Schiit Valhalla Tube Rolling thread.

[MacMan31]

Yeah, I would follow Schiit's instructions to be safe, but know that I've never damaged a tube by rolling it when the amp was off, but plugged in. Also, I would def wait for the tubes to cool or at least the light to be off completely. The V2 is very dependable so I would assume the issue is with the tube or electronic interference.

Burn in of 3-5 hours and 2-3 on/off cycles should be enough to stabilize the tube from dropouts and static. I've only had this happen for a couple of my tubes so take my advice with a grain of salt

So after doing some various swaps it seems the issue is only with the GE 6CG7 / 6FQ7 tubes. The JJ E88CC / 6922 Gold tubes are fine. I have those in with the Novosibirsk 6N6p / 6H6pi tubes. So far so good. I do wish they had a bit brighter glow. The JJ E88CC / 6922 Gold tubes have barely any glow to them. I'm still waiting on the Brimar CV455 tubes but the adapters arrived today.

 

[G0rt]

So after doing some various swaps it seems the issue is only with the GE 6CG7 / 6FQ7 tubes. The JJ E88CC / 6922 Gold tubes are fine. I have those in with the Novosibirsk 6N6p / 6H6pi tubes. So far so good. I do wish they had a bit brighter glow. The JJ E88CC / 6922 Gold tubes have barely any glow to them. I'm still waiting on the Brimar CV455 tubes but the adapters arrived today.

You're in for a treat!

Mine arrived yesterday, and are just a few hours warm, but are already quite the tasty.

3am-ish, totally quiet town and house, VH2 on lo, Grado GH2/G, Bifrost 4490, and some John Kaizan I digitized myself from Tokyo vinyl, and it's ... Superb.

 

[GumbyDammit223]

Just an FYI regarding tube swapping. Obviously powering the amp down and letting the power LED extinguish are no-brainers if you don't want a nasty surprise. I always leave the power cord plugged in so that the unit is grounded. That way I'm not going to risk ESD damage to any of the internal electronics. Again, that also assumes I'm not going to go poking around the Valhalla's insides with a metal poker. YMMV.

 

[jonathan c]

~ After extended listening to favourite jazz / R&B tracks through the Linear Tube Audio MZ3, I wanted to put the Valhalla II - with Foton 6N6Ps and Brimar CV455 KB/FBs - through the gauntlet. I was curious to see how close to the MZ3’s altitude the V-II could fly. Biggest shoes to fill, in my experience…a new set of shoes for the V-II for the occasion.
~ With the same tracks, the V-II constantly put a grin on my face: the goods were being brought HOME .
~ The MZ3 was not to be surpassed by V-II, but I felt a ‘perverse’ glee that the V-II gave the MZ3 a fabulous run for the money. Think bantamweight vs heavyweight for twelve rounds: no TKO, victory to heavyweight from point total. Again, a $349 base amp vs a ‘10X’ contender. With NOS tubes, a $600 amp vs a ‘8X’ contender.
~ If asked the question “what percent of the MZ3 performance does the V-II offer”, I say 90-95. I will absolutely keep both. To me: the MZ3 is ‘state of the art’, V-II is great beyond belief.

 

[regaet]

Thanks for this report! I have been listening to my Valhalla 2 with Foton 6N6Ps and Brimar CV455s coupled to a Bifrost 2 and a pair of Elears. I also bought a Wywires Platinum HPC at the same time I plugged the CV455s into the Valhalla about two months ago. The performance of my system has surpassed my expectations but I don't have access to better headphone systems to compare it to. Your comparison validates my impressions of the performance of this little amp .

 

[didxogns1]

There may be better sounding tubes for Valhalla 2, but they are very few and far between. The CV4033 is an excellent combo and no one would blame you if you stopped right there. But we all know that's not gonna happen, right?

Hi, I have a question about the tube recommendation.

I recently purchased a pair of cv4033 from 1970 after a lot of positive reviews in this thread from tubemonger.

Link is https://www.tubemonger.com/Brimar_CV4033_NOS_NIB_1970_Prem_CV4003_STC_England_p/2040m.htm


I do like the detail that it provides in the high, it is too fatiguing for my ears. Additionally, the vocal is too recessed for my liking and I find myself rising the volume higher than I should (which might be why my ears are in pain oof)

My question is, what would you recommend for someone looking for a very intimate, closed sound, with highlights in vocal/ acoustics?

It seems like Wes S's impression of Amperex 7308 is probably the closest thing to what I am looking for. However, I am hesitant to try because of the price of that tube.

Do you have any other recommendations that I should look at?

Additionally, foton 6n6p is recommended by many here. I also read that JJ ecc99 has a very solid and clear sound compared to the stock 6n6p. Has anyone tried both of them? if so, what is the difference?

Thank you in advance to anyone who would like to help this lost soul.

I wish I can try out all the tubes, but I am still a student so my budget is limited

 

[G0rt]

Hi, I have a question about the tube recommendation.

I recently purchased a pair of cv4033 from 1970 after a lot of positive reviews in this thread from tubemonger.

Link is https://www.tubemonger.com/Brimar_CV4033_NOS_NIB_1970_Prem_CV4003_STC_England_p/2040m.htm


I do like the detail that it provides in the high, it is too fatiguing for my ears. Additionally, the vocal is too recessed for my liking and I find myself rising the volume higher than I should (which might be why my ears are in pain oof)

My question is, what would you recommend for someone looking for a very intimate, closed sound, with highlights in vocal/ acoustics?

It seems like Wes S's impression of Amperex 7308 is probably the closest thing to what I am looking for. However, I am hesitant to try because of the price of that tube.

Do you have any other recommendations that I should look at?

Additionally, foton 6n6p is recommended by many here. I also read that JJ ecc99 has a very solid and clear sound compared to the stock 6n6p. Has anyone tried both of them? if so, what is the difference?

Thank you in advance to anyone who would like to help this lost soul.

I wish I can try out all the tubes, but I am still a student so my budget is limited

How many hours do you have on the CV4033's?

I ask because most tubes tend to be brighter right out of the box, and mellow more or less as they 'burn in'.

Between 15-150 hours, things do change, and generally for the best.

 

[didxogns1]

How many hours do you have on the CV4033's?

I ask because most tubes tend to be brighter right out of the box, and mellow more or less as they 'burn in'.

Between 15-150 hours, things do change, and generally for the best.

I only had it for a week. So hopefully it will change. Burn-in is such a mystery area to me.

 

[MacMan31]

What is the difference between the BRIMAR CV4033 and Brimar CV455?

 

[Ripper2860]

Assuming same year and same plant, I believe the difference is that CV4033 is natively 'flying lead' with no base or pins and designed to be hardwired and soldered to circuit boards. The TM versions have been adapted for 9 pin (Noval) socket use. The CV455 is pretty much the CV4033 but natively terminated for use in sockets.

 

[G0rt]

I only had it for a week. So hopefully it will change. Burn-in is such a mystery area to me.

Burn-in can be a contentious topic. Lots of variables.

I've got some old 5965's in my Valhalla 2 lately. They were meant for digital use, flip-flops, multivibrators and such.

Regular tubes were unreliable in computers because of cathode poisoning, AKA 'sleeping sickness', a result of running the tubes at cutoff for much of their service life.

Cathodes are actually systems, with tungsten alloy heater filaments, inside nickel alloy sleeves coated with porous rare earth compounds, all engineered to optimize electron emissions.

Researchers eventually found that, under cutoff conditions, various impurities in the nickel could migrate to form a resistive interface between the sleeve and the coating, dramatically reducing emissions.

The same process happens under analog conditions, but much more slowly, over thousands of hours vs hundreds.

Back in the day, you could 'regenerate' a tube by briefly running the filament at higher than normal volts for a little while, breaking down that interface layer and restoring emissions, at least somewhat, and temporarily.

Tubes for digital service take special care to control alloy purity and such, and the best can expect a service life of 10's of thousands of hours.

Anyway, WRT break-in, it's not too farfetched to speculate that over decades of disuse, some similar electrolytic process could form a thin interface layer that would dissipate in a few 10's of hours of burn-in, perhaps audibly.

I'm no chemist, but I'm hearing no changes in my 5965's, so I started wondering why.

 

[jonathan c]

They may not be Jack Lemmon & Walter Matthau but they probably stand as this thread’s ‘odd couple’. Don’t snicker - they sing! (Audeze LCD-4: 200 ohms).

 

[G0rt]

Just to sort of complete the thought, having now studied, a little, the 1962 edition of RCA's Electron Tube Design, the evolved semiconductor interface between the actual cathode and its oxide layer can add some hundreds of ohms of resistance to the cathode circuit (and some small capacitance) which could be quite audible in most circuits. Just sayin'.

My triple mica, tall black plate Arcturus 5965's sound great. I got a pair of old IBM triple mica, tall black plate 5965's, and they sounded the same. I suspect both were actually made by RCA.

One of the IBM's developed a short, and a pin broke on one of the Arcturus, so now running the mixed survivors, and they sound: the same, at least as good, to my senses, as the Brimar CV455, CV4033, CV1988, RFT ECC81 and 7728 pairs I've recently tried.

5965's are plentiful and cheap, although the elite, military triple mica, tall black plates are running out. That seems to be the winning formula in any of the 12A class bottles.

 

[regaet]

Well Wes S. did it to me again! I said I was done for a while after buying the Brimar CV455's but when he started raving about the RFT ECC81's and I saw they were only $15.00 a tube I snagged a pair. When I first started listening to them the term "detail monsters" kept popping in my head and the soundstage was definitely improved but they had a tendency to be a bit bright and edgy. They kept improving and at about 50 to 60 hrs they really smoothed out and now at about 80 hrs they sound incredible. Everything Wes S said about them on the Mjolnir 2 thread is spot on. The other thing that keeps amazing me is that the Valhalla just keeps getting better with every improvement and $15.00 a tube is a steal!!

 

[Wes S]

Well Wes S. did it to me again! I said I was done for a while after buying the Brimar CV455's but when he started raving about the RFT ECC81's and I saw they were only $15.00 a tube I snagged a pair. When I first started listening to them the term "detail monsters" kept popping in my head and the soundstage was definitely improved but they had a tendency to be a bit bright and edgy. They kept improving and at about 50 to 60 hrs they really smoothed out and now at about 80 hrs they sound incredible. Everything Wes S said about them on the Mjolnir 2 thread is spot on. The other thing that keeps amazing me is that the Valhalla just keeps getting better with every improvement and $15.00 a tube is a steal!!

Yes sir! Glad those RFT worked out for you. The V2 is a magical amp no doubt, and just like with good tubes, it can scale with better DAC's as well. I have since sold my V2, but I did listen to it with my Sonnet Morpheus right before I sold it, and it sounded insanely good with that pairing. In fact, it's been months and I still can't get that sound out of my head. . .I can see myself owning another V2 in the future.