LuFo Amp - 39w SE Class A from 28v Rail

[Vunce]

Excellent stuff here X!
I’m thinking about a suitable chassis already

 

[zman01]

X,

Looking good.

Hope that JPS64 can get the PCBs done soon so that a full stereo build can commence.

 

[xrk971]

Indeed, JPS64 finished the layout yesterday but it is me who is the holdup. I have not had a chance to review and share it yet.

 

[zman01]

Take your time X. The thread is moving pretty fast anyways.

 

[AKSA]

Very good info, X. I suspect this amp will be very popular in the US where the MOT is easy to find. 230Vac MOTs are not suitable, so Asia, Oz, Europe are not so well served.

But thanks for the Hammond suggestion. Expensive, but outstanding results; 100mH DCR 0.42 is just the cats whisker.

Hugh

 

[zman01]

Hugh,

Anand has reached out to Toroidy - let's see what they say. Toroidy can be an option for folks in Europe.

 

[nautibuoy]

Looking good X

 

[chermann]

Did the big Hammond 195T5 get dismissed? It's ~$3.00 more expensive than the 193V when I checked just now. Just thinking out loud... I seem to recall seeing those on a couple of Big MoFo builds.

its not so easy to find a coil that fit to this amp...
yes in digikey has the 195T5 about 78 euro each


what about this?
Würth Elektronik WE-CMBNC 7448050490 Netzdrossel THT XL 90 mH 110 mΩ 3.5 A

%product-title% kaufen

 

[danny_66]

That one is worthless for this application, it's only for AC.

You need a choke that is specified for DC filtering, like those from Hammond.

 

[chermann]

thx danny


chris

 

[xrk971]

Hammond 195T5 on Digikey is 100mH, 5A and 0.64ohm for very reasonable price! $95.
Blocked

An externally hosted image should be here but it was not working when we last tested it.

To go to 10A, 0.42ohm is then $300.

 

[chermann]

thanks X..i got it

 

[xrk971]

Very good info, X. I suspect this amp will be very popular in the US where the MOT is easy to find. 230Vac MOTs are not suitable, so Asia, Oz, Europe are not so well served.

But thanks for the Hammond suggestion. Expensive, but outstanding results; 100mH DCR 0.42 is just the cats whisker.

Hugh

Taiwan uses same electrical infrastructure as US. 120vac 60Hz and same outlet plug style even. MOTs from Taiwan?

50.4vpp from 27.3vdc input. That’s 1.85x multiplier for output voltage swing. Pretty cool what a choke can do. That’s 85% efficiency I think.

 

[poseidonsvoice]

To all,

Just heard back from Toroidy. Unfortunately they cannot make the choke as specified!

Best,
Anand.

 

[danny_66]

What about the Hammond 195S4 ?
70mH, 4A, 0.6R and best of it all, it only weights 2.6kg
compared to the 6.4kg 195T5 and the heavyweight champion 195T10 with 14.6kg

 

[xrk971]

Hammond 195S4 will probably work fine. You want some headroom for the current swings though.

I just got a shipment of AliExpress LD1014Ds. They are so easy to solder into the adapter boards. I installed and tested. Works fine. Bias current is stable and music sounds good.

 

[marconi118]

Can you share with us the seller of LUs on aliexpress?

 

[xrk971]

This is where I got mine from. The price is amazingly low - so the risk is low in the event they do not turn out to be real. But the ones I got seem to be the real deal.

5pcs/lot LD1010D LD1014D TO 252 In Stock|Integrated Circuits| - AliExpress

 

[nautibuoy]

Thanks X, I ordered a small batch from that seller based on your positive experience.

 

[xrk971]

I think there is a way to take two of these using a common choke, and have them driven by a balanced preamp and drive them in bridged output for 150w. Plus, double the slew rate. That would be interesting.