[L0rdGwyn]

Good to know. Thanks! Never paid much attention to that, but now that you point it out a 12AT7 has more than twice the plate resistance of a 6SN7 (15,000 versus 6,700 at 90 - 100v on the plates). I want to try the Brimar in an OTL (the Incubus), but don't have a clue how the circuit is set up.

15K isn't too bad, but something like the 12AX7 with its >60K plate resistance could be a problem depending on the output stage. I think you will be fine with the Incubus, as the output stage likely has very low input capacitance - surely if it is a cathode follower of some kind. Cathode followers, like in most headphone OTL amps, are used as buffer circuits due to their high input impedance and low input capacitance, you can run just about anything into them and get good bandwidth

 

[UntilThen]

I use AmpCoin. So this is how I envisage head-fi's journey's end will be for me. The trio of amps to serve my needs are Oblivion, Destiny and Odyssey. In the order of their arrival. Oblivion is a tube hybrid design that is the brain child of Mr Cuwen and specialty of Tomas. Destiny is a triode 300b SET amp and is from McChanson amps and Eric is a veteran making tube amps all his life and he's in his 70s now. Odyssey is a KT88 SET amp and I've pick Tomas to build this because he has a wealth of experience modding the Little Dot Mk8 / 6. He was old school before he became new school.

This was Tomas LD Mk6 with extreme modifications.
https://www.head-fi.org/threads/little-dot-mk-vi-super-modified-we421a.885848/

This is Oblivion with my then LCD3f.


Destiny my 300b amp that is amazing with both speakers and my LCD4.


Odyssey. My pride and joy and I haven't heard it yet.

 

[L0rdGwyn]

Thanks. It's fascinating to read technical stuff. I'm a software guy but I read tech stuff out of interest. Basically in the world of audio, I'm a consumer. I consume.

Of course, just something I wanted to point out for the sake of learning! Triode-strapped pentodes typically have lower input capacitance than true triodes, like 300B, so most input tubes should work well, only those of the highest plate resistance might cause an issue, like 12AX7.

 

[UntilThen]

only those of the highest plate resistance might cause an issue, like 12AX7.

I’m not sure I want to try the 12ax7. There was a very rare Brimar 12ax7 on sale in the local classifieds but I pass on it. Just not sure about using 12ax7 in Odyssey. After all there are plenty of driver choices already.

 

[jonathan c]

Cash? Are you guys still using that in Pennsylvania? Wow. We switched to BcowenCoin in NC a long time ago.....

Just a moment…I thought that it was bitcowen that became standard fare for Bangybang…the tubes and the payment fizz out at a moment’s notice…

 

[UntilThen]

Bitcowen is patent now. Hey Bill sell me some of your 6SL7 collection.

 

[UntilThen]

I'm back to my main setup now. For some reason, I don't think I spend enough time with He1000se and Oblivion because what I'm hearing now is breathtakingly beautiful and the air and scale of the music enveloping my head is mesmerizing.

I listen to 4 song on Tidal HiFi :-

Time to say goodbye - Sarah Brightman and Andrea Bocelli
Everything I do I do it for you - Katherine Jenkins
What a wonderful world - Willie Nelson
Wonderful world - Sam Cooke

and I'm spell bound.

Oblivion deserve a spot on top of the rack. I'll have to rearrange that.

 

[baronbeehive]

That is when I know instinctively what tubes to use in the Wa22 to make it warmer. I chose Ken Rad 6sn7gt black glass, Bendix 6080wb....

I found the Bendix 6080WB to be rather bright on my Little Dot amp.

 

[baronbeehive]

One thing you need to watch out for with these high gain tubes is high-frequency rolloff.

I was wondering if that was the origin of Joes tube lore in which he claimed that 12AX7's were more fuzzy sounding than 5751 equivalents. I swallowed this for a while but since using my Philips 12AX7's I have not found this to be the case, and what's more the frequency band is very extended on both ends.

 

[baronbeehive]

You should probably get some of these for that adapter before they're all gone. I haven't heard them yet myself, but have a couple on the way:

https://pulsetubestore.com/products...4-12at7-factory-tested-plug-play-ready-to-use


This is a good starting point into the quickly rising pool of slobber on these. If the monikers are unfamiliar they are all long-term HeadFi'ers with nice equipment and a ton of tube rolling experience, so when there's universal OMG's happening with them it's a "where there's smoke there's fire" kind of thing:

https://www.head-fi.org/threads/schiit-mjolnir-2-listening-impressions.778250/page-239#post-16380762

That guy who described Brimars as insane.. I agree! I had some CV1988 and they were definately the most insane tubes I've tried, very holographic as he said.. but far too insane for me.

 

[jonathan c]

So when there's universal OMG's happening with them it's a "where there's smoke there's fire" kind of thing.

An apt description of DarkVoice ownership…?

 

[UntilThen]

I found the Bendix 6080WB to be rather bright on my Little Dot amp.

Very unusual description of Bendix 6080wb. Something else in your chain must be the cause of the rather brightness.

 

[baronbeehive]

Very unusual description of Bendix 6080wb. Something else in your chain must be the cause of the rather brightness.

Yeah! Maybe not so much bright as very defined and airy, but warm.. well I don't know about that.

 

[jonathan c]

Very unusual description of Bendix 6080wb. Something else in your chain must be the cause of the rather brightness.

Agreed. I have heard the Bendix sound deep, sound full, sound weighty but never bright.

 

[UntilThen]

That guy who described Brimars as insane.. I agree! I had some CV1988 and they were definately the most insane tubes I've tried, very holographic as he said.. but far too insane for me.

Ah CV1988. They sound insanely beautifully. My friend was insane too when he adorned these tubes on his Wa5le and loan it to me for 2 weeks. That was the weeks when my GOTL arrived.