Silicon Chip ULD Mk3 amp - 0.0006% distortion

[Circlotron]

July 2011 SC mag.

[Circlotron]

Another pic to encourage you all to go out and buy a copy of the magazine.

[lineup]

The circuit has:
- PNP input with mirror output
- Darlington VAS
- MJE15030/31 drivers of
- 2 Thermal Trak pairs for output

All is pretty standard for getting high Open Loop Gain
in a blameless topology.
What is 'extra' is the Thermal Trak for good current control.
The amplifier's concept has been tested good many times before.
With a good power supply, I am sure this amplifier is worth the money

[VHF man]

Originally Posted by lineup

The circuit has:
- PNP input with mirror output
- Darlington VAS
- MJE15030/31 drivers of
- 2 Thermal Trak pairs for output

Changes from the mk2 version:

Only 2x thermaltrak diodes used
2 pole compensation
vbe multiplier and bias trim adjustment
really big cap in the fb network
lower pole frequency input filter

Adds up to - more consistent performance and low measured THD above 2kHz and below 50Hz.

[MurphyUHF10]

Hi There,

Thanks for the heads-up :-)

I'm a big fan of the MK 1 (stereo kit) which I converted to 'power amp only', and mono-block with custom aussie made transformers,, Sounds great!!

I have no personal experience with the MK 2, but feedback I've always heard is that MK 1 was far superior than the MK 2.. So it will be interesting to see (hear) how Mk 3 compares to MK 1 ??

Thanks
Murphy

[abraxalito]

Originally Posted by VHF man

Adds up to - more consistent performance and low measured THD above 2kHz and below 50Hz.

Have you checked the clipping performance? With 2 pole compensation your fellow countryman GK mentioned there were a few caveats somewhere on this forum.

[wahab]

Originally Posted by VHF man

Changes from the mk2 version:

2 pole compensation

Adds up to - more consistent performance and low measured THD above 2kHz and below 50Hz.

I thouhgt they used TMC , but no , they choosed a less stable method..

Dont they visit DIYaudio sometime ??..

[VHF man]

Nicholas does visit us from time to time and I'm sure he will take note of comments.

But to be sure I will forward a link to his e-mail address.

[jcx]

Originally Posted by wahab

I thouhgt they used TMC , but no , they choosed a less stable method..

Dont they visit DIYaudio sometime ??..

maybe they read and understand my posts on the issue - TMC is not "more stable"

post #1333: Bob Cordell's Power amplifier book

[wahab]

Originally Posted by VHF man

Nicholas does visit us from time to time and I'm sure he will take note of comments.

But to be sure I will forward a link to his e-mail address.

Well, it s funny since a version of this amp was discussed by there
and even simulated to see what improvement would bring TMC..

New Amplifier - ULD Extreme

Diy audio popular amps simulations