Lounge Audio LCR III Phono Preamp- Build and Review Thread - The Doorway Giant Killer?

prime minister

Site Owner
Staff member
Time to jump in and try this little guy. For once I'm gonna jump in first and actually review it myself before sending it off to you fine folks.

Some details from the manufacturer:

The LCR MKIII is a high quality, dual-mono, pure analog phonograph preamp. This topology allows a unique application of smaller inductors that yields an ergonomic approach to LCR (L=Inductor, C=Capacitor, R=Resistor) phonograph reproduction. Vinyl minded audiophiles are growing in numbers with collectable, vintage releases often bettering the best digital formats and new vinyl issues being added to catalogs with increasing frequency. It is known by many in the audio community that LCR RIAA correction is a preferred way of capturing the experience and atmosphere of the original performance.


The passive LCR network is a topology that brings out the detail of small instrument inflections yet keeps a musical cohesiveness in context of the performance and room. Advanced hi-speed op-amps allow for transformerless direct drive of the LCR network. Current sources are employed to bias each amplifier stage into class A operation.


The LT1358 op-amp is still made in a through-hole package allowing this preamp to be made with no surface mount parts. One set of dedicated inputs allows for the simplest path to the op-amp input. There are no switches between your cartridge and the amplifier. Discrete series/shunt power supply regulators are used with one dedicated to each amplifier IC power supply pin. Also for ease of current delivery the pass element of the series regulator is vastly over-rated in current capacity. No power supply ground shares audio grounds or left-right channels. Critical components in the audio section are hand matched. All assembly is done in the USA.

RIAA Equalization type: Passive LCR network
Gain: 40dB
Input impedance: 50k Ohm
Output impedance: 50 Ohm
Input capacitance: 120pf
Full scale output level: 7.4Vrms
Signal-to-noise ratio: -74db with1/f noise dominating (ref. to 0.774Vrms output)
Distortion: 0.15% THD @ 0.774Vrms 1khz output. Composed mostly of 2nd and 4th harmonics.
AC Adapter: 120VAC 60Hz, 18VAC, 500ma Wall Cube type.
Amplification Type: Class A biased Op-amp
I/O’s: RCA jack Dimensions: Height 3”, Width 7 1/2”, Length 5 9/16” Weight: 2 3/4lb
Hi-speed, video bandwidth op-amps for accurate transient response
Class A biasing on all op-amp stages
Separate discrete voltage regulators for each channel to reduce L-R channel interaction
Shunt regulation on DC power lines
Separate ground paths for audio and power supply circuits
Hand matched capacitors for left /right channel accuracy
High quality low noise Dale resistors used in critical audio path positions
Film capacitors used in audio path
Polystyrene Foil and Mica capacitors used for cartridge loading
Bulk Foil resistor used for cartridge loading
Hand crafted in the USA
 
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prime minister

Site Owner
Staff member
And the Haven LCR is under construction. So far the Lounge folks have been great to deal with. And yes, every Lounge product is built to order!
 

mhardy6647

Señor Member
hubba-hubba, cheezecake photos! :)
Thanks, Mr. PM!

So, what's going on with the little transformer/autoformer/chokes that are twinned in the topless shot? (I realize this is probably a rhetorical question!)

It's funny, I was just reading about this preamp model Someplace Else in the past week or two -- it was new to me at that point. Synchronicity, I suppose.

PS I will watch the videos.
 

mhardy6647

Señor Member
that (i.e., the photodocumentation) is really, really nice of them to do.
Really nice.

PS the level of circuit documentation silkscreened on that board is impressive.
 

prime minister

Site Owner
Staff member
that (i.e., the photodocumentation) is really, really nice of them to do.
Really nice.

PS the level of circuit documentation silkscreened on that board is impressive.

Yeah, the Lounge folks are something else. Everything they do seems to just reek of care and quality. Can't wait to watch it grow.
 

prime minister

Site Owner
Staff member
Some really nice specs:

RIAA Equalization type: Passive LCR network
Gain: 40dB
Input impedance: 50k Ohm
Output impedance: 50 Ohm
Input capacitance: 120pf
Full scale output level: 7.4Vrms
Signal-to-noise ratio: -74db with1/f noise dominating (ref. to 0.774Vrms output)
Distortion: 0.15% THD @ 0.774Vrms 1khz output. Composed mostly of 2nd and 4th harmonics.
AC Adapter: 120VAC 60Hz, 18VAC, 500ma Wall Cube type.
Amplification Type: Class A biased Op-amp
I/O’s: RCA jack Dimensions: Height 3”, Width 7 1/2”, Length 5 9/16” Weight: 2 3/4lb
Hi-speed, video bandwidth op-amps for accurate transient response
Class A biasing on all op-amp stages
Separate discrete voltage regulators for each channel to reduce L-R channel interaction
Shunt regulation on DC power lines
Separate ground paths for audio and power supply circuits
Hand matched capacitors for left /right channel accuracy
High quality low noise Dale resistors used in critical audio path positions
Film capacitors used in audio path
Polystyrene Foil and Mica capacitors used for cartridge loading
Bulk Foil resistor used for cartridge loading
Hand crafted in the USA
 

mhardy6647

Señor Member
glad to see it's passive EQ -- and I guess that kinda answers the transformer/inductor question I posed earlier :)
 
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