Pearl 3 Burning Amp 2023

[6L6]

Those clear LEDs in the kit should be blue when lit.

The clear LED in the Pearl 3 kit are green.

I have to ask, I have good ground to all chassis pieces except the front panel, is this particularly necessary?

Very necessary if you want good noise performance.

 

[ClaudeG]

+ 1 on 6L6... RIAA preamps are the most sensitive HIFi device I know

I tried to measure mine (DIY but not Pearl 3) while on my working bench, without casing, just to make sure all was Ok... and I failed miserably. It measured awfully without casing, to the point I thought it was defect (it wasn't, perfectly noise free in a cookie later, sounds great)

 

[GKTAUDIO]

It is certainly advisable, at least, and possibly necessary. It's also pretty easy to accomplish if your front panel screws make good contact with the panel, since they will also make good contact with the other parts of the chassis into which they are screwed. Why doesn't your front panel make good contact?

 

[GKTAUDIO]

Ah, yes, green. I forgot - it's been awhile, and I ended up replacing mine with blue. Thanks for the reminder, 6L6

 

[Toys4Boys]

Very necessary if you want good noise performance.

Yeah, guess I sort of knew you would say that! I assume people are sanding the coating on the faceplate, any tricks, it seems pretty hard?

 

[6L6]

I use a flat blade screwdriver and scrape/gouge the mating surfaces. Much faster then sanding.

 

[Toys4Boys]

I use a mini belt sander 😁

 

[GKTAUDIO]

Probably better to use the method 6L6 indicated. You can also install a star washer beneath one screw head.

 

[Toys4Boys]

The combination of my mini belt sander, actually a knife sharpening station, and some wet/dry paper seems to do the trick.

 

[mhenschel]

@Toys4Boys
@6L6
But it's still aluminum, right? Not steel like the top and bottom plates. Or like my cookie tin.
I've been wondering about this shielding aspect. There is "RFID fabric" out there that the purveyors suggests works like a Faraday cage -- what we want, right? Maybe "bagging" the enclosure with this stuff too would help?
Or is a properly bonded intact (complete) aluminum enclosure -- with remote PSUs... all of them -- OK?

 

[Russellc]

Yeah, guess I sort of knew you would say that! I assume people are sanding the coating on the faceplate, any tricks, it seems pretty hard?

Drill small hole on backside, tap, screw with wire to chassis ground?

 

[Toys4Boys]

Sanding seems to work well, I have checked continuity at all gnd pts. If mt meter beeps am I good or is there the possibility that a better gnd could be established?

 

[TungstenAudio]

The aluminum faceplate itself does not need to be altered to get a good ground. The steel top and bottom plates should be sanded / filed to expose some bare metal that will contact the faceplate.

 

[Toys4Boys]

@TungstenAudio I wasn't getting continuity on the faceplate until I sanded it.

 

[Toys4Boys]

I was having some questionable results where the top/bottom plate and rails meet. I ended up tinning the panels very lightly with solder 👍

 

[6L6]

The aluminum faceplate itself does not need to be altered to get a good ground. The steel top and bottom plates should be sanded / filed to expose some bare metal that will contact the faceplate.

Re: the aluminum, this is incorrect information. The anodizing can act as a very good electrical insulator and in most cases it will need to be scraped to bare metal to ensure electrical connection to the rest of the chassis.

Yes, 100% the paint needs to be scraped from the steel.

@mhenschel A (properly bonded) all-aluminum chassis is more than good enough for shielded. My prototypes are aluminum.

 

[Toys4Boys]

Just went through the tests checklist and everything is pretty spot on, including R27 measuring 2.3V . Getting very close values left to right channel, so I got that going for me! Time to see if I have a 500R in my bag of stuff.

 

[Toys4Boys]

Nothing even close!

 

[Toys4Boys]

Is this a good variety pack with the appropriate replacement for R27? Clearly it has the correct values and wattage rating, probably as good as the Dale?

 

[Toys4Boys]

Nix that, this is much better, next day delivery vs the other 2 day