EAR834P Project

I ordered some Solen Caps today, they are on sale at PC. Gonna use these for the 6 caps on the power rails in place of the 33uf caps in there now. should be interesting.

The EAR clone is going through its normal ugly faze of the break in that I always get with any upgrade. 15 hours on it so far but I'm hearing way more info off the LP than before that was covered up with noise from the power supply in stock mode.
 
was covered up with noise from the power supply in stock mode
I have replaced the resistor with a 20h choke and ordered a 300uf Nichicon cap to replace the 100uf one in front of it. I have the ultra high speed diodes but haven't installed them yet. The Zener diodes to tweak the supply voltage are on the way.

What else should I look at upgrading?

Pete
 
Pete. make sure you put that 330Uf cap is on the correct side of the choke according to the EAR 834P clone schematic. The Picture on the LH site is wrong, it shows the 330uf in wrong place and where its at in the picture is after the Choke. I traced it out to be sure when I was putting mine in.

After going back and reading the main EAR 834P build post, I saw that it mentioned to use 4 of the 1N5373B in the Zeners spot. :rolleyes:

Today listening to music, the EAR is coming back to sounding very nice. I expect one more ugly change before they settle into what they will sound like and get better from there on from my experience with upgrades. So far it is a totally sounding Phono preamp than the stock version and still has that basic EAR signature sound but way better. Lets see what happens over the weekend.
 
I've been looking at various schematics for this phono stage and none of them seem to show the choke. I think that this is the resistor that I replaced with it.
Screenshot_20231117-000617.png


So, I am going to replace the 100uf capacitor on the right side closest to the diode bridge, not the left side with the transistor and Zeners, right? I'm increasing it to 300uf.

One step at a time! Thanks in advance.

Pete
 
Okay, I've finished the next phase of upgrades to my EAR834P project. I replaced the two 1N5374B Zener diodes with 1N5373Bs. They each have 72vdc across and my final B+ is now 288vdc, which is an improvement over the 299vdc that it was at before.

I also swapped the 100uf electrolytic capacitor in front of the choke for a 300uf Nichicon. As Drummerboy pointed out, the correct cap is the one on the left, away from the choke.

The last change to the power supply (so far) is that I swapped the diodes in the bridge to ultra fast ones. The devices recommended on the Lenco Heaven thread were out of stock so I went with a Panjit part, UF4010G_AY_00001.

It's now back in service and warming up. At first listen these upgrades are much more subtle. I'll have to spend some more time with it after it's fully warmed up before I'll be able to report the results.

Pete

PXL_20231122_203022047.jpg
 
"I also swapped the 100uf electrolytic capacitor in front of the choke for a 300uf Nichicon. As Drummerboy pointed out, the correct cap is the one on the left, away from the choke."

Pete, The 330uF cap goes before the choke. Where you put it is after the choke.

Last night I was listening for at least 4-5 hours and that EAR clone is really opening up with a wider/deeper soundstage. Very nice! only have 25 hours on it now.
 
Well, bad news. I went to use my EAR clone and it has a loud humming noise that rises and lowers with the volume. Almost like a DC offset or a component went bad. I can very vaguely heard it in the right with the Volume turned and shorting plugs in which before it was dead silent. So I have to put it back on the bench and see what is the cause. It's got to be in the power supply, it was work in fine over the Thanksgiving holiday. Audio gear sometimes. :)

Good thing I still have the original PS pcb to throw back in to compare if I need to.