T2 - Finally bought one!

[mulveling]

LOL, that is a great meme @Rhamnetin - stole-eded

@mahesvara As this implies, there's no commercial builder that makes T2 amps. You have to find a builder, and commission a build from them - and there are at least a couple T2 versions now. There are very few people in the world you should trust with such an undertaking. My builder was @georgep and he's probably completed more successful T2 builds than anyone in the world now. I was very happy to get him to agree to build me one. I feel like this must be the best T2 version, though I haven't heard others. It certainly makes a laughingstock of any other amp I've ever owned. But the silicon parts for his version are OOP. There's also a guy who goes by the handle "Kerry" that builds a very beautiful T2 version with a custom chassis of his own design, and SMD and in-production silicon parts.

Also I have no self-control so I ordered a quad of those Philips SQ E88CC, and some Siemens A-frame gold pin E88CC. The latter because I actually found a NOS pair I'd forgot I had while cleaning/organizing around home, and figured I should order another to complete a quad so I can try 'em in the T2. Wish I forgot I had some Telefunkens or CCA's

 

[JimL11]

Is there a consensus on the longevity of NOS EL34 in the DIY T2? I know that the BHSE was running them so low that they were loafing and could practically last forever, but it seems like the T2 is pushing more Watts through them. I have a spare set of Hollands, but would like to get a sense for what the timeline might be - and mine were really "used, tests strong", not true NOS sets. And now that I think of it, what's the expected longevity of NOS 6922 in this circuit?

According to an old post by Kevin Gilmore the DIY T2 runs its EL34s at 500 volts and 14-20 mA, or 7-10 watts plate dissipation, while the BHSe runs at 400 volts and 18 -25 mA, which is also 7.2 - 10 watts plate dissipation. Since the EL34 is rated at 25 watts plate dissipation, in either case we are talking about running at 30-40% of rated plate dissipation, so they should last a very long time, I would guess 10,000 hours or more for NOS tubes.

 

[mulveling]

According to an old post by Kevin Gilmore the DIY T2 runs its EL34s at 500 volts and 14-20 mA, or 7-10 watts plate dissipation, while the BHSe runs at 400 volts and 18 -25 mA, which is also 7.2 - 10 watts plate dissipation. Since the EL34 is rated at 25 watts plate dissipation, in either case we are talking about running at 30-40% of rated plate dissipation, so they should last a very long time, I would guess 10,000 hours or more for NOS tubes.

That's great news! Thanks so much for your knowledge, as always @JimL11 . I knew the voltage was higher on T2, but didn't realize the current was lower too. A NOS EL34 should be loafing at 10 Watts. Unlike us humans, they live longer the less they exercise. So I probably have a nearly lifetime supply of lush Holland EL34 sound

 

[Whitigir]

That's great news! Thanks so much for your knowledge, as always @JimL11 . I knew the voltage was higher on T2, but didn't realize the current was lower too. A NOS EL34 should be loafing at 10 Watts. Unlike us humans, they live longer the less they exercise. So I probably have a nearly lifetime supply of lush Holland EL34 sound

Or you can buy 10 set of Nos quad in preserve

 

[purk]

Where do you keep those precious tubes again @mulveling ?

 

[mulveling]

Or you can buy 10 set of Nos quad in preserve

LOL only at 3 quads now. And used-tests-strong, not proper NOS. One of them is only really matched pairs, but that's good enough if you're careful.

Where do you keep those precious tubes again @mulveling ?

We have a history here, folks. I accidentally broke one of Purk's Holland EL34 a few years ago, and before that lost one of his nice small-signal tubes (still really no idea where it went)
I got him a replacement pair of Hollands, and buy him ribs occasionally to try and make up! His continued friendship is worth it, I guess

 

[Whitigir]

Lol, I remembered the first time I swapped tubes...it flew out of my hands and I didn’t know how it could happened, but it wasn’t damaged as I had carpeted floor...given that it was the cheap modern Mullard el34, still freak me out LOL!

 

[mulveling]

Lol, I remembered the first time I swapped tubes...it flew out of my hands and I didn’t know how it could happened, but it wasn’t damaged as I had carpeted floor...given that it was the cheap modern Mullard el34, still freak me out LOL!

Yep, no such luck here with old hardwood floors (which are more vintage than even my oldest tubes, at more than 100 years old - lots of foot splinters too). I knew how to be careful then; I was just stupid and careless. From a drop of merely 2.5 - 3 feet up, the elongated EL34 tube just shatters. I am much more careful now! Two hands, always.

I feel really guilty, having destroyed something of such beauty.

 

[Jones Bob]

I’ve got a quad of Valvo branded “Holland” (Brussels manufactured actually) DD getter, brown base EL34s for sale. Bought as NOS, matched quad with closely grouped manufacturing dates. Around 300 hours on them. They are the ones seen in my profile photo.

Will post on the marketplace after I get some good photos in the next few days, if anyone is interested.

 

[mulveling]

Rocking my first set of "premium" 6922 tonight. Siemens gold-pin E88CC, West Germany, late 60s or early 70s. Not even properly construction matched - one pair is "A frame" style, the other is not. But they are extremely low in noise/microphony, and tightly matched within each pair. When georgep said the input tubes were more important, he wasn't kidding. Wow! This roll (from Japanese 7DJ8) made an even bigger difference than the roll from EL34 from Russian Mullard to Holland brown base DD (and the latter are truly superb tubes; someone snag Jones Bob's pair before I get tempted).

The difference is in the midrange and imaging. Significantly more holographic; better 3D imaging. The midrange is sweeter and more natural, so damn liquid, while being supremely detailed. This new configuration represents the most realistic, enjoyable sound I've ever heard rendered from headphones. Really liking what I hear so far. I'll keep 'em in for a couple more sessions, then try the Philips E88CC SQ. Just when I thought it couldn't get any better...

 

[Whitigir]

So, interest check here!

Well, today my life starting to take a corner. It could be a good thing and it could be a bad thing. But I will be moving to another bigger place, and in the future I will no longer be able to listen to my Stax at work anymore. So, if anyone want to pick up this T2 of mine, shoot me a PM.

I will call off this hobby in headphones for a while, maybe back later and regret doing this. But I will be moving toward loud speakers setup, and may still be seeing you guys around. This means I am going to list up my SR009S and SR009 as well.

 

[purk]

I would totally buy your amp if I don't already have one. Justin once told me that he was going to charge more than $12k minimum for him to even build one and that was when the price for those exotic parts were not that expensive. He even said that his new DHT amp will not be as complexed as the T2.

 

[Whitigir]

I would totally buy your amp if I don't already have one. Justin once told me that he was going to charge more than $12k minimum for him to even build one and that was when the price for those exotic parts were not that expensive. He even said that his new DHT amp will not be as complexed as the T2.

Thanks Purk, the T2 is mind blowing in complexity, and so I agree with what Justin said. To build a T2, it is better to be building 3-4 BHSE in it place

 

[mulveling]

@Whitigir
What the heck man!! You were the chosen one to lead the Stax 009/T2 holy crusaders. I am loud, repetitive, and annoying enough but have no knowledge or skill to building these amps. Purk is not good enough because he listens too much to dynamic headphone gear (I think he is afraid to turn his T2 on every night)

 

[Whitigir]

I hope I will get to keep it ! And pass it down to my boy! Or hell, I will just tuck it in the corner and get back to it in 10 years LOL

I think Purk is afraid of his XF2 burning up and that he can’t use it anymore. T2 and XF2 are too sacred