Sunfire Tracking Downconverter Delta V adjustments?

[Zero Cool]

Anyone have any service info on how to adjust the Delta V adjustments int he sunfire amps that use the Tracking downconverter scheme??

 

[f350bronco]

Old thread but for reference: doesn't Bob Carver state the offset should be set for six volts in his white paper? I'm guessing that would be measuring the outputs of the downconverters. IMHO

 

[Pmat]

Sunfire schematics

There are now some Sunfire schematics available at carversite.

 

[f350bronco]

Only partially related, it appears the BCarver sub amp designs incorporate a forced positive DC offset. For example an R100 2.7M to -13V or an R74 3.9M to -12V resistor on the NFB. I have a +200mV DC offset on a Knight Shadow and I'm trying to determine if there's a problem or that's just the way BCarver wanted it for some reason (what reason?). Thanks for helping me out.

 

[f350bronco]

For those that don't have the schematic handy...

An externally hosted image should be here but it was not working when we last tested it.

 

[f350bronco]

Better schematic pic

This is an example of the DC offset resistor I believe. Why a DC offset?

 

[AVWERK]

Do you have a schematic of the 300/2 or the 600/2 ?


Regards
David

 

[f350bronco]

Sorry, I do not.

 

[f350bronco]

A friend suggested a possible reason for the small DC output offset in the BCarver designs: to preload the massive speaker cone assembly. I cannot think of a better reason.
Bueller?

 

[rextech]

Anyone ever solved this? I have some trouble with the downconverter in my Sunfire True Subwoofer Signature Edition. The downconverter shows far higher dutycycles on the negative side than the positive side, resulting in more negative voltage, and almost nothing on the positive.
How does one adjust the two delta V offset adjustments RP1 and RP2 ?

 

[rextech]

How convenient. It was actually printet in the ad on the sunfire website. 6 volts higher than the output voltage

Tracking Downconverter | Sunfire

 

[AVWERK]

Anyone ever solved this? I have some trouble with the downconverter in my Sunfire True Subwoofer Signature Edition. The downconverter shows far higher dutycycles on the negative side than the positive side, resulting in more negative voltage, and almost nothing on the positive.
How does one adjust the two delta V offset adjustments RP1 and RP2 ?

On the Carver site WRF (member) in a repair of the Sunfire 600 and similiar TDC issue you mention, had a 2 volt higher - rail (8.5v) than the
positive side (6.5v) and was able to adjust down to match the + side and ran full power tests afterwards
He also mentioned that he had no prior information to go on but it worked out well in the end