[Xcalibur255]

I personally wouldn't operate a tube that has rust on the internal plate. There has to be oxygen for there to be rust and oxygen inside the glass envelope means the tube isn't safe to operate. Even if it happened when the tube was originally made and not due to air sneaking in over the years that's still pretty sketchy.

 

[LobalWarming]

Maybe sell the tube to @bcowen - he can exfoliate the oxygen with his new highly reactive cardboard getter technology. Or at least exfoliate the rust - while it sleeps. Except rust never sleeps.

 

[Xcalibur255]

If it had been a quality GE tube it never would have rusted in the first place..... Bill needs to stop hoarding all those good GE tubes.

 

[leftside]

Blue Monday. Strange that only one tube is feeling a little blue.

 

[xtr4]

Blue Monday. Strange that only one tube is feeling a little blue.

That's because of your nickname lol

 

[A2029]

Merry Christmas and Happy Holidays everyone!!

 

[raindownthunda]

Happy new year 1101 fam! New year calls for new experiments.....

Tonight I'm testing the pre-out for the first time feeding the Blue Halo+ into the DSHA-3FN amp. Having fun going wild A/B testing the DSHA-3FN with/without the Blue Halo+ in the mix.

Surprisingly, I'm failing to pick up any meaningful difference in sound between the two chains:

• Bifrost 2/64 (Balanced out) > DSHA-3FN
• Bifrost 2/64 (SE out) > Blue Halo+ > DSHA-3FN

Maybe 2-3% smoother/fuller/more rounded with the Blue Halo+ as pre-out? If so, it's very subtle. I wonder if these tubes (6528 + 5A/152M) in the Blue Halo+ are just really low distortion? Going to try another night with some more "tubey" tubes and possible RES mode (instead of CCS) to see if there is more tangible difference. I'm curious what other's experiences have been using tube amps as pre-out into SS as this is the first time I've ever tried.

As an aside, going back to the Blue Halo+ on it's own IMHO sounds noticeably better. Bigger stage, better separation/layering, more musical and life-like. Still blows my mind with how good the DSHA-3FN sounds that the Blue Halo+ can sound that much better! The Atrium Closed is especially a much better pairing with the Blue Halo+, it's not even close. The Verite Closed has some kind of special magic going on with the DSHA-3FN that makes it a worthy amp to keep in the stack for those sans-tubes sessions, however if I had to pick just one the BH+ would easily win out.

Just for fun here's some pics of the current setup testing pre-out mode:

 

[raindownthunda]

Things are getting weird over here... Tried the 6AS7G (Chatham) as a driver in the Blue Halo+. I also used a pair of 6AS7G (Chatham) as power tubes. Order of operations went like this:

1. Blue halo mode: This sounds pretty good! A little looser and more spacious perhaps when compared to "normal" driver tubes. Bass quality/quantity is still solid. Overall clarity remains good as well. I could enjoy this... but why? It's not "better" than running the more common driver tubes. I have to turn the volume wayyy up to ~3-4 o'clock to achieve normal levels.
2. BH+ w/ CCS: Much thinner sounding. Less bass quantity/worse quality. Veiled and far less enjoyable.
3. BH+ w/ RES: Even more veiled and flatter. No redeeming qualities. The least "euphonic" I've ever heard this amp. Like if someone took an amazing etch-a-sketch drawing and started shaking it up. Or a detailed pencil drawing and started smudging it up with their finger tips. This is taking things in the wrong direction.

I tried pre-out BH+ w/ RES > DSHA-3FN and the difference was much more noticeable than the tube roll in my previous post. Fuller, smoother, rounder sound with noticeably less clarity.

Possible conclusions:

1. Power tubes (particularly 6AS7G) are not great drivers (Duh?)... Even in BH mode where it still sounds pretty good: Just because you can, doesn't mean you should. Especially since power tubes have much lower typical lifespan.
2. Blue Halo mode does an amazing job at taking not-great driver tubes and making them sound pretty awesome.

The adapter can also be used with other types of power tubes (6BL7/6BX7/6080/5998) so might be fun to try a few different variants some other time, esp. with BH mode.

 

[ScornDefeat]

I know this is a long shot, but has anybody tried Mod House Tungsten with Blue Halo?

I suspect Tungsten will be a tougher test for an OTL, requiring around 20v at 150 ohms (not the ideal impedance for an OTL).

 

[leftside]

I know this is a long shot, but has anybody tried Mod House Tungsten with Blue Halo?

I suspect Tungsten will be a tougher test for an OTL, requiring around 20v at 150 ohms (not the ideal impedance for an OTL).

I'm sure something can be made that will be suitable. I had @A2029 build me an OTL amp with the LCD4 in mind. Also drives my Abyss well. It's a little OTT for an OTL amp, but I already had a SET amp and wanted to try something (very) different.

 

[ScornDefeat]

I'm sure something can be made that will be suitable. I had @A2029 build me an OTL amp with the LCD4 in mind. Also drives my Abyss well. It's a little OTT for an OTL amp, but I already had a SET amp and wanted to try something (very) different.

Agreed, he's a wizard with this stuff. I'm confident he could find a way to make an OTL work for nearly anything haha. LCD-4 isn't too dissimilar from the Tungsten outside of 20 dB of sensitivity.....impedance is close enough, at least.

I happen to move on from gear fairly regularly; my C2029 Power Conditioner is one of the few components I'd never see leaving. I believe I was one of the first to commission one of those. 3 or so years later, I'm thinking about finally getting a matching amp from him to plug into it!

 

[A2029]

Surprisingly, I'm failing to pick up any meaningful difference in sound between the two chains:

• Bifrost 2/64 (Balanced out) > DSHA-3FN
• Bifrost 2/64 (SE out) > Blue Halo+ > DSHA-3FN

Maybe 2-3% smoother/fuller/more rounded with the Blue Halo+ as pre-out? If so, it's very subtle. I wonder if these tubes (6528 + 5A/152M) in the Blue Halo+ are just really low distortion? Going to try another night with some more "tubey" tubes and possible RES mode (instead of CCS) to see if there is more tangible difference. I'm curious what other's experiences have been using tube amps as pre-out into SS as this is the first time I've ever tried.

One interesting thing to note with the BH/BH+ is that the lighter that it is loaded, the lower the output distortion. So if just using the pre-outs and combining it with super low distortion tubes like the 5A/152M, the tube distortion should be super low for a tube amp; even as low as 0.005% or so for some of the lower distortion driver tubes.

 

[A2029]

I know this is a long shot, but has anybody tried Mod House Tungsten with Blue Halo?

I suspect Tungsten will be a tougher test for an OTL, requiring around 20v at 150 ohms (not the ideal impedance for an OTL).

I'm sure something can be made that will be suitable. I had @A2029 build me an OTL amp with the LCD4 in mind. Also drives my Abyss well. It's a little OTT for an OTL amp, but I already had a SET amp and wanted to try something (very) different.

Agreed, he's a wizard with this stuff. I'm confident he could find a way to make an OTL work for nearly anything haha. LCD-4 isn't too dissimilar from the Tungsten outside of 20 dB of sensitivity.....impedance is close enough, at least.

I happen to move on from gear fairly regularly; my C2029 Power Conditioner is one of the few components I'd never see leaving. I believe I was one of the first to commission one of those. 3 or so years later, I'm thinking about finally getting a matching amp from him to plug into it!

The BH/BH+ has good gain and can do around 107dB into the Tungsten headphones, so should work well overall (best if the low impedance capacitor option is added to get super low frequency extension in the bass)

For even more dynamic headroom, I'm in the process of designing a slightly modified version of the Blue Halo that will be able to pump out up to 8-10+ watts into the Tungsten's and reach upwards of ~115dB output. I don't believe that a Blue Halo+ is possible with this new Tungsten Ed. BH design though, so it would remain only a BH for now. It will also likely be some time before that design is ready as I've been working on another amp design in the shadows for a long while that I hope to release very soon.

 

[ScornDefeat]

The BH/BH+ has good gain and can do around 107dB of max volume into the Tungsten headphones, so should work well overall (best if the low impedance capacitor option is added to get super low frequency extension in the bass)

For even more dynamic headroom, I'm in the process of designing a slightly modified version of the Blue Halo that will be able to pump out up to 8-10+ watts into the Tungsten's and reach upwards of ~115dB output.

Thanks for your insights into this! I usually aim for 110db as my personal "rule of thumb," just to account for dynamics swings, transients, etc., but 107db is really quite impressive and adequate for 95% of any situation that can reasonably arise!

The new potential design with 8-10 watts into that load is super impressive for an OTL headphone amp design! This might wind up being the ultimate Tungsten amp.....I've heard good things about Tungsten on tubes.

I might have to join the queue for a BH or BH+ in the interim......quick question, what's the case dimensions and weight of the completed amp?

Thanks!

 

[A2029]

Thanks for your insights into this! I usually aim for 110db as my personal "rule of thumb," just to account for dynamics swings, transients, etc., but 107db is really quite impressive and adequate for 95% of any situation that can reasonably arise!

The new potential design with 8-10 watts into that load is super impressive for an OTL headphone amp design! This might wind up being the ultimate Tungsten amp.....I've heard good things about Tungsten on tubes.

I might have to join the queue for a BH or BH+ in the interim......quick question, what's the case dimensions and weight of the completed amp?

Thanks!

Dimensions are approx 340mm width, 320mm length; Same dimensions as the C2029 conditioner (they can be stacked if desired). Weight of approx 32lbs or so.