Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login


Options
View
Go to last post Go to first unread
needsp  
#1 Posted : Thursday, September 17, 2009 4:06:37 PM(UTC)
needsp

Rank: Advanced Member

Groups: Member
Joined: 7/22/2009(UTC)
Posts: 81
United Kingdom
Location: Norwich, UK

Thanks: 2 times
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

Rank: Advanced Member

Groups: Member
Joined: 7/22/2009(UTC)
Posts: 81
United Kingdom
Location: Norwich, UK

Thanks: 2 times
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

Rank: Advanced Member

Groups: Member
Joined: 8/26/2008(UTC)
Posts: 45
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

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
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

Rank: Advanced Member

Groups: Member
Joined: 7/22/2009(UTC)
Posts: 81
United Kingdom
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

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
Good work indeed!
krgaunt  
#7 Posted : Monday, September 28, 2009 12:35:15 PM(UTC)
krgaunt

Rank: Advanced Member

Groups: Member
Joined: 8/26/2008(UTC)
Posts: 45
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
Rss Feed  Atom Feed
Users browsing this topic
GuestUser (6)
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.