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needsp  
#1 Posted : Thursday, September 17, 2009 4:06:37 PM(UTC)
needsp

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Hi Russ and Brian and all

I received my Buffalo 32S about a week ago

I finished it last Saturday. By Sunday it was sounding wonderful- quite a bit better than an NOS design I've been helping to refine for some time, and hence the best CD reproduction I've ever heard. Many thanks!

But, I confess to being an incurable tweaker. Perhaps my subconcious was miffed by my existing DAC's inferiority. Whatever-
on Monday I had a day I will long remember, but would do well to forget. In short I managed to destroy my Buffalo in several stages!

I'll spare the details of my various idiocies. Partly to keep this brief, but mostly to save my embarrassment....Sick

I thought I'd just damaged the left output OPA1632, and then the right's AVCC lme49710 voltage buffer. But I also managed in the process to put both 0V, then 6.3V on one or both AVCC pins, and it turns out- after replacing the offending op amps- that the DAC's damaged. (Found the relevant 317 reg was shutting down- only 1.5V out. "Cured" by removing IC5- one of the 176333 regs feeding the DAC. Subsequently found that the resistence between the ungrounded ends of C9/C12 and ground is only 1.8R; i.e. the DAC is totalled!)

If necessary I'll buy another Buffalo, but would prefer to repair this one, for now at least. I stll want to try out a few mods, but would be reluctant to do this on a second unit (a good thing to some might say. But I can't help myself)

So can I buy a ES9018S chip? I reckon I could manage to install it OK (more concerned about cleanly removing the old one in fact. Anybody have any hints? I guess cutting the pins before desoldering them, but even this would be tricky)

Help!

Paul
needsp  
#2 Posted : Friday, September 18, 2009 11:53:03 AM(UTC)
needsp

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Location: Norwich, UK

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Hi

Perhaps I should explain what I was doing when I got into the mess I describe above. I was just trying out a couple of high performance 3.3V shunt regs as alternative sources of L and R VACC. Simple in principle, the board is even set up to do this- I just made an unholy mess of it!

Can I get a replacement ES9018S?

Thanks

Paul
krgaunt  
#3 Posted : Friday, September 18, 2009 12:39:09 PM(UTC)
krgaunt

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Location: Livermore, CA

needsp wrote:
Hi Russ and Brian and all

...the DAC is totalled!)

If necessary I'll buy another Buffalo, but would prefer to repair this one, for now at least. I stll want to try out a few mods, but would be reluctant to do this on a second unit (a good thing to some might say. But I can't help myself)

So can I buy a ES9018S chip? I reckon I could manage to install it OK (more concerned about cleanly removing the old one in fact. Anybody have any hints? I guess cutting the pins before desoldering them, but even this would be tricky)

Help!

Paul


Replacement ES9018S DACs are sold at a minimum quantiy of 2. BUT, due to my initial problems with the Buffalo board, I made a purchase and have one unused, untouched ES9018S that I will sell you at my cost, $55 USD. If you are interested, give me a email at krgaunt@pacbell.net

RossG
Brian Donegan  
#4 Posted : Friday, September 18, 2009 5:45:17 PM(UTC)
Brian Donegan

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I don't have any spare ES9018s at the moment. I usually buy them in the same quantity as the boards.
needsp  
#5 Posted : Friday, September 25, 2009 3:37:23 PM(UTC)
needsp

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Location: Norwich, UK

Thanks: 2 times
Hi

Thanks to Ross I got hold of a replacement ES9018S. I fitted this, and replaced the first opa1632 in the left channel's I/V analogue circuit. The board now works perfectly again

Hand desoldering and soldering the chip with a needle point bit and fine solder was more than a bit tricky. I'm feeling rather pleased with myself! Almost makes up for my initial idiocy....

Paul
Brian Donegan  
#6 Posted : Friday, September 25, 2009 3:48:59 PM(UTC)
Brian Donegan

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Good work indeed!
krgaunt  
#7 Posted : Monday, September 28, 2009 12:35:15 PM(UTC)
krgaunt

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Location: Livermore, CA

needsp wrote:
Hi

The board now works perfectly again

Paul


Congratulations! I'm very pleased that you received the chip and all is well. Happy listening

Ross
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