CJ MF 2300

[Cwatters0]

I just picked one of these up at an auction and I’m wondering if there is any way to tell if it was upgraded to MF 2300a? The is on the back plate says 2300.

I’ve seen where folks have upgraded their 2300 to 2300a. Is that factory or is there a kit you can buy and install? My understanding is that upgrade consists of different capacitors/resistors. Is there more to it than that?

Thanks

[Big Dog RJ]

G'day mate, greetings from down unda.

Yes, there were different versions of the MF2300, and if memory serves correctly, the one I used way back in 97/98 was in fact the 2300A. The thing is, I ordered it directly from CJ HQ at the time, along with the rest of the MF series amplifiers- MF2100, MF2200 & 2300A. So I'm really not quite sure what the upgrade in parts were... it's too long ago.

Also, CJ will not have nor support this gear anymore, they don't have the resources. If you sent the amp directly to them and asked them about it, my guess is that they won't have the required parts for any upgrade. CJ doesn't even make any more SS design amps, all their current gear is all tube design.

Just recently, one of my good mates wanted to get his MF2550 upgraded to the SE version, CJ HQ said unfortunately they didn't stock any of those parts, other than the main items. So he's a bit annoyed... but that's the MF2550SE which was their very last SS design amp.

If they can support the much older MF series, such as the MF2300A, I'd be very surprised!

As far as I can recall, the A version was much quieter, basic elements such as mains tranny and power supplies remained the same. Perhaps a few caps and resistors were upgraded in the A version, I would think.

Sorry mate, not much help here. If the amp works well and doesn't flinch under difficult loads, well that's the main thing. Just enjoy it as it is!

Mine was diving a pair of Maggie's MG3.5/r and it was wonderful, until I eventually switched over to their Premier series tube amplifiers (Prem11A, Prem12's and Prem8A's) outstanding with ribbon panels.

Cheers, RJ

[AnotherJohnson]

I just picked one of these up at an auction and I’m wondering if there is any way to tell if it was upgraded to MF 2300a? The is on the back plate says 2300.

I’ve seen where folks have upgraded their 2300 to 2300a. Is that factory or is there a kit you can buy and install? My understanding is that upgrade consists of different capacitors/resistors. Is there more to it than that?

Thanks

As RJ points out, there probably aren’t any parts.

But even if there were, CJ will not sell them for field repairs.

You might try one of the guys who works on old CJ. If I were you, I would not put more money into this.

[Cwatters0]

Thanks. My thought is to use this as a SS backup to my Quicksilver Silver 90 monoblocks. Being that I bought it through an auction all I know about it is it turns on. If I have to have a local guy look at my thought was why not upgrade while it’s open if that’s all it was. Fingers crossed it’s plug, play and enjoy.

Thanks

[Cwatters0]

Follow up……New fuses and some deoxit. Don’t think this is going to be the backup. Sound is amazing. Does hum a little when your are next to it. Don’t hear it coming out of the speakers but I’d live to figure it out and eliminate it.

[AnotherJohnson]

It’s probably transformer hum if it’s mechanical emanating from the unit. Check for transformer screws that may be either too loose or too tight.

Be careful poking around inside. There are potentially lethal voltages, even if the unit has been unplugged for a while.

Glad to hear it sounds great. It was a very nice, powerful amp in its day, and will still sound better than many units of the current crop.

Happy Thanksgiving!

[admin]

Glad it is sounding good.

If the hum is in the MF2300, it's most likely transformer hum as AJ points out. If you can hear it in the speaker and it's 60 hz, most likely ground loop.

[joemarsh]

I’m using one of these. Well, the A version. And yes, it says so on the serial number plate. I know the A versions have Vishay capacitors. It’s worked perfectly since 2003ish. Jeff told me on the phono a couple years ago that if they were to make this amp today, it would retail for at least $10,000.

[AnotherJohnson]

Yes … but no one would buy it.

[gymee425]

I also recently inherited a MF 2300 and am already in need of repairs. I need a technician near me if possible in the Greenville, SC area. The repair i need is minor but needed, broken plastic mounting nut for the speaker fuse holders. If anyone can suggest remedies it would be greatly appreciated. My soldering skills are weak!

Thanx to all.

[AnotherJohnson]

I also recently inherited a MF 2300 and am already in need of repairs. I need a technician near me if possible in the Greenville, SC area. The repair i need is minor but needed, broken plastic mounting nut for the speaker fuse holders. If anyone can suggest remedies it would be greatly appreciated. My soldering skills are weak!

Thanx to all.

Tractor Supply, Home Depot, Lowes, and Ace Hardware are all sources of specialty fasteners. Take the broken one in and ask them to match it.

[gymee425]

well easier said than done as it is mounted before several connections are wired. Will take you suggestion to heart though as i frequent those places often.

[AnotherJohnson]

A picture would help.

If you send it to CJ, you’ll be out several hundred for sure.

And their policy is to not supply parts to third parties.

If it’s really just an insulated standoff, it may be simple to sort.