Pearl 3 Burning Amp 2023

[ClaudeG]

Yes, on something if you want

I believe they came with various "bodies" to adjust the height, but that was decades ago.

No prob at all to elevate it somewhat to make sure it is high enough...

Good luck

Claude

 

[6sX7]

Got the PS running. Next up is the umbilical then finishing out the actual preamp part.

 

[DualTriode]

Got the PS running. Next up is the umbilical then finishing out the actual preamp part

Nice bench full of Tools / Toys especially the note book to document your adventures.

Thanks DT

 

[6sX7]

The GF is a keeper. When we moved to the new rental she flat out stated I was to go to Home Depot, buy some workbenches and set up shop in the extra bedroom. I think she knew I needed to be working on something even though we hadn't bought our settle-in home yet.


After the umbilical, back to practicing SMDs.

 

[OnAudio]

There may be possible minor errors in the schematic on the first post, who has the latest update from Wayne?, here's a reference https://www.diyaudio.com/community/threads/pearl-x-mc-mm-phono-preamplifier.410767/post-7651725

 

[wayne]

The noise in your sims is helped from the 100 Ohm resistor in series on the input. 100 Ohms is 1.3e^-9
The pearl 3 doesn't have that.

 

[OnAudio]

Thanks Wayne, Yes that adds 60nV/√Hz, so its more like 300nV/√Hz rather than 360nV/√Hz, pls check R1,R20 on post 1 of your schematic

 

[wayne]

If you build the kit with the provided parts it will work just fine. If you use some other input devices like the LSK or BF862 etc the collector load resistor can be adjusted as well as the cascode voltage. It doesn't show up in measurements but might in sims.

 

[OnAudio]

As always, thanks Wayne for taking the time to look at it and clarifying the values

 

[rhthatcher]

For those who are purchasing the latest round of kits in the store - if you want to get in an power supply parts kit group buy, have a look here:
https://www.diyaudio.com/community/...o-crcrc-power-supply-parts-kit.406461/page-11

 

[freebee]

Yeah! Finally put it together after a long wait for a 4-pin XLR. 😃

 

[tonyEE]

OK, I found a place where they sell opamps pre-mounted on a DIP.

which ones should I start with?

https://www.cimarrontechnology.com/product-category/single-dual-op-amp-adapters

https://www.cimarrontechnology.com/product/browndog-970601-so8-to-dip8-adapter


Thanks @Auricle

 

[mworthin]

I really like the sound of the OPA1656 in this circuit.

 

[ClaudeG]

I haven't tested it in this particular circuit, but I am using OPA1656 in my Chipomatic RIAA preamp with great results.

OPA1656 is as "accurate while slightly euphonic" as it gets IMHO, to my taste of course. While OPA1612 (no FET though, can be a problem in some cases...) is probably amongst the most neutral and very transparent & accurate OPAs I know (you can easily add it to a circuit without even noting/hearing it), I still prefer a small tad of warmth when it comes to RIAA preamps, especialy given the (non forgiving) nature of the vinyls I own...

Note we are talking nuances here, both OPAs are "accurate and neutral" generaly speaking... all these modern OPAs are trully amazing and a majour step forward - at least to my ears - vs what we had to play with decades ago...

What I like in this RIAA preamp (as in mine) is the ability to play with flavours / adjust your system to your liking... by simply rolling op amps - genius strike by Wayne and Jim !

All IMHO and IME

Enjoy OPA1656... and most importantly music

Claude

 

[wanders]

Just received my Pearl 3 kit and checking components. Both C2 caps read 8.1pf, BOM call for 4.7pf. Thoughts welcome.

 

[6L6]

I wouldn’t worry at all about that, C2 sets a HF roll off way above audible to make sure nothing strange happens at RF.

Out of curiosity, what are you measuring with? I don't have anything that can accurately read 5pF... wish I did.

 

[wanders]

Out of curiosity, what are you measuring with? I don't have anything that can accurately read 5pF... wish I did.​

LCR-T4 Mega328​

​

($20 on Amazon), not bad.​

Many thanks

Out of curiosity, what are you measuring with? I don't have anything that can accurately read 5pF... wish I did.

 

[6L6]

Both (color and mono) my Mega328 are reading it as no, unknown, or damaged. They both test fine. (which is discouraging...)

My 5-digit DMM doesn't have the proper leads to read a cap that small, I can't get repeatable readings much smaller than 100pF.

 

[vanofmonks]

I measured the ones that came with my kit with my BK precision 815 and they were as close to 4.7pf as it could measure. That is on the edge of it's range.

 

[jackinnj]

My 5-digit DMM doesn't have the proper leads to read a cap that small, I can't get repeatable readings much smaller than 100pF.

You need a VNA!