Benchmark LA4 preamp and AHB2 power amplifier review

jdjohn

I like the small footprint. Is that shelf standard rack width? Cool that both fit on the same shelf.

VR3

Congrats!

Clipdat

jdjohn wrote: »

I like the small footprint. Is that shelf standard rack width? Cool that both fit on the same shelf.

The shelf is 23" wide.

Clipdat

SIHAB wrote: »

Does the LA4 really do nothing at all to the sound?

It does do something to the sound, it controls the volume.

Clipdat

The LA4 & AHB2 combo sounds perfect. I love it.

Clipdat

Because neither component imparts any of its own sonic character, the XLR interconnect cable between the preamp and amp becomes even more noticeable.

I've tried two different XLR pairs so far, and it was effortless to hear the difference between them. Each had a very different presentation.

I look forward to trying different 0.5m XLR cables here, to determine what sounds "best" to my ears.

Clipdat

Other interesting observations and things that I like:

They're ready to go as soon as you turn them on, no perceptible warm-up time before they are at maximum performance.

The AHB2 gets only slightly warm to the touch during use, the LA4 hardly feels like it's above room temp.

No mechanical noise whatsoever from the units, nor any hiss through the tweeters.

And lastly, they put my name on the front panel, twice! How cool is that?!

Mike Reeter

Talk about Personal Touch

Clipdat

The best way to describe the sound would be that it simply lets me hear more. I can now fully appreciate my source components, because I know that their S/N ratio isn't being limited by the preamp or amplifier.

Both my Vega G1 and SA-KI Ruby are sounding absolutely fantastic today.

Not sure what else to say, other than I love this Benchmark AHB2 and LA4 pairing. I wish all of my fellow audiophiles could hear its performance in their own systems.

audioluvr

Clipdat wrote: »

I wish all of my fellow audiophiles could hear its performance in their own systems.

I'll PM you my shipping address 🤪

Clipdat

I was thinking it would be cool if there was an official Benchmark-sponsored forum demo program with the AHB2 and LA4 pairing.

Like we've had in the past with the MIT speaker & interconnect cables, Backert Labs preamp, Polk Legend L200 speakers, etc.

invalid

I would need to demo 2 of them with my 80db sensitivity speakers.

Clipdat

I had to put a hat on my LA4 if I wanted to be able to play vinyl:



It's the Channel Islands Audio PEQ-1 MKII phono preamp. I'm using the Ortofon OM-30 cartridge which has a recommended capacitance of 200-500pf. I can set the PEQ-1 to either 100pf, 270pf, or 370pf or capacitance.

I tried it with it set to 100pf and the high frequencies seemed a little muffled/laid back/rolled off. I then switched it to 270pf and the highs were back and crisp, without sounding bright. I might try the 370pf setting later just to see what it sounds like, but for now will likely stick with 270pf. Here's how it's set currently:



All-things-phono-expert Jody @jdjohn what say you?

So, I'm not currently using the optional AC-15 upgraded linear power supply that I have which goes along with this, just the standard wall-wart style adapter that was included. I already didn't want to have to stack the phono pre itself like this, but I literally don't have any other way/room to make it work.

I checked the manual for the LA4 and it states the following: "The LA4does not emit strong magnetic fields and for this reason, it will not create interference with audio devices that are placed above or below the LA4."

In the manual for the AHB2, it states: "The AHB2 is magnetically shielded, and will not interfere with sensitive equipment mounted above or below theAHB2."

But for some reason I'm still hesitant to put the AC-15 power supply on top of it, knowing that it has a toroidal transformer inside.

Was actually considering one of these because I could actually put it under my turntable thanks to how thin it is, and then I wouldn't have to have anything stacked on either the amp or the preamp: https://www.musicdirect.com/phono-preamps/iFi-Micro-iPhono-3-MMMC-Phono-Preamplifier-Black-Label-Edition

jdjohn

Clipdat wrote: »

All-things-phono-expert Jody @jdjohn what say you?

Haha...I would say experiment, and whatever sounds best to your ear. The OM-30 is a very fine cartridge. It's akin to cables, and tuning to your preference. You are fortunate to have multiple settings for experimentation.

My personal inquisition is: How does the LA4 compare to the DAC3/HGC? The latter does have two analog inputs. The LA4 clearly has a larger footprint, but no incorporated DAC, so I'm curious about comparisons between the two units.

displayname

Clipdat wrote: »

I had to put a hat on my LA4 if I wanted to be able to play vinyl:



It's the Channel Islands Audio PEQ-1 MKII phono preamp. I'm using the Ortofon OM-30 cartridge which has a recommended capacitance of 200-500pf. I can set the PEQ-1 to either 100pf, 270pf, or 370pf or capacitance.

I tried it with it set to 100pf and the high frequencies seemed a little muffled/laid back/rolled off. I then switched it to 270pf and the highs were back and crisp, without sounding bright. I might try the 370pf setting later just to see what it sounds like, but for now will likely stick with 270pf. Here's how it's set currently:



All-things-phono-expert Jody @jdjohn what say you?

So, I'm not currently using the optional AC-15 upgraded linear power supply that I have which goes along with this, just the standard wall-wart style adapter that was included. I already didn't want to have to stack the phono pre itself like this, but I literally don't have any other way/room to make it work.

I checked the manual for the LA4 and it states the following: "The LA4does not emit strong magnetic fields and for this reason, it will not create interference with audio devices that are placed above or below the LA4."

In the manual for the AHB2, it states: "The AHB2 is magnetically shielded, and will not interfere with sensitive equipment mounted above or below theAHB2."

But for some reason I'm still hesitant to put the AC-15 power supply on top of it, knowing that it has a toroidal transformer inside.

Was actually considering one of these because I could actually put it under my turntable thanks to how thin it is, and then I wouldn't have to have anything stacked on either the amp or the preamp: https://www.musicdirect.com/phono-preamps/iFi-Micro-iPhono-3-MMMC-Phono-Preamplifier-Black-Label-Edition

I had the iphono 2 a few years ago. Great sound for the money, but they have a documented history of power failures after a year or two. I don't think the 3 has been out long enough to be time tested yet, but it was frequent enough that I was relieved I moved on before having an issue. I'd be hesitant with the 3 because of that.

jdjohn

Clipdat wrote: »

Was actually considering one of these because I could actually put it under my turntable thanks to how thin it is, and then I wouldn't have to have anything stacked on either the amp or the preamp: https://www.musicdirect.com/phono-preamps/iFi-Micro-iPhono-3-MMMC-Phono-Preamplifier-Black-Label-Edition

That is not a sound reason for selecting a phono preamp.

Clipdat

I agree that normally something's physical size alone shouldn't be the determining factor, but the iFi is really one of the only options unless I want to stack one on top of my pre or amp. There's not too many thin phono preamps that are also "good".

jdjohn wrote: »

My personal inquisition is: How does the LA4 compare to the DAC3/HGC? The latter does have two analog inputs. The LA4 clearly has a larger footprint, but no incorporated DAC, so I'm curious about comparisons between the two units.

You'd have to ask Benchmark to be sure, but I think I recall reading somewhere that the LA4 is superior in several ways. I'm sure Rory at Benchmark would be happy to expand on what makes the preamp section of the LA4 different than that of the DAC3 HGC. I can give you his email address if you'd like.

Clipdat

displayname wrote: »

I had the iphono 2 a few years ago. Great sound for the money, but they have a documented history of power failures after a year or two. I don't think the 3 has been out long enough to be time tested yet, but it was frequent enough that I was relieved I moved on before having an issue. I'd be hesitant with the 3 because of that.

Was it the plug in power adapter that failed, or the power supply section inside the unit itself?

displayname

Clipdat wrote: »

displayname wrote: »

I had the iphono 2 a few years ago. Great sound for the money, but they have a documented history of power failures after a year or two. I don't think the 3 has been out long enough to be time tested yet, but it was frequent enough that I was relieved I moved on before having an issue. I'd be hesitant with the 3 because of that.

Was it the plug in power adapter that failed, or the power supply section inside the unit itself?

Something inside the unit, can’t remember the exact details. I believe the most comprehensive thread is over on the Hoffman forums, but it was discussed on a few sites.

Clipdat

Well hopefully they fixed it with the latest version! I don't like that all of iFi's products only have a 1 year warranty. Just seems chintzy.

BlueBirdMusic

Happy to see your review on the Benchmark site. I really like your writing style.

I want a DAC3/HGC - been reading about them for a few months. Jody I didn't know you had one until today.

jdjohn

Harry, the DAC3/HGC is not much to look at, but man it sounds good. I really like the incorporated DAC, and the headphone outputs are also an important feature for me personally.

Clipdat

Clipdat wrote: »

Because neither component imparts any of its own sonic character, the XLR interconnect cable between the preamp and amp becomes even more noticeable.

I've tried two different XLR pairs so far, and it was effortless to hear the difference between them. Each had a very different presentation.

I look forward to trying different 0.5m XLR cables here, to determine what sounds "best" to my ears.

Since I greatly preferred the AQ Red River XLRs between my LA4 and AHB2, I decided to order the AQ Yukon XLRs to try for this connection.

I ordered both a 0.5m pair and 1m pair so I can try them between preamp and amp, as well as with G1 to preamp.

Differences between Red River and Yukon:

Red River:
Solid Perfect-Surface Copper (PSC) Conductors
Nitrogen-Injected Hard-Cell Foam Insulation
Metal-Layer Noise-Dissipation System (NDS)
Triple-Balanced Geometry
Cold-Welded Gold-Plated Plugs

Yukon:
Solid Perfect-Surface Copper+ (PSC+) Conductors
Polyethylene Air-Tube Insulation
Carbon-Based 3-Layer Noise-Dissipation System (NDS)
Triple-Balanced Geometry
Cold-Welded Hanging-Silver Directly Over Pure Purple Copper Plugs

Main differences appear to be quality of the copper conductors, dialectic material, and connector metal plating.

Milito

I got some AudioQuest Mackenzie XLR's I run from my DAC1 to my Music Hall a70.2 integrated amplifier last month.

Solid Perfect-Surface Copper+ (PSC+) Conductors
Nitrogen-Injected Hard-Cell Foam Insulation
Carbon-Based 3-Layer Noise-Dissipation System (NDS)
Triple-Balanced Geometry
Cold-Welded Hanging-Silver Directly Over Pure Purple Copper Plugs

I was running Big Sur RCA's before I got these. They aren't fully broken in yet, but they opened up the highs compared to the Big Sur cables and just an overall better more open sound.

SIHAB

Clipdat wrote: »

SIHAB wrote: »

Does the LA4 really do nothing at all to the sound?

It does do something to the sound, it controls the volume.

This actually answers my question. Thanks.
I'll stay focused on a phono pre.

Clipdat

At this point I'm sure I just sound like a raving lunatic who's talking to himself, but I am beyond thrilled with the performance of the Benchmark LA4 and AHB2 combo.

It feels incredible to know that for my personal tastes, these two components tick all my boxes. I have found my reference. I will never sell them.

Their detail retrieval is simply stunning. They let me hear everything. Having a power amplifier with a better S/N ratio than many preamps and DACs is the key.

I am continually astounded by the uncanny sensation of being able to hear every single sound contained within my favorite music. It is a luxury which I do not take for granted.

Mike Reeter

Clipdat wrote: »

At this point I'm sure I just sound like a raving lunatic who's talking to himself, but I am beyond thrilled with the performance of the Benchmark LA4 and AHB2 combo.

It feels incredible to know that for my personal tastes, these two components tick all my boxes. I have found my reference. I will never sell them.

Their detail retrieval is simply stunning. They let me hear everything. Having a power amplifier with a better S/N ratio than many preamps and DACs is the key.

I am continually astounded by the uncanny sensation of being able to hear every single sound contained within my favorite music. It is a luxury which I do not take for granted.

Happy for you Drew, I knew when you first reviewed this combo, they would be in your future. Congrats on reaching Nirvana

JayCee

Clipdat wrote: »

I will never sell them.

I never use the word "never". Unless I'm pointing out that someone else used it or that I said I'd never say never. I never liked the word never. Wait, never mind.

Pretty awesome that it's such a great combo.

marvda1

You can donate the Norma to me and I'll put it away as a backup

Clipdat

Say what?!