New "Kit" on the Bolck - BrianGT /LM3886 Upgrade

[syklab]

Hi Uriah,
I am planing to try it on the Fetzilla power amp where there is a 1K resistor located after the 1uF Cap, would that be ok?

Thanks

http://www.diyaudio.com/forums/attac...chematic-5.pdf

[udailey]

If you mean to replace R2 this is exactly the kind of place we want to use a Resistor Replacer. Perfect.

[Marra]

Which resistor on Peter Daniels LM3875 board would this kit replace?I'm running with 32v supplies.

[udailey]

R1 for sure. You could try R2 but probably the value is to high however that would only make input impedance wobble a bit and would probably be an improvement. R3 has been tried with good results by another use. I have not tried R3. I have only tried R1 and loved the results.
Uriah

[Marra]

Thanks Uriah.Would this be an improvement if used as well as an LDR attenuator?This is what I intend to use as soon as I get my VCCS kit back from Paul Hynes.

[udailey]

Marra
For a attenuator you need the LDRs to match, so this wouldnt work well as an attenuator. The power supply on this board, however, will sound better than the simple basic LDR attenuator supplies.
Paul's supply is likely incredible. The guy is a genius. So I think your kit will be really good.
Uriah

[udailey]

By the way the LM334 on this tiny board is a VCCS. You vary the controlling voltage with a variable resistor so you could remove the trimmer and add in a pot and wire it to the outside of a chassis for control if you found some situation where this would be an advantage.

[Marra]

Thanks Uriah.The matched LDR's I bought from you some time ago;one set already in use in an paralled LM4780 build and sounding damn good which I built for my brother.The second set are on the Paul Hynes pcb's which I will install in my system once they arrive back with me.I think I'll still give this little mod a go in the meantime though.

[danielwritesbac]

Next kit? You know how LM3886, LM3876, LM1876, LM4780, LM3876 will screech while clipping because of the on-chip spike system hard clipper? I think you can fix that problem with an LDR based soft limiter like this. So, if you like your music loud with powerful bass and no clipping. . . then you might want another LDR.

[carlmart]

Originally Posted by bcmbob

I would suggest Uriah’s LDR Resistor Replacer does for the BrianGt what Siva’s LF01 does for the MyRef. Uriah is still developing these modules and I suggested the only thing I would want is a touch more mid frequency energy. There is no doubt the concept Uriah uses here can and should be explored for use with a variety of power amps – maybe even the MyRefs. The RR allows the BGTs to produce a lot of the refined character of the MyRefs, but to my ears is a somewhat dryer sound. That’s not a criticism – just a personal preference. The depth and width of the soundstage beats the Haflers hands down, but is just short of what the MyRefs can do.

The module is available in both kit and completed forms on Uriah’s web site. Build An Amp

Bob,


An obvious question: did you try the LDR kit on your MyRefC?