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Old 17th August 2015, 02:39 PM   #1
405man is offline 405man  Scotland
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Default Ebay Current Feedback Amp

Is anyone familliar with this Ebay amplifier

2 SETS DELUXE CURRENT FEEDBACK AUDIO POWER AMPLIFIER WITH DC SERVO CONTROL KIT | eBay

does anyone know what it is based on

Thanks

Stuart
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Old 18th August 2015, 01:18 AM   #2
fab is offline fab  Canada
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Marantz Ma-9S2 but wihout the input HDAM circuit. Therefore it is an adaptation and not a real "clone".

Fab

Last edited by fab; 18th August 2015 at 01:24 AM.
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Old 18th August 2015, 07:42 AM   #3
sajti is offline sajti  Hungary
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Quote:
Originally Posted by fab View Post
Marantz Ma-9S2 but wihout the input HDAM circuit. Therefore it is an adaptation and not a real "clone".

Fab
I would say, very bad adoptation...

Sajti
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Old 18th August 2015, 12:51 PM   #4
fab is offline fab  Canada
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But regardsless if it is not a real clone of the Marantz amp several diy members have built it and they like it.....so you can get your money's worth. However, the ground may not be optimized on the pcb since some builders have reported Hum in the mono power supply configuration and it was fixed using dual mono PS....

Also, I would use caution when using components from a kit if you are not sure if all parts are genuine or new. Maybe buy only the pcb and source the parts by yourself....

Fab

Last edited by fab; 18th August 2015 at 01:02 PM.
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Old 19th August 2015, 08:29 AM   #5
405man is offline 405man  Scotland
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Thanks very much for all the replies

Stuart
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Old 19th August 2015, 09:30 AM   #6
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I built the amplifier. It works. He has 3 disadvantages. It has a low slew rate. The heat sink of the drivers are dimensioned too small. The distortion factor is high. The original Maranz amplifier has pre-drivers and drivers. The Clone has only drivers. This has the consequence that the input stage is too heavily loaded. Thus, a higher harmonic distortion arises.

Gerd
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Old 20th August 2015, 09:41 PM   #7
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Hallo Stuart.
I've bought a Named "Mimesis" Clone Amp from jims- audio- ist a seriosly Seller.
Amp is in same Männer like mono set but have Speakerprotection
The Driver Heatsinks to short- use bigger one for 2SA1930/SC5171.
The max. Rail Voltage i use 24-0-24VDC ~18VAC with ~25mv.
It works well with my own used Sanken 2SA1294/SC3263- they are latest Generation
BJT(profusion- uk).
The Sound is detailled and clear, with good acoustic Information in my oppinion.
It's not a bad one for Everyday use.

Regards Hagen.
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Old 4th September 2015, 03:35 PM   #8
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Very good,open sound,better,than my nap140 clone,or original mission cyrus2,or sony590es..
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Old 5th September 2015, 11:42 AM   #9
AndrewT is offline AndrewT  Scotland
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Ask what customer support that they provide.

A kit build may run into problems that need support to sort.
Rather different from a complete ready to use amplifier. It either works, or doesn't. In which case you demand a full refund.

Customer support from China is probably non existent and you may end up with a non working amp that you cannot sort and cannot send back.
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Old 5th September 2015, 02:28 PM   #10
fab is offline fab  Canada
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Quote:
Originally Posted by Bangla H View Post
Hallo Stuart.
I've bought a Named "Mimesis" Clone Amp from jims- audio- ist a seriosly Seller.
Amp is in same Männer like mono set but have Speakerprotection
The Driver Heatsinks to short- use bigger one for 2SA1930/SC5171.
The max. Rail Voltage i use 24-0-24VDC ~18VAC with ~25mv.
It works well with my own used Sanken 2SA1294/SC3263- they are latest Generation
BJT(profusion- uk).
The Sound is detailled and clear, with good acoustic Information in my oppinion.
It's not a bad one for Everyday use.

Regards Hagen.
But it is a completely different amplifier than the pseudo Marantz clone since it is input jfet single ended front end, lateral MOSFET output and voltage feedback amplifier.....I have heard both of them but not compared them one after another. They both sound good but one important thing, the builder ordered its own parts from good reputation suppliers to populate the board so I do not know if the parts provided with the kits are all the best. Jimsaudio is probably amongs the best China audio diy supplier that I know
from my experience but still sometimes I had to throw away the parts provided with the kit....

Fab
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