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Parts sources for aging M400

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generatorlabs

Newbie

Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Sun Dec 09, 2012 2:05 pm

Parts sources for aging M400

I was wondering if one of you fine folks could point me in the right direction.
I am trying to source the large 4000MFD 80VDC filter caps found in a M-400t cube amp. (newer style power supply)
My caps have vented so I am on a mission to replace the opto-coupler and the filter caps.

Any resources would be highly appreciated.
I use this amp as a primary driver in my studio.
I have had to resort to using a Kenwood receiver I had lying around my garage. Uggghhhh.

Thanks!
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angelod307

SILVER-7 TUBE AMP

Posts: 2708

Joined: Sat Jun 06, 2009 10:56 pm

Location: manning, sc

Post Sun Dec 09, 2012 2:41 pm

Re: Parts sources for aging M400

first and foremost, welcome. as the 80 volt venue is limited, i would suggest using a stantard 100v cap instread. the bob father has long ago approved of this. you can sub a part that is close and over volt rating is ok. the cap will form itself to what is needed.
CarverFest: I just go for the arts and crafts
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angelod307

SILVER-7 TUBE AMP

Posts: 2708

Joined: Sat Jun 06, 2009 10:56 pm

Location: manning, sc

Post Sun Dec 09, 2012 2:43 pm

Re: Parts sources for aging M400

oh yeah, mouser.com, digikey.com, mcmelectronics.com and partsexpress.com
CarverFest: I just go for the arts and crafts
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hewlew1

"You Fuckin' Fucks"

Posts: 1248

Joined: Tue Feb 17, 2004 11:02 pm

Location: Northeast, Pa

Post Sun Dec 09, 2012 5:22 pm

Re: Parts sources for aging M400

Welcome, Everything is aging I am reminded of this everytime I look in the mirror. :lol:
"Carver Audio, why settle for less, just ask my neighbors"
C1,C2,CT3,CT6,CT7/3,CT23,CT26,C4000,The Receiver,M500,M500T/6,M1.5T,TFM24/2,TFM/25/2,TFM35,TFM35X,TFM/42,DTL200,TDR1700,DPL20,TX11,5.2Center,5.1Sub/3,Original Amazings,Platinum Amazings/2,AL3'S,Polk SDA SRS, Polk SDA 1C's, Polk RTA11's, Polk Monitor 10's,Monitor 7's, Sunfire 300x2 /5, Sunfire pre, Sunfire MK2 Sub, 4 Carverfest monoblocks, Mapletree Audio Designs Tube Preamp,Phase Linear Andromeda III speakers, Phase Linear 4000 Preamp, Dahlquist DQ-10's
CERTIFIED AMPLE PLIERS EXPERT
Some of the best fuckings we get during our lifetime will come from a relative!
I don't kiss ass and I dont take peoples shit, so dont expect it from me!
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generatorlabs

Newbie

Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Sun Dec 09, 2012 6:57 pm

Re: Parts sources for aging M400

Thanks to all for your responses.

My first inclination was to look into Digikey, Mouser, Newark etc.
With the disappointing results I found there I was prompted to look around for user groups that love Carver products.
A little "Googling" brought me to this site.

This is what I looked for:
Electrolytic Cap: 4000MFD: 100-150 Volts: Can Type with Screw Terminals.

There are a number of good candidates that popped up BUT the 100 VDC caps are 2 inches in diameter.
The 150 VDC caps are even larger at 3 inches.
So unless I can find a similar dimension cap, even one that I can solder in place, it looks like I will have to do a Frankenstein to get my trusty M400 running again. I might even have to create a bank of four or more smaller diameter caps to get the equivalent reserve.

This is going to sound insane to some, maybe not so insane to others.
If I have to Frankenstein this amp I don't think I will ever be happy with it. Why? Because I know under that slick aluminum cover will be a patch job at best. It's like putting a V6 motor where a V8 used to be. Sure it will work but by doing so the value of the car has been diminished. Just call me nuts.....really....I don't mind.

Have any of you modded or installed newer caps of different dimensions in a M400t? I would love to see pics and part numbers if possible.

Thanks!

Now another really interesting question comes to mind. I see this over and over again in TV power supplies. Caps exploded because they are operating at the fringe of their rated capacity. I almost always bump the voltage up when replacing them and the equipment runs great for years to come. Why is this the norm? For example, in the M400, if the TRIAC fails in a conducting state then the caps are going to see a charging voltage greater than 80 volts. This is well known. Then why not build it with caps that exceed the highest voltage the caps could ever see, whether the charging circuit is operating under normal or abnormal conditions? Is it purely cost that drives this? Or is there some other factor about the charging or discharging characteristics of higher voltage caps?
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generatorlabs

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Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Sun Dec 09, 2012 7:33 pm

Re: Parts sources for aging M400

Not ten minutes after I entered my last post I decided to widen my search parameters a little.

Now I can find 35mm diameter capacitors. The voltages are from 100 to 120 VDC. I can live with the higher voltages, in fact I really like the idea that the caps are a little more robust.

The problem lies in the capacitance. 4000 MFD is not an option. However I could either go 3900 MFD or 4700 MFD.
My gut is saying go with 4700 MFD for a little more storage capacity but I am no power supply engineer.

Any thoughts or suggestions on selecting a good value?

Here is what I found:

http://www.mouser.com/ProductDetail/EPC ... ahAxEHA%3d

http://www.digikey.com/product-detail/e ... ND/2095916


Thanks again. I think I may see light at the end of this tunnel.
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helicopterpilotdoug

User avatar

SILVER-7t

Posts: 1924

Joined: Sun Mar 21, 2010 8:04 pm

Location: Austin TX

Post Sun Dec 09, 2012 8:29 pm

Re: Parts sources for aging M400

\:D/ WELCOME!! \:D/

You've come to the right place. Lots of knowledgable folks here who can guide through this.
Best of luck, and hope you get the amp going soon.
Sunfire: Theater Grand IV, Cinema Grand Signature.
Carver: TFM-45, PST-24 Cassette, Extra Carver Gear: CT-6, C-11 (S/N 00001).
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hewlew1

"You Fuckin' Fucks"

Posts: 1248

Joined: Tue Feb 17, 2004 11:02 pm

Location: Northeast, Pa

Post Mon Dec 10, 2012 10:25 am

Re: Parts sources for aging M400

The 4700 mfd is an acceptable replacement.If they are the same physical dimensions as what is in there now buy them its not an issue.
"Carver Audio, why settle for less, just ask my neighbors"
C1,C2,CT3,CT6,CT7/3,CT23,CT26,C4000,The Receiver,M500,M500T/6,M1.5T,TFM24/2,TFM/25/2,TFM35,TFM35X,TFM/42,DTL200,TDR1700,DPL20,TX11,5.2Center,5.1Sub/3,Original Amazings,Platinum Amazings/2,AL3'S,Polk SDA SRS, Polk SDA 1C's, Polk RTA11's, Polk Monitor 10's,Monitor 7's, Sunfire 300x2 /5, Sunfire pre, Sunfire MK2 Sub, 4 Carverfest monoblocks, Mapletree Audio Designs Tube Preamp,Phase Linear Andromeda III speakers, Phase Linear 4000 Preamp, Dahlquist DQ-10's
CERTIFIED AMPLE PLIERS EXPERT
Some of the best fuckings we get during our lifetime will come from a relative!
I don't kiss ass and I dont take peoples shit, so dont expect it from me!
<<

generatorlabs

Newbie

Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Mon Dec 10, 2012 10:30 am

Re: Parts sources for aging M400

Thank you very much!
In a few days I am hoping to bring my little creature back to life...Muuuaaaahhhahhahhhaaaa [ sinister laugh :) ]
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generatorlabs

Newbie

Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Fri Dec 14, 2012 2:27 am

Re: Parts sources for aging M400

For those of you who have some experience with repairing Carver equipment I please need a nudge in the right direction.
This unit has a new style rev 7 power supply

I was so excited today.
I got two new really nice looking main caps for my M400.
I also ordered some spare opto couplers (Fairchild CN17-1)

My old caps had vented over time so there was a lot of residue to clean up.
I installed the new OC1
Installed the new caps.
Put the amp on a variac and brought it up to 95 VAC. (Just under the rating of the new caps)
I was expecting to see @ 75VDC on the rail (collector of large Q6) but it was just way off. It is much too high.
The voltage just seemed to follow variac voltage. It would increase and decrease with the adjustment of the variac.
It never stabilized somewhere around 75VDC.
Adjusting pot RP2 has no effect on 75V rail.
I kept the variac turned down to a safe level to prevent venting the new caps.

So now I am stuck.
I looked at small transistors Q5 and Q6 on the PS board and they test OK.
Pot RP2 tests fine.
12+ and 12- test fine.
Putting a scope on the center pin of the triac shows what appears to be a normally chopped up sine wave.

So now I am left scratching my head.
Any ideas?

Thanks!
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elgrau

SILVER-7 TUBE AMP

Posts: 2892

Joined: Wed May 31, 2006 9:33 pm

Post Fri Dec 14, 2012 1:31 pm

Re: Parts sources for aging M400

generatorlabs, for more "horsepower" (or just more eyes on the problem), I'd suggest that you also post your issue at thecarversite as well. They have chased away/alientated some pretty knowledgeable folks (electronics wise..) over there, but still some left that will be able to most likely solve your problem. Not saying that a bunch here could not, but sometimes they just don't have the time...
Family room: 400 disk changer with PS Audio Digital Link III DAC; Technics SL-1100A TT. QED Quenx1 IC's from DAC & TT to Adcom GTP-602 preamp/Tuner. AudioQuest King Cobra IC's from preamp to M1.0t mk-II opt2. QED Silver Spirals 4M wires to EPI 1000’s.
Living room: AudioQuest Black Mamba 8M IC's from family room preamp to Barcus-Berry 2002R Sonic Maximizer to GlowPower Zyxt IC's to Sunfire 300x2 to Nordost 6M bi-source wires to AOS 28" MDF spherical speakers using six 8" woofers and eight 1" dome tweeters symm. arranged around the surface.
SS system: CX-995V DVD to AV-705x 5 channel amp (center/rears) & M1.0t mk-II opt2(fronts).
Garage: TLM-3600 CDP to MXR150 Receiver (pre) to TFM-42 to EPI 400 speakers.
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generatorlabs

Newbie

Posts: 6

Joined: Sun Dec 09, 2012 1:58 pm

Post Fri Dec 14, 2012 3:36 pm

Re: Parts sources for aging M400

Roger that.....
I have posted the same question this morning on the other forum.
I think they have provided me an enlightened path ( or at least I hope so )

Thanks
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F1nut

User avatar

SILVER-7 TUBE AMP

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Location: The Mars Hotel

Post Sun Dec 16, 2012 4:05 am

Re: Parts sources for aging M400

It's like putting a V6 motor where a V8 used to be.


You got that one backwards.
Political Correctness...defined

A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.



In a recent press conference, President Obama remarked, "If I had a city, it would look just like Detroit."

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