What are you favorite 845 tubes?

[Ovenmitt]

Hi @dr-db2 ,

‘congratulations on the new amp! I loved mine and thought it made a fantastic partner with the Duo’s....

I wish that you would have found this thread and asked about PX25’s about a month ago. I just sold my last two pairs and would have liked to see them go to a WBF member..... to answer your question; out of all the PX25’s I rolled, I preferred a very early pair of Valvo’s overall. Early GEC’s were also really nice. They looked very similar and for all I know they may have been made in the same factory. These were both balloon shaped with massive frames and getters. Do know that you will need an adapter to go from the old pin type to the 300b pin type that the Art audio uses.

you can also take a big leap forward with that amp when you roll the 274 rectification tubes. You can PM me for more details.

 

[dr-db2]

Thanks Ovenmitt; I'll keep an eye out for a NOS pair of Valvos. Now my fingers are crossed for a damage-free delivery....

 

[dr-db2]

Hi @dr-db2 ,

‘congratulations on the new amp! I loved mine and thought it made a fantastic partner with the Duo’s....

I wish that you would have found this thread and asked about PX25’s about a month ago. I just sold my last two pairs and would have liked to see them go to a WBF member..... to answer your question; out of all the PX25’s I rolled, I preferred a very early pair of Valvo’s overall. Early GEC’s were also really nice. They looked very similar and for all I know they may have been made in the same factory. These were both balloon shaped with massive frames and getters. Do know that you will need an adapter to go from the old pin type to the 300b pin type that the Art audio uses.

you can also take a big leap forward with that amp when you roll the 274 rectification tubes. You can PM me for more details.

Ovenmitt, I previously tube rolled the rectifier tubes in our Audio Note Conquest Silver Sigs and noticed no difference; apparently that is not the case with the Art Audio. What tubes did you use? As you are probably aware, the new Art Audio PX25 amps now have solid state rectifiers and I had to special order them and pay additional for the prior tube build. I appreciate your guidance; since we have the same speakers I presume we'd have similar results. BTW, did a change of the input tubes make much difference? Thanks again, Dave

 

[calloway]

I have Psvane WE 845s that are great but i will be replacing them with the new Psvane ACME 845s soon..

 

[christensenleif@msn.com]

Nagra VPA have a major heat problem issue, due to the tubes going down under the top cover.
I know several who´s been forced to change the caps ...They were 85 degree rated but should be 105
Also other components may suffer from extensive heat.
In my opinion the VPA are not the optimum design for other than looks....very sexy

 

[Suona Divina]

Hi all,
my first post here. I recently bought a pair of VPAs that came with PSVANE (don’t know witch model) but not Nagra branded. I good friend of mine, who is about to acquire a couple of VPSs for himself, just sent me a picture of the Nagra branded 845s that come with the amps he’s getting and the interior structure of the Nagra branded 845 is way more robust that’s the PSVANEs I own. They thickness of the vertical metal structure looks like the one used by the legendary Amperex 845. I’m attaching both pics for you to see.
I just mailed Nagra so they can confirm that the Nagra branded tubes are still made with this internal construction. Do you think this could make a big difference in sound? Any experiences with with will be appreciated.
Also, I’m using a pair of Tannoy GRF Corner with Monitor Gold. What speakers are you driving with your VPAs?

 

[Kingrex]

I have Black Shadow 845s. I was bouncing around the Grant Fidelity site. They have Psvane and Linlai tubes. I have a batch of Shuguang and a set of Psvane HIFI B tube. The Psvane is much thicker and more rich than the Shuguang. The shuguang have more detail depending on the tube, but lack the body. I would like to find a good full bodied tube with rich flavor and good clarity. That is my prefered tone.

Do the Psvane ACME Supreme and Linlai WE give the clarity and body. I don't know I want to spend $2000 on the Elrog. That is alot when these others are P=$1,055 and L=$700

 

[Kingrex]

I have Psvane WE 845s that are great but i will be replacing them with the new Psvane ACME 845s soon..

Any feedback yet?

 

[Jazzhead]

Running KR 845s and very happy, just when I think can settle down... up comes a stash of NOS RCA 845s . Matched pairs with the Black engraved lettering and another with Red screen printing . Looking for feedback on these tubes, is one variant better/different to the other. Worth an expensive punt? What should I be looking out for , asking the seller etc... I know the mantra being buy the seller and not the tube, but in this case logistics provide this a go to . Look forward to thoughts and experiences with the RCA845. Cheers!

 

[VerdantAudio]

Regarding 845s, the KRs can be a bit analytic but the departure from spec is important to note. The standard 845 has a 3.5 Amp filament current and the KR has a 1.0 Amp filament current. Art Audio amps like the Carissa or Quartets will accept these without modification but many amps require a resistor to be added to reduce the filament current.

It does lead to a more detailed presentation but it radically limits who can use the tubes.

 

[Anchorman]

Hi Ovemitt,

Did you ever pursue some 845 tubes for your VPAs? I'm just about considering some replacements (I change them early and keep the prior quad as spares). I did notice that PSvane have launched some new 845 with standard size glass that will fit. I include a link here. If you tried anything, please let me know, alternatively I may just play safe and go with Nagra tubes. Cheers.

 

[Ovenmitt]

Hi Ovemitt,

Did you ever pursue some 845 tubes for your VPAs? I'm just about considering some replacements (I change them early and keep the prior quad as spares). I did notice that PSvane have launched some new 845 with standard size glass that will fit. I include a link here. If you tried anything, please let me know, alternatively I may just play safe and go with Nagra tubes. Cheers.

Hello @Anchorman... I'm glad that you bumped this thread forward again. I have not swapped tubes in my VPA's but am still interested - work and this awful pandemic kind of got in the way of a lot of my free time. If you don't mind me asking, which PSvane 845's are you considering?

 

[Anchorman]

Hey Ovenmitt, . . .

On to tubes.... it is less obvious than it might be but click on “here“ in my thread and that will take you to them!

 

[Anchorman]

Hi all,
my first post here. I recently bought a pair of VPAs that came with PSVANE (don’t know witch model) but not Nagra branded. I good friend of mine, who is about to acquire a couple of VPSs for himself, just sent me a picture of the Nagra branded 845s that come with the amps he’s getting and the interior structure of the Nagra branded 845 is way more robust that’s the PSVANEs I own. They thickness of the vertical metal structure looks like the one used by the legendary Amperex 845. I’m attaching both pics for you to see.
I just mailed Nagra so they can confirm that the Nagra branded tubes are still made with this internal construction. Do you think this could make a big difference in sound? Any experiences with with will be appreciated.
Also, I’m using a pair of Tannoy GRF Corner with Monitor Gold. What speakers are you driving with your VPAs?

 

[Anchorman]

Hi,

Not sure if anyone answered your question. So here goes, The tubes with the larger metal structure are Shuguang. There's various grades of these, but they are all mid tier. The other PSvane tube is a splinter of Shuguang dedicated to making "top tier" tubes at premium prices. Point is, there's alot more to the sound quality than the mass of the grid frame; though the frames strength (and design) does help reduce shipping failures caused by trauma. Plate, grid materials and (crucially) tolerances all play a significant part in sound reproductive quality.

So to tolerances... The PSvane tube you have will almost certainly be better than the Shuguang tube out of the factory. This is because PSvane will pay more attention to materials and tolerances than Shuguang - it is a more costly tube of course. However, NAGRA will take a modest factory tube like the Shuguang because it's readily available, not too expensive, and subject it to various additional tests design to assess its tolerances both electrical and physical. As a result they disgard a huge quantity of those tubes that passed the factory QC, but are insufficient or out of tolerance for a Nagra branded deployment. The Nagra vetted tube, in my experience tends to sound better than any of the comparisons I have done to date. This suggests that QC (i.e. tolerances) have a huge part to play in sound reproductive quality and longevity. That said, there are a new crop of very high end tubes emanating from China including bolted metal plate (as opposed to mounted graphite) reputedly manufactured to higher tolerances. I have not tried these tubes as yet. Separately, Elrog, a German based manufacturer of tubes using the latest CAD processes has released a series of tube built using 2020 standards of engineering and science. These are reputedly very good, but their 845 will not physically fit into a Nagra VPA... All the best and hope that helps.

This will be be my last post here as I will NOT be censured for simply mentioning "election".

 

[Anchorman]

Following up on this thread I wanted to update folks on what I discovered since. All of my description is referenced against the fact that I change tubes frequently and never use them to anywhere near the point of exhaustion.

Nagra sourced: Recently (ish) Nagra have stopped supplying Shuguang and switched to PSVane. I had assumed (given the 100% price increase) this meant the PSVane “WE845” and such a tube with additional rigorous testing by Nagra might be “something”. However, PSVane actually do a selection of far cheaper tubes and Shuguang (a state owned company) has ceased production indefinitely due to a factory move. My conclusion (and it is circumstantial) is that Nagra are merely replacing the standard 845B with a PSVane equivalent. Certainly Nagra couldn’t tell me which specific tube I would receive so enter Grant Fidelity and Linlai….

Linlai: These did not disappoint. Straight out of the box they looked meticulously built. Slotting them in, the fired up with only the most minor of biasing adjustment. Normally, only Nagra serial # matched tubes ever slotted in this easily. I don’t normally have much expectation on the sound of current production tubes, but again I was in for a pleasant surprise. Even fresh out of the box they sounded vivid, palpable and with a moderately extended soundstage both in terms of width and depth. Instruments were better delineated in the stage and the whole presentation of various programme material was rendered simply better. Ok, so this is a not a difference in gestalt per se, but it is a modest and worthwhile improvement regardless of price. That and you get the customer service of Grant Fidelity run by a sensible and personable audiophile (Rachel). That last part is pretty rare… In conclusion, highly recommended

 

[Golum]

Many thanks for the report above. Having VPAs as well what is your "average" time used for a quad of 845s?
Thanks in advance!

 

[Anchorman]

You're welcome. Less than 4000 hours and probably nearer 3000. Now I should point up that at weekends, I leave my amps on 24 hours, i.e. I don't shut them down Saturday and fire them back up Sunday - they just stay on and it reduces the stresses on the components. If it's summer, I leave the airconditioning on to control the room temp.

 

[Anchorman]

Although long in the tooth now, I wanted to come back around to update this thread on the Linlai vacuum tubes. I'll cut right to it, they became a disaster.

For whatever reason after about the 200 hour mark, one or more started wild bias fluctuations causing the amps to engage the protection circuits and shutdown. Re-biasing only ever provided a temporary solution and eventually, even that was not possible. Just before I removed them, one amp would make a sizzling sound on start up and I'd have to immediately shutdown manually. The tubes were lit, but the sound of frying electronics was disconcerting....

Needless to say, the supplier was irritated (they and me both!) and resorted to accusing my amplifiers of overdriving the tubes. I did point out that these Nagras are a 20 year old design, one of the last batches made and strangely perform flawless when the original Nagra sourced tubes are reinstalled. I did get to return them, but ended up slightly worse off regardless.

I'll hypothesise that in trying to differentiate themselves with a competitive advantage on, presumably sound, tube manufactures are experimenting with specifications causing some issues when used with certain designs. If you have Nagras, your choices are limited due to the fitment (no Elrogs or other wider glass bottle designs - 59mm is the max size for Nagra) and the substantial protection circuits (would one have it any other way?). Thus far, only PSvane ("WE edition") and Nagra supplied stock have worked without issue. I think the Nagra selected tubes, although from bland stock, sound the best and are the most reliable, courtesy of that rigorous selection process. It does however, make them expensive.

Hope that's helpful experience and if it save one Audiophile a nasty expense, well, glad I posted it.

 

[Golum]

Thanks for this valuable information.
As I'm VPA user myself and in general very prone to experiments with tubes from some reason I stayed away from doing so with the VPA. Having said that I even acquired two new factory sealed quads from Nagra and I (or my kids) can happily enjoy using the amps for many years to come.
BTW outside 845 I took them last year to Nagra for technical inspection and after many years of work they measured like they left the factory floor a day before -> quality never goes out of style.