DCP going south??

roccus said:
"a 510 Ohm 5 W resistor connected between + and - of the speakers"

What s the advantage to this?? is that not a short putting across + and - ?
Click to expand...

This official modification was developed by Phase Linear expecially for Infinity speakers equipped with Watkins
cross over !!! Use this only with some Infinity models !!!!
Anyway 510 0hm is not a short compared to 4/8 Ohm .
It's a "special " Zoebel network , just like Lee said .
Ciao
Marco
 
What exactly is a Watkins crossover?

Ron brought it up in my FS ad for the dual voice coil 8" Optimus NIB speakers and I don't know much about that.
 
http://www.infinity-classics.de/technik/manuals/RS_IIIA_technical_sheet.pdf
Two clarifications are necessary :
- It's not Watkins crossover but Watkins Woofer ( TM ) .Sorry !
- In PL 400 manual you'll find 150 Ohm 10W and in PL 700B manual you'll find 500 Ohm W
For me it means that this value is not so critic , but I have preferred to use the higher values .
Anyways in the infinity Manual woofers ad mid has big caps in series .
Ciao
Marco
 
marcok said:
http://www.infinity-classics.de/technik/manuals/RS_IIIA_technical_sheet.pdf
Two clarifications are necessary :
- It's not Watkins crossover but Watkins Woofer ( TM ) .Sorry !
- In PL 400 manual you'll find 150 Ohm 10W and in PL 700B manual you'll find 500 Ohm W
For me it means that this value is not so critic , but I have preferred to use the higher values .
Anyways in the infinity Manual woofers ad mid has big caps in series .
Ciao
Marco
Click to expand...

Seems like the 70's was the gimmick era of high fidelity everyone had gimmicks to try to get an edge or turn into a selling point you just could not live without
 
The Watkins woofers were pretty amazing but also known as "amp eaters"....
 
laatsch55 said:
The Watkins woofers were pretty amazing but also known as "amp eaters"....
Click to expand...

You got that right. I had a pair of Quantum 5's with the 12" Watkins woofs and they ate a pretty powerful Pioneer amp and then munched on a Yamaha amp. When I used the PL400 on them, it was just popping line fuses any time I tried to gas it and the amp would get pretty warm. I ended up parting them out, still have the grills and badges somewhere. Had I known about this mod I would probably still have them
 
Guys ,
I don't know anything about this kind of woofers .
I have only fix the problem at power up , using the official modification by Phase Linear .
The system works perfectly and there no problems to drive RSiii with PL 400 .
This system has approx 30 years and I have introduced the resistors four or five years ago .
The sound is good for my father , but to be honest,I prefer Allison One and my AR 9 .
But this is another story .
Ciao
Marco
 
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
 
marcok said:
Guys ,
I don't know anything about this kind of woofers .
I have only fix the problem at power up , using the official modification by Phase Linear .
The system works perfectly and there no problems to drive RSiii with PL 400 .
This system has approx 30 years and I have introduced the resistors four or five years ago .
The sound is good for my father , but to be honest,I prefer Allison One and my AR 9 .
But this is another story .
Ciao
Marco
Click to expand...

I totally believe you Marco, your word is good with me. I just know how to turn the throttle knob to the right

I just cranked the shit out of Gordon Lightfoot's Wreck of the Edmund Fitzgerald two versions on records and that song just totally roars like a mofo. If you listen to the words, you can almost see the plight of the lost mariners. The original is so haunting for lack of a better word

My buddy who founded Jag Panzer did the other version which is done up as a metal epic. The lead guitarist is Chris Broderick who a year or so later went on to Megadeth, dig it

<iframe width="560" height="315" src="https://www.youtube.com/embed/rAra9YYFpis" frameborder="0" allowfullscreen></iframe>
 
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
Click to expand...

Here is offset with DCP removed
Right .585 mv dc ( this went up from when DCP was in and is pretty jumpy compared to left)
Left .038 mv dc

Looks to me like something may be going on in that right channel??
 
Northwinds said:
I totally believe you Marco, your word is good with me. I just know how to turn the throttle knob to the right

I just cranked the shit out of Gordon Lightfoot's Wreck of the Edmund Fitzgerald two versions on records and that song just totally roars like a mofo. If you listen to the words, you can almost see the plight of the lost mariners. The original is so haunting for lack of a better word

My buddy who founded Jag Panzer did the other version which is done up as a metal epic. The lead guitarist is Chris Broderick who a year or so later went on to Megadeth, dig it

<iframe src="https://www.youtube.com/embed/rAra9YYFpis" allowfullscreen="" frameborder="0" height="315" width="560"></iframe>
Click to expand...


Ron ,
now I have a doubt :
the PL modication is related to Watkins woofers ,
but at this point I'm not sure that RSiii have this kind of woofers .
I have simply looked at the crossover diagram and I have seen
the big caps in series . These speakers were produced in the 80s' and not
in the 70s' .
Anyway the volume position is 12 / 1 o'clock .
Not only I have added two 12Kohm in series at the output of Pl 4000 ,
due to the high gain of preamp.
The levels of all sources are adjusted at 0dB Vu
The cart is Grado Z1+ ( now probably renamed as Gold 1 )
The size of the living room is 13'x13' with wooden floor and carpet .
Ciao
Marco
 
Carver tech found what trashed my C-1 and damaged my wopl amp I got the opamps new from the same people who make the browndog adaters...

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.
 
roccus said:
Yep I would say so poor Geri is ill :(
Click to expand...

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.
 
roccus said:
Carver tech found what trashed my C-1 and damaged my wopl amp I got the opamps new from the same people who make the browndog adaters...

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.
Click to expand...

I never had luck with the adaptors. I GOT A PILE OF BRAND NEW ONES... I used the dips with sockets.
 
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