Review and Measurements of Lounge LCR MKIII Phono Amp

[SIY]

SUTs are better than "MC head amps" for LOMC cartridges.

I'll defend that one.

 

[Soniclife]

I'll defend that one.

Please do. I'd really like something useful to understand what difference the options make, I've often been tempted to try one but never have.

 

[SIY]

Please do. I'd really like something useful to understand what difference the options make, I've often been tempted to try one but never have.

Take a look at my article "His Master's Noise" over at diyAudio.com for a discussion. The basic points are that the stepup carries essentially no noise penalty and the CMR allows a balanced input that is remarkably effective at suppressing hum pickup. I can actually touch any of the pins of my MC cartridge with the volume up and not get ear-shattering noise.

Downside is that in order to do things right (and most people don't), you have to tune an RC network across the secondary.

 

[Soniclife]

Take a look at my article "His Master's Noise" over at diyAudio.com for a discussion. The basic points are that the stepup carries essentially no noise penalty and the CMR allows a balanced input that is remarkably effective at suppressing hum pickup. I can actually touch any of the pins of my MC cartridge with the volume up and not get ear-shattering noise.

Downside is that in order to do things right (and most people don't), you have to tune an RC network across the secondary.

But for those of us not building our own phono stage and making the other changes, then what's the answer? Sounds like a don't bother, if all that is required to make it work better.

 

[SIY]

But for those of us not building our own phono stage and making the other changes, then what's the answer?

Digital.

 

[Soniclife]

Digital.

My phono stage is already, it's the bit before that I'm interested in.

 

[SIY]

Since you're in the UK, I'd go to Sowter, tell them what cartridge you're using (DCR is important) and what preamp you're using, and get a recommendation for a transformer and network values.

 

[Soniclife]

Since you're in the UK, I'd go to Sowter, tell them what cartridge you're using (DCR is important) and what preamp you're using, and get a recommendation for a transformer and network values.

Thanks.

What benefits would it bring, if you don't have a noise problem to start with?

Dynavector xx2mk2 into Devialet fwiw.

 

[SIY]

If everything already works, you don't need a step-up.

 

[jackenhack]

Hmmm. Is this what a production unit looks like?

The changes on the PCB looks very much like the standard beginner's modded board. If you need to decouple that much all over your PCB, you've designed it wrong. And why do the star grounding with wires? Shouldn't that be done on the PCB when designed? Maybe go to a four-layer board instead? Or does the four-layer board smear the sound and make it less airy? After the SMD comment, I expect any crazy reply.

 

[patient_ot]

The changes on the PCB looks very much like the standard beginner's modded board. If you need to decouple that much all over your PCB, you've designed it wrong. And why do the star grounding with wires? Shouldn't that be done on the PCB when designed? Maybe go to a four-layer board instead? Or does the four-layer board smear the sound and make it less airy? After the SMD comment, I expect any crazy reply.

Just a guess - I wonder if too many boards were ordered at the outset and then design changes were made along the way. Rather than throw out the old boards they just use them this way.

 

[SIY]

Just a guess - I wonder if too many boards were ordered at the outset and then design changes were made along the way. Rather than throw out the old boards they just use them this way.

There is a relatively old-line manufacturer of tube equipment (won't mention any names but it rhymes with Bawdio Tee Perch) who made a very complex preamp, the design of which a couple of us were trying to analyze. It looked like there were succeeding stages that had opposite effects (gain, then loss) and contributed nothing otherwise.

It finally dawned on us- they had made a change in the design which eliminated two stages and updated the model number, had a lot of the old boards left, but couldn't leave the spaces blank for fear that customers might wonder about why there's fewer parts but a higher price... So some dummy circuitry inserted.

Then again, this is fashion-audio land, so who knows what wacky marketing story might be part of that.

 

[dinglehoser]

Before we get too pointy with the commentary, let's not forget that a) Lounge is a one-man shop, so design rework involving pull-and-respin would probably be too expensive relative to revenue, and b) these units are only $300. If after all is said and done, Robert finds and implements areas of both objective and subjective improvement based on our input, both he and his customers will benefit. It doesn't have to be one school of thought vs another - there's substantial overlap (and, I'd argue, cross-association between objective measurements and subjective observation).

 

[Lounge Audio]

My suggestion would be for Amir to first send to SIY, so he can run his characterization on the same unit. Then, SIY could send to Lounge for evaluation/confirmation. If Lounge then also decides to tweak the unit, I ask that there be an audit trail of all changes/adjustments made, then the unit can make its rounds with Amir and SIY again.

I love this forum for its rigor - this debate is no exception! Thank you, all.

Send it off to SIY so he can test it. Then have SIY send it to me. I will see if there are any repairs needed taking into account the data posted here and from anything SIY reports to me. Once that is all taken care of I will, with your permission, make it into a Gold unit sans the volume control and headphone jack. Then I will send it off to whoever you direct me to. Hopefully sooner than later, after it leaves my hands, someone will actually listen to it.

 

[Lounge Audio]

Hmmm. Is this what a production unit looks like?

View attachment 24802

And what is the signal generator? You only show a scope, the meter and frequency counter.

It is a customer's unit sent in to be upgraded. This unit was not finished in the picture you had. It was operational to pass audio and do cursory testing like FR, noise... The finer points of voicing relating to power supply response were still to be done. After it was all done it looked like this,

As you can see things got a bit more dense. The only thing left is to clean it up a bit, get the temporary power cable off and secure some components with glue. Then into the chassis it goes. Notice there are some SMD parts if you look closely

 

[Lounge Audio]

I'm sure Robert will want it directly, but if possible, I'd like to have a crack at it first to verify Amir's measurements and add a few of my own, then I'll send it on to him.

If that's OK with you, please send me a PM.

I'm suggesting that dinglehoser sends it to you first.

 

[SIY]

I'm suggesting that dinglehoser sends it to you first.

Thanks, I'd very much like to add a few other measurements into the mix. You may find them helpful.

 

[dinglehoser]

Absolutely. I've asked @amirm to send to @SIY, who will then send to @Lounge Audio for assessment and repair, if necessary.

@Lounge Audio you're welcome to make any upgrades/changes you see fit, provided you also document those changes. Once that's done, and the unit operates to your satisfaction, please send it back to @SIY for retest.

@SIY please send it back to @amirm after the retest.

 

[SIY]

If Amir is willing, I am able.

 

[Lounge Audio]

Seems like you bamboozled him with technical jargon.

No. I got him over a "shock of the new" experience he had. Many of my customers have had similar revelations. The vast majority of vinyl listeners have only heard playback through a standardized set of components. Most phonostage circuits go something like this: low noise opamp(s) with a 20v/us or less slew rate, low cost film resistors or common chip resistors, low cost electrolytic caps in the power supply and often times in other places, power supply rectifier diodes with marginal current rating and slow reverse recovery and the dreaded IMO three terminal preset voltage regulator.... All these things add up to a bloated compressed sound. It's hard to identify until you get to listen to your favorite music without it. Once you do it is like a breath of fresh air but like I said it can be shocking at first.

I really like the way Stevehoffman forum member put it: "Not everyone listens for the same things. Some people even listen for the wrong things. Some of those people do gear reviews. Some people actually hear solid state glare or harshness as added detail and will criticize gear that has a smoother sound and mistake that smother sound as a lack of treble or lack of detail. Some people don't listen for soundstage depth or openness at all, and won't recognize those sound qualities when they're there. They'll actually prefer gear with flatter soundstage and a closed in sound because that sort of gear can have more punch and stronger bass, even though that sort of sound robs the music of musicality and robs the stoundstage and imaging of separation and layering. What can you do about reviews like that? They honestly prefer what I would consider lesser sound qualities. They like what they like. "