[LobalWarming]

Can the Blue Halo be used as a preamp with speakers? Personally, using my amps with speakers, I have found that almost any combination of tubes sound noisy a very high volumes, but by judiciously using both the volume knobs on the headphone/preamp and the volume knob on the receiver for the power amplifier, I can eliminate the noise to the point of not being noticeable at all, even without music playing.
IMHO listening to tube amplifiers, even with the noise being masked by the music, is just fine. There are combinations that are really quiet, but that is not generally the rule.
Audiophile proverb: If they make it, it hums. JUST KIDDING!

I like to consider the odd noises a tube make as added thermionic dither. Just another bonus from the sweet glow of valve sonics.

Unless it's cell tower RFI - digital RFI makes me nutz.

 

[Xcalibur255]

I have had pretty lousy luck getting noise free 6080/6AS7 tubes over the years. I don't think I have a single pair in my collection that has been consistently quiet, and I've gotten rid of most of them over time because I got tired of fighting with them.

This hybrid setup where you can option in or out of the tube output stage is a best of both worlds solution. If one were to get exasperated from tapping that one 6080 that just won't stop buzzing they can just switch to the other mode and take a break from it.

 

[mordy]

I have had pretty lousy luck getting noise free 6080/6AS7 tubes over the years. I don't think I have a single pair in my collection that has been consistently quiet, and I've gotten rid of most of them over time because I got tired of fighting with them.

This hybrid setup where you can option in or out of the tube output stage is a best of both worlds solution. If one were to get exasperated from tapping that one 6080 that just won't stop buzzing they can just switch to the other mode and take a break from it.

It seems to me that how quiet a tube is behaving is dependent on the design of the amp.
But I am wondering if you lose out on frequency response or harmonics in those very quiet amps. Perhaps a very good design can accomplish everything…

 

[Xcalibur255]

It seems to me that how quiet a tube is behaving is dependent on the design of the amp.
But I am wondering if you lose out on frequency response or harmonics in those very quiet amps. Perhaps a very good design can accomplish everything…

I'm sure there's some truth to this. How hard you push a tube is a big factor in how prone it is to noise, so an amp with conservative operating points will probably be less likely to bring the noise gremlins out. How the stage is configured probably plays a part too, if it's actually contributing gain then the noise will be amplified. Power supply design and regulation probably matters too.

It's almost like there's a reason us tube folks have so much nervosa.

 

[raindownthunda]

Next up: Cetron 6336B + GEC L63

These tubes take forever to warm up and when they finally get there, they are HOT!! They sound pretty great. Much closer to the clarity and speed of BH mode than the 6x 6BXL7 or single 6080/6AS7G. These slam HARD and fast with the VC.

 

[mordy]

Next up: Cetron 6336B + GEC L63

These tubes take forever to warm up and when they finally get there, they are HOT!! They sound pretty great. Much closer to the clarity and speed of BH mode than the 6x 6BXL7 or single 6080/6AS7G. These slam HARD and fast with the VC.

As they say in the car racing world: There is no substitute for horsepower!
Actually, each 5A tube is capable of 30W which together equals 0.08hp.

 

[raindownthunda]

As they say in the car racing world: There is no substitute for horsepower!
Actually, each 5A tube is capable of 30W which

No replacement for displacement? According to Mischa they are running "only" at 9-10W per plate in BH+. Can't even imagine what 30W per plate would be like. Definitely fire hazard!

together equals 0.08hp.

How many 6336 tubes does it take to tow a boat?

 

[mordy]

No replacement for displacement? According to Mischa they are running "only" at 9-10W per plate in BH+. Can't even imagine what 30W per plate would be like. Definitely fire hazard!


How many 6336 tubes does it take to tow a boat?

I really don’t know how many watts they put out in our headphone amps, but I suspect just a fraction of the full output.
Don’t consider them a fire hazard, but you need to watch your fingers around them - touching them inadvertently can give you a nasty burn.

 

[ThanatosVI]

Next up: Cetron 6336B + GEC L63

These tubes take forever to warm up and when they finally get there, they are HOT!! They sound pretty great. Much closer to the clarity and speed of BH mode than the 6x 6BXL7 or single 6080/6AS7G. These slam HARD and fast with the VC.

I'm usually no Fan of Voltmeter, but that looks great!

 

[Marutks]

It seems to me that how quiet a tube is behaving is dependent on the design of the amp.

L0rdGwyn makes quiet tube amps. Even his OTL amp doesn't hum.

 

[TylersEclectic]

Thanks @mordy! I’ve never heard the GOTL unfortunately (I was in the queue for a few years before Glenn stopper building). I have a Bottlehead Crack that I’ll be able to compare to when I get some more hours in. Hopefully I can get the amp in the hands of someone like @TylersEclectic who have heard many more amps than I have for some more nuanced impressions


Definitely. I’m able to control the lights with my phone via an app or web browser as the controller is on the local network. I have a few other WLED lights and other smart lights around the house all integrated with Home Assistant, which is a nice solution to have a single dashboard to control everything.

Originally we were going to use a WiFi controller board with an external antenna on the back of the amp, but chose the Ethernet route to limit any potential for WiFi signal interfering with the audio. We also explored externalizing the controller, which for future builds may be an easier thing for @A2029 to implement and is far more user serviceable and would allow you to use WiFi outside ot the amp.

Looking forward to our next meetup bro!!

 

[raindownthunda]

Is it dead silent when no music is playing? Do you use Verite Closed cans?
I wonder what makes your amp dead silent. Is it 6080 tubes ?

My BlueHalo is dead silent only when I use 6N6P tubes ( or single 6080 ).

L0rdGwyn makes quiet tube amps. Even his OTL amp doesn't hum.

I feel like it's worth calling out that I'm finding the Blue Halo+ to be quietest / blackest background I've ever heard in a tube amp. Sorry you're having the noise issues though, that is frustrating. I'd hazard a guess that the noise is either bad luck with tubes and/or environmental factors. Have you tried out any other tube amps where you are now for comparison?

 

[A2029]

Is it dead silent when no music is playing? Do you use Verite Closed cans?
I wonder what makes your amp dead silent. Is it 6080 tubes ?

My BlueHalo is dead silent only when I use 6N6P tubes ( or single 6080 ).

Is it hum, or just the white noise/tube rush noise that all tubes have?

All tubes, no matter what quality, will have some amount of white noise that kind of sounds like constant air/wind moving across a microphone. This "whooshing" is referred to as tube "rush" noise, and is louder for tubes when tubes are more worn out or when tubes are NOS and need burn in. Some tubes, maybe due to their design or the materials used, never really quiet down.

How loud the tube rush noise is depends on the topology of the amp. Amps like the Blue Halo and Blue Halo+ will have higher tube noise than a transformer coupled SET amp as the BH/BH+ are OTL amps and have a high gain. Transformer coupled SET amps will have the tube rush noise reduced by a factor of the primary to secondary turns ratio. BH has a slightly higher noise floor than the BH+ for the same tubes as the BH has slightly higher gain than the BH+, so finding low noise tubes is more important. When running 6N6P tubes via adapters in the Blue Halo, not only are 6N6P tubes pretty low noise to start but the 6N6P to 6J5 adapters tie their tube sections together which averages out more of the noise and makes then even lower noise.

 

[Marutks]

I'd hazard a guess that the noise is either bad luck with tubes and/or environmental factors. Have you tried out any other tube amps where you are now for comparison?

I have ECP T4 amp which is dead quiet but it is a transformer coupled amplifier and it uses 12AT7 tubes.

 

[Marutks]

Is it hum, or just the white noise/tube rush noise that all tubes have?

It is tube rush noise.