IMO clarity and focus are low hanging fruit for this phono. It does nuance and timbre fantastically even with chinesium tubes.
What you are describing I totally agree with when it's in stock form and that's what I heard, after the upgrades I did it's a totally different Phono preamp now in that regard. Like I said, different responses for different systems. Enjoy!
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.
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.
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. 🙄
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.
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. 🙄
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.
Thanks, I'll be careful!
I agree, I'm quite impressed with where mine is after simply changing a few critical components.
Pete
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.
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
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
Excellent, thanks!
I see that this shows 300uf in front of the choke and 200uf after. The diagram that I have from Stephe shows 2 100uf caps here, which is what is on my board.
Pete
Sorry, my bad. I should have said this is the schematics for the upgrades mentioned on the Lenco Heaven site in the main EAR 834P Clone thread. It has the list of the parts and upgrades that this schematic shows. This is what I'm doing to mine and thought you were too.
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
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
"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.
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.
I'll double-check but I found which capacitor was connected to the 200k resistor.
Is this the picture that you said is incorrect?
It matches what I found. It will be a couple of days before I get to check this out.
Pete
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.
Good thing I still have the original PS pcb to throw back in to compare if I need to.
Bad news! I hope that you are able to find the problem.
Do you have the single chassis version or the separate power supply like the version that I have?
Pete
Yeah, bad new. It's either the power supply or tube. Might be a heater on a tube or tubes. I have to see what the voltages on the heater supply line. It's like a 60hz tone so it's has to be on the heater side.
I have the two chassis
I have the two chassis
I got into my EAR clone today and checked all the grounds and found out something that I don't know if others know that the 834P Clones with the tw separate enclosed chassis has a different ground than the post over on LH site. They dont use the main ground by the big capacitors, they use a standoff pad that next to a through hole that is attached to the main ground on the power supply board. You need to solder the standoff and through hole together if replacing with a new power supply board. Or you can put a wire to the main ground. So I corrected this and now have ground which I didn't before after I performed a PS switch with a new PS with upgraded parts. You can see ythis in post #111 lower right corner.
The Hum was still there and was from a tube going bad. Put new tubes in hum is gone and now I'm back to how the EAR Clone was before I did the switch.
The Hum was still there and was from a tube going bad. Put new tubes in hum is gone and now I'm back to how the EAR Clone was before I did the switch.
Ok, another update. I went back and put the ground in it's proper place at the GND point by the caps. The builder had it on the other side which it was pretty quiet but began to give issues with hum and noise. So I added a jumper wire from both side of the main thick grounding plain by the caps at the corner to insure proper ground where the bolt goes to hold the PCB down. That did the trick! The EAR is now Dead quiet from hum and you can only hear the tubes at full VC. So now I know how to kill the hum and can move onto the phono preamp side to finish the installment of the 30uF Solen Film Caps in place of the 33uf Electrolytics and the TKD 50K stereo Pot.
I want to replace the Input/Output connectors but I need that special tool with 3 points to fit in the 3 holes in the connectors to loosen them up. I have better connectors to install and with change out the AC input plug with a Furuteh and place a NTC inline for softstart. When I was looking at the output when tracking down the hum from the bad tube I saw a pretty good surge on power up from the supplies, so I want to slow it slow a bit.
I want to replace the Input/Output connectors but I need that special tool with 3 points to fit in the 3 holes in the connectors to loosen them up. I have better connectors to install and with change out the AC input plug with a Furuteh and place a NTC inline for softstart. When I was looking at the output when tracking down the hum from the bad tube I saw a pretty good surge on power up from the supplies, so I want to slow it slow a bit.