diy amp for grado rs1's?
post-204316
Thread Starter
Post #1 of 27

roos

New Head-Fier
Joined
Sep 6, 2001
Messages
30
Reaction score
0
Joined
Sep 6, 2001
Posts
30
Likes
0
ive been using my rs1's with my nad receiver, and recently a friend let me her ra1. it is a amazing improvement, but from what ive read the ra1 itself is pretty cheap inside and nothing special. so i thouht id investigate a diy amp before i buy the ra1. are there any recommened designs to match with the rs1s?
 
     Share This Post       
post-204317
Post #2 of 27

skippy

Making Grados better through surgery.
Joined
Jun 21, 2001
Messages
1,022
Reaction score
17
Joined
Jun 21, 2001
Posts
1,022
Likes
17
i don't have the rs-1, but i like grados with the szekeres amp. i haven't heard it, but kevin gilmore's dynamic amp has been getting good press.
 
     Share This Post       
post-204344
Post #3 of 27

andrzejpw

May one day invent Bose-cancelling headphones.
Joined
Jun 25, 2001
Messages
6,636
Reaction score
10
Joined
Jun 25, 2001
Posts
6,636
Likes
10
I have also heard good things about the szkeres/grado combo. Haven't heard the gilmore. . .
 
     Share This Post       
post-204443
Post #4 of 27

erix

500+ Head-Fier
Joined
Jun 25, 2001
Messages
835
Reaction score
16
Joined
Jun 25, 2001
Posts
835
Likes
16
Why not just build yer own RA-1?

It's *really* simple.

ok,
erix
 
     Share This Post       
post-204465
Post #5 of 27

Budgie

Never looks a gift amp in the jackhole.
Joined
Jun 22, 2001
Messages
2,154
Reaction score
18
Joined
Jun 22, 2001
Posts
2,154
Likes
18
Skeres gets my vote. I love mine.
 
     Share This Post       
post-204614
Post #6 of 27

antness

Member of the Trade: HeadAmp
Joined
Aug 21, 2002
Messages
491
Reaction score
10
Joined
Aug 21, 2002
Posts
491
Likes
10
Just about any of the popular DIY amps will be a huge improvement over the NAD receiver, and a good improvement over the RA-1. The RA-1 is basically a no-frills cmoy amp (see www.headwize.com project library) with extremely cheap components.

If you've never built your own amp, you should probably either build a cmoy or a META42. both are relatively inexpensive. The Gilmore amp is excellent with Grados, Kevin Gilmore designed this amp for his Grados, but it's not a good choice for your first build.
 
     Share This Post       
post-204661
Post #7 of 27

Tomo

DIY tube amps can be SHOCKING
Joined
Jun 22, 2001
Messages
1,067
Reaction score
12
Joined
Jun 22, 2001
Posts
1,067
Likes
12
Hello,

I would like to give my vote to Szkeres amp as well. RS-1 does not require much voltage gain, but sucks up lots of current. Szkeres amp can offer pretty high current. (Note it is not suited for headphones requiring high voltage swing due to inherent non-linearity.) I recommend primarily because it offers rare "single-ended" sound.

Note opamp-based amps are wonderful also, but you will need to decrease the voltage gain to 2~5 and add a buffer. Very simple, ... (too simple. It's boring for audio electronics fanatics like me.)

KG amp should be able to drive Grado headphones according to my recollection. You should contact him directly to confirm.

Tomo

P.S. I use opamp-based amp because I need a big voltage swing for my headphones. Yeah. The design specifications change with headphone impedances.
 
     Share This Post       
post-205079
Post #8 of 27

roos

New Head-Fier
Joined
Sep 6, 2001
Messages
30
Reaction score
0
Joined
Sep 6, 2001
Posts
30
Likes
0
thx for all the reply's

time do to some research
 
     Share This Post       
post-205111
Post #9 of 27

The Quality Guru

Blah! he says.
Joined
Jan 27, 2002
Messages
887
Reaction score
10
Joined
Jan 27, 2002
Posts
887
Likes
10
Quote:

Originally posted by antness
Just about any of the popular DIY amps will be a huge improvement over the NAD receiver, and a good improvement over the RA-1. The RA-1 is basically a no-frills cmoy amp (see www.headwize.com project library) with extremely cheap components.


With my experience, I find this untrue. The CHA-47 is regarded as being better than the Cmoy, and when I compared my CHA-47 (with premium components) I thought the RA-1 was a significant improvement and was noticeably more transparent. So, with my experience, the RA-1 is far better than "a no-frills cmoy amp with really cheap components." It does have cheap components, but somehow manages to be of very good value because of its transparency and neutrality. IMO, the cmoy and RA-1 are not really in the same league. In fact, another Head-Fier, Zanth, believed that the RA-1 was more neutral than the $750+ Sugden Headmaster. Just a thought.
 
     Share This Post       
post-205446
Post #10 of 27

Budgie

Never looks a gift amp in the jackhole.
Joined
Jun 22, 2001
Messages
2,154
Reaction score
18
Joined
Jun 22, 2001
Posts
2,154
Likes
18
And you could build one for about 10 bucks, minus the wood block they put it in.
 
     Share This Post       
post-205528
Post #11 of 27

roos

New Head-Fier
Joined
Sep 6, 2001
Messages
30
Reaction score
0
Joined
Sep 6, 2001
Posts
30
Likes
0
has anyone replicated the ra1 with better quality parts and compared that to a ra1? did grado use these cheap parts because of the sonics they end up creating or was it just a matter of cost. also, is there a recommended parts list for building a better ra1? thx
 
     Share This Post       
post-205545
Post #12 of 27

Wodgy

Headphoneus Supremus
Joined
Feb 24, 2002
Messages
4,657
Reaction score
12
Joined
Feb 24, 2002
Posts
4,657
Likes
12
My theory is that Grado used those parts because they were all available at Radio Shack (except the Solen capacitors). In fact, the only source I know of (in the US) for the particular potentiometer Grado uses is Radio Shack. Radio Shack also sells the op-amp they chose, as well as resistors with the specific values they chose. Even the cheap 9v battery snaps are sold at Radio Shack.

There is no recommended "better RA-1" parts list because the amp is so simple. I would suggest the following though (remaining true to the spirit of the RA-1 design):
1) replace the two Solen capacitors with four Black Gates with the same rating
2) replace the potentiometer with an ALPS Blue
3) use Vishay/Dale or Holco resistors
4) consider replacing the op-amp with something else; changing it would alter the RA-1 "sound" though.

Incidentally, these changes still wouldn't raise the parts cost above $70.
 
     Share This Post       
post-205563
Post #13 of 27

Budgie

Never looks a gift amp in the jackhole.
Joined
Jun 22, 2001
Messages
2,154
Reaction score
18
Joined
Jun 22, 2001
Posts
2,154
Likes
18
You could most likely just remove the input coupling cap from the circuit, if your source does not have dc on the line out (most don't). It is just there as a safety feature.( Unless you like the sound of caps in the signal path.) That would most likely be a huge improvement.

(disclaimer- don't do this unless you know how to check for dc voltage in the source, or the ouput of the amp.)

Build it with a socket so you can try another opamp in the circuit.
 
     Share This Post       
post-205749
Post #14 of 27

eric343

Member of the Trade: Audiogeek: The "E" in META42
Joined
Jun 23, 2001
Messages
6,033
Reaction score
11
Joined
Jun 23, 2001
Posts
6,033
Likes
11
I'd build it with the original components first, then try upgrading/tweaking it.

And Kevin designed his amp to work with Grados...
 
     Share This Post       
post-205753
Post #15 of 27

Dreamslacker

500+ Head-Fier
Joined
Oct 7, 2002
Messages
555
Reaction score
10
Joined
Oct 7, 2002
Posts
555
Likes
10
Quote:

Originally posted by Budgie
You could most likely just remove the input coupling cap from the circuit, if your source does not have dc on the line out (most don't). It is just there as a safety feature.( Unless you like the sound of caps in the signal path.) That would most likely be a huge improvement.

(disclaimer- don't do this unless you know how to check for dc voltage in the source, or the ouput of the amp.)

Build it with a socket so you can try another opamp in the circuit.


How do you check for DC voltage in the source. I do have a simple digital multimeter.
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top