Michelag

And merry Christmas! Can we call this cfa full class A?

guess i'm trying a mix MELF/thin film

then let's find some other kind resistors 😁

Just built as per schematic, and worked straight at first attempt?

So, friends, anyone built this portable with success ?

Perhaps Better to get down go 380 the other one, no?

I guess it should be max 10mA. These bricks output max 20mA. If we take only the right or left half, the upper amp (+) draws 10mA, that are "vacuumed" by the lower PS (-400V). Then add other 10mA for the lower part, and you're at max acceptable draw. I'm testing with the 10k pot, until now it drew really more than 10mA, so the PS started "pulsing" under my dim bulb tester. I'll keep you updated.

And so, yes it is, quite unstable due to drifting. Problem is not the PS, it's that the current draw grows slowly with time, then it begins pulsating, then flames or short. I'm now assembling the stabilized version with dn2540 and pot, so that you can dial in the desired current, yet I'm having some issues with that, but as said, I started this morning (and now it's early afternoon). Who sold this unit made the error of "marketing" it too early, perhaps not testing nor listening at it. Here it's all about patience, testing, doing it better and listening. So probably a new PS will not solve the issue.

Yes, they're quiet to my ears. No noticeable noise in the cans. In the main thread, Dr. measured "ringing" at I don't know how many MHz. If you can find them, go for them. The supplier that I bought from, has them out of stock now. And yes, the difference is the input voltage. Yes, thanks, I'll see some video on YouTube and I'll become a pro! 😁

Thanks, I've already built them, Dr. sent me the file.

where?

Who helps me finding a chinese? Had a chat today with the Staxmafia boss, he didn't do the names, but indicated that some time ago, a chinese was selling this modded set with stax plug... Does someone want to be a spy? Or if you do not wanna do the name, also some hint about getting to him would be appreciated? Thanks a lot 😁

Wow! But just for my understanding, this is the limit after which damage to earspeakers can occur, right? I mean, so much power is really needed to drive the most demanding e-stats? Or is it thought as an exercise of pushing it to the boundaries ?

Thought I never shared pictures of my build, et voilà. Those 3.5 and 4.4 input connectors on the front do really a pragmatic job... I fit a normal bias plug (thanks @JoaMat) so the writing is now aged 😁

PBHV2160ZX seem to be out of stock at Mouser?

Same here, 1206 and 50ppm, but drifting

You are one of the greatest, here on my side it's easier to open the mouth instead of go checking updates on the two repositories 😁😔 Hope it addresses also the thermal runaway...

Yes, but it introduces noise 😁

Tried a test build, with silicone thermal sheet, alu plate on some alu piece. Yes, there's thermal runaway. Power consumption begins at 24V/0.8A and slowly takes up to almost 2A, when the board reached 80°C I shut it down. The 400V B+ rail (so the B-) started around 9mA, up to 20mA before shutdown. Offset was around 2V on one channel, 5V on the other one. Amp was in idle condition. @kevin gilmoreDr., you were saying putting a 12V sender in series to 1.1Meg resistor, newbie question, with what polarity? What about trimming the bias ? Do you foresee adding a trimpot in the next release? Thanks, hope it helps other fellow builders.

I'm still getting better at it

Let's see if I'm gonna have a happy birthday...

As written privately to @willsw, I'm in need for some 6 pins plugs, and I'm happy to lend a hand down what regards cad design, 3d printing (will order from jlcpcb though, so beware shipping times), and or pin variants. Unfortunately on the web the set of kt88/el84 pins with screw is to be found quite expensive, 10€ 10 pieces from audioaholics in France. Stax lambda NB already in, and don't have any socket for it 😞 Glad to help.

In what part of the world are you?

Perhaps a little early, compiled a BOM: https://www.mouser.de/api/CrossDomain/GetContext?syncDomains=www&returnUrl=https%3a%2f%2fwww.mouser.com%2fTools%2fProject%2fShare%3fAccessID%3dd8cfd9e908&async=False&setPrefSub=False&clearPrefSub=False

still looking for a reputable source of that lovely DC bricks.... Taobao doesn't work (or I am not able to) for me...