Hello Everyone,
there is a review of the 4-2LSE in the German magazine Stereoplay (August 2005) that has some superb photos of the inside of the line amp, and also has plenty of informatio about the circuit topology, and also about its components.
The article can be downloaded here: http://www.stereoplay.de/sixcms/media.php/188/stp0805Lyra.pdf
MRupp wrote "I could translate the relevant passages in a few days but maybe somebody else is quicker? In the meantime you may try to get a reasonable translation from babel fish."
I will do a translation/resumé of the important stuff from that article:
* The power supply PCBs are right on top of the audio signal PCBs makeing the PS wires connect directly to the signal amplifiers
* A differential cascode on the input
* output stage with linear bipolars, powerful MOSFETs (IRF 510) and super fast JFETs are used to have a high bandwidth and a current potent amplifier
* dual mono power supply all through the amp.
*special iron plate circular transformers
* huge 20 000 uF caps in the PS
* Carr uses no ICs for the power supplies. Instead he uses 24 discrete regulators
* important signal wiring is done with wires and not on the PCBs
* Schottky diodes in the PS (20A diodes)
* the 20 000 uF caps are mounted in a way to minimize microfony effects
* input rotary switch and stepped attenuator with specially made Shallcos - Carr do not find potentiometers sonically good enough
* it is not balanced inside the line amps, but it can take balanced connectors
* star ground
That was it. If I have missed something, I apologise.
Photos in the next post.
Regards,
Sigurd
there is a review of the 4-2LSE in the German magazine Stereoplay (August 2005) that has some superb photos of the inside of the line amp, and also has plenty of informatio about the circuit topology, and also about its components.
The article can be downloaded here: http://www.stereoplay.de/sixcms/media.php/188/stp0805Lyra.pdf
MRupp wrote "I could translate the relevant passages in a few days but maybe somebody else is quicker? In the meantime you may try to get a reasonable translation from babel fish."
I will do a translation/resumé of the important stuff from that article:
* The power supply PCBs are right on top of the audio signal PCBs makeing the PS wires connect directly to the signal amplifiers
* A differential cascode on the input
* output stage with linear bipolars, powerful MOSFETs (IRF 510) and super fast JFETs are used to have a high bandwidth and a current potent amplifier
* dual mono power supply all through the amp.
*special iron plate circular transformers
* huge 20 000 uF caps in the PS
* Carr uses no ICs for the power supplies. Instead he uses 24 discrete regulators
* important signal wiring is done with wires and not on the PCBs
* Schottky diodes in the PS (20A diodes)
* the 20 000 uF caps are mounted in a way to minimize microfony effects
* input rotary switch and stepped attenuator with specially made Shallcos - Carr do not find potentiometers sonically good enough
* it is not balanced inside the line amps, but it can take balanced connectors
* star ground
That was it. If I have missed something, I apologise.
Photos in the next post.
Regards,
Sigurd