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mbskeam

Bob Carver on amp mods.....

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it WILL not hurt the transformers on power up with bigger UF/ VOLT  caps....
 
it cant happen.....
 
end of debate ....
 
THE BOBFATHER HAS  SPOKEN.....
 
emteeth.gif

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Thanks for posting the answer from Bob Carver, about this highly debated question.

This should put an end to all the naysayers who have repeatedly made unfounded insuations that   rcapping with upgraded caps will harm / damage / destroy the transformers, as per the BOBFATHER !!!

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yes, and right after  the Q&A I was able to make sure I got the answer  about bigger caps, ie voltage/UF in the power supply and the
start up/triac firing angle etc....
there where at least 3 tapes being made during this session.....emteeth.gif

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The last two times I met with Bob Carver to discuss circuit design I brought a stack of schematics for issues at hand.  Bob would sit quietly for several minutes studying the schematics before questions and answers.  He would say "Wow, this brings back old memories."

It was great fun.  We discussed why Phase Linear amps blew up and were called "Flame Linear" (they were undercompensated and broke out into ultra-sonic oscillation.  Phase Linear never knew the root cause.  They simply replaced pre-drivers and drivers.  The only reason I knew was my tweeter crossover smoked - literally, and I put 2+2 together.  Mine's been stable for 28 years now.)

We discussed the PL-1000 and PL-4000 control signal clipping bugs I fixed in those mods(Bob only listened to records when tuning those products and wasn't aware of problems related to high output levels of other sources.  And of course, there were no CD players then.)

Other topics were reasons for the C-4000 redesign mods.  Many of the problems Bob also addressed in the 4000t.  We never could agree on the transfer function of the correlator log amp.

Bob insisted logarithmic, I think it's square root, at least that's what the equations say. Bob also explained to me how he got the phono stages so quiet with the transistor front ends.

I also learned where Bob got the design for the delay circuits used in sonic hologram version 'B.'

'A' was simply a low pass filter as I had used when I did my own DIY sonic hologram design

in college because I had to money to buy the real thing.  'B' uses a sophisticated Pade approximation.

Carver found it on the cover of an electronics book in a bookstore.

As much of the conversation was my bringing up problems and fixes for issues out in the field after 30 years soak time in the marketplace.  Bob was very interested, as it takes years for problems to show up.  He was unaware of the problems I had found.

In short, the problems are complicated enough that they require soak time with a schematic.

I can't remember sufficiently the stuff I did on Xbox if someone asked a specific question.

Next time I see Bob Carver, we'll talk about overcapping to the detail required.

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Stickers

Quote
.....In short, the problems are complicated enough that they require soak time with a schematic.
.....Next time I see Bob Carver, we'll talk about overcapping to the detail required.
 
I agree that a technical question of this nature requires a bit of preparation (not your normal 'Q&A' session question).
 
Prior to the fest, I'd sent Bob email forewarning that the question would arise, along with all the pertinent schematics, my thoughts, and yours.

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Stickers

i recall as bob and i were talking about some caps in the tfm15 that i swapped at cf10, that he stated " a capacitor will reform itself to the application it is in if say the uf is more than the original, it will adjust itself to have a higher voltage rating as well if the voltage is a higher rating, the cap will form to have more energy storage." this is when you use somthing real close to what is needed in a curcuit. that's the jist of it anyway.

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I heard something like that from another member somewhere, but the context was a little different.  Bob was talking about not needing any margin in the voltage.  So, you could run a 100V cap in a 100V circuit.  However, the context didn't have to do with surge voltages in power supplies.

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Guest jjd9417
Wow, good stuff in this discussion! Never knew any of this accept that of Flame Linear as my PL died years ago, and now I wish I kept it...

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Guest dancer666
hi all, i have just replaced the caps in my m- 1.5t power amp, using the 50/80v capacitor assembly sold by les at circuitsnconcepts@gmail.com. this is a excellent upgrade which gives a cleaner clearer sound  ( big improvement ) also it seems to have stopped the "POP" you get with this amp when turning off, i recomend to anyone who may own one of these amps > cheers rodney  

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hi all i have just replaced the caps in my m- 1.5t power amp, using the 50/80v capacitor assembly sold by les at circuitsnconcepts@gmail.com. this is a excellent upgrade which gives a cleaner clearer sound  ( big improvement ) also it seems to have stopped the "POP" you get with this amp when turning off, i recomend to anyone who may own one of these amps > cheers rodney  
 
Are those the same ones being sold on eBay?

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hi all i have just replaced the caps in my m- 1.5t power amp, using the 50/80v capacitor assembly sold by les at circuitsnconcepts@gmail.com. this is a excellent upgrade which gives a cleaner clearer sound  ( big improvement ) also it seems to have stopped the "POP" you get with this amp when turning off, i recomend to anyone who may own one of these amps > cheers rodney  
 
Way to go dancer666!
 
BTW - I think the "pop" has more to do with your turn on/turn off sequence than the recap.
I always had a little thump from my M-1.5t's until I put them on a timed sequencer.
Adding a 10 second delay before power up (last) and power down (1st) eliminated the thump.

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