DIY EAR 834p phono stage - a short evaluation/ test with those chinese PCBs

[GrooveGrinder]

See the TRLH build thread in this forum

[PatrickJones]

Many thanks for the response and I apologise, I can appreciate how annoying it must be having newbies popping up and asking these questions, but the excellent grounding diagram in the build thread is (though fundamentally generally applicable) a Douk board. I have the blue Xuling board which doesn't have the predrilled holes for earth connection - all I'm trying to establish is whether I should surface mount an earth wire from the four signal ground pads back to the star point on the psu or if it's cool to leave them alone if the sound is good. I've read the build thread (and this one) many times over the course of my build and can't find an answer. Again, apologies if this isn't the right place to ask.

[Tomcat1969]

Hi Patrick.

It sounds as if you will be fine.

I am using the same PSU and xuling board.

Earth the PSU to the IEC and to the case. The case earth will also be the point for connecting the tonearm earth.



You can't see in the photo, the earth to the IEC is connected to the baseplate and the earth terminal of the IEC.

[PatrickJones]

Magic, thank you so much Tomcat! I'm actually just over the Forth from you in Edinburgh, so if it does all explode you might be able to see it. Like you, I'm also looking at the various Pass options for my next project, so will follow with interest...

[Davidrp]

PCB Rectifier

Hi I'm attempting a build which is stretch for me using the Xuling board set and I was struggling to find what rectifier I should choose from Mouserau it's marked D10A/100V on the board. I would very much appreciate any help.

thanks

David

[PatrickJones]

Hi, and apologies, again. I’m running with my DIY  EAR834 now and after about 30-90 minutes of play my integrated amp (Marantz 8005) kicks into protection mode, presumably because it’s overheating. Granted, it could probably do with a bit more ventilation, but I’m not listening at high volume and it’s never happened in years with my previous phono stage (Rega). Could anyone give me a pointer as to where to start investigating? Cheers.

[PatrickJones]

Hi, and apologies, again. I’m running with my DIY  EAR834 now and after about 30-90 minutes of play my integrated amp (Marantz 8005) kicks into protection mode, presumably because it’s overheating. Granted, it could probably do with a bit more ventilation, but I’m not listening at high volume and it’s never happened in years with my previous phono stage (Rega). Could anyone give me a pointer as to where to start investigating? Cheers.

Just in case anyone else is having a similar issue, I think I've cracked it by switching the cathode follower from a 12AX7 to a 12AT7. Now I'm still very much a novice when it comes to amplification but I think this is something to do with the 12AT7 having a lower plate resistance / higher transconductance? Presumably this means the integrated amp down the line isn't having to work as hard but, as I say, I'm purely speculating here as my knowledge / understanding is pretty much zero...

[GrooveGrinder]

The emerging consensus seems to be that it's a better sounding amp with the 12at7 in v3...
(Provided its enough gain for you... and seems to be for most)

Consensus also seems to be that the at7 is a better sounding tube.

The big question is whether it would sound better with the 12at7 in all 3 positions....

Anybody tried it?

Sent from my SM-G950U using T***talk

[Jessica_K]

I have not tried it manually but on simulation there is not enough gain with the AT’s in all three positions, it works in V3 as it is a cathode follower where the circuit gain is approx 1 and is used as a impedance converter to provide a low output impedance

Jessica xx

[Drummerboy2]

Hi everyone, I'm new here and this is my first post. I just wanted to say I have been enjoying and taking in all the info that has been posted for this EAR 834P kit. I have mine on the way from China and will be here later this week or early next week. It's the Zili Audio pcb and I have already ordered the Caps for the main PCB and PSU boards. All Nichicon KX caps, I have used these caps in another tube phono preamp with great results. I was going to use Jensen Copper Foil PIO caps for the coupling caps but they may not fit but I will try and see.  if not, I will use Audience Auricap XO caps.

I wanted to do the mods for this kit but I will first build it to the original and see how it sounds like first and work out any bugs. Then, I will look into the mods. Hopefully everything goes well?

[Jessica_K]

Hi everyone, I'm new here and this is my first post. I just wanted to say I have been enjoying and taking in all the info that has been posted for this EAR 834P kit. I have mine on the way from China and will be here later this week or early next week. It's the Zili Audio pcb and I have already ordered the Caps for the main PCB and PSU boards. All Nichicon KX caps, I have used these caps in another tube phono preamp with great results. I was going to use Jensen Copper Foil PIO caps for the coupling caps but they may not fit but I will try and see.  if not, I will use Audience Auricap XO caps.

I wanted to do the mods for this kit but I will first build it to the original and see how it sounds like first and work out any bugs. Then, I will look into the mods. Hopefully everything goes well?

Hi drummerboy welcome to the LH. Have fun building the amp and send in pics, we all love pics. Best to start your own build thread when you start then the posts do not get lost in this very very very long thread

Jessica. Xx

[valrak66]

Hi guys,

To match the toroidal transformer specs needed for the DIY Ear 834p phono stage, I consider buying one of this custom made transformer :
https://www.audiophonics.fr/en/toroidal-transformers/custom-toroidal-transformer-all-power-p-3675.html

The thing is there is apparently a secondary winding but I dont know what specs I should select.
Any help on this ? What are the specs I should ask for this transformer

Thanks a lot

[Jessica_K]

You will need two secondary windings
250v at 150mA
6.3v at 2A
These currents give you plenty of headroom, the 6.3V could be reduced to 1.5A without sacrifice if there is a cost difference, I just like to keep the current headrooms to the max

Jessica xx

[Taso]

hello guys, greetings from Italy !! ..I would have a question being that they are still being optimized.

I have to buy the 6 caps that are on the PCB valves .. those at 400-450v.

On my ear..which I bought on ebay..they were self-built by a fan..the 100uf 400v caps were mounted..Sanwa brand, SD..85 ° series .. and I would say very normal.

Since I have a doubt about their state of health ... I avoid explaining why ... I was about to buy another 6 ... to assemble.

I would have found some Kendeil .. K05 series..a great price..I can choose between 100uF 450v or 220uF 400v..all 105 °.

I'm also finishing to solve hummm problems .. which are not however given by any mass loops .. those I have already fixed for good ... having excellent results.

I was wondering ... I was asking you..so .. if you buy back 100uF .. Kendeil..o if you switch to 220uF.

I would not, however, with such a higher capacity ... create noise problems .. overload diodes .. in short .. what I am looking for is exactly the opposite ... or improve something!

On some forums .. also on this ... I see in some photos that, for a fee, one cap, 4 caps are the same .. I don't know the value however .. but the other two are bigger .. I think the ones near the valve V1 or V3.

anyway give me some advice? while I buy them .. if I can benefit from them ... I would go to 6 x 220uF ... or maybe .. if I had to follow the photos I see on some forums .. put 4 of 100uF and 2 of 220uF ... even if not I know where the big two go !!

The fact is also that it seems to me that the original ear mounts 6x22uF ... and that the Chinese kits provide 6x47uF.

I point out that I have also redone the power supplies .. both anodic and filaments .. if you want to place the pattern and give me an opinion. maybe it can be useful to someone.

Thanks !!! and sorry for my english

[mike]

Hi there, I'm looking to start a build of this phono stage and am wondering about current board options. The start of the thread advises to use the Xuling boards. Blank Xuling boards are now 4x the cost ($199USD) of the Douk boards ($50.00USD). The Douk boards are shown partially built with other components off to the side. I couldn't find any A/B comparisons of these boards. There was some info buried in threads, like the Douk boards are thicker. The Douk boards are set up for separate channels. I think I've read the Xuling board traces are better. I didn't find any comparisons of the overall performance of the boards. The Xuling boards are advertising gold plating. Are the Xuling 4x the board or is this consumer hype? Thanks for any assistance.