Zenductor

[Nelson Pass]

I used the Vishays, but no reason the Infineons won't work, might
even be slightly better.

Plenty of other parts will also do the job, but the IRFP048's were cheap...

 

[nikon f]

Thank you Nelson, hope to see you in October!

Cary Chin

 

[Nelson Pass]

I am hoping to be there....

 

[nikon f]

I used the Vishays, but no reason the Infineons won't work, might
even be slightly better.

Plenty of other parts will also do the job, but the IRFP048's were cheap...

I like cheap.

 

[e_fortier]

Hi

Could I please have some help with my question from post 511 above.

I have received a few PM regarding this.

Thanks in advance.

Eric

 

[nesha]

+1 ?

 

[Nelson Pass]

As presented the issue would be the inductor. The Triad is rated at 2 amps, but I have
noted some saturation above 1.6 amps. If you are looking to increase power beyond what
you can get with that, probably want to look at a Hammond catalog.

 

[e_fortier]

Thank you very much Nelson 👍
I’ll stick with the output of 10W@8 ohm with the 19V, 1.5A setting using the Triad choke.

 

[mr_zener]

.. Going the other way, what would be a suitable choke for 30Ohm headphones? 400mA rating tops? I'm hoping for something small enough to PCB mount.

 

[Stanislav]

I don't see a reason to change the choke, just bias the CCT lower with P2. What you might need is to change the fet to something with lower Ciss and Qg, maybe even with a to220 case.
I run my Zenlite headamp, with irfz40, at 0.7A.
Drives every pair of headphones, no matter it's Z, effortlessly.

 

[uptownsquash]

As presented the issue would be the inductor. The Triad is rated at 2 amps, but I have
noted some saturation above 1.6 amps. If you are looking to increase power beyond what
you can get with that, probably want to look at a Hammond catalog.

How far fetched would 15 watts be?
24v rails?

Say you used:
Hammond 159ZE 28mh 3A
or
Hammond 159ZG 15mh 4A

 

[6L6]

Quite easy. Once the choke is big enough then the trick will be having enough heatsink.

 

[uptownsquash]

I was thinking the 2u mini dissipante 300mm
It should be just enough room to get it in there.
I want to avoid using the $100+ chokes.
What else would need to be done?

 

[Ben Mah]

How far fetched would 15 watts be?
24v rails?

Say you used:
Hammond 159ZE 28mh 3A
or
Hammond 159ZG 15mh 4A

You probably do not want to use the 159ZG. The much lower inductance will hurt low frequency response.

The 159ZE's inductance is probably close enough.

24V and probably about 2A, so dissipation for heat sink would be around 45W per channel.

Another Hammond choke to consider is the 159ZC, 60mH 2A 0.7 Ohm. I use that in my cascoded Semisouth SJEP120R100 follower amp running at 2A with no problem.

 

[uptownsquash]

I think I’ll give that a go. Anything else need to be changed? I think every else should
Be good to go?

24v 2a supply should get me to wear I am wanting to go. Now time to figure out a PSU.

 

[Ben Mah]

25V C2 and C3, especially C3, may be a bit close to 24V power supply voltage, with little room for error. I would go with 35V and then not worry about capacitor life and reliability.

The voltage dropping resistor, R5, in series with the LED should be increased. These days LEDs are bright at low current. A 20k to 24k resistor can easily work.

 

[uptownsquash]

Okay, I’ll increase the size of the caps up to support the voltage as well. That way when I get this PCB made up there’s options to do it all. Nothing crazy. I’ll keep the capacitance the same as well.

Then I’ll increase r5 as well.

I’ll use the Hammond part that was suggested earlier.

24v 1.5-2.0a should be a fun little guy.
Itll all go into a mini dissipante from modu shop. 2u 300mm.

Then I’m thinking a SLB PSU for each Channel.

 

[Nelson Pass]

With a larger sink and Inductor you would want to think in terms of 2+ amps with the 24v, and I would expect
something like 20 watts. If you wait a bit, the design of BAF 2024 Zenductor would be attractive...

 

[nesha]

Any chance 35mH chokes would go in Zenductor 2 ? I have nice custom 2,3A pair...
PS , I like how Zen teacup looks on your loudspeaker😁

 

[Mark Johnson]

The waiting is the hardest part.

_