[Xcalibur255]

When I got the 1951 ribbed plate Fotons, I sort of scoffed at "100-hour" burn-in. Having experienced the required 400 hours needed for some of Rick Schultz HFC Magnetic Conduction cable, I came to the conclusion that Fotons are a roller-coaster ride that eventually levels out. The HFC cables sounded better every day. So I know there is "something to" burn-in.
When my new Brimars CV4033 arrived they sounded great right out of the box, and have improved daily.

Yeah, when you burn in enough of these a pattern starts to become familiar. Some tubes take longer than others, but the sonic behavior seems to be more or less the same ride every time in my experience. It sort of resembles an impulse response graph actually if you were to treat the graph to represent swings in sonic character from bright/edgy to dark/flat every few hours of use. The swings become more subtle every time until one day the line goes flat and you can just tell it's locked in.

 

[dieslemat]

A brief update on the "Weldenheim" project: the prototype direct-drive amp is now clipping at 10A per channel, both channels driven, into the Raal SR1a headphone load. It plays very loud and works as a one-box solution. The chances this will become a product have increased significantly. However, there's still a long road to production, starting with talking to Raal/Requisite to make sure they are cool with this craziness, and to make sure the amp will work with whatever their future product plans may be. So don't throw away your Vidars yet!

Now, as to why we're chasing this niche product, here's the thing: I learned quite a bit about amp design in general, in the process of tweaking a product to deliver huge amperage into very low impedance loads. There's a long-standing joke in amp design about "driving a screwdriver." The Raal headphones are pretty much a screwdriver. And delving into all the tweaks necessary to increase power transfer efficiency means that we now know much more about this aspect of amp design--and will likely apply this knowledge to other products in the future.

I will forgo my Loki Maxi chant in exchange for: Weldenheim! Weldenheim! Weldenheim!

 

[bcowen]

A brief update on the "Weldenheim" project: the prototype direct-drive amp is now clipping at 10A per channel, both channels driven, into the Raal SR1a headphone load. It plays very loud and works as a one-box solution. The chances this will become a product have increased significantly. However, there's still a long road to production, starting with talking to Raal/Requisite to make sure they are cool with this craziness, and to make sure the amp will work with whatever their future product plans may be. So don't throw away your Vidars yet!

Now, as to why we're chasing this niche product, here's the thing: I learned quite a bit about amp design in general, in the process of tweaking a product to deliver huge amperage into very low impedance loads. There's a long-standing joke in amp design about "driving a screwdriver." The Raal headphones are pretty much a screwdriver. And delving into all the tweaks necessary to increase power transfer efficiency means that we now know much more about this aspect of amp design--and will likely apply this knowledge to other products in the future.

10 AMPS? You might need to change the sticker on the back from "No user serviceable parts inside" to "If you open this you will probably die."

 

[Ripper2860]

It's a new high-powered SS HP amp with 10 opAMPS per channel.

 

[leonthebumme]

Is a little exposed wire a problem with speaker cables? Giving monoblock Aegirs a shot and I had to cut back the shrink wrap on the mogami cables to reach the terminals. I am (without really any particularly educated background) *assuming* it isn't a problem, and will wrap the exposed areas with electrical tape. I would greatly appreciate any feedback to my thinking and approach here...

 

[Paladin79]

Yeah, when you burn in enough of these a pattern starts to become familiar. Some tubes take longer than others, but the sonic behavior seems to be more or less the same ride every time in my experience. It sort of resembles an impulse response graph actually if you were to treat the graph to represent swings in sonic character from bright/edgy to dark/flat every few hours of use. The swings become more subtle every time until one day the line goes flat and you can just tell it's locked in.

I have two tubes that are for all intents and purposes, identical, or as close as possible. On both tubes I replaced the solder in the pins just to eliminate that as a factor. Some of the Russian tubes are bad about that and my logic is, you have this combination or tin, lead, rosin, etc that has been sitting unused for 65 years. You put that in an amp and subject it to some heat, not as much as soldering of course, but how does it affect the rosin? Are you suddenly making a little better metal to metal contact inside the pins? The fact that some say the quality goes up and down like a roller coaster made me wonder about that a bit. It is about the only variable I can spot, that and the cleanliness of the outside of the pins but that is a quick and easy remedy. Besides which, these tubes having gone through the hands of @bcowen i know they were well cleaned prior to his testing them.

After tonight one tube will have had 100 hours and once again the two tubes will be compared. Final tests will be just blind listening and even if I cannot spot a measurable difference, perhaps someone with exceptional hearing/listening abilities can consistently pick one tube over the other. Fun stuff.

 

[r2muchstuff]

https://www.moon-audio.com/auris-au...ource=Moon Audio&dm_i=5B5W,7388,3942X7,QR0D,1

Why, just why???
I will take some great looking/sounding Schiit anyday.

 

[Derrick Swart]

Is a little exposed wire a problem with speaker cables? Giving monoblock Aegirs a shot and I had to cut back the shrink wrap on the mogami cables to reach the terminals. I am (without really any particularly educated background) *assuming* it isn't a problem, and will wrap the exposed areas with electrical tape. I would greatly appreciate any feedback to my thinking and approach here...

Effective not very beautiful though
Reassamble the amps end of the cable again with shrink wrap it gets nice and tidy.
Child can do the laundry! as we say in NL

 

[audio philestine]

but there are 4 things I know of where there is no such thing as too much: sex, money, tube stash...and power.

And lists of 4 things... with 5 items on them!

EDIT: my bad, I throught there was a comma in there. Guess I can't count to 4 on a friday...

 

[bcowen]

And lists of 4 things... with 5 items on them!

EDIT: my bad, I throught there was a comma in there. Guess I can't count to 4 on a friday...

Guess that could be looked at as tubes, stash....

I'm too old for the latter anymore.

 

[Philosoraptor42]

With respect to "portable", what we're working on is one box the size of a Jotunheim that would allow a pro to connect one AC cord and one USB and not have to carry around a stack of speaker amp/DAC/preamp. Personally, I don't see how you get a battery version of something that runs several amps on musical peaks. Even something like a 10000mAH lithium cell would last for minutes in normal use. But I could be missing something.

Why only USB? Wouldn't pro's want to have it run out of their interface so they don't have multiple USB devices fighting over each other?

 

[leonthebumme]

Effective not very beautiful though
Reassamble the amps end of the cable again with shrink wrap it gets nice and tidy.
Child can do the laundry! as we say in NL

Thanks! Unfortunately I need to settle for effective. I didn't make the cables and don't know cablemaking/shrinkwrapping/etc. but they're hidden in the back, so as long as there's no loss of SQ then the beauty in the music will suffice...

 

[Paladin79]

And lists of 4 things... with 5 items on them!

EDIT: my bad, I throught there was a comma in there. Guess I can't count to 4 on a friday...

I was scratching my head when I first read that lol You have always been a quality person A P and it was nice of you to clear that up.

 

[Ableza]

A brief update on the "Weldenheim" project: the prototype direct-drive amp is now clipping at 10A per channel, both channels driven, into the Raal SR1a headphone load. It plays very loud and works as a one-box solution. The chances this will become a product have increased significantly. However, there's still a long road to production, starting with talking to Raal/Requisite to make sure they are cool with this craziness, and to make sure the amp will work with whatever their future product plans may be. So don't throw away your Vidars yet!

Now, as to why we're chasing this niche product, here's the thing: I learned quite a bit about amp design in general, in the process of tweaking a product to deliver huge amperage into very low impedance loads. There's a long-standing joke in amp design about "driving a screwdriver." The Raal headphones are pretty much a screwdriver. And delving into all the tweaks necessary to increase power transfer efficiency means that we now know much more about this aspect of amp design--and will likely apply this knowledge to other products in the future.

Harmon Kardon tried to trademark the term "high current amplifier" but it was denied, so be sure your nomenclature is along the lines of Continuity and Nexus. Maybe "HiFlow" or "Bug Zapper." No wait, Bug Zapper would be for a 'Stat amp...

 

[David Aldrich]

PrimaLuna and Cary do auto bias as I recall, I can be pretty happy combining one or the other with a Gumby and Freya + but YMMV. Now I just need to sneak some Sonus Fabers into my house when my wife is away and pretend like they have always been there when she gets back.

What shelving is that?