Input wiring now completed. Under test I found the voltage over R27 on each board was running at 2.2V with the 220ohm resistor fitted so I was dissipating 10mA. Way too much. I rooted around in my parts bin and found a bag of 475 ohm resistors. I fitted those and got that current down to 4.63mA on each channel - easily within spec. With the front panel fitted you can see the full damping. The top panel of the phono stage is also heavily damped.
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The damping is to counteract bad vibes getting into the music during playback!! LOL. It's DIY after all.
My previous phono stage was the Pearl 2 so comparing the two stages was fun. They both share the same sound signature but I would say that the Pearl 3 is more revealing. Both phono stages sound great, but I think the Pearl 3 is the new King of the castle.
I would like to thank Wayne for his generosity is making this design available, Randy Thatcher for the superb PSU board. Seriously check it out, it's a really sorted PSU design. And finally all at DIYAudio.com for putting this all together for the community to enjoy.
Much Love!!
I would like to thank Wayne for his generosity is making this design available, Randy Thatcher for the superb PSU board. Seriously check it out, it's a really sorted PSU design. And finally all at DIYAudio.com for putting this all together for the community to enjoy.
Much Love!!
It's a nice traffo, and the other 2 transformers were unobtainium when I was buying the parts for the PSU.
@freebee
Having an enclosed chassis where each panel is electrically connected to all the others is fundamental to the performance of this circuit... to the extent that they be wired together -- via bare metal patches -- as required.
If you connect the ground lug on the XLR then the housing of the XLR should be part of that shielded enclosure. That lug must be connected beneath the paint on the XLR. Right?
Having an enclosed chassis where each panel is electrically connected to all the others is fundamental to the performance of this circuit... to the extent that they be wired together -- via bare metal patches -- as required.
If you connect the ground lug on the XLR then the housing of the XLR should be part of that shielded enclosure. That lug must be connected beneath the paint on the XLR. Right?
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Somehow this wasn't the case with mine and I had to run a separate wire to the ground post.
I thinks that 2.3 volts is cutting things kind of close.
When I was checking things out I used the bench power supply to power up the P3 PCB's including the 7815 and 7915 +/- regulators.
For my measurements +/- 20 pre regulator voltages worked out better, as in less noise.
Thanks DT
Pearl 3 balanced v single ended output question.
Dear Friends I recently completed my Pearl 3 phono stage and it has moved into my main system replacing a Pearl 2 phono stage I built about 18 months ago. The sound of both phono stages is very similar to my ears on single ended operation and this is a good thing.
Then I tried the balanced output to my line stage to see if there was a difference.
Oh boy!
I thought I was listening to a different record.
Quick system description:
Thorens TD 160 (from 1973) using a SME 3009 from around the same time fitted with a Sumiko Pearl cartridge (I like the symmetry of a Pearl cartridge for a Pearl phono) feeding into the Pearl 3 then feeding into a Nelson Pass Bride of Son of Zen line stage, afterwards feeding into a diy First Watt F5 Turbo and then to Kef reference 104/2 loudspeakers from about 1992. Yes it's an old fashioned system in it's own way (don't laugh)
Now the system sounds great to me.
Everything else connected to the system is single ended output. DAC, Radio tuner (I like listening to NPR jazz and blues stations) and a streaming device (Amazon echo)
All the diy gear have separate PSUs, BoZoS has a remote PSU, Pearl 3 has a remote PSU and the F5 Turbo has a remote PSU.
This system is absolutely silent unless receiving signal.
Now here's the thing: I've read this forum posting multiple times before I went ahead and built my Pearl 3 and the general consensus was that the balanced output on the Pearl 3 was much the same as the Single ended output not withstanding the extra 6db gain.
That has not been my experience.
Now my BoZoS has about 20db gain normally which can overload the F5 Turbo so I fitted a pair of 500ohm pots (in position P5 for those who know the circuit) so I can adjust the line stage gain between 10db and 20db. This is very useful and the overloading issue is a thing of the past.
Now for the real question:
When listening to vinyl playback through this system I'm hearing a massive difference in musical retrieval, but the extra gain is overloading my linestage and then the power amp. Lowering the gain to its lowest setting removes the overloading/clipping.
But the level of extra musical information I'm hearing is confounding me.
Has anyone else experienced such a large difference in playback?
I listened to 2 records in particular (as I know them quite well) Dave Brubeck - Time's out and Robbie Robertson - Sinematic. These are very well recorded vinyls.
The difference was astounding, I thought I was listening to re-recorded versions of the albums.
Dear Friends I recently completed my Pearl 3 phono stage and it has moved into my main system replacing a Pearl 2 phono stage I built about 18 months ago. The sound of both phono stages is very similar to my ears on single ended operation and this is a good thing.
Then I tried the balanced output to my line stage to see if there was a difference.
Oh boy!
I thought I was listening to a different record.
Quick system description:
Thorens TD 160 (from 1973) using a SME 3009 from around the same time fitted with a Sumiko Pearl cartridge (I like the symmetry of a Pearl cartridge for a Pearl phono) feeding into the Pearl 3 then feeding into a Nelson Pass Bride of Son of Zen line stage, afterwards feeding into a diy First Watt F5 Turbo and then to Kef reference 104/2 loudspeakers from about 1992. Yes it's an old fashioned system in it's own way (don't laugh)
Now the system sounds great to me.
Everything else connected to the system is single ended output. DAC, Radio tuner (I like listening to NPR jazz and blues stations) and a streaming device (Amazon echo)
All the diy gear have separate PSUs, BoZoS has a remote PSU, Pearl 3 has a remote PSU and the F5 Turbo has a remote PSU.
This system is absolutely silent unless receiving signal.
Now here's the thing: I've read this forum posting multiple times before I went ahead and built my Pearl 3 and the general consensus was that the balanced output on the Pearl 3 was much the same as the Single ended output not withstanding the extra 6db gain.
That has not been my experience.
Now my BoZoS has about 20db gain normally which can overload the F5 Turbo so I fitted a pair of 500ohm pots (in position P5 for those who know the circuit) so I can adjust the line stage gain between 10db and 20db. This is very useful and the overloading issue is a thing of the past.
Now for the real question:
When listening to vinyl playback through this system I'm hearing a massive difference in musical retrieval, but the extra gain is overloading my linestage and then the power amp. Lowering the gain to its lowest setting removes the overloading/clipping.
But the level of extra musical information I'm hearing is confounding me.
Has anyone else experienced such a large difference in playback?
I listened to 2 records in particular (as I know them quite well) Dave Brubeck - Time's out and Robbie Robertson - Sinematic. These are very well recorded vinyls.
The difference was astounding, I thought I was listening to re-recorded versions of the albums.