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RA1 - Page 2

post #16 of 27
10/20/06 at 7:55pm
Quote:
Originally Posted by Andrea
There aren't even any reservoir caps on the power lines... No wonder that it has a sweet sound
Well, it does have the 0.12uF bypassing on the rails. That's not fantastic, but it may be enough to run the thing without making distortion unpleasant. It probably does have higher distortion than it would with proper power, although I think people grossly overestimate the sort of rail capacitance you actually need for these op-amps. The 5uF caps in the input concern me as well, though. I haven't tested the 4556 but some chips don't react favorably to capacitance at the input.

Garrett - Your Guzzler CMoy has 50 ohm resistors on its output as well as filter caps on the input. It's not really surprising to me that it sounds different. You may recall that the chips I brought over were granier in their sound in your CMoy than they were in my test box as well.
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post #17 of 27
10/20/06 at 8:05pm
Quote:
Originally Posted by robm321
I have the X-cans v.3 and the RA-1. The RA-1 sounds better with the RS-1 and GS-1000 for that matter (at times anyway). I haven't modded my X-cans and some more tubes rolling may change this, but then you are adding cost. I've flip flopped about which is better for awhile but just can't get over that creamy, sweet RA-1/RS-1, GS-1000 synergy.

I will say thought that the Mapletree that iamdone had (don't know which tubes he picked) had that synergy and improved on it.
I had a Raytheon 5751 tube in the gain position. I actually prefer the GE 5-star for the PS-1 because it makes the bass is a little tighter. These NOS tubes are very close to the stock tube sound, so it's not even necessary to swap out. If you want to find old stock tubes, the GE 5-star can be found for under $25.

The Mapletree is perfect for the PS-1 and RS-1. I didn't spend too much time with the GS1000 hooked up to it but it seemed to have no problem controlling the bass.

When I owned the GS1000, I think the RA-1 was the best because it brought out the mids better than anything else I used with it. The RA-1 has a little bass bloom, very sweet harmonic mids, and was the most fun.. Most solid state amps have a tighter sound but sacrifice some of the fun.
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post #18 of 27
10/21/06 at 5:00am
Quote:
Originally Posted by Filburt
Well, it does have the 0.12uF bypassing on the rails. That's not fantastic, but it may be enough to run the thing without making distortion unpleasant. It probably does have higher distortion than it would with proper power, although I think people grossly overestimate the sort of rail capacitance you actually need for these op-amps. The 5uF caps in the input concern me as well, though. I haven't tested the 4556 but some chips don't react favorably to capacitance at the input.
You would call 112 nF (ceramic?) "reservoir" ?

That's just needed for high frequency bypass, not to have the op-amps oscillate. Fast and clean energy for audio signals is something they just won't provide.
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post #19 of 27
10/21/06 at 2:00pm
Thread Starter 
Quote:
Originally Posted by kramer5150
But it is a good amp, just a little over priced IMHO.
How much would it cost to build an exact clone of this amp? looking at those pictures from patu doesn't makes it look too complicated...
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post #20 of 27
10/21/06 at 2:08pm
Quote:
Originally Posted by Chiliman
How much would it cost to build an exact clone of this amp? looking at those pictures from patu doesn't makes it look too complicated...
This has been done before and several clones showed up on eBay, iirc they seemed to go for about $100 or so. I think the parts cost excl case was about $25
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post #21 of 27
10/21/06 at 2:22pm
Thread Starter 
Would it actually sound the same? 25 dollars is cheap, and i could probably do the case myself.
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post #22 of 27
10/21/06 at 2:35pm
Quote:
Originally Posted by Chiliman
Would it actually sound the same? 25 dollars is cheap, and i could probably do the case myself.
Why would it sound any different?

If it has the same parts, same circuit , same signal path and length and design and is competently assembled any two instances of the same class should behave the same, unless parts matching is an issue(*) i.e. QA is poor on a range of components , a home built one should sound identical to a commercially assembled one, I would have thought.


* - The G&W TWJ1 had notorious sample variability and has since pretty much disappeared but some examples were very good (apparently)
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post #23 of 27
10/21/06 at 2:55pm
Quote:
Originally Posted by hciman77
Why would it sound any different?

If it has the same parts, same circuit , same signal path and length and design and is competently assembled any two instances of the same class should behave the same, unless parts matching is an issue(*) i.e. QA is poor on a range of components , a home built one should sound identical to a commercially assembled one, I would have thought.


* - The G&W TWJ1 had notorious sample variability and has since pretty much disappeared but some examples were very good (apparently)

i bought an RA-1 clone from a head-fi member for 40 bucks shipped, and i'm very happy with it so far.

i can't wait for my sr60s to come in the mail
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post #24 of 27
10/22/06 at 7:35pm
I deleted a handful of posts that linked to a webpage tha aids in "cloning" an amp of a manufacturer, something this site prohibits. Please do not post such links again.
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post #25 of 27
2/19/07 at 6:25pm
JRC4556 or JRC2114?
which is better OPA in this case?
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post #26 of 27
2/20/07 at 9:01am
Improvements to the RA-1?


Caps sizes.




Other Opams: Original JRC4556 - JRC2114D - AD826 (no work fine) - OPA2604


JRC4556 - Mylar caps 0,1uF - Auricaps 4,7uF
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post #27 of 27
7/14/11 at 9:11pm

or you can try something like this -> http://cgi.ebay.com/YULONG-Mini-Portable-Battery-RA1-Headphone-Amplifier-/250671692157?pt=LH_DefaultDomain_0&hash=item3a5d32797d

 

I'm using it.

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