RA-1 clone.. who can make me one, please
Dec 16, 2003 at 7:22 AM Thread Starter Post #1 of 116
AdamZuf

AdamZuf

Headphoneus Supremus
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thanks!
 
Dec 16, 2003 at 9:09 AM Post #3 of 116
hey
smily_headphones1.gif

always new faces, once you enter the DIY forums
tongue.gif


i'm in israel, but going to be in hong kong from saturday, probably until the next thursday.. then i'm continuing to new-zealand.

can it be cloned exactly? do you have experience with this particular amp?
 
Dec 16, 2003 at 9:33 AM Post #4 of 116
You can clone it exactly. If you haven't seen this link already, check it out:
http://www.geocities.com/rubin_jpk/rubin/page_4.html
All the parts, except the coupling caps, appear to be identical to parts that are or were once available at Radio Shack. The volume pot definitely still is. So it's fairly easy to source the exact parts. There was some discussion a while ago that the op-amp was hard to find, but then one of the big resellers (Mouser, I think) started carrying it.
 
Dec 16, 2003 at 9:36 AM Post #5 of 116
thanks
smily_headphones1.gif

i got to check out on how to try to maintain the sonic balance, yet to see if the frequency extrems could be better.
 
Dec 16, 2003 at 9:42 AM Post #6 of 116
You can always run it from more power. That's what Hirsch does when he uses the Plainview batteries, and he thinks that it sounds better. This probably wouldn't change the sonic balance much.

Currently it runs on +/- 9v. You could bump that up to +/- 15v (check the op-amp's datasheet though).

Also, consider leaving out, or jumpering, the input caps. These are just a safety measure for bad sources. Most of the new DIY designs just omit them entirely. However, this may change the sonic balance a bit, since the coupling caps in the Grado are electrolytics (poor) and thus may "slow down" the amp's high frequency response a bit.
 
Dec 16, 2003 at 9:45 AM Post #7 of 116
Shalom. I will be making one, with a better powersource and a better pot, an Alps Blue. I had to change some things, but bassically it's the same configuration, just with upgrades that could benefit the sound. Perhaps you could try a similar route.
 
Dec 16, 2003 at 9:57 AM Post #9 of 116
wait, wait, wait!
i don't know crap about DIY, i'm just looking for someone to build me a clone
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i'm afraid to ruin the sonic balance with the RS-1..

i was thinking of battery compartment like the XP-7. can it be done?
 
Dec 16, 2003 at 3:01 PM Post #11 of 116
Yes, you can do a battery compartment. Check out this thread.
http://www4.head-fi.org/forums/showt...threadid=54072
The photos shows a couple of RA-1 clones sitting on the cd player built with the Bulgin battery tray (same as the one used in the XP-7). The input caps in the RA-1 are Solen Metallized Polypropylene Film Capacitor 100V 5.1uf. My recommendation would be to build it as close to the original design if you want a clone, otherwise built yourself a C-moy or something else.

edit: forgot to insert thread.
 
Dec 16, 2003 at 4:43 PM Post #12 of 116
Would you guys say that it's even best to stick with the RS pot and not use something like an Alps Blue?
 
Dec 16, 2003 at 5:49 PM Post #14 of 116
Quote:

Originally posted by was ist los?
The RS pot is one of the synergetic parts in the RA-1 that gives it its sound.


i wonder how big the difference will be..
 
Dec 16, 2003 at 7:23 PM Post #15 of 116
You might also try the MAD EAR+. In all the research I've done on the amp I've yet to find a single person who preferred the RA-1 to it. They are similarly priced if that matters.

www.hollowstate.netfirms.com
 
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