Lumin AMP (Class AB)

Apologies for belated reply.
I have just followed standard procedure for identifying root cause of ground loop.
I have noticed that with rca cables coming out of Lumin A1 into tube monoblocks and xlr coming out into AMP there is a very loud hum.
Disconnecting RCA from A1 reduces hum.
Replacing XLR into AMP with RCA eliminates hum.
For RCA setting, A1 should be set to normal output, by the way. While with XLR directly from A1 to AMP it has to be set as Low output.
Since my power strip is not grounded from wall socket, it looks to me like classical ground loop case.
I have also tried power strip with filters (excellent Tomanek TAP8), but it didn’t solve the issue. This has proven again it is a ground loop case.
I don’t know if that will be useful to anyone, but as BlueFox requested - sharing the details.
Cheers
 
Jsa said:
I have just followed standard procedure for identifying root cause of ground loop.
Click to expand...
It sounded like a group loop problem to me when you described it, but hadn't mentioned the other tube amps before and given the previous connection diagram I didn't see much that you could change.

However with the new description you've provided, then for safety reasons you should get a 3-prong power strip plugged into a 3-prong outlet. Past that, you could consider connecting an insulated wire from the A1's rear ground pin to one of the screws on the rear of the AMP (strip the wire at the connection points, of course)—it's a hack but it may help and should not present a safety hazard.
 
Some nice pictures and a preview from Matej from Mono and Stereo

[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]https://www.monoandstereo.com/2019/09/lumin-amp-review-is-coming.html[/FONT]
 
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A picture shared by one of our dealers in the US - Audio Archon. Picture credits to Mike Kay!

LUMIN X1 with LUMIN AMP to Harbeth 40.2
 

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Well i might be so lucky that my local dealer will have an Lumin Amp coming in , that he thought i might like to try , and yes i am in for that :) . So after they have put some hours on the Lumin Amp he will message me so i can pick it up for loan.
Will be really interesting for me , as i haven't tried a gazillion amps....... currently i am using Accuphase E-470 with my trusted Lumin T1, that if all goes as planned i will upgrade to an Lumin X1 in around 10 month's time.
But still the Lumin Amp will be interesting to test out to get an idea on what it does.
 
Keep us updated on this. Keen to know your thoughts.

FDPDK said:
Well i might be so lucky that my local dealer will have an Lumin Amp coming in , that he thought i might like to try , and yes i am in for that :) . So after they have put some hours on the Lumin Amp he will message me so i can pick it up for loan.
Will be really interesting for me , as i haven't tried a gazillion amps....... currently i am using Accuphase E-470 with my trusted Lumin T1, that if all goes as planned i will upgrade to an Lumin X1 in around 10 month's time.
But still the Lumin Amp will be interesting to test out to get an idea on what it does.
Click to expand...
 
FDPDK said:
I will do that.
Click to expand...

May I ask how did you like it?

I took my Aesthetx Atlas Eclipse back to my dealer for repair, and he offered me to take home the Lumin Amp to try it with my X1 until they fix the Atlas.

I did not know anything about it and to be honest I did not expect too much from a "little" amp like this but I am pleasantly surprised.
It sounds more transparent and detailed and it is not too harsh at all, except on some lower quality recordings.
The Atlas is more fluid and warmer but it would be difficult to choose, both have their advantages.

Does anyone else have this Amp, or has compared it with other amps?

Zsolt
 
Well as corona and other things got in the way i unfortunately didn't have the opportunity yet to listen to it....when things get better and i can have a chance to listen to it i will for sure get back and report what i think.
And Zsolt welcome to the forum.
 
FDPDK said:
Well as corona and other things got in the way i unfortunately didn't have the opportunity yet to listen to it....when things get better and i can have a chance to listen to it i will for sure get back and report what i think.
And Zsolt welcome to the forum.
Click to expand...

Thank you, hopefully you will get a chance soon...
 
Someone asked about Bridged Mode vs Dual Mono mode of Lumin AMP in another forum, so I'll post the answer here as well.

With two units of Lumin AMP:

In Bridged setup, you connect only two (not four) speaker terminals which are labeled Bridged + - in the back of each of the AMP to each speaker. You get quadruple power this way for high end speakers.

In Dual Mono setup, for each AMP you connect one pair of speaker terminals to the HF, and another pair to the LF of each speaker. You do not need to use a Y cable for the input signal because the signal is internally sent to both amplification sections.
 
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