jose

Beautiful. I have to do this amp right now.

I was with Alex in his first judo championship... My champion. [emoji16]

I´m waiting for the answers to the appraisals of Jim

It's interesting to see how Hifiman cares about the safety of its customers ... hopefully they will worry about the same way of not releasing versions of their headphones every year. When will the Jade III be ready?

It´s interesting Hifiman's answer about the dissection of his amplifier... However, they have not said anything about the electric discharge video.

I do not think that Hifiman has the same fate as Cavalli. Maybe they give up electrostatic headphones but I doubt they will disappear from the headphone business.

Thank you. I am very satisfied with this amplifier although I'm thinking of modifying some detail. It´s not a Carbon but I think it is a very, very interesting option if you are looking for an SS amplifier. (Thanks Dr. Gilmore) For control the offset I recommend the Joamat trimmer mod. (100R resistors negative rails) ?

I think mine is already finished but I need to touch up something. My pocket CFA.

On the other hand, the Hifiman depreciate a lot in a very short time.

Your policy about pre-orders seems to me quite logical and honest. I want to try one of your headphones. Will you do direct sales (through internet) or through suppliers?

I would like to think that yes ... I have it in my sights.

Happy Birthday!

They would be the first Grados to reach Mars

Offset around +-150mVdc and balance at 100mV in both channels. The resistive value (121R + 1K trimmer in parallel) after regulation is 79.9 Ohm in all channels. My amp passed from 18mA to 20mA BIAS. This works and I'm quite plaised. I could leave it like that but I'm thinking about how to do this mod something more "elegant" and at the same time I with this kind of trimmers but I dont´want to separate the pcb to heatsink because is a pain.

Different 121r and 1k trimmer in parallel. Ok, it's no nice but we haven't space on the PCB.

Nice Michael !!!! I am going to try the same Mod but changing 100r for 120r and add a trimmer of 1K in parallel. In theory the result should be "similar" but who knows. Without magic smoke, not can be glory ... I suppose

Thanks Michael!! Please, two sets for my if it´s possible.

The guy who sings the chorus is spectacular.

I guess you already had me in mind, right?

My amplifier was sounding about 5 hours continuously. I had no problem handling 18mA. Temperature with this heatsinks makes all measurements very stable. The body of the transistors was at about 40º after one hour and it remained in a range of about 40 ~ 45º all the time. I think it's right in choosing big heatsinks. As I mentioned, working with SE sources the amplifier goes perfectly, although with a balanced source the volume increases a little. I do not see anything wrong with modifying the BIAS. Maybe a trimpot could be added to future pcb´s ¿?. I will leave it at 18mA for the moment. What worries me a little is the offset. Although it´s stable (hardly varies ~ 0.7Vdc after being so long on) I don´t feel very comfortable with values of 14.5 / 9.22Vdc channel L and 13.76 / 11.88Vdc channel R maybe because I'm used to having levels close to 0Vdc.

Probably a minor work of Bruce but for me it has a very special meaning.

Thanks but my amps are very simple... besides this is a temporary wiring. It's all pretty chaotic. For the moment, I prefer to start with the values that Congo5 selected. Anyway, with these heatsinks, my amplifier stays moderately hot, so I rule out changing anything if it's not necessary.

I have not changed any value. I guess you mean R33 / 35 according to Dr. Gilmore's scheme ? Yes, 2K.

My CFA is already singing. Thanks to Kevin, Congo5 and Michael I´m using a SE source without problems (bridge "cold" channel to ground). My unicial assembly is a bit precarious but only because I wanted to check that everything works correctly. My "Mini BH PSU" to -407Vdc and + 404Vdc. Offset at the start with 14.5/9.22Vdc channel L and 13.76/11.88Vdc channel R. After one hour it is very similar on all channels. Balance 4Vdc and 2Vdc. I hope this is not worrisome. I am using "adequate" heatsinks ?. Temperature transistors after one hour of use is barely 40º. I guess that's why the offset remains so stable.