[Shakeydeal]

My preamp came stock with a walwart PS (LDR is from Abacus Audio). It is clear that the walwart induces noise into the system and does not like to be plugged in near any other component. I have a DPS power supply that runs my Well Tempered Amadeus. It has two optional 12vdc 500ma outputs for devices like the LDR. One is center pin positive, the other is reversed. I have tried to use this with my preamp, but they don't get along well. See link.

http://www.welltemperedlab.net/welltemperedlab/products/dpspowersupply/

My first question is why this wouldn't work? It powers up the LDR display, and looks normal, but the preamp won't pass any audio signal.

My second question is what inexpensive aftermarker linear PS would you recommend?

Thanks,

Shakey

[ClefChef]

Any linear power supply of 500mA should work fine. http://www.ebay.com/itm/TENMA-VARIABLE-LINEAR-POWER-SUPPLY-NEW-3-12V-2A-/331355191501?pt=LH_DefaultDomain_0&hash=item4d264ef8cd

eBay is full of them.

It is unclear why your Well Tempered Labs PS does not work. As long as the preamp is connected with12V DC +tip -sleeve it should work fine. WTL PS also has a 100mA output, and it is not sufficient to power the Tortuga board.

[tortugaranger]

While all wall-wart style switch mode power supplies are not created equal we've had very good performance (without noise) using 12 volt switch mode power supplies. We use both a 12 VDC and a 5 VDC switch mode dc-dc regulator in our current LDRx/LDRxB models with an unregulated linear front end that puts out around 18 VDC. Our earlier LDR1, LDR3 and LDR6 models all used a 12 VDC external wall-wart  power supply. Even if you used an external linear 12 VDC supply, the V2 board has a 5 VDC switch mode dc-dc regulator. We found that this (rather expensive) regulator outperformed most linear regulators.

[Shakeydeal]

The 100ma output is for the turntable. The other two outputs are for optional devices. I tried the one on the left with center pin positive, should have worked. Not only did I not get an audio signal, but there was a burning smell. I immediately disconnected, so no harm done. But this seems unusual.

Shakey

[tortugaranger]

Not only did I not get an audio signal, but there was a burning smell. I immediately disconnected, so no harm done. But this seems unusual.

"Burning smell" and "no harm done" rarely go together in one sentence.

[ClefChef]

DMM is your friend - get one ASAP.

[Shakeydeal]

"

Burning smell" and "no harm done" rarely go together in one sentence.

I agree. and I thought the preamp was toast (burnt toast at that). But it seems to work fine. Did I get lucky?

Shakey

[Shakeydeal]

DMM is your friend - get one ASAP.

So DMM = what exactly?

[ClefChef]

So DMM = what exactly?

[Shakeydeal]

I have one. I just need to check the output of the DPS. I suspect it is not what it should be.

Shakey

[ClefChef]

I have one. I just need to check the output of the DPS. I suspect it is not what it should be.

Shakey

Check for correct voltage and polarity.

[Atlplasma]

Fluke makes great equipment. I have one of their DMM. There are probably cheaper alternatives, though.

[tortugaranger]

Fluke makes great equipment. I have one of their DMM. There are probably cheaper alternatives, though.

I bought a used Fluke 78 III off eBay a few years back. Very reasonable. Looks very similar to 787 model below. Best meter I've even owned. Eats batteries though. Then again I use it most every day.

[srb]

I bought a used Fluke 78 III off eBay a few years back. Very reasonable. Looks very similar to 787 model below. Best meter I've even owned. Eats batteries though. Then again I use it most every day.

Would 8.4V work?  2 X 9V 600mAH Li-Ion + charger (recharge 1000 times) for < $15.

 

[tortugaranger]

Would 8.4V work?  2 X 9V 600mAH Li-Ion + charger (recharge 1000 times) for < $15.

 

Looks like a winner! (for the Fluke)

[gregfisk]

"Burning smell" and "no harm done" rarely go together in one sentence.

 

Now that was funny!