[hpamdr]

Burn-in is subjective to me. Some say so many hours for this and so many hours for that.. Impossible to say IMO. There's not many components inside the amp that would require burn-in. The electrolytic caps needs to settle but there're only four of them in the amp and none is in the signal path.
I always run the amps, with signal, for 48 hours before shipping. I've had a little extra time with this one so it has over 50 hours already. I do this to build up heat inside the amp and stress it to see if there's gonna be a component failure.

Do you use a thermal camera to see if some parts ca get too hot ?
Does eternity/infinity needs a fan underneath ?

 

[SonicTrance]

Do you use a thermal camera to see if some parts ca get too hot ?
Does eternity/infinity needs a fan underneath ?

No I visually inspect. I know that nothing gets too hot as I know the dissipation of each component. The burn-in is to make sure there's no faulty components inside. It is electronics after all.

None of my amps have fans. It's been over a year since I shipped an amp with a fan.

 

[UntilThen]

Spectacular looking Eternity. You done it again Tomas. Looks great !

The beauty of a custom amp. This one done to Octavarian’s requirements. Finally all the tubes he has amassed can be put to good use in amp suitable for it.

Unfortunately this one I won’t get to sample.

Congrats both Octavarian and Tomas.

Now let the impression begin.

P/S whatever you do please take your time with tube rolling.

 

[hpamdr]

Spectacular looking Eternity. You done it again Tomas. Looks great !

The beauty of a custom amp. This one done to Octavarian’s requirements. Finally all the tubes he has amassed can be put to good use in amp suitable for it.

The design is very compact as Octavian asked and embed a lot of features. This is a great achievement Tomas

 

[UntilThen]

Easy, easy there!
I had to wait for the final part, the Eternity nameplate. That has been in customs for about two months and finally got here yesterday!

Here it is! Populated with 7581A's and 6J5's. The bias adjustments are in front of the meters. There's one meter for the input stage and one for the output stage. Then there's a toggle switch behind each meter so you can toggle between the two channels to measure the bias current.

This one also has VU meters which you can turn ON/OFF, "stock bias" switches, impedance switch, a dual triode input tube socket, teflon sockets, XLR inputs, XLR output, and an input tube selector switch.

You had to order the nameplate from far away? Would have thought that Sweden can make nameplates !

Ah 7581A.... now I know what it is. An upgraded 6L6GC. I have to try it.
https://www.thetubestore.com/tung-sol-7581a

Input tube selector switch? What's it for? Will I have it?

I hope you get more than one

Heh heh, he's also getting for Odyssey. O d y s s e y.

None of my amps have fans. It's been over a year since I shipped an amp with a fan.

Except my priceless Oblivion. It's got a fan !!! and it's silent. But no fan for Odyssey. It's naked like the naked transformers.

 

[OctavianH]

Input tube selector switch? What's it for? Will I have it?

The input switch let's you populate all 3 input slots and you can switch between single/double triode. Usually amplifiers with output speakers do not have this. They have instead the OFF/Headphone/Speaker output switch. I do not have outputs so I could add this which is for me useful.

 

[UntilThen]

I see. Have gone through this with Tomas. Decided that less is more, so I won't have that input selector switch. If I have 2 x EL11 and one 6SL7, then all 3 tubes will work together. If I wanted either or, then I just remove whichever driver(s).

 

[hpamdr]

The input switch let's you populate all 3 input slots and you can switch between single/double triode. Usually amplifiers with output speakers do not have this. They have instead the OFF/Headphone/Speaker output switch. I do not have outputs so I could add this which is for me useful.

Octavian forgotten to mention that he also have a fixed bias option so he can use single tube with manual bias and dual triode with fixed bias.. or the opposite...

 

[hpamdr]

I see. Have gone through this with Tomas. Decided that less is more, so I won't have that input selector switch. If I have 2 x EL11 and one 6SL7, then all 3 tubes will work together. If I wanted either or, then I just remove whichever driver(s).

As you have auto-bias this is ok (even if mixing triode is not the best imo). With eternity or infinity we need to adjust manually the bias to 4mA at 180V. If we have one or two triodes by side this will not be the same bias point ! The selector allows to let all preferred tubes populated and chose in one/two switches the one you run.

 

[UntilThen]

Gotcha Hpamdr. A very versatile amp this Eternity.

Meanwhile I have Oblivion powering my Axis speakers. At nearfield listening it's perfect.

 

[OctavianH]

Octavian forgotten to mention that he also have a fixed bias option so he can use single tube with manual bias and dual triode with fixed bias.. or the opposite...

Exactly, the "fixed bias" switches for both stages (input and output, on the back on the picture) commute from variable bias (what you set on the measuring points) to a fixed predefined value set in my case for KT66 in output and 6SN7/6J5/7N7 (these have same bias) in input. This is helping me a lot to roll easily because I can have in this way 2 presets of bias at the same time (for example I set KT88 on variable output and have at the pressing of a switch KT66/KT88 without needing to use the voltmeter). On input the same, the fixed bias works with 6SN7/6J5/7N7 and I can set on variable one the bias for 6N7G. In this way my life is much easier when rolling. These switches combined with the input switch allow me to have a lot of flexibility. Of course, another reason for these fixed bias were the need of simplicity, when being tired and you just want to drink a beer, you can keep your amp on the fixed bias and just try to take a break. This is why, these Input bias switches are also called by me "beer rolling on". And yep, last advantage I see is that you can combine easily for example fix bias for output (using KT66 only) with variable bias for input and just roll the inputs. Or any other combo. Seems a good feature to me even if I never saw this on any amplifier until now.

The other switch on the back is the VU meter off switch. Again need for simplicity, you can turn of the VU meters if you want silence, darkness or something like that.

 

[Galapac]

Easy, easy there!
I had to wait for the final part, the Eternity nameplate. That has been in customs for about two months and finally got here yesterday!

Here it is! Populated with 7581A's and 6J5's. The bias adjustments are in front of the meters. There's one meter for the input stage and one for the output stage. Then there's a toggle switch behind each meter so you can toggle between the two channels to measure the bias current.

This one also has VU meters which you can turn ON/OFF, "stock bias" switches, impedance switch, a dual triode input tube socket, teflon sockets, XLR inputs, XLR output, and an input tube selector switch.
The stock version of Eternity will use 6AV6 and 6S19P tubes.










Here you can see the size difference between Infinity and Eternity!



Burn-in is subjective to me. Some say so many hours for this and so many hours for that.. Impossible to say IMO. There's not many components inside the amp that would require burn-in. The electrolytic caps needs to settle but there're only four of them in the amp and none is in the signal path.
I always run the amps, with signal, for 48 hours before shipping. I've had a little extra time with this one so it has over 50 hours already. I do this to build up heat inside the amp and stress it to see if there's gonna be a component failure.

Take my money please!

 

[SonicTrance]

The design is very compact as Octavian asked and embed a lot of features. This is a great achievement Tomas

Thanks! It was a challenge to fit everything on the inside, lol!

You had to order the nameplate from far away? Would have thought that Sweden can make nameplates !

When I first started building amps I got the plates from a guy in the UK. So far everything has gone pain free with my orders until brexit happened. I probably could get plates from someone in Sweden but I want them exactly the same!

Except my priceless Oblivion. It's got a fan !!! and it's silent. But no fan for Odyssey. It's naked like the naked transformers.

You can disconnect the fan if you want.

 

[bcowen]

Where are the pictures!!! Or should I post another pic of the double smiley Akai that Bcowen loves.... or an open reel deck?

An 8-track would be more in keeping with the genre.

 

[UntilThen]

Populated with 7581A's and 6J5's.

Hi Tomas, could I trouble you to tell me if Eternity with these tubes has more tube tone than Oblivion? Also what other aspects are different in terms of sound between the 2 amps ... from your recollection. I know you do not have an Oblivion with you right now. Thanks.