I used to retube my amps once a year.

Dan

organ

Ouch. Good thing you had a spare lying around. I also heard great things about the EH. I have their 12AU7 and they sound damn good. So far my experience with EH is great. IMO, they're the best bang for the buck when it comes to current production tubes. After reading a lot of posts at the asylum, most members say NOS will last a lot longer.

It might not be a good idea to turn off the CD player instead of leaving it on 'standby'. If your CD player doesn't have a 'soft start', it will kill your tubes faster than leaving it on standby. If your warranty is over, you can get a technician to install a 'soft start'.

Maurice

pjdami

Maurice,

I'll take your advice on the "standby" mode. Probably better to do that than to cycle the tubes every day from a cold start.

$20 bucks for a matched pair of SED tubes every 6 months isn't too bad.... although I was expecting them to last longer than that. I'm still debating what to get as my next spare set.

RuSsMaN

You should get 8000-10000 hrs on the ECC81,82,83's.... (at,au,ax).

Suprised to see them used as output tubes though. Try some Russians, they'll have a darker, lush sound to them. Not for everyone, but I dig em'.

Cheers,
Russ

organ

Paul,
That's what the technician I talked to recommended. He said a 'soft start' is a must when you have SS rectification. I'm going to get a soft start on my ASL after I get it fixed.

Russ,
The SED are Russians. I think Paul likes them the most too. We both felt that the SED 12AX7 have the darkest and warmest sound. Did you get to play around with some AX7 on your Radii?

Maurice

pjdami

The SED are Russians. I think Paul likes them the most too. We both felt that the SED 12AX7 have the darkest and warmest sound.

Yeah, SED and Svetlana are the same Russian company. Something about legal rights to the name in the US that caused the SED label. I think that's over now though right?

I do like the SEDs but my mood may be changing. I have the Sovtek 12AX7LPS that I also find to be more exciting in the treble extension.

I can get some NOS Brimars or Mullards 12AX7s for the same price that I'm itching to try out. What do you think Maurice?

Hmmm some Sylvania NOS 1961 Air Force 12AX7s I eying down too.

organ

Reflektor owns the rights to the Svetlana name now. Reflektor makes Sovtek and Electro Harmonix.

I agree with you on the Sovtek. I heard the same thing. I can't say I hear a difference with their X7LPS and 5751 though. The 5751 is an X7 substitute with a slightly lower voltage and gain. They also look identical.

Are you saying you can get those NOS for the same price as SED???? Never had experience with Brimar or Sylvania but the Mullard 12AU7 are my favorite for the ASL. They have the warmth, dynamics, bass and punch all in one package. If you could get a good deal on them, go for it. If you don't like them, you can sell them for whatever price you paid. So far, when it comes to signal tubes, I find NOS to sound better.

Maurice

organ

Forgot to mention this but it seems like the Mullards I own have this very interesting characteristic they add to the sound. They have a 'wet' and 'splashy' sound that I love. I haven't heard this sound on any other 12AU7 tubes I own. I'm sure their 12AX7 should have the same sound signature.

Maurice

pjdami

Are you saying you can get those NOS for the same price as SED????

Man I wish. LOL.

I can get the Brimar or the Mullards at the same price of $100 / pair. I know kind of pricey for tubes.

The Sylvanias I can get for about $70 / pair and are supposed to work good with the Jolida cd player.

Thanks for the tip on the Mullards. Seems like they are very popular amongst the tube crowd and why I'm thinking about trying them out.

CrazyHead

EI 12AX7's are virtually indestinguisable from the famous Telefunken ECC83's as EI bought the Telefunken/Philips equipment back in the day. They are 99% of the Telefunken quality and are readily available at most reputable tube dealers. So, unless you must have NOS tubes from the 60's, these are a great buy.

I can confirm this, as I use the EI tubes in my gear. In fact, my entire 2-channel setup is EI 'cept for my MG-Head headphone amp, which uses an old Westinghouse 5751. Yes, the EL84's are EI as well.

My push-pull main amp uses EI 12AX7's, 12AT7's, and a pair of the awesome type-3 EI KT90 power tubes -- the BEST 6550 replacement money can buy. The KT90's are the best power tube ever. I can run 'em hot, hot, HOT and they don't complain a lick.

pjdami

This is the response I got from the guy who modified my Jolida cd player when I asked him about what tubes are an upgrade from the SED that he installs:

"Brimar's are my favourite in this category...the CV4004 has a special
style of construction (box anode)....$49.95 each, less 10%. They are
a 10,000 hour (double life tube), made specially for low noise and microphonics."

The Ei Yugo I have heard great things about too although the stories have been mixed. If you get a pair that test and last then they are sweet like you mention. These are supposed replicates of the "flat plate" Telefunken that you mention. I am looking for a little more sparkle than what I am getting with the SEDs (which are warm and have nice midrange).

I'll probably put in an order for the Yugos right now; will think about the Brimars some more.

Paul

RuSsMaN

On the 12ax/u7's, I've toyed with Sovtek, JJ Tesla, Mullards, Rca Black and Grey plates, some NOS GE, and Telefunken Smooth Plates.

I think I have an old Heathkit preamp with Telefunken smooth plates in it. If either of you guys would like to check them out, I'll happily forward them on.

I have a lot of weird ones too, Executone, Conn etc. The Sovtek seem to be the best 'all around', at least in the gear I had.

Cheers,
Russ

gidrah

Crazyhead? Welcome back. You're probably the member that turned me to tubes the most.

pjdami

Actually Russ you just gave me an idea; I will temporarily "rob" the Sovtek 12AX7s from my tube amp to try out on the cd player. Just got to find a screwdriver now.....

Hmmm... I've been thinking about a tube pre w/ SS amp as my next adventure as well.

P.

CrazyHead

Originally posted by gidrah
Crazyhead? Welcome back. You're probably the member that turned me to tubes the most.

Yeah, it's been quite a while since I've been here. I totally forgot about the joint until yesterday. I pretty much built up my system and was happy with it, so there was not much reason to float around the forums much. My first generation LSi9's are still going great (I read a post wherein it was disclosed that they've changed the design of the speaker cabinet a bit and have moved production to red China).

I am surprised to see that this forum has as many higher-end types as it does. When I was here last, it was mostly people with Sony and JVC amps from their local mega store. I am seeing a lot of tube talk now and that's pretty damn cool! Tube stuff is really starting to catch on.

Nice to see some of the old folks are still around. Hope my postings didn't result in an empty wallet.

pjdami

I like the way the Sovtek 12AX7LPS sound in my Jolida cdp. Kind of gives it that sparkle that I was looking for. I preferred these over the SEDs in my Rogue amp as well for the same reason.

I went ahead and ordered another pair of Sovteks and a pair of the gold pin Ei Yugos to try out for now.

Will let ya'll know what I think of the Yugos.

Paul

organ

Russ,
Damn dude, you got to play with some of the best tubes from the old days.

Do you know who made those Conn tubes? I got 4 of those from the batch you sent me. I hear they're re-labelled but can't find out who made them.

Paul,
The Yugos are nice tubes. I have their regular 12AX7 not the 'Elite' version. Both are copies of the flat plate Telefunken. I felt the Sovtek had more dynamics but the Ei sounded 'rounder' and more robust in the mids. I'm sure the 'elite' stuff should be similar. Let us know how it turns out.

Maurice

gidrah

Originally posted by organ
.

Do you know who made those Conn tubes? I got 4 of those from the batch you sent me. I hear they're re-labelled but can't find out who made them.
Maurice

I know RCA made some for Conn.

RuSsMaN

That's what I thought Mark.

organ

Now that's great news. Thanks guys.

Maurice

pjdami

shoot. i clean forgot about that goodie bag.. LOL.. I remember some Conns in there too...

Where did I put that bag???

pjdami

Another question for ya'll. Do you guys own a tube tester? I'm hating the day my tube amp will go bad with the tubes. At this point it will be a matter of trial and error for me to find out which tubes crapped out. Of course I'm expecting the power tubes to go first.

organ

The Conn tubes I got are 12AU7. Better check your stash. Maybe you have some 12AX7 in there.

Maurice

organ

I think Tour2ma owns a tube tester. You can find them on ebay. You really need to becareful with them. They're all pretty old and will need re-calibration or you could get a wrong reading.

Maurice