Conrad Johnson Mf-2500a amp and PF-1 Preamp Recap?


Does anyone have experience or educated knowledge on if it makes sense to recap these.  I've owned them for 6-7 years but at this point they are getting to be 20+ years old and was wondering if there would be benefit.  I've read somewhere CJ doesn't really like to do recaps on old gear so looking for some guidance.  Costs?

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Depends how long you plan to keep them. If these are lifetime purchases for you, it’s worth doing. Not the signal caps but the power supply caps, ESPECIALLY in the amp as their failure can cause a cascade of failures that may leave you with a boat anchor instead of an amp, and take a speaker out with it.  With the latest caps, using high temperature variants, you coudl be set for 30 years.

Otherwise, sell them and let the next person deal with it.

I've read somewhere CJ doesn't really like to do recaps on old gear so looking for some guidance.  Costs?

I vaguely remember hearing this as well. I own/owned the MF-2300A and PV-14LSII. What I can say is that I’ve contacted cj multiple times through email and they’ve always been transparent and responsive with their repair estimates. If I was in your position, I’d try sending them an email. Side note of interestingness: I’ve been told that cj doesn’t like to share their schematics - unsure if this unique or common?

If we're talking PS caps, which really should be done every 25-30 years with modern caps, you don't need a schematic.  The caps will be labelled in big bold numbers. Any tech can do them.

I'd leave the signal caps alone.  At the point where you start chaning those you'll just want a new piece of gear. :)

CJ gear is top tier equipment and well worth fixing if you are going to keep it. The 2500a gets lots of love from its owners. I recapped my CJ PFR preamp and it was well worth the $$$ spent.

PS - In the case of large PS film caps, those will probably outlast all of us.  CJ does use a mix in their preamps. Just replace the electrolytics.

As a longtime CJ owner, I would ask this question on the CJ owners group site. There are a number of individuals with a great deal of institutional knowledge you may find extremely helpful. CJ also has information posted on their website regarding which vintage items they will upgrade. You could also pick up the phone and call CJ regarding your equipment. The owner, Jeff, frequently answers the phone. The best time to call is between 9:30 - 11:30 am EST. If you don’t live near CJ’s shop in Virginia, the cost of shipping a heavy amp etc. is expensive. Someone on the owners group may know a technician they know and trust near you.
 

As previously mentioned, If you don’t plan on keeping the equipment, it’s probably not worth the cost of servicing the equipment, especially if it is functioning flawlessly. Sell or trade up if you have the $$$$. Best of luck!

 

@rubicon15 I cannot figure out how to find or get to the cj group you mentioned. I live in Tampa Fl so you are correct… super expensive to ship 2 ways. Only tech I’m aware of in our area is called Proaudio and I do believe they do good work. I will likely approach them but wanted to be able to give them direction (based off of advice here) on what to quote on.

Here is the link. Big Dog RJ is very knowledgeable. However, he lives in Australia. He may be able to point you in the right direction or share a few contacts stateside. Just join the group and post your questions. https://www.conradjohnsonowners.com/

Bill Thalman, (THE cj expert) passed away almost a year ago, but I think his company is still doing repair work.  Pretty sure both Corey & Tim are still active.

https://musictechnology.com/

Check with them...

IMHO, recapping/referbing "vintage" gear is worth it. 

If you are unsure, just pull and test a few of the caps, see how good/bad they are. From my experience, lower voltage caps go first, they usually start to drift up, ESR goes up. When you replace these, you will get bigger soundstage, more clarity, wider dynamics, just more of everything. 

Finished my pre and power amp refresh a couple weeks ago, got all audio grade caps, diodes, metal film resistors, and new fuses. Total cost was under $150, took me about 12 hours total for both pieces. should be good for another 20 years. 

For shops doing it, look in the $500-1000 range for a full refresh per unit. But they will sound better than new. New caps are superior to old ones.