1101 Audio custom crafted headphone amps
May 14, 2023 at 3:00 PM Post #1,186 of 1,281
Solar flare can drive anything except for possibly your car, or can it?
It might, but it's too heavy for me to carry it downstairs to the parking garage to try...
 
May 15, 2023 at 1:49 AM Post #1,187 of 1,281
After several attempts, I finally passed the quiz on the operation, and got permission from Mischa to fire Solar Flare up! :laughing:
In its new home in my rack, and running with 45 Globe tubes driven by 12AU7 tubes in SET mode with Resistor Load (a.k.a. Orange mode):

1684128998936.png


Driving my Grado GH2 (SPL 1mW: 99.8 dB, Nominal Impedance: 32 ohms), testing for noise:
* 2-stage mode and high gain, closing my eyes and listening carefully, I can BARELY make a noise floor.
* Switching to low-gain, I am not sure if I can hear it anymore or not.
* 1-stage mode and high-gain - I cannot hear it anymore! Totally silent.

On a semi-related note: switching between 1-stage and 2-stage modes requires power-off and waiting for 30-seconds (for caps to discharge).

Being a tube amp, it is important to note that different tubes may have more or less noise. I will report back after testing with different tubes.
Also important to note that 2-stage / high-gain mode that had the "most" noise floor - was still VERY low. This is one of the quietest tube amps that I ever tested!
Usually, noise floor is a problem for me - but here it was definitely NOT a problem at all. That is just me nitpicking :wink:
 
May 15, 2023 at 12:09 PM Post #1,188 of 1,281
@Zachik - beautiful piece of work. Congratulations and thanks for posting the pics!
 
May 15, 2023 at 12:54 PM Post #1,189 of 1,281
I think your greatest challenge on noise will be when you try the 71A. They're kind of infamous for it. I think they were originally designed for battery power supplies if memory serves?

The 45 is typically not a fussy tube when it comes to noise/microphonics, but the filament power supply matters a great deal for this tube. Mischa touched on that already in his post. My old Glenn 45 uses DC on the filament supplies with regulators and the noise floor is completely inaudible with every headphone I've ever plugged into it. In fact it remains the quietest amp I've ever heard in my life, tube or solid state. Not too shabby for a DHT. There are downsides to the DC filament supply route too as Mischa pointed out and it's possible to end up with some bad trade-offs in sound quality if not done well.
 
May 15, 2023 at 4:14 PM Post #1,190 of 1,281
After several attempts, I finally passed the quiz on the operation, and got permission from Mischa to fire Solar Flare up! :laughing:
In its new home in my rack, and running with 45 Globe tubes driven by 12AU7 tubes in SET mode with Resistor Load (a.k.a. Orange mode):



Driving my Grado GH2 (SPL 1mW: 99.8 dB, Nominal Impedance: 32 ohms), testing for noise:
* 2-stage mode and high gain, closing my eyes and listening carefully, I can BARELY make a noise floor.
* Switching to low-gain, I am not sure if I can hear it anymore or not.
* 1-stage mode and high-gain - I cannot hear it anymore! Totally silent.

On a semi-related note: switching between 1-stage and 2-stage modes requires power-off and waiting for 30-seconds (for caps to discharge).

Being a tube amp, it is important to note that different tubes may have more or less noise. I will report back after testing with different tubes.
Also important to note that 2-stage / high-gain mode that had the "most" noise floor - was still VERY low. This is one of the quietest tube amps that I ever tested!
Usually, noise floor is a problem for me - but here it was definitely NOT a problem at all. That is just me nitpicking
Congrats Zachik, that is a very impressive finished product. I hope it brings you great listening pleasure.
 
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May 22, 2023 at 12:10 AM Post #1,191 of 1,281
Tonight is IEM night...
What happens when you plug $35 IEMs to Solar Flare, using Mischa's impedance adapter for IEMs? Hold to that question for a minute longer.

Solar Flare in Orange mode (SET mode and Resistor load). 12AU7 drivers and 100 years old (or so) 45 Globe tubes.
One little cheat (on the $35 IEMs front) - so the IEMs are Kiwi Ears Cadenza which DO cost $35, but I upgraded the cable to NiceHCK Black Cat (paid $20 or so on AliExpress). So I guess it is a $55 IEM, single 10mm Beryllium dynamic-driver. Plugged to XLR through Mischa's 4.4mm to 4-pin XLR impedance dongle.
The result? TLS (Time Loss Syndrome) - "really?! an hour went by???" :ksc75smile:

I started in 1-stage mode, and the sound was super clean and delicate. No noise floor audible AT ALL. Volume cranked up to between 1-2. The Kiwi Ears is 32 ohms (but with Mischa's impedance adapter) and 110dBSPL/mW sensitivity, so not hard to drive.
Power off, wait 30 seconds, flick to 2-stage mode, power on... O M G ! ! ! Sound is thicker, louder, grander, and noise floor is still inaudible.

Just crazy how Solar Flare can drive hard to drive headphones with ease, and sensitive easy-to-drive IEMs. Both with jaw dropping results and inaudible noise floor.
Once again, hats off to Mischa! Such a talented engineer AND artist... :clap:
 
Jul 12, 2023 at 9:48 PM Post #1,192 of 1,281
As everyone knows, one of the many impressive features Mischa designs into his amps is the extreme versatility in tube rolling with adapters. I've been methodically planning and collecting various tube families over the past few years in anticipation of experimenting with a number of different tube families. I placed two batches of orders for adapters from Mischa, the first of which arrived a little while ago. I've been apprehensive at starting the journey due to the sheer number of tube rolling ahead. This week I decided to take the plunge. I will try to share impressions as I work my way through the different tube families.

First batch of adapters are here!
2x C3G to 6J5
2x 6J7 to 6J5
2x 6DJ8/6922/6N6P/ECC88 to 6J5
2x EL34/KT66/KT77/KT88 to 6J5
2x 12BY7/12HL7/12GH7/12GN7 to 6J5
1x 12AU7 to 6SN7
1x 6080/6AS7/5998/6BL7/6BX7 to 6SN7
adapters.jpg
These adapters are filled with black silicone to minimize microphonics. I have to say, they have a very premium feel to them. For anyone on the fence, these are a huge upgrade over the eBay stuff from China. For a little extra money you're getting a much, much better quality adapter.

First up: C3g -> 6J5
I'm starting out with the Lorenz C3g with embossed tops with a pair of Chatham/Bendix 6080WB for power tubes. It's been a long time coming - I bought these tubes over 4 years ago when I first joined Glenn's queue for one of his OTL amps. First impressions are tremendous air and soundstage with captivating detail + clarity. I've spent the last few months listening to a newly acquired Vioelectric V280 FE and was shocked by how identical the tonality/sonic profile is between these tubes and the V280. That's a very good thing IMO! The key difference is that the BH+ with these tubes has much, much more spaciousness and fluidity to the sound. The BH+ with these tubes is at least resolving (if not more so) than the V280. The Chatham 6080WB round out the sound a bit giving a paradoxically smooth yet detailed and resolving sound I could listen to all day long without getting tired. I'm impressed with how the BH+ with these tubes are easily able to best a well regarded SS amp in technicalities.

6080.jpg

On to the 6528 power tubes: Compared to the 6080WB, the spaciousness and clarity is taken up another notch (or two). The stage is now completely immersive. The transient attack / treble detail is certainly beyond anything I've heard before on a tube amp. This is like steroids for the beryllium coated drivers in the Verite Closed. Despite the insane clarity/treble presence there's still enough smoothness that I'm not hearing any fatigue. It might be a little too much with a different DAC/Cables, but in my chain I've been listening for hours without needing to take a break. At risk of sounding hyperbolic, I believe this is the most "hi-fi" sound I've heard so far. It's an incredibly engaging listen and a must-hear for those seeking to squeeze out as much resolution as possible in the music. I'm going to have some late nights ahead doing critical listening with high-res masters.

After spending time with these tubes, going back the the V280 makes the music sound completely dull and two dimensional (never thought I would say that about that amp!). One area the V280 excels in comparison is in the sub-bass. The extensions/quantity isn't at quite the same level with this tube roll. Some of the 6J5's I've tried seem to extend lower and with more quantity. Next, I have a pair of Siemens C3g that I plan to compare with once I can get myself to take these out.
6528 2.jpg6528 3.jpg
 
Jul 13, 2023 at 12:11 AM Post #1,193 of 1,281
As everyone knows, one of the many impressive features Mischa designs into his amps is the extreme versatility in tube rolling with adapters. I've been methodically planning and collecting various tube families over the past few years in anticipation of experimenting with a number of different tube families. I placed two batches of orders for adapters from Mischa, the first of which arrived a little while ago. I've been apprehensive at starting the journey due to the sheer number of tube rolling ahead. This week I decided to take the plunge. I will try to share impressions as I work my way through the different tube families.

First batch of adapters are here!
2x C3G to 6J5
2x 6J7 to 6J5
2x 6DJ8/6922/6N6P/ECC88 to 6J5
2x EL34/KT66/KT77/KT88 to 6J5
2x 12BY7/12HL7/12GH7/12GN7 to 6J5
1x 12AU7 to 6SN7
1x 6080/6AS7/5998/6BL7/6BX7 to 6SN7
adapters.jpg
These adapters are filled with black silicone to minimize microphonics. I have to say, they have a very premium feel to them. For anyone on the fence, these are a huge upgrade over the eBay stuff from China. For a little extra money you're getting a much, much better quality adapter.

First up: C3g -> 6J5
I'm starting out with the Lorenz C3g with embossed tops with a pair of Chatham/Bendix 6080WB for power tubes. It's been a long time coming - I bought these tubes over 4 years ago when I first joined Glenn's queue for one of his OTL amps. First impressions are tremendous air and soundstage with captivating detail + clarity. I've spent the last few months listening to a newly acquired Vioelectric V280 FE and was shocked by how identical the tonality/sonic profile is between these tubes and the V280. That's a very good thing IMO! The key difference is that the BH+ with these tubes has much, much more spaciousness and fluidity to the sound. The BH+ with these tubes is at least resolving (if not more so) than the V280. The Chatham 6080WB round out the sound a bit giving a paradoxically smooth yet detailed and resolving sound I could listen to all day long without getting tired. I'm impressed with how the BH+ with these tubes are easily able to best a well regarded SS amp in technicalities.

6080.jpg

On to the 6528 power tubes: Compared to the 6080WB, the spaciousness and clarity is taken up another notch (or two). The stage is now completely immersive. The transient attack / treble detail is certainly beyond anything I've heard before on a tube amp. This is like steroids for the beryllium coated drivers in the Verite Closed. Despite the insane clarity/treble presence there's still enough smoothness that I'm not hearing any fatigue. It might be a little too much with a different DAC/Cables, but in my chain I've been listening for hours without needing to take a break. At risk of sounding hyperbolic, I believe this is the most "hi-fi" sound I've heard so far. It's an incredibly engaging listen and a must-hear for those seeking to squeeze out as much resolution as possible in the music. I'm going to have some late nights ahead doing critical listening with high-res masters.

After spending time with these tubes, going back the the V280 makes the music sound completely dull and two dimensional (never thought I would say that about that amp!). One area the V280 excels in comparison is in the sub-bass. The extensions/quantity isn't at quite the same level with this tube roll. Some of the 6J5's I've tried seem to extend lower and with more quantity. Next, I have a pair of Siemens C3g that I plan to compare with once I can get myself to take these out.
6528 2.jpg6528 3.jpg
I enjoy reading about your tube rolling adventures - I have an amp where I use a 6528 power tube and it sure has added punch compared to the "weaker" 2.5A siblings. Since you mentioned beryllium coated drivers in the Verite, I want to mention that the C3g has Zirconium/Barium getters and the 6528 has Zirconium coated graphite anodes and gold plated molybdenum wires. Seems both tubes were very expensive when new...
https://frank.pocnet.net/sheets/127/6/6528.pdf
https://www.jacmusic.com/techcorner/ARTICLES/English/Portraits/C3g/C3g-C3m-info.html
(The second reference about the C3g is well worth reading)
 
Jul 13, 2023 at 11:28 PM Post #1,194 of 1,281
The Siemens are noticeably brighter sounding tubes, I'm curious if you'll find them just a bit too much overall like I used to. The Lorenz have less energy in the upper mids and are quite a bit more forgiving. That's how they presented to me in the Glenn 45 anyway....... or they did before the amp suddenly started sounding different a couple of years back. Whatever it was that happened there I actually ended up going back to Siemens because the amp got so much darker sounding.

This post reminded me that I have a pair of C3g adapters for my 1101 Audio amp too. I love the way things sound with 6J5s so much I never got the urge to try them.
 
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Jul 30, 2023 at 3:42 AM Post #1,195 of 1,281
Say hello to the OG BH+. :ksc75smile:

I received the amp from Mischa almost a month ago but haven't had time to test it. Now, with some free time to spare, I finally got it up and running after reading the online manual Mischa provided. Straightaway, it blew my mind how detailed the sound can be.

Currently running it in the BH mode with TS 6J5s, producing very clean-sounding and balanced output.

I can say it's worth every penny and time queuing up for the amp. Thank you, Mischa @A2029!

IMG_9358.jpeg
 
Jul 30, 2023 at 3:15 PM Post #1,197 of 1,281
Say hello to the OG BH+. :ksc75smile:

I received the amp from Mischa almost a month ago but haven't had time to test it. Now, with some free time to spare, I finally got it up and running after reading the online manual Mischa provided. Straightaway, it blew my mind how detailed the sound can be.

Currently running it in the BH mode with TS 6J5s, producing very clean-sounding and balanced output.

I can say it's worth every penny and time queuing up for the amp. Thank you, Mischa @A2029!

IMG_9358.jpeg
YES!! Congrats on this amazing amp! Many, many glorious tube rolling days ahead. The BH+ is the amp that keeps on giving. Thanks to you and Mischa for willing this wonderful creation into existence. Looking forward to hearing your impressions along the way.
 
Jul 30, 2023 at 3:47 PM Post #1,199 of 1,281
@A2029 is very knowledgeable and talented amp designer and builder.
I have been super busy in the last few months (startup employee life), but whenever I can find a little time - I listen to my Solar Flare, and have nothing but utmost respect and gratitude for Mischa!!! :beerchug:
 
Jul 31, 2023 at 2:22 PM Post #1,200 of 1,281
The KT150 amp Mischa built for me is truly the best piece of audio gear I've ever owned. Heck it might be the best material object I've ever owned. Every time I turn it on it brings me joy. In the past with other audio gear this feeling would fade away and it stops feeling "special" after a few great listening sessions, but not this time.

Building these amps and making people happy is not an easy job either. We're lucky to have builders like Mischa.
 

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