Archon 50w Pre-Amp Tube

[FatFingerBlues]

Okay my Archon 50w MKII died today
it popped went dead then came back on for a few minutes died again and isn't working currently
I spoke to the people I bought it from 9 months ago
He said it was probably a pre-Amp tube and even picked the one it was
I pulled the covers and looked, half of the first pre-amp tube is dead
so He nailed it
and I need to buy a new tube

This is new to me so I am looking for advice
The tubes are JJ ECC83S
please walk me through what I need to watch out for or buy

is it as simple as calling Sweetwater and ordering a couple of tubes and plugging in a replacement?

Also noted they are lumped together with the 12AX7 tubes
Are they the same tube or is there something I need to look out for?

 

[andy474x]

Yes, JJ ecc83s would be the direct replacement, and you can’t go wrong quality wise. Tubes go bad from time to time for all brands, but JJ are generally very reliable. Although personally I think their other 12ax7 types are slightly better - ecc803 or e83cc. Plug in and go.

 

[László]

ECC 83S, ECC 803, and E 83CC are all 12AX7s.

European tube nomenclature is different from US, but they’re all variants of the same tube. The JJs are made in Slovakia in the old Tesla tube plant I think, and IMHO are better sounding and more reliable than the Russian (or especially) the Chinese tubes.

PRS also used them in the high end CAD amps.

If you’re not into “tube rolling” experiments, you might want to stick with the factory’s choice. Doug Sewell is known to be picky about his tubes!

 

[FatFingerBlues]

Thank you for the replies

Its been an afternoon of educating myself
but I ordered a 3 pack of JJ ECC83S from Sweetwater
hopefully they will be here Saturday

I have had a tube amp since 2006 and never had to replace a tube
so the PRS at 10 months caught me off guard

 

[DreamTheaterRules]

Thank you for the replies

Its been an afternoon of educating myself
but I ordered a 3 JJ ECC83S from Sweetwater
hopefully they will be here Saturday

I have had a tube amp since 2006 and never had to replace a tube
so the PRS at 10 months caught me off guard

Tubes don't last forever. Normally they deteriorate slowly over time. So much so, that you may just some day go "my amp doesn't sound as good as it used too," throw in some new tubes and it's good as new. So sometimes they still work fine, but don't sound good anymore. But yes, sometimes they just "go" and need to be replaced immediately.

 

[László]

Essentially, tubes are like light bulbs. They’re consumables, though most preamp tubes will last for decades.

Tubes are only expensive because there’s still hand work involved in assembling the interior components due to their design, and they aren’t made in the tens of zillions any more, so there’s less economy of scale.

Modern tubes are often made using very old machines, however, and they don’t last as long as the old ones, which is one of several reasons I buy NOS tubes for the most part.

Back in the ‘60s when I was a kid, every drugstore (at least in Detroit) had part of an aisle stocked with tubes, and a tube testing machine so you could bring your tubes in to see if the problem was the tube (which you’d then replace and buy a new one) or if a different repair was needed.

Most radios, medical equipment, aircraft electronics, hi-fis and TVs were still tube devices, not just guitar amps.

But back then tubes weren’t expensive. They still failed occasionally and needed replacement.

I had a tube Heathkit radio, a tube record player, and a tube TV in my room as a kid. My family’s hi-fi rig was a Fisher tube receiver and other tube gear. The radios in our cars were tube devices until the makers switched over to transistor in the ‘60s. Remarkably, the only tube changes ever needed were to my parents’ TVs that saw a LOT of use.

I don’t recall ever changing a tube in my ‘60s guitar/keyboard amps, and I had them a long time!

 

[Prina]

I ordered a 3 pack of JJ ECC83S from Sweetwater; hopefully they will be here Saturday

Too bad you had to go thru the experience. Hope it works out well.

A question for tube experts: Some places, like Tube Depot, have the option for 'Low Noice & Microphonics' with a slight upcharge ($4 at TD for their JJ ECC83S).
Worth it?

 

[FatFingerBlues]

FYI
replacing the first preamp tube did not fix my problem
so its off to amp repair first of next week
fortunately there is a highly recommended guy not to far away from me

 

[László]

FYI
replacing the first preamp tube did not fix my problem
so its off to amp repair first of next week
fortunately there is a highly recommended guy not to far away from me

Did you try the tube in any of the other preamp tube positions? Any of them is just as likely to go bad as any other one. If you go to the Mesa website, and download some of the manuals, you’ll discover that most Mesa manuals have a section that will tell you how to sort out a bad tube and figure out systematically which one is the culprit.

So, for example, if it’s a preamp tube, and V1 isn’t the problem, you put the original tube back in V1, and try V2. If that isn’t the bad one, try V3.

Et cetera.

If none of the preamp tubes proves to be the bad tube, then the next step is to do the same thing with power tubes.

If none of the power tubes are bad, and none of the preamp tubes are bad, that’s when to take the amp to a tech for repair.

You’ll feel pretty silly if you have to shell out a lot of money to have someone else do this exact procedure and find out it’s a bad tube - I know because I’ve been there and done that!

 

[FatFingerBlues]

Did you try the tube in any of the other preamp tube positions? Any of them is just as likely to go bad as any other one. If you go to the Mesa website, and download some of the manuals, you’ll discover that most Mesa manuals have a section that will tell you how to sort out a bad tube and figure out systematically which one is the culprit.

So, for example, if it’s a preamp tube, and V1 isn’t the problem, you put the original tube back in V1, and try V2. If that isn’t the bad one, try V3.

Et cetera.

If none of the preamp tubes proves to be the bad tube, then the next step is to do the same thing with power tubes.

If none of the power tubes are bad, and none of the preamp tubes are bad, that’s when to take the amp to a tech for repair.

You’ll feel pretty silly if you have to shell out a lot of money to have someone else do this exact procedure and find out it’s a bad tube - I know because I’ve been there and done that!

Thank you for the help

I have played with it some more
I am not convinced it is a tube anymore
I did plug the Guitar directly into the effects loop and got nothing
it could be the power tubes but they look good and lite up evenly while the logo is still red and the glass clear
At this point I am ready for the tech

 

[DreamTheaterRules]

Thank you for the help

I have played with it some more
I am not convinced it is a tube anymore
I did plug the Guitar directly into the effects loop and got nothing

I wouldn't think you would get anything plugging an instrument into a loop return. Do you have a modeler? Or at least a good OD/Distortion pedal? Plug the guitar into that, and that into the effects return.

 

[DISTORT6]

I wouldn't think you would get anything plugging an instrument into a loop return. Do you have a modeler? Or at least a good OD/Distortion pedal? Plug the guitar into that, and that into the effects return.

Plugging into the return will bypass the preamp section and you should still get some sound. It will just be using the power amp.

 

[FatFingerBlues]

Plugging into the return will bypass the preamp section and you should still get some sound. It will just be using the power amp.

That is what I read to try
you should get some sound,
diminished but audible
I did not unfortunately

 

[DreamTheaterRules]

Plugging into the return will bypass the preamp section and you should still get some sound. It will just be using the power amp.

“Some?” I didn’t figure a guitar straight into a loop would have enough signal to drive the back end. I mean, maybe a little sound but I wouldn’t think much. Honestly, I’ve never tried it because I figured it didn’t really work.

 

[Bogner]

Get Some Wooden Chop Sticks Or A Pencil And Tap On The Tubes..Both Power Amp And Preamp. Rotate your Tubes around In The Preamp Section And See What Happens If Anything. The Preamp Tube Closest To The Input Is Typically V1 And Usually Is The First To Go If All Things Are Equal. Check Your Fuses As Well. Switch Channels And See If That Triggers Anything And Make Sure Your Master Is Up A Bit So You Can Hear. Let Me Know What You Find And I Will Help As Much As I Can.

 

[DISTORT6]

“Some?” I didn’t figure a guitar straight into a loop would have enough signal to drive the back end. I mean, maybe a little sound but I wouldn’t think much. Honestly, I’ve never tried it because I figured it didn’t really work.

It’s just straight up power amp “tone”. You’ll absolutely hear it.
Now if you take one of those AMT pedals and run that into the return…

 

[DISTORT6]

Here’s a video from YouTube using the loop return to play an acoustic electric through a Marshall full stack.

 

[FatFingerBlues]

From the website Tubeampdoctor.com

Preamp or power amp?​

If the amp is simply not producing any sound, even though all tubes seem to be running, the position of the faulty valve can also be determined using the effects loop – if available.


If the problem disappears when the guitar is plugged directly into the effects return (the signal will be faint but audible), the defective electron tube is in the preamp. But if the problem persists, the power amp tubes should be replaced.

 

[FatFingerBlues]

Okay
The amp tech called today
a resistor failed and burned up both Power Amp tubes
He can fix it and I will get it tomorrow
But here is my new dilemma
He felt that my speaker cabs may have caused this
I am skeptical
I was playing it through my Marshall full stack MG412 (8 speakers)
My tech asked if it could be a bad cable but these were 2 brand new PRS classic speaker cables (the blue ones)
my question is
is there a way to test any of this with and ohm meter?

 

[Bogner]

As Long As Your "Ohmage" Is Correct You should have No Issue. A Bad Speaker Cable Will Act Similar To A Bad Guitar Cable. If Everything Is Matched Up Accurately (Ohms) I Don't See A Cable Being The Issue. Parts Fail, Tubes Fail, Etc. I Wouldn't Worry Too Much About It As Long As The Problem Gets Sorted Going Forward.

On The Flip Side...If Ohms Are Off And You Are Hammering The Cabinet Beyond Its Capabilities And Pushing Your Amp Beyond Its Comfort Zone Then Things Can Happen. I Am Not Sensing That Is The Case With You So I Stick With My First Comment Above.

Hopefully It is Nothing That Happens Again And The Amp Sounds Great, Plays Great And Feels Great And You Can Play The Heck Out Of It.