Preamp to MC 2300 Power Amp - Stereo or Mono?

Re: Preamp to MC 2300 Power Amp - Stereo or Mono?

Postby czyfingers » Mon May 03, 2010 10:05 am

Sweet rig man! Did you make the silver face for the 2105? It looks great.
Regarding the switch in question, here's an answer I found on another forum to the same question. So I take no credit for how accurate it is, but it sounds reasonable.

The input coupling switch when in the direct position will bypass a .22mfd input coupling capacitor that is in the input circuit when the switch is in the normal position. Basically the capacitor is their to block any DC Voltage Offset from say a pre-amp that might get into the amplifier otherwise. The safe way to use the amplifier is with this switch in the normal position if your not sure if a pre-amp has any DC Offset on its Output!
czyfingers
Mickey
Mickey
 
Posts: 179
Joined: Sun Feb 17, 2008 4:22 pm
Location: Poughkeepsie, New York

Re: Preamp to MC 2300 Power Amp - Stereo or Mono?

Postby 540EYE » Mon May 03, 2010 12:22 pm

Thanks man, for the compliment. I did see that capacitor on the schematic, but could not figure out what it is there for. Thanks for clearing it up. Normal position it is !!

Yeah, the aluminum front is a homespun deal. I got the 2105 with busted glass and figured this would be a good fix. Trouble is, if I had one with good glass, I wouldda broke it so I had an excuse to do the metal front !! I can't leave NUTHIN alone. That Mc emblem has been in a "junk box of stuff" for the last 15 years or so.......it finally found a home.

Stay upwind

Gerv*
540EYE
tiger
tiger
 
Posts: 22
Joined: Tue Nov 03, 2009 5:38 am

Re: Preamp to MC 2300 Power Amp - Stereo or Mono?

Postby mijknahs » Mon May 03, 2010 5:19 pm

540EYE,

Nice looking rig. How old are those speakers? Are they reconed? They look so new. My JBL cones are not even black any more. Kinda faded looking. Still work fine though.

Jim
User avatar
mijknahs
Senior Member
 
Posts: 1515
Joined: Fri Nov 13, 2009 8:51 pm
Location: Los Angeles, CA

Re: Preamp to MC 2300 Power Amp - Stereo or Mono?

Postby 540EYE » Tue May 04, 2010 1:47 pm

Jim,

The (2) E's on the bottom cab are original cones. They are a bit "blacker" than the upper (2). The grain of the paper is just a tad smoother on them as well. If you look close, you can see that I had to fix the domes w/ some black silicone. They started to separate from the cone and would "buzz" every now and again. Haven't had any issues since the fix.

The top (2) are kinda "grayer" and a bit more grainy on the cone.......I would guess recones.....? I have (4) K's also and seem to have the same thing going on........(2) are blacker and have a bit less grain, while the other (2) are grayish with a bit more grain.
On both of the "blacker" cones (K's & E's) you can easily see they are original.
I've compared sound between the E's and the K's . Maybe the K's are slightly less "edgy" but kinda hard to tell. They all "sound like JBL's" !!

I'll probably change the E's for the K's just because they are lighter.

Thanks checking my rig.

Gerv*
540EYE
tiger
tiger
 
Posts: 22
Joined: Tue Nov 03, 2009 5:38 am

Re: Preamp to MC 2300 Power Amp - Stereo or Mono?

Postby mijknahs » Tue May 04, 2010 2:07 pm

I think I have about 6 JBL E120s and I know 2 of them I bought new in May 2003 (I wrote it on the back of the speakers). They are all now more "grey" than dark black like they were originally. They still work fine but the dark black of the cones seems to have faded. Maybe the climate? I live about a mile from the beach. I have two that were recently reconed and the cones on those are very black. Yeah, to me E-120s and K-120's aren't that different except for weight and power rating.

Jim
User avatar
mijknahs
Senior Member
 
Posts: 1515
Joined: Fri Nov 13, 2009 8:51 pm
Location: Los Angeles, CA

Previous

Return to Jerry Tone

Who is online

Users browsing this forum: Bing [Bot] and 1 guest