[Leo246]

I don't know if it has been said, but on the Viva you have to use not a normal 6sn7,
but a 6SN7 GTA-GTB upgrade of the basic version with maximum anode voltage of 450 Volt.

Does it mean that i cant use Cv181?

 

[biscottino]

Does it mean that i cant use Cv181?

http://www.r-type.org/pdfs/cv181.pdf

in the datasheet I read about a maximum current of 300v at the anode, I don't know if it's ideal, I think you've noticed that when it's on the Viva's tubes are all hot, I'd say very hot compared to other tube amps, I have a Raal here wm1a with 6sn7 and are much less hot....this makes you assume that much more current flows in the Viva than in other tube amplifiers, for this reason the gtb/gta series are to be preferred because they are more robust and better withstand higher currents high.
When I had the Viva, the instruction booklet indicated precisely which valves to use.

 

[donato]

I don't know if it has been said, but on the Viva you have to use not a normal 6sn7,
but a 6SN7 GTA-GTB upgrade of the basic version with maximum anode voltage of 450 Volt.

That's a good reminder. I haven't really been paying attention to the distinction. I found this information below. Presumably if I don't use a GTA/GTB, it will shorten the tube life at the least.

5692 - 275 Volts maximum & maximum 1.75 Watts per section
6SN7GT/WGT -- 300 Volts maximum & maximum 3.5 Watts per section
6SN7GTA/GTB - 450 Volts maximum & maximum 5.0 Watts per section

I was very happy with a pair of Marconi 5u4g, but today I see that they have reached very high prices.

That's a similar question I have with the 5u4g. Viva also technically requires 5u4gb which has higher current (275ma vs 225ma for non-B version) requirements. Any concerns running a 5u4g vs 5u4gb?

For me best option for 6sn7 was Mullard CV181 with pan getter
For 5U4G I use NOS RCA

The Mullard has always had me curious. I've read that typical 6SN7 heaters draw about 0.6A and Mullard CV181 draws 950mA. General concerns I've read about using CV181 in place of 6sn7 is the extra current draw and if transformer can handle it. In the case of the Viva, I can't imaging this is much of a concern compared to how much current the 845s must be pulling. Sounds like it works for you. I may procure one to try out also.

The NOS RCA 5u4gb I bought sound quite good. I'll try Elrog at some point since I liked that so much for 845. They call it a 5u4g, but it is spec'd out to run 275ma so it meets 5u4gb current specs. EDIT: at € 810 each, maybe not. Also, they are only selling direct now and they don't have any 5u4g being produced at this time.

 

[Polygonhell]

I have been told that pretty much any modern production 6SN7/CV181 will work in place of a 6SN7GTB, but that’s not necessarilly true of NOS tubes.
Does anyone know why it requires a GTB variant, it’s unlikely to be power delivery, given where it is in the circuit, but they could be running at higher anode voltage, I just wonder if anyone can confirm that’s the requirement?
I’m currently running a pair of NOS RCA 5U4GB, Elrog 845’s ( which are a huge improvement over the Shugang), and a PSVane CV181T.

 

[donato]

Does it mean that i cant use Cv181?

It doesn't mean you "can't" since obviously you're already running it that way. it might mean shorter tube life if you are pushing tubes beyond their spec as biscottino mentions.

I'm guessing Viva wouldn't "recommend" it. Does anyone have a decent relationship with a Viva dealer (when I've e-mailed Viva before, they've only referred me to local dealer)? I bought mine used and don't have any dealer relationship.

http://www.r-type.org/pdfs/cv181.pdf

in the datasheet I read about a maximum current of 300v at the anode, I don't know if it's ideal, I think you've noticed that when it's on the Viva's tubes are all hot, I'd say very hot compared to other tube amps, I have a Raal here wm1a with 6sn7 and are much less hot....this makes you assume that much more current flows in the Viva than in other tube amplifiers, for this reason the gtb/gta series are to be preferred because they are more robust and better withstand higher currents high.
When I had the Viva, the instruction booklet indicated precisely which valves to use.

Yes, agreed. It does seem like the Viva pushes tubes to require the higher limits of specs for a specific tube type (e.g. 5u4gb instead of only 5u4g, 6sn7gtb instead 6SN7GT, 6n1p-EV instead of only 6n1p).

I have been told that pretty much any modern production 6SN7/CV181 will work in place of a 6SN7GTB, but that’s not necessarilly true of NOS tubes.
Does anyone know why it requires a GTB variant, it’s unlikely to be power delivery, given where it is in the circuit, but they could be running at higher anode voltage, I just wonder if anyone can confirm that’s the requirement?
I’m currently running a pair of NOS RCA 5U4GB, Elrog 845’s ( which are a huge improvement over the Shugang), and a PSVane CV181T.

That is largely my understanding of modern 6sn7 as well. Re; NOS, it seems to be primarily because of the lower power spec (both voltage and overall power draw).

6SN7GT/WGT -- 300 Volts maximum & maximum 3.5 Watts per section
6SN7GTA/GTB - 450 Volts maximum & maximum 5.0 Watts per section

I’m currently running a pair of NOS RCA 5U4GB, Elrog 845’s ( which are a huge improvement over the Shugang), and a PSVane CV181T.

Looks like we're both running NOS RCA 5U4GB and Elrog 845. Nice!

 

[Polygonhell]

it seems to be primarily because of the lower power spec (both voltage and overall power draw).

I very much doubt that, given it's not the output tube, it'll be driving into the next stage, probably a load in the 100K Ohm plus (probably a lot larger) range, so the plate power draw will be next to nothing. Ohms law into 100K Ohms with a voltage swing of say 250V P-P would require a plate draw of ~81mW, round it up to 100 (maybe a bit more) with the bias current.
6SN7's are used as output tubes, as a pre tube in an amp like the 845, they are really not being heavily loaded

As I said it's more likely to be the plate voltage is over 300V, I just wondered if anyone could confirm.
I guess either way all that's likely to happen with a standard 6SN7 is reduced tube life.

 

[Polygonhell]

Looks like we're both running NOS RCA 5U4GB and Elrog 845. Nice!

I really like the Elrogs a lot.
People just need to know that in the US at least there are no approved local distributors and the only way to order and get a warranty is to send an email.
Process is relatively painless and mine shipped inside a week, had them in just over a week.
I also would love to try his 5U4G's, and if it wasn't a pair required I'd just do it.

I have a couple of other 6SN7's to try including a Lin Lai Elite, but new production tubes all take so long to break in I hate swapping them, when I have something I like.

 

[BlakeT]

In case anyone is in the market, I'll be listing some regular KR Audio 5u4g and also limited edition KR Audio Riccardo Kron 5u4g and Takatsuki 274b, Marconi 5R4 rectifiers this weekend.

 

[OnlySoMany]

Recently received mine, and holy crap this amp is good. I really can't say enough good things about it. I have had some pretty high-end headphone amplifiers (see sig) but nothing compares to the power, clarity, and musical nature of this unit. The closest one I would say is the WA33, but even it can't compete.

Hard to describe the sound, but I would say "real" and "honest" are the first that come to mind. The energy is unreal.

Expensive? Absolutely. Money well spent? 100000000%

 

[donato]

Recently received mine, and holy crap this amp is good. I really can't say enough good things about it. I have had some pretty high-end headphone amplifiers (see sig) but nothing compares to the power, clarity, and musical nature of this unit. The closest one I would say is the WA33, but even it can't compete.

Hard to describe the sound, but I would say "real" and "honest" are the first that come to mind. The energy is unreal.

Expensive? Absolutely. Money well spent? 100000000%

Congrats! Nice to have more owners here. Keep us posted on your experience.

Also, once you start rolling tubes, that will take it to another level. But definitely enjoy what you have and you'll appreciate upgrades that much more.

 

[BlakeT]

Recently received mine, and holy crap this amp is good. I really can't say enough good things about it. I have had some pretty high-end headphone amplifiers (see sig) but nothing compares to the power, clarity, and musical nature of this unit. The closest one I would say is the WA33, but even it can't compete.

Hard to describe the sound, but I would say "real" and "honest" are the first that come to mind. The energy is unreal.

Expensive? Absolutely. Money well spent? 100000000%

Great choice, Egoista is amazing and glad you are enjoying it!

For those with speaker systems, they make some killer preamps and power amps as well. I love my Linea:

 

[OnlySoMany]

Great choice, Egoista is amazing and glad you are enjoying it!

For those with speaker systems, they make some killer preamps and power amps as well. I love my Linea:

Yes I am interested in hearing more from their range.

 

[dsyzling]

Recently received mine, and holy crap this amp is good. I really can't say enough good things about it. I have had some pretty high-end headphone amplifiers (see sig) but nothing compares to the power, clarity, and musical nature of this unit. The closest one I would say is the WA33, but even it can't compete.

Hard to describe the sound, but I would say "real" and "honest" are the first that come to mind. The energy is unreal.

Expensive? Absolutely. Money well spent? 100000000%

Do you have the WA33 standard version?

I heard an Egoista at London Cam Jam and I'm not sure if there was an issue with the unit. It was connected to a Rossini Apex with Susvara, I just had to keep turning the volume up and couldn't say I was impressed. I remember thinking, this can't be right, doesn't sound like it has the power and slam I would expect. Should be said, show conditions etc. But was I was comparing it to the Primavera immediately next to it which had the Dave/m-scaler and Susvara and on that day I far preferred that combination. What I heard doesn't match how people have described the amp in this forum, which is why I was personally questioning whether there was an issue with the setup.

Or may be this is down to personal preferences - I listened to a Holo Audio May, Bliss, Caldera combo on the same day and really found that problematic - mainly down to the NOS affect I think. I left wanting to hear the Holo Audio with DSD/PCM upsampling before making any further judgement on the chain.

 

[Polygonhell]

I heard an Egoista at London Cam Jam and I'm not sure if there was an issue with the unit. It was connected to a Rossini Apex with Susvara, I just had to keep turning the volume up and couldn't say I was impressed.

I can't comment on what you heard.
I own a WA33 and a EC Studio T, I've also owned a DNA Stratus and I've heard the Riviera AIC10 (though not in my system). I haven't heard a Primavera.
I personally would take the Viva over all of them, and it pairs extremely well with the Susvara.

I usually run about 10-11 AM volume depending on the track into the Susvara. About the same as I do on the WA33. Your not going to find many amps that require less volume than that just because volume pots are logarithmic, not linear, so 12 o'clock is more like 10% volume than 50%.
WA 33 runs 10W into 32 Ohms, probably closer to 6-8 into 64, I believe the Viva is 15+W into some unspecified impedance so it's hard to directly compare power.

The obvious difference between the Viva and other amps is in the truly massive stage (I've never heard another amp approach it), and macro dynamics/leading edge portrayal are stunning, better than the EC or WA33. The leading edge is so aggressive that I think with the stock tubes it can end up being fatiguing with the wrong DAC.
It also pushes more pronounced bass and better control of it into the Susvara than the WA33 manages.

 

[BlakeT]

See also:

https://www.head-fi.org/threads/canjam-socal-2023-impressions-thread.969902/page-14


EDIT: I also wonder if the London Can Jam setup had volume attenuated via software upstream?