Many modern tube manufacturers are doing essentially that: take the 40W plate structure and large ST-19 glass envelope of the 300B, fit it with a 2.5V filament, and call it a 2A3. The original 2A3 uses a smaller plate structure with 15W dissipation rating in the smaller ST-16 envelope.

No, working on a new version of it - same look. Trickness has been evaluating the proto.

I have had a pair of EML 2A3 meshplates which would start silent and after a few minutes of operation start making a sputtering sound. Some people have also had this problem with some Psvane tubes. I’m happy to take a look at your amp and tubes. Email or PM me to discuss further.

Parallel - they have their own series

Email me for pricing. The Stellaris & Stellaris Special have more input capacitance than an original 274B can safely handle. An amp would have to be custom made to safely accommodate that rectifier.

There’s more to it and I need to update the webpage accordingly. The Special includes speaker outputs with binding posts on the right hand side of the chassis. The output transformers are different from the standard Stellaris and have dual secondaries which can be switched between series and...

From my experience the primary winding composition is significant and you’ll hear a difference between copper & silver. If you have the opportunity, listen to a Neiro vs Kageki; Kassai vs Kegon; Tomei vs Ongaku

Russian 6N1P and 5U4G I used to include the Shuguang 2A3B but their tube factory is closed since last summer and not sure when it will reopen. So i’m considering switching to either Psvane or Sovtek.

Email me for current pricing

Hi Eric, I’m good but cannot find your mail or PM. Can you resend?

In general the wait time is much shorter now.

The Stellaris is a class A design (all single ended outputs are) and accordingly the power consumption is roughly the same at idle or when playing loudly. Thus, enjoy your power hungry headphones with it. Push-pull class AB and B have differing power consumption at idle versus full power.

Doing a quick sim with estimate for current draw, the KR 4A3 is not a good match. The filament voltage will be insufficient.

I am actively working to reduce the wait time

Always use a grounded power cord and A.C. outlet. From experience, if you hear noise while turning the volume control, either the amp is being fed some DC into the pot and/or the input tube is not getting a good electrical connection with the socket, most often caused by tube rolling and...

Congrats! What is their serial number? Remember you can adjust the left and right rear temple pads, sliding them forwards/backwards, to adjust the fit and comfort.

In version 3 I change the ground point location for audio path to shorten it; I also change the grounding on the balanced outputs. These changes help reduce the noise floor further. The other major change in version 3, and even more influential on the sound, are the cathode bypass capacitors.

Correct, the current version of the Stratus incorporates knowledge learned while developing the Stellaris. While I currently believe this max I can take the Stratus without moving to a Stellaris, who knows the future... Frihed89’s Stratus was a version 1 model with the upgrades he listed above...

The RCA 5U4G is also good to try. Another interesting comparison would be with the bass-heavy K1000.

I recommend also trying a directly heated rectifier, like the EML 5U4G, in the amps.

The latest version includes the Audio Note Kaisei caps for cathode bypass duties, revised grounding of the audio path, revised DC heater supply for the 6N1P, among other changes.

No problem :) I wanted to explain my rationale behind the design.

I continued the component layout of the Stratus in the Stellaris, which is optimized in flow of the power supply path, flow of the signal path, and distancing of the audio components from the power supply. The Audio Note output transformers are large and there is not enough free space inside the...

The Stratus chassis have all been made to fit a 9-pin tube socket. More importantly, I looked up the specs and plate curves for the 6N7. While it has a mu of 35 the plate impedance is 22k, which around 3 times higher than the 6N1P, and makes it much more difficult load with a high resistive load...

The Stratus (and Stellaris) use the 6N1P for driver duties and has more than enough gain (mu of 35) to drive the 2A3 to full power. The 6J5 and 6SN7, for example only have a mu of 20. The 6SL7 has too much gain, in my opinion, combined with a high plate impedance with associated complications...