Audio Sector vs. Brian Bell chip amp

[chuck55]

I searched but could not find a comparison between the LM3875 amp by Peter Daniel Amp vs. Brian Bell. Has anyone compared the two as far as sound quality?
Thanks

[Nuuk]

No real point IMHO unless both have been built into the same chassis with the same power supply etc.

[pacificblue]

Is there any technical difference between them other than the colour of the solder resist?

[Peter Daniel]

AFAIK, Brian sells kits based on LM3886 chip, not LM3875. So yes, there is a technical difference.

[chuck55]

These were made in 2006. I will be using with a 4" single driver speaker. Full range, no crossover or filtering components, nominal impedance 8 ohm, DCR impedance 6 ohm, in a .25 cu-ft box. These run just fine on my 22 wpc Denon UD-M31.

Technical Details

Chip AMP Type: Two (2) National Semiconductor LM series National Semiconductor - LM3875 - High-Performance 56W Audio Power Amplifiers with a total power output in excess of 100 watts (50 watts per channel)

Main Board: Chipamp Brian Bell’s - Please see website that sells the PCB’s and LM Series amplifier kits. All are high quality printed circuit boards.

Power Supply: The Dual PSU is constructed with Brian Bell PCB that utilizes dual pairs of four MUR860 diodes. Filtering is accomplished through 4.7 UF 100V capacitors on PSU board.

Transformer (Toroidal): 160VA 22v/22v, made by Avel Lindburgh Inc. (Y236503)

We have plenty of power as the rectified power output is approximately 1.4 times the output of the transformers, so we have about 31v feeding each amp PCB.

[Peter Daniel]

Originally posted by chuck55
These were made in 2006.

I understand you are talking about old production boards I was selling together with Brian before we split our operations. Those boards were actually designed by me, with Brian doing some final touches. It all started with a simple drawing you see in attachment.

They would be basically the same as the current Audiosector boards, with possible exception of not having Zobel components option.

If you are talking about Classic kits, there is not much difference as we were using generic resistors. When it comes to Premium kit version, which I still offer, the resistor types are much better and that may have the influence on actual amp performance.

[chuck55]

Thanks Peter. It appears to have stock components so would imagine your current amps would be quite a bit better.

[pacificblue]

Originally posted by chuck55
Chip AMP Type: Two (2) National Semiconductor LM series National Semiconductor - LM3875 - High-Performance 56W Audio Power Amplifiers with a total power output in excess of 100 watts (50 watts per channel)

Originally posted by chuck55
Transformer (Toroidal): 160VA 22v/22v, made by Avel Lindburgh Inc. (Y236503)

We have plenty of power as the rectified power output is approximately 1.4 times the output of the transformers, so we have about 31v feeding each amp PCB.

If the power supply didn't sag and no voltage did drop across the rectifier diodes, you would get ~45 W with 31 V rails. The power supply will however sag under load, so you will probably have 30-35 W per channel.

Not that it matters much. The difference is only 1 or 2 dB.