DCP going south??

Ray, .(point) 125 MILLIVOLTS is 1/8 of a millivolt----EXCELLENT OFFSET, and .(point) 585 MILLIVOLTS is 1/2 a millivolt , also EXCELLEN OFFSET.....
 
WOPL Sniffer said:
Nothing that can't be repaired. We try not to introduce more than one change at a time to the system so we don't have to chase problems like this. Never rebuild both amp and Pre at the same time... Too many variables.
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Amp was working fine so was the preamp up until I put those opamps in the preamp so this is a one change thing at a time that raised hell with everything to me looks like something in the right channel is not right hope the problem is not a backplane will be a bitch to have to remove those.... will see what the pros says with my findings from today
 
laatsch55 said:
Ray, .(point) 125 MILLIVOLTS is 1/8 of a millivolt----EXCELLENT OFFSET, and .(point) 585 MILLIVOLTS is 1/2 a millivolt , also EXCELLEN OFFSET.....
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Hello Lee you see what the Carver tech found?? bummer... so ok we are finding what is good but I need to find what is bad! lol
 
I think Lee is asking about your NOTATION

.585 is 585 millivolts

.585 mv is a half a millivolt


What are you Actually measuring
 
roccus said:
Want to record my readings here before I disconnect DCP next I will take the DCP out of the loop and and see what offset is

Offset
Right .125 mv dc
Left .065 mv dc

Bias
Right .3447 mv dc
Left . 3486 mv dc (the bias seems to have dropped just a tad since break in)

Rail volts
84.02 vdc

DCP pins
J1-1 .082 mv dc
J1-2 not used
J1-3 .001 mv dc, 0.27 ohms

J2-1 .296 mv dc
J2-2 not used
J3-3 .006 mv dc, .31 ohms

J3-1 83.46 v dv
J3-2 .0002 v dc, .51 ohms
J3-3 61.50 v ac
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All your readings are POINT something MV's

Which are NO PROBLEM

is it .5VOLTS or .5 MILLIVOLTS
 
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WOPL Sniffer said:
So were these not yours? I noticed you said "Im done with your amp and your Pre"???????
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That was a quote from the Carver tech on the C-1 he finished the repair got it all working good again.. he has not looked at or have my amp, my amp is out on my bench in the shop now sorry for confusion
 
Except bias, ya don't want just a third of a millivolt for bias....
 
Shit, you got me confused................. 2 different amps????????????????????? Anything with less than a mv is awesome (except bias).

Lee, sorry, you got this.


Notation will kill ya.
 
WOPL Sniffer said:
All your readings are POINT something MV's

Which are NO PROBLEM

is it .5VOLTS or .5 MILLIVOLTS
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Sorry again for confusion... mv = mili volts so all my readings marked with mv are milivolts just a V = volts
 
Perry sometimes it takes 2 to unconfuse.....must be a hell of a meter to go 3 places on a one millivolt reading scale...
 
laatsch55 said:
Perry sometimes it takes 2 to unconfuse.....must be a hell of a meter to go 3 places on a one millivolt reading scale...
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Indeed, he's not seeing that he was putting a point in front of, and an mv behind of his bad reading which made them look good.
 
WOPL Sniffer said:
Shit, you got me confused................. 2 different amps????????????????????? Anything with less than a mv is awesome (except bias).

Lee, sorry, you got this.


Notation will kill ya.
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lol Perry you must have skipped some posts..... My amp is the wopl 400 it was running great I also have a Carver c-1 preamp there is a thing called the BillD mod that improves the c-1 preamp performance the mod is 2 stages 1st stage is swapping out caps for new ones I did this and all was well the c-1 carver preamp worked great with the wapol 400 ran it the c-1 with the 400 stage 1 mod for near a week waiting for parts for stage 2 mod..... I decided to do stage 2 mod on the caver c-1 preamp which involves swapping out the old 4136 opamps for newer more modern 2134 opamps the 4136 opamps are a quad pin mount amps the newer 2134 are a dual surface mount amp so you need to get adapters called browndogs the adapters on top are made to solder 2- 2134 dual opamps on it to make a quad amp the bottom of the adapter has pins to mount to a through hole pc board or plug into and IC socket

Ya still with me???

After I installed the new opamps in the C-1 preamp I powered up slowly with dim bulb all looked ok so I connected the C-1 to my wople... when I connected the C-1 to my wopl all I got was pops hums scratches and howling. I shut it down and knew there was a serious problem. I got ahold of a Carver tech to look at the Carver C-1 preamp. he found 3 or the new 2134 opamps were bad and this is what he reported to me....

Quote from Carver tech on the C-1
"I am done with your C-1. All is good now. I know what caused this big failure. Two of the new OpAmps on the Browndog's are bad. One of them has enormous gain. Both of them oscillate. This would explain what hosed your amp as well as the muting JFET's in the C-1."

While he had my C-1 preamp I found I also now have a problem with my wopl 400 and I told him I had a feeling what ever happened to the Carver C-1 preamp damged my wopl 400 amp when he says "hosed your amp" he is saying this is what most likely damaged my wopl 400

Hope this clears up any confusion here I have 2 units that went down at same time seems the Carver C-1 damaged my wopl 400 so I have been dealing with 2 repairs at same time looks like the Carver tech has the Carver C-1 set but now I need to fix the wopl 400
 
laatsch55 said:
Perry sometimes it takes 2 to unconfuse.....must be a hell of a meter to go 3 places on a one millivolt reading scale...
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Tomorrow I will try to get pic of meter connected to offset
 
"Which way did he go George".................

I think I got it now but look what you did to me............. That's why I wear my sunglasses

:wink:


feldman.jpg
 
roccus said:
Now you know what it's like to live in my world this is pretty much how everything goes for me.... I can't get no.. lol
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It's a big learning curve doing these amps. I learned some hard lessons. Iffn it weren't for the crazy goombahs here that helped me through my mistakes, Id still be employed... Crap, that didn't come out right.. LOL
 
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