KOC Standard Amplifier - has anyone ever built or heard one?

[stephenl]

Ian, what did you think of the SAG control? Is it pretty useful? Does it provide for useable sustain in both clean and driven modes?

[gingertube]

I found the SAG Control did'nt audibly do much until the control hit one end. Which is weird cause it had huge affect on the voltage out of the supply. With SAG at minimum I was getting a +345V rail, with SAG at max This was down to +125 Volts from the current limit limiting the charge into the main caps.
Here is "something I prepared earlier" when trying to explain "stuff" to a guy on anyother forum.

Cheers,
Ian

[stephenl]

Ian, would you bother with the SAG control? You don't sound impressed with it's use...

[John_P_WI]

Ian, did you fiddle around with trying different values of the 33r current sense resistor?

It seems that of all of the kits that Kevin has offered all of these years, the sag / sustain kits have had the most iterations...

John

[tictac]

I've used the TUT power scale/sag circuit before and found I like the amp best with the sag turned to it's lowest setting; i.e. no sag.

If I ever do another power scaling amp I wouldn't include the sag control.

The amp seems more responsive without the sag turned up....

TT

[gingertube]

My set to work notes here (about the 10th post in that thread).
https://tubeamparchive.com/viewtopic.ph ... b7683f2da2

Toward the bottom you can see that winding the Compression (SAG) Control from 0 to 10 reduced the B+ from 345V to 105V. The effect was not as dramatic as that would suggest.

For one pot, one transistor and a couple of resistors I would probably leave it in BUT if panel space is at a premium then loosing it would not be a major compromise.

Cheers,
Ian