Pearl 3 Burning Amp 2023

[6L6]

Perhaps U3 or U4?

U3 and U4 are the halves of the dual opamp.

This would be very simple to check, swap the opamp left to right.

 

[cubicincher]

I would say, that it was a not so lazy sunday...
PEARL 3 - single OPAmp in the cases.
Greets
Dirk

 

[PierreQuiRoule]

Very nice. I like the big caps 👍. What is the second DIP switch for?

 

[bpr]

Verify that the TTA004 and TTC004 are in the proper positions on the bad board.

U3 and U4 are the halves of the dual opamp.

This would be very simple to check, swap the opamp left to right.

A004 and C004 are in the correct positions, and I've swapped the opamps between the boards to no effect. I've also re-checked all of the cabling and channel connections and it does indeed seem to be a problem with that board and not anything pre- or post- the Pearl 3.

 

[cubicincher]

Very nice. I like the big caps 👍. What is the second DIP switch for?

Hello PierreQuiRoule,
the left DIP-switch is for resistor loading (MC), the right DIP-Switch is for capacitance loading (MM).
Greets
Dirk

 

[6L6]

@bpr

On the inoperative PCB, are both the LED lit?

What is the voltage from opamp pin 4 to gnd? From pin 8 to gnd?

How tall are your standoffs? Perhaps someting is shorting out underneath?

 

[PierreQuiRoule]

A004 and C004 are in the correct positions, and I've swapped the opamps between the boards to no effect. I've also re-checked all of the cabling and channel connections and it does indeed seem to be a problem with that board and not anything pre- or post- the Pearl 3.

Troubleshooting can be frustrating. If you have not done so already, flip the board and carefully inspect for solder bridges. It happens...

Next, set your Voltmeter to DC, ground the black lead, then probe and compare bias voltages between your known-good and faulty boards to verify that they are the same. Check supply rails, output, and both sides of R1 as a start.

 

[PierreQuiRoule]

and follow 6L6's tips

 

[freebee]

Had it at 100ohm, however perhaps I should have used a different setting. Hagtech site mentions that, with the SUT in place, the cartridge sees:
Phonostage: 47k, Turns Ratio: 13, Loading = 278.1 ohms.

Piccolo Zero

The Piccolo Zero is an active transimpedance gain stage meant to replace an SUT. Gain of such a transimpedance stage is given in Ohms (volts per amp), which is also the feedback resistor value. A good starting guess for gain can be made knowing the cartridge's internal resistance (plus resistance of tonearm wiring) and output voltage:

Resistance: 40 ohms,
Voltage: 0.15mV
Gain = 1333 ohms

Pearl 3 - Denon DL-S1 MC cartridge load 1000ohm seems to get close to the sound with SUT.

 

[PierreQuiRoule]

 

[freebee]

There's actually quite a lot of hiss and a British radio station in the background if turn the volume up.

 

[6L6]

I’ve always lived in a place that has lots of background radio interference, a snap-on ferrite clamp attached to the turntable interconnects will fix it.

 

[wayne]

Fet and bipolar inputs are good for picking up radio stations. Ferrite clamps or the small beads with a few turns of wire on the RCA inputs usually fix it.

 

[Porthos]

@bentconvert and all,

Dip # 8 and #6 did the job. #8 Took away nearly all of the whine, but there was still a very high-frequency whine (I mean very high). So I tried various combinations, and #6 took that away and did not affect the sound much...Of course, I read about number #8 for HOMC in the build docs, but did I remember ?noooo.....LOL! So many thanks to @bentconvert and @6L6 ..

The unit sounds significantly better than my older pre and I absolutely love the sound of the Hana! It's a whole new level of audio experience for me.

 

[freebee]

Tried my Sony XL55ProII and there's no hiss nor radio anymore. Sounds great 😃