Marantz 2500 restore

Blaine,
Let me show my better half.
I ask for your forgiveness.
I also just canceled PayPal claim.
I am very sorry what we had to go through.
I was wrong.

I too feel bad.
Forgive me.

The scars will fade but will always remain.

Gentlemen, you have restored my faith. I'm sorry that both of you had to go through this via this particular 2500. I agree, there were some limits and maybe a few compromises with the power supply that were really pitfalls in the end. This is from the issue of trying to pack so much into a receiver chassis and expecting so much power output from the system. The physical space constraints on the toroidal transformer, current and voltage outputs for 8 ohm (and limitations for 4 ohm power output) plus either wire insulation or thermal fuse technology of the day still exist to a large extent today.

I haven't been able to follow many other 2500 threads lately so I'll ask the following questions as followup to this thread:
1) anyone know what the serial number is of this beast so we can consider being cautious if it ever resurfaces? :eek:

2) Has there been any movement on a replacement or reproduction power transformer design, test samples, or production details/costs? I've got a 2500 which has been sitting for 13 years so concerned about any potential turn on, failure, or general need for refurbishing/rebuilding.

3) What became of the 2500 in question when sent to the next shop? Did they actually have a correct transformer, or did they substitute something else (which probably disabled the scope and/or reduced power output)? What did they eventually do?

4) Although this thread apparently got moved to feedback, IMO, there could be and would be a lot of good done by putting it back into the Marantz or Solid State forums as a cautionary tale of buying, hoping, restoration, repair pitfalls, etc. for all vintage gear fans. That the owner and troubleshooter/repairer have (sorta) settled their differences in mutually forgiven way is also another testament to AK values, and IMO, should be shared in a larger context besides feedback forum.

5) If the original 2500 was unsalvageable from a time or $$$ aspect by the owner, one wonders if it was parted out whether the problems it had would then propagate through the Marantz 2500 population at large that needed parts? I only say this partially tongue in cheek, I'm a firm believer in "parts is parts" but sometimes "a lemon is simply a lemon".
 
This saga started an effort to get reproductions made. That effort has run onto a lot of delay.
I am sitting on a restored 2500 that up an died one day. So, getting a reproduction is still a goal. Many folks watching and waiting and hoping.
The shop has a designer that has become too busy.

I has some messages with the shop that claimed they could fix it, a while after this nightmare, it sounded like it was sitting there still!
I tried to contact the shop to get info on their plan. I was told they would get it done quick. Their hours and the time difference made it impossible to get them on the phone. I gave up. They never answered the phone when I could call.
I have read good things about the shop, but I can't get them on the phone.

I think the nightmare continued and there are dead 2500s lying in Chicago.

Hmmm, shops promising things they can't deliver seems to be a theme here.
 
I just ran across this thread. An amazing story. Like a greek tragedy. I am truly sorry all who have suffered starting with the best of intentions. Based on the end of the story there is some redemption. Still i am sorry this gut wasn't resurrected. That our hero wasn't triumphant and the owner wasn't blessed with a cherry of a 2500 in the end. Maybe we can all enjoy the pieces that come through their repair/restorations that much more after sharing this story.
 
Hi Blaine, thanks for the followup and info. Seems to me that a shop that can't or won't help with the transformer design or cransan't even get their designer with the program just isn't interested in a (relatively) small run of 10-20 (or more) transformers. I had once looked at a number of off-the-shelf toroidal transformer suppliers with VA designs in the secondary output range only (not withstanding the need for the scope windings - might be able to get away with a separate transformer here to simplify requirements?) and found the transformers to be just a little taller or wider (due to cores and windings) than the originals, probably due to needing a bit more core and large wiring. I can't recall but I'm assuming the toroid is double wound on a single core rather than being two cores stacked on top of each other. I might assume there's a number of 2500's out there with repair needs, some of which involve the power transformer.

Obviously, there's lots of big, medium, and small transformer companies out there in the US or maybe Far East which has the design capability, and likely small run production capability to create a suitable (if not dimensionally appropriate) transformer, its just about finding the one that wants to do the work (design) for a $$$ fee, and then could make a run of transformers for the 2500 / 2600, and maybe the 2385, not to mention the 500/510 and similar. I studied toroidal transformer design a bit in my spare time and there's nothing particularly magical about it, it is straightforward engineering, materials, and cost considerations for prototyping and production. Money talks, but actions complete the job and sorry to hear of the delays encountered with the tranny shop.

As for the other repair shop, it wouldn't be the first time a shop has offered but found out the patient was in much worse shape, or their repair plan didn't work, despite good intentions. Perhaps the unit owner can also fill us in?

I've a Concept 16.5 that was sent down to Fred Longworth and JP Dylon some years ago (maybe a decade now, how time flies), that had a problem with intermittently sending DC to one channel output. They rebuilt that amp board twice with all new components and twice it glitched and blew their test speakers. We suspected the board had developed unseen conductive paths within (no cracks, bad traces, or major cap failures had been seen or noted) that caused it to go bonkers. Fred and JP worked on it for many many hours but ultimately we could not solve it. In my mind and his, the fix for this would be a copy / replacement amp board using new and modern materials - which should be relatively easy to prototype and design with some photos, CAD software, and a fair amount of time and effort before sending the design off to a board prototype maker - a relatively straightforward exercise if one has the interest, means, and time for the above. If that still didn't solve it, then more work and troubleshooting would have to be done.
 
I did a little research on tranny's. Not rocket science.

The shop is perfectly willing to spin 1, 2, 10 trannys.
The designer knows the shop's ability.
The designer does it "on the side" and has been swamped with real life.

We have some "specs" from offshore that are supposedly good.
Just need the design.

As far as the 2500 that started all this. I'll bet its still sitting in Chicago, in the back of the shop.
Used working 2500 trannys don't appear often.
Parts 2500 don't show up often either.

I'm sure the shop and the owner thought I was "wrong" about the problem.
NOBODY listens to me.
I hand them the rope, give them a chair and point out the tree.
Do they make a swing?
Nooooooooo.
 
Well I'm rooting for you. Having a spare one would be great insurance policy for the future. *Fingers crossed*.
Does anyone have a bare naked transformer? Kinda curious as to what it looks like.
 
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