Lux91 Monoblocks - Our Best Ever

[bcherry]

We have playing in house a monoblock version of the Lux91.


The original Lux was Thorsten Loesch's circuit and excelled in drive and dynamics, putting out 12w on musical peaks.

The key feature was the reactive interstage - a 5687 with choke on the cathode and direct coupled to the grid of the 300b. The role of the reactive interstage is best understood by viewing the 5687, choke and direct coupling as a unit.


Thorsten has been at it again and we've been tweeking the implementation these few months. These are:

1. 310a used as driver tube: This tube just has such a luscious tone -- it's too good not to have.

2. Monoblock chassis: needed as the extra parts would be too much to fit into a single stereo chassis

3. FCUPS power supply: Big L, small c gives even more 'kick' when needed, and all film caps as should be the standard for any highend products to be taken seriously

4. Fixed Bias: The Active Bias Supply (ABS) module is used to provide bias on the grid as supplied by the FCUPS. This allows the cathode of the 300B to have only a single small extreme high quality resistor -- NO CAP!
5. Choke input power supply: together with 5U4. nothing more need be said!

6. Of course our VCS filament supplies round out the module complement for lowest noise - best sound.


result?
dynamic range of 100dbA
0.3-0.4mv output noise

16w from a single 300B!


No sacrifices! You should hear these driving our Tutti horn ribbon speaker system. If you pass by HK, drop in for an audition.


Hmmm.... how about 300B+ implementation? An 845 slayer?

Stay tuned.
more....

[bcherry]

It's now on the 6moons site. Great job by Chris Redmond organizing a panel of listeners.
Have a read and let us know what you think.
regards
Brian
DIY - Done Right!

• Lux91 Max review (Open in New Window)

[JoMoCo]

Hi, looks like a very nice piece of hardware. Which 310a, 5u4, 5687 tubes are supplied and do you plan to offer a basic selection of those on your web site also? Thanks

Also I could not find a shipping cost to the US for the Mono's on the web site...

[JoMoCo]

Could you elaborate on the differences in the standard output transformer and the Premium output transformer other than the pricing as shown on the web site...Which one was used for the units used for the 6moons review?

[bcherry]

Originally Posted by JoMoCo

Hi, looks like a very nice piece of hardware. Which 310a, 5u4, 5687 tubes are supplied and do you plan to offer a basic selection of those on your web site also? Thanks

Also I could not find a shipping cost to the US for the Mono's on the web site...

Fedex to US is $303USD.
We supply Russian 310a, 5Z3p for rectifier and various 5687 (currently United which we think made by Sylvania).
No plans to lay in a stock of NOS selection as these are getting hard to buy in quantity.

regards
Brian

[bcherry]

Originally Posted by JoMoCo

Could you elaborate on the differences in the standard output transformer and the Premium output transformer other than the pricing as shown on the web site...Which one was used for the units used for the 6moons review?

The 6moons review has the premium output tx.
The standard OPT are not lacking in any way. The Premium OPT are made for us by Silk with premium materials and using Kittipols winding methode which gives wider bandwidth and less distortion. If you have or plan to get a truly wide bandwidth speaker 20hz>>20k+khz then it is worth getting the premium opt.
regards
Brian

[anka58]

Hi Brian

is it possible to make the LUX91 monos also as 2.5v 2A3 monos?

[anka58]

Can u make this amp as a2.5v 2A3?
anka

[ThorstenL]

Hi,

Originally Posted by anka58

Can u make this amp as a2.5v 2A3?
anka

No, cannot, nor would there be much of a point. The Lux 91 is explicitly designed as "Max Headroom" and "Max Power" amp, so it needs 300B's and ones that are no frightened Mimosas either.

Given my experience I would also doubt this kind of circuit will harmonise well with the "sound of the 2A3" if there is such thing.

The Lady Day or Lady Day 91 would probably be a better choice to use with a 2A3. The mains transformer already has taps for lower HT to use with 2A3 and 45, as well as the required heater windings etc., I personally would probably tend towards the 6SL7 driver version with gridchoke for 2A3 (so to speak a Lady Day 2A3), but that is a subjective thing.

Ciao T

[anka58]

Thanks Thorsten

Is on your side some experiance with Emission Labs tubes for THE Lux MonoMax? EML 300XLS or 5U4G ? I use them with in my 4 year old LD91 monos.
I got notice that Brian had some problem with the EML on the Tram pre. Can you explain on that?

Anka