[bcowen]

Question for those with much more knowledge than I possess.

What happens when a tube fails in the Vali 2 or another tube amp? Does the amp go into a protection mode if it has it? Or does the failed tube hurt the amp in any way?

Depends on how the tube fails. If it just wears out (cathode material is depleted to the point there are insufficient electrons boiling off), it's not going to hurt the amp. You'll just get no sound. If it develops a short, it depends on which elements are shorted and whether the amplifier has any protection to handle that specific short. I know that doesn't help much, but there are a number of variables involved. Most amps that use large output tubes (KT-88, 6550, EL-34, etc) will have some sort of protection circuit or fuse that will trip or blow if a tube starts drawing too much current. I don't know whether Schiit has any protection built into their amps though.

 

[mystaiced]

Depends on how the tube fails. If it just wears out (cathode material is depleted to the point there are insufficient electrons boiling off), it's not going to hurt the amp. You'll just get no sound. If it develops a short, it depends on which elements are shorted and whether the amplifier has any protection to handle that specific short. I know that doesn't help much, but there are a number of variables involved. Most amps that use large output tubes (KT-88, 6550, EL-34, etc) will have some sort of protection circuit or fuse that will trip or blow if a tube starts drawing too much current. I don't know whether Schiit has any protection built into their amps though.

Thanks!

Edit : according to Schiit talker, Vali 2++ has a relay mute for delayed startup and fast shut down. But Freya has no protection whatsoever, so matched tubes from a reputable seller was recommended. FWIW

 

[Mr Trev]

Question for those with much more knowledge than I possess.

What happens when a tube fails in the Vali 2 or another tube amp? Does the amp go into a protection mode if it has it? Or does the failed tube hurt the amp in any way?

I bought my Vali2 second-hand and the stock tube (made in Canada 6BZ7) was making noises, ungodly noises - hissing/buzzing, I don't completely remember. Needless to say it didn't stay in the amp very long once I heard that. None of my other tubes make anything close to that type of noise, so I'm going to assume that the tube is failing, and since I'm still waiting for @bcowen to offer to lend me one of his testers, I can only assume
Good news is the amp and phones survived

 

[bcowen]

I bought my Vali2 second-hand and the stock tube (made in Canada 6BZ7) was making noises, ungodly noises - hissing/buzzing, I don't completely remember. Needless to say it didn't stay in the amp very long once I heard that. None of my other tubes make anything close to that type of noise, so I'm going to assume that the tube is failing, and since I'm still waiting for @bcowen to offer to lend me one of his testers, I can only assume
Good news is the amp and phones survived

I have a fully restored Weston 981 sitting here waiting for you. Only weighs 38 pounds, so shipping across the border shouldn't cost more than $200 or $300. Each way. I haven't checked at UPS, but there's a possibility, even if remote, that it might cost less to send the tube to me. I promise I'll return it. Yup. Sure will.

 

[LobalWarming]

I have a fully restored Weston 981 sitting here waiting for you. Only weighs 38 pounds, so shipping across the border shouldn't cost more than $200 or $300. Each way. I haven't checked at UPS, but there's a possibility, even if remote, that it might cost less to send the tube to me. I promise I'll return it. Yup. Sure will.

Seems fair. It's a mutual conductance tester after all. And we know how you both conduct yourselves. What go wrong?

 

[Mr Trev]

I have a fully restored Weston 981 sitting here waiting for you. Only weighs 38 pounds, so shipping across the border shouldn't cost more than $200 or $300. Each way. I haven't checked at UPS, but there's a possibility, even if remote, that it might cost less to send the tube to me. I promise I'll return it. Yup. Sure will.

Looking at the pic of your tester I gotta ask… what kind of tube uses 115v heater filaments

 

[LobalWarming]

Looking at the pic of your tester I gotta ask… what kind of tube uses 115v heater filaments

The usual northern winter tubes...

 

[bcowen]

Looking at the pic of your tester I gotta ask… what kind of tube uses 115v heater filaments

Can't say I've ever seen one. Might be fun though to see what happens to a Philips ECG 5814 at 115v. Assuming it would die a very rapid death it would be a fitting end to its miserable life.

 

[jonathan c]

Can't say I've ever seen one. Might be fun though to see what happens to a Philips ECG 5814 at 115v. Assuming it would die a very rapid death it would be a fitting end to its miserable life.

Why be ‘tubemane’ ? Give it bursts of Captain & Tennille at escalating intensity, pause with good stuff such as Allman Brothers, resume the CAT pulsars …

 

[Mr Trev]

Can't say I've ever seen one. Might be fun though to see what happens to a Philips ECG 5814 at 115v. Assuming it would die a very rapid death it would be a fitting end to its miserable life.

PM me your address and I'll send that dodgy 6BZ7 as a sacrifice

 

[bcowen]

Why be ‘tubemane’ ? Give it bursts of Captain & Tennille at escalating intensity, pause with good stuff such as Allman Brothers, resume the CAT pulsars …

So now I run into a moral dilemma. Should I fry them for fun, or put them on Ebay for money? Either way I'm rid of them. But if the latter I miss out on the fun, and I'm also knowingly accepting money for one of the nastiest sounding tubes ever produced in the history of mankind from some poor, unsuspecting soul. That would be mean. I think I'll just fry them as that would bring about enjoyment without any regret or remorse.

 

[Mr Trev]

So now I run into a moral dilemma. Should I fry them for fun, or put them on Ebay for money? Either way I'm rid of them. But if the latter I miss out on the fun, and I'm also knowingly accepting money for one of the nastiest sounding tubes ever produced in the history of mankind from some poor, unsuspecting soul. That would be mean. I think I'll just fry them as that would bring about enjoyment without any regret or remorse.

Even better… Fry them, and post the videos online for money. I'm sure there's folks out there that'd get off on that sort of thing

 

[HWB3]

Kind of like Only Fans.

 

[HWB3]

Those would be the transconductance values. A NOS 396A is spec'ed at 5500. So you have one triode with emission that is around 85% of new, and the other that's at about 36%. Not a very good testing tube. However, there are many sellers on Ebay (and elsewhere) that post bogus numbers, and many more using vintage testers that have not been rebuilt or calbrated....ever. An old tester with deteriorated electrolytic caps and calibration that's way off doesn't give you any better information than not testing the tube at all. Of most importance, if it sounds good to you, it's good. Ignore the numbers.

I returned the tube and got a better testing one that cost half as much as my amp. If I liked the first tube, I can't wait to hear the new one. It comes in later on in the week.

 

[HWB3]

The new tube came in and I've got my first hour on it. I like it. The first tube went back because it wasn't seating properly in the amp. So, I figured pay a bit more to get a better tube and I'm glad that I did it.