Omega and first watt

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peter59

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Re: Omega and first watt
« Reply #60 on: 19 Apr 2017, 05:27 am »
Hey Peter,
Great looking ACA amps.. I have sent you a PM.. about changing the DC on these amps.. I own these same amps and they are a very good match for my omegas..

pstrisik

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Re: Omega and first watt
« Reply #61 on: 19 Apr 2017, 03:27 pm »
Hey Peter,
Great looking ACA amps.. I have sent you a PM.. about changing the DC on these amps.. I own these same amps and they are a very good match for my omegas..

Thanks Peter! 

You probably are aware of the diyAudio thread on building these unless maybe you bought them already built.  Here's the last page: http://www.diyaudio.com/forums/pass-labs/215392-amp-camp-amp-aca-329.html.  Derekva is asking about changing to 24v and information about doing this is pulled forward to the last couple of posts.

The short answer is that you change the voltage bias in each amp to read 12v using the screw adjustment on the board.  You need a multimeter to do this.  Easy, but may seem complicated if it is all new to you.  24v has definitely improved the sound over 19.  It supposedly increases power from 6 to 8 watts and the increased dynamics are audible.

Here is a build video: https://youtu.be/RjqJeF34adk
Here is the pictorial build guide: http://www.diyaudio.com/forums/pass-labs/247361-aca-illustrated-build-guide.html


......Peter

pstrisik

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Re: Omega and first watt
« Reply #62 on: 19 Apr 2017, 03:33 pm »
VERY COOL Peter... am I understanding it correctly that the two chassis pictured are what the 24v power supplies came installed in?  The chassis, interior assembly and wood exterior all look positively amazing!

I'll read through the Bride of Zen preamp information and see if I can muster the courage to attempt that project :o

Sorry, I missed your post until now.  Thanks for the compliment.  And you are correct: the chassis are what the 24v PS's came in.  I modified the back plate, removed the top plate and used standoffs to raise the new wooden top plate that holds the amp board and its heat sink.  The side heat sinks are for the power supply chips and the top sink is for the amp's. 

.....Peter

WC

Re: Omega and first watt
« Reply #63 on: 19 Apr 2017, 05:32 pm »
Sorry, I missed your post until now.  Thanks for the compliment.  And you are correct: the chassis are what the 24v PS's came in.  I modified the back plate, removed the top plate and used standoffs to raise the new wooden top plate that holds the amp board and its heat sink.  The side heat sinks are for the power supply chips and the top sink is for the amp's. 

.....Peter

I have the ACA amps. I am curious about the linear PS. Where did you get it from?

pstrisik

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Re: Omega and first watt
« Reply #64 on: 19 Apr 2017, 06:05 pm »
I have the ACA amps. I am curious about the linear PS. Where did you get it from?

eBay - from China.  This is it:
http://www.ebay.com/itm/100VA-Ultra-low-Noise-LPS-HI-END-Linear-power-supply-for-audio-DC5V-24V-Optional-/131962052051?hash=item1eb98d1dd3:g:ut0AAOSwN6JY9JJ3

There are a number of similar supplies, some more fancy with voltage readouts, etc.

You can build something like I did, or you can just use these supplies as is connecting with supplied umbilical to the DC inlet on the ACAs (and adjusting the voltage bias of course).  There is something to be said for keeping the power supplies separate from the amp chassis.  Just too many boxes for me.  Oh, I also added a ferrite noise filter on the AC line coming in to the power supply.  It's the white square-ish piece in the photo I posted above.  Zero noise, so it worked out fine.

If you, or anyone, wants to do a similar build, I can save you some time with specs for threads, etc.

WC

Re: Omega and first watt
« Reply #65 on: 19 Apr 2017, 07:34 pm »
eBay - from China.  This is it:
http://www.ebay.com/itm/100VA-Ultra-low-Noise-LPS-HI-END-Linear-power-supply-for-audio-DC5V-24V-Optional-/131962052051?hash=item1eb98d1dd3:g:ut0AAOSwN6JY9JJ3

There are a number of similar supplies, some more fancy with voltage readouts, etc.

You can build something like I did, or you can just use these supplies as is connecting with supplied umbilical to the DC inlet on the ACAs (and adjusting the voltage bias of course).  There is something to be said for keeping the power supplies separate from the amp chassis.  Just too many boxes for me.  Oh, I also added a ferrite noise filter on the AC line coming in to the power supply.  It's the white square-ish piece in the photo I posted above.  Zero noise, so it worked out fine.

If you, or anyone, wants to do a similar build, I can save you some time with specs for threads, etc.

Thanks,

I may do this in the future when I finish all the other current projects. I would probably buy another set of amp boards without the enclosures and add the amp boards into the PS enclosures. The enclosures seem well built. Looks like you can get them with silver front faces.

roncagg

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Re: Omega and first watt
« Reply #66 on: 20 Apr 2017, 12:47 am »
I also want to recommend the F7 amp, I now have the Wyred 4 sound STP-SE (stage 2 upgrades) preamp and it is really showing this amp off to its best I feel. My Manley Shrimp (tube) also did a fine job, but the amp has such character I liked the idea of not coloring it, hence the (mostly) no-gain buffer. I use Devore super 8s (please forgive me!), though Louis graciously lent me Omegas to try some time ago when I had Red Wine Audio gear, so I know how good they are.