I checked the voltages as much as I could understand. This as far as I have gotten:
- Checked if each board had 0.0 voltages at P5. The left board was way off by 2.4v, so I readjusted. I think it might drift again over time.
- I checked the voltage coming from the power supply before regulation and it's 30v.
- I checked the voltage at R6 and the right board is fine at 1.5v but the left board is at 1.7v (is that ok?).
I don't know how to check the rest of the voltages.
It seems that the left board is having the most issues.
I plugged it in and the noise floor has dropped considerably. If I play at moderate volumes and I put an ear up to the midrange of my Yamaha NS-1000, I cannot hear anything, except for hum coming out of the left speaker.
It seems that I getting almost there. I need to chase down the hum and checked the rest of the voltages.
I am appreciating the help.
Hmmm...
I'd be tempted to consider re-routing the wiring such that power conductors were well away from the signal wiring.
The order of grounds might bear inspection. 6L6's excellent advice in Post 33 (and, I should say, throughout diyaudio) might help too.
Twisting the signal wires more regularly and including a shield on the input wires might help.
I'd be tempted to consider re-routing the wiring such that power conductors were well away from the signal wiring.
The order of grounds might bear inspection. 6L6's excellent advice in Post 33 (and, I should say, throughout diyaudio) might help too.
Twisting the signal wires more regularly and including a shield on the input wires might help.
Thanks the left input wire is going over the power connector so that could be a source of the problem. I had some leftover silver wire from a project a long while ago, but it's not shielded, just teflon, so maybe I'll change over to some shielded Mogami mic cable instead.
Codyt, I am not sure what you meant by the input impedance? I have a .3mv moving coil that needs at least 100ohm load which is what is in R20, is that what you were talking about?
Codyt, I am not sure what you meant by the input impedance? I have a .3mv moving coil that needs at least 100ohm load which is what is in R20, is that what you were talking about?
Yeah, for some reason I was thinking you had an MM cart. Your setup is correct. Awesome chassis btw!
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No worries. Thanks for the chassis compliment!! It didn't come out the way I wanted it, but it's a learning process.
Still getting that dreaded hum in the woofer of the left speaker, but I order some shielded cable, so maybe that might help. The latest weird thing is that when the preamp is on when I switch the input select knob to another input it makes a loud screech? I think there might be something to the exposed power jack and the tight area of the enclosure?
No worries. Thanks for the chassis compliment!! It didn't come out the way I wanted it, but it's a learning process.
Still getting that dreaded hum in the woofer of the left speaker, but I order some shielded cable, so maybe that might help. The latest weird thing is that when the preamp is on when I switch the input select knob to another input it makes a loud screech? I think there might be something to the exposed power jack and the tight area of the enclosure?
I had some time between meetings today, and I rerouted the input wires on the left channel to be away from the power supply wires. I also rerouted the ground wires from the chassis to the ground post, as suggested. Hooked everything up again and the hum is gone. I can hear a little buzz if I crank it and put my ear up to the midrange, but I think that is the noise of my Thorens TD-124 motor that is unavoidable. I am still going to change the wiring our for shielded cable regardless. Thanks for the help with this problem.
The Pearl sounds great. Lots of detail and great tone. I've had some really nice phono stages, but this stage has had the best tone and timbre that I have experienced.
Special thanks to 6L6, for the great help that went way beyond anything that I expected. This project wouldn't have come this far without him. DIY Treasure!! Also, thanks to everyone along the way who helped me when I had questions, very much appreciated! I'd like to learn about the fundamentals of electronics before I start my next project, but there will be another one soon, perhaps a linestage or amp?
Shouldn't be a problem I use a Stanton 881s into an Xono and it SINGS. This setup is "till death do we part"......
My son used the Stanton 681EEE when he was making a few bucks as a DJ -- and I used it for years. Inductance is something like 930mH and resistance 1.3k -- this offers the intriguing possibility of using the cartridge load resistor to effect the T5 pole. This prevents overloading the second stage of the Pearl2 at frequencies over 2kHz.
Thinking of just getting evg. Closest sound to original
Tried jico on the gold Stanton 500.. It's fine but lost the magic from the old stylus.. I guess thats the gotya. I think near original sound is safe bet
Oh yea.. I got an email from jico stating..
Epc205c II use eps 205ed
CiiL or ciii then use their sas..
Should I get them or focus on Stanton
Rooting for pearl 2 as nice as xono
Tried jico on the gold Stanton 500.. It's fine but lost the magic from the old stylus.. I guess thats the gotya. I think near original sound is safe bet
Oh yea.. I got an email from jico stating..
Epc205c II use eps 205ed
CiiL or ciii then use their sas..
Should I get them or focus on Stanton
Rooting for pearl 2 as nice as xono
I have an EPC205 with Jico SAS/B and it's good but the 881 with OEM stylus is better. I was able to do a back to back with both mounted on removable headshells in my EPA100. What is immediately noticeable is the separation of the 881 imaging and sound stage fills the room more, the only place the 205/SAS beats the 881 is surface noise is lower.
There is a guy on eBay goes by the handle cartridge_retipping-5, I have one of his D3000 retipped stylus and I can't pick the difference to my OEM D81. The D3000 is currently in use.
If you have the original stylus get it retipped. I haven't tried any of the aftermarket stylus for the Stanton so I can't comment first hand.
I nearly built the Pearl 2 until I found a guy in Germany selling Xono kits so I bought that instead. Pass Labs certainly know how to design great gear and kudos to NP for allowing the DIY community to build and enjoy these wonderful phono preamps...........
There is a guy on eBay goes by the handle cartridge_retipping-5, I have one of his D3000 retipped stylus and I can't pick the difference to my OEM D81. The D3000 is currently in use.
If you have the original stylus get it retipped. I haven't tried any of the aftermarket stylus for the Stanton so I can't comment first hand.
I nearly built the Pearl 2 until I found a guy in Germany selling Xono kits so I bought that instead. Pass Labs certainly know how to design great gear and kudos to NP for allowing the DIY community to build and enjoy these wonderful phono preamps...........
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Hi all... I just ordered the Pearl boards from PASS diy and working through some of the build details.
I'm generally new to vinyl, my current phono is a Bugle2 so hoping this one is a noticeable step up.
I'll have a bunch of questions, but a few to start off:
(1) Regarding PSU and ground -- the pearl doc states:
If I understand this correctly, connecting the circuit ground through the third bridge rectifier (as described in the schematic) is only required if the PSU and the Pearl boards are in the same chassis.
If using separate chassis, then the only connection in the PSU chassis is the AC earth.
In the Pearl chassis, we need to connect the signal ground to the chassis. Can this be achieved by simply using non-insulated RCA jacks (for the inputs, or both input/output?)
(2) For multiple input loads via front panel switch (e.g 47K for MM, and 100R for MC), is the extra wiring between the resistors on the switch and the PCB an issue?
(3) Pearl has 55dB gain by default, where as I've seen 40dB used for most MM phono stages. Is there any advantage (noise or distortion wise) to using a higher resistor to reduce the gain to 40dB ?
I'm generally new to vinyl, my current phono is a Bugle2 so hoping this one is a noticeable step up.
I'll have a bunch of questions, but a few to start off:
(1) Regarding PSU and ground -- the pearl doc states:
If I understand this correctly, connecting the circuit ground through the third bridge rectifier (as described in the schematic) is only required if the PSU and the Pearl boards are in the same chassis.
If using separate chassis, then the only connection in the PSU chassis is the AC earth.
In the Pearl chassis, we need to connect the signal ground to the chassis. Can this be achieved by simply using non-insulated RCA jacks (for the inputs, or both input/output?)
(2) For multiple input loads via front panel switch (e.g 47K for MM, and 100R for MC), is the extra wiring between the resistors on the switch and the PCB an issue?
(3) Pearl has 55dB gain by default, where as I've seen 40dB used for most MM phono stages. Is there any advantage (noise or distortion wise) to using a higher resistor to reduce the gain to 40dB ?
Going through this thread from the beginning is helpful.
6L6 in particular has valuable advice all through.
Take a look at post 33 on page 4 for a good grounding scheme. The grounding bridge is recommended in every event as are insulated connectors and jacks and a remote PSU.
The Pearl 2 was designed for MC cartridges.
I'm sure others will address any questions you have. They're a really good bunch.
6L6 in particular has valuable advice all through.
Take a look at post 33 on page 4 for a good grounding scheme. The grounding bridge is recommended in every event as are insulated connectors and jacks and a remote PSU.
The Pearl 2 was designed for MC cartridges.
I'm sure others will address any questions you have. They're a really good bunch.
1) Put the PSU in a separate box. Period. It will hum if you don't. Use the bridge ground lift as shown in the schematic.
2) Not really an issue, but you'll introduce the chance for more hum. Try to keep things as short and tight as you can.
3) Maybe? It's worth trying, try both and see what works better in your situation.
2) Not really an issue, but you'll introduce the chance for more hum. Try to keep things as short and tight as you can.
3) Maybe? It's worth trying, try both and see what works better in your situation.
Yes, I was planning on using a separate box regardless. I learn something new with every project, so hoping you could explain the rationale behind the ground lift as its not entirely clear to me in the 2 box scenario.
On every project I've done until now, lifting the ground was required only to prevent a ground loop (Wayne specifies this as well) with other components if AC ground is tied to signal ground.
If the PSU box is tied to AC ground, and the Pearl box is signal ground, then why is it still needed?