PRESONUS ADL 600 (tube preamp)

[Anderton]

Okay, so a bunch of you have downloaded the examples and seen the JPG...whaddya think?!?

[Lee Knight]

 

Originally posted by Anderton Okay, so a bunch of you have downloaded the examples and seen the JPG...whaddya think?!?

 

 

Really interesting. Transients are pronounced as is low level detail... I want one. I wish I had a couple of grand.

[diamondjim]

Nice work, Craig!

 

Its good to get the visual impact as well as the subjective audio. This was my 2nd big gear purchase, following on the heels of an RME FF800, and having the visual helps explain what I am hearing. It would be interesting to compare this result with a Neve Portico, or Groove Tubes Supre.

 

I would show this to my wife as proof of my amazing skills at picking gear, but she would just roll her eyes......she calls it my vocal warmer upper thingey.

[modul8]

The mojo...um... I mean... compression is distinct and has, dare I say, an almost "just right" quality to it. The Kick and snair exhibit excellent benefits.

I think when I can afford to add a new color to my humble preamp selection, the ADL will be at the top of the list.

If I may request, I would be interested to also hear the tonality differences you mentioned when pushing the input. I feel this will give us a better sense of the ADL's sonic dimensions.

Thanks again for your efforts! I am waiting with great anticipation for the synth results :-)

[Anderton]

>

 

If I have time, I'll go back and revisit this. I will say that the next (and final) batch of NAMM videos I did for the site used the ADL 600 in the vocal chain. Even when squished down via WMA data compression, you can hear a difference compared to the narration on previous videos.

[Anderton]

>

 

Me too! What I want to try is taking the output from Cakewalk's Dimension Pro and Rapture, which have exceptionally clean audio engines, running it through the ADL, then bringing the result back into Sonar. I have a feeling the ADL 600/Dimension Pro/Rapture combination would be a good one.

[diamondjim]

Craig,

I am curious about how you will approach this. Are you going to take single audio tracks out, and then record them back in? If so how will you adjust for latency?

 

Or will you take the entire stereo mixdown and record it, for example:

1. export to stereo

2. import into a new project, play that through the ADL

3. record it back onto a new track, and toss the first

 

I am anticipating doing the second approach to some of my old mixes, just to see how they sound. I.e. using the ADL as an outboard mastering processor just prior to dithering down to 16 bit.

[Anderton]

 

 

Well in this case, latency doesn't matter as I just want to generate a set of tracks for comparison. But if it was a "real-world" situation, I'd just compare the new waveform to the old one visually, and line up the peaks.

 

FYI Cubase SX is set up to do this kind of thing -- it will "ping" your system to measure the delay, and compensate automatically.

[ivorycj]

Hey Craig,

 

Thanks for doing this -- you give a lot of creedence not only to HC as a 'pro' forum, but also to these products that you review. I just got my ADL600 today -- I can't wait to play my K2600 through it

[Anderton]

I decided not to try bringing synth sounds of the computer and back again the ADL, as the additional conversions would likely skew the results. Instead, I figured out dragging out a good old-fashioned hardware synth, and recording it both with and without the ADL.

 

But as I wanted to try out both synths and mixed tracks, I figured why not have a dual-purpose test, and try a mixed track of synths?

 

The signal source was an Ensoniq TS-10 with some sequences I had loaded in some time ago. The reason why I chose these was because they had really punchy drums, some sampled acoustic guitars with a lot of “zing,” some analog-type handclaps – a nice mix of sampled “real” sounds and synthetic sounds. I was hoping that by using a diverse collection of sounds, I could readily pick out differences in individual tracks as I compared the ADL-ified version with the straight version.

 

Another point of interest is that I believe the TS-10 response tops out at about 15kHz. I didn't want to have too many highs, so I could hear if the "sparkle" that the ADL seemed to add would work with a more muted signal source. In other words, was the ADL generating harmonics, or working with the ones that were already there?

 

I did the usual trick of recording one track straight through the FireBox into Sonar, then another track through the ADL 600 and then through the FireBox into Sonar. On playback, as I switched back and forth between the two, the differences appeared to be subtle. I thought I recognized the ADL 600 "signature," but was concerned that because I had already listened to so many signal sources through the ADL 600, I was “psyching” myself into hearing something that maybe wasn’t there. Also, as I transitioned between soloing one track and another, there was a long enough pause that my auditory memory was fading by the time the second track was lined up and ready to go.

 

I needed some way to do more of a blind test. So I took identical sections from the two tracks, put them end to end, and looped the combination. I then left the room for a minute, came back in, put on headphones, and listened. The looping process was already occurring, so I had no idea whether I was coming in for the first segment (recorded through the ADL 600) or the second segment (no ADL).

 

Well, I gotta say…as one segment played back, I was absolutely 100% sure it was the ADL 600 – it had that definition/compression/peak massaging mojo. I looked at the screen and sure enough, the first segment of the loop was playing.

 

This is also an interesting example of psycho-acoustics in reverse: Because I wanted so much to be objective, when I knew which segment was which, I tended to hear the similarities more than the differences. When I came into it “blind,” the differences between the two segments were obvious. It was easy to tell one from the other.

 

Unfortunately an MP3 example at a high enough bandwidth and of sufficient length won’t fit in the allowed file size for a post, so in a bit, we’ll get graphic.

[Anderton]

I put the two waveforms into Wavelab, and was surprised that the “higher average level” effect I’d seen on individual instruments wasn’t as pronounced here. With the ADL, the peaks had been softened a bit, but other peaks were brought up. This didn’t seem to jibe with what the waveforms looked like on previous tests, but the sonic signature was the same.

 

So what exactly is that sonic signature? Well, of course this ventures into the wildly subjective. But I would identify the following as the components of the “ADL sound.”

 

“Punchier” transients. It seems counter-intuitive, as the peaks are typically reduced a bit to allow for a slightly higher average level. Yet without going through the ADL, peaks sound more “smeared” and less distinct. It’s not the FireBox doing this, because as it’s following the ADL, it would smear the ADL’s transients. It seems to me that something within the ADL is actually “sharpening” the transients. Slight ringing from the transformers, maybe?

 

More defined midrange. The sense I get when listening to the mixed tracks is that the stereo positioning is more precise, and it’s easier to pick out individual instruments. This seems particularly true with harmonics from bass, which are brought out a bit. This gives the illusion of better bass response, because the bass sounds fuller rather than having more of a low frequency “blur.”

 

”Sweet” high end. Put a screechy FM patch through the ADL, and you’ll hear what I mean. There’s a certain sparkle that’s very subtle.

 

Better bass. It’s hard to describe what I’m hearing here, because the waveforms don’t seem to indicate that the bass is any louder; in fact, the reverse appears to be true. But it just seems “rounder.”

 

Slightly higher average level. Of course, just increasing a signal level somewhat will make the bass and treble seem larger, due to the way the ear works. But I went out of my way to try to also listen at lower (not matched) volumes compared to the reference signal, and you could still hear the effects mentioned above.

 

All right…let’s see what some spectrum analysis says about all this.

[Anderton]

I used Wavelab’s 3D Spectral Analysis feature to analyze the two different tracks, and besides, it looks cool. Click on the attachment to see a picture of the two spectra; each signal lasts a little under 2 seconds. The upper one is going through the ADL 600.

 

At first glance, the differences appear to be minor. And that’s right, because the ADL is about adding a subtle character to the sound, not hitting you over the head. Still, as you look closer, there are some significant points of interest.

 

The top peak is definitely rounded off a bit, and not quite as high in amplitude. But the big difference extends from about 50Hz to 500Hz. The ADL signal clearly has a slightly higher level, with more definition. Note how the yellow bass region “blob” on the lower shot around 50-115Hz is much more defined in the upper one. And while it’s not all that easy to see, look in the upper shot around 500-1500Hz, and follow the response toward the left. Those blue ridges are higher, and more defined, than what’s happening in the lower shot.

 

Once again, we have a strong visual correlation to what we’re hearing. Interesting…

 

At this point, I think I’ve pretty much found out what there is to know about the ADL 600. Even though I couldn’t book a make-up session (at Maricam Studio) for the one that I canceled during the snowstorm, I did some acoustic recording here and the ADL stayed in character – I was mistaken to think that I would need to go to a studio specializing in acoustic recording to hear the difference. Percussion (shaker, tambourine) in particular sounded wonderful.

 

So I’m going to sleep on this a bit, mull over some additional thoughts, and present my conclusions next. As usual, that doesn’t mean the end of the Pro Review, as there will likely be follow-ups and additional discussion. But I feel I know the unit really well, and it’s time to wrap all this data and all these subjective impressions up into a nice, compact package.

[Anderton]

You never know what's going to happen with a Pro Review, which is part of the fun for me, and of course, a bit of a nail-biter for manufacturers. Of all the Pro Reviews done so far, this has probably had the least amount of interaction from both readers and the manufacturer, even though it's clear a lot of people have been following the review.

 

Why is this? I decided to spend some time checking out what people were saying about the ADL 600 on other forums. It could pretty much be summarized as: "Sounds great, built like a tank." This is basically the same conclusion I came to (although I'd like to think this review delved a little more into the objective reasons behind that conclusion). And when users did post here, their reaction was pretty much the same as well. I even called up EQ magazine's editor, Eugene Robinson, because I knew they had done a shootout recently with the ADL 600...yes, their reviewer liked it too.

 

There was one variation I found a couple times: "Well, it didn't work when it arrived, but PreSonus took care of that. Sounds great, built like a tank."

 

So basically, although the Pro Review format allows "checks and balances," there seemed to be virtually zero controversy around this piece of gear. I expected at least some "Well I don't hear anything different" or "$2,000+ is a lot for a stereo mic preamp" or even a few "tubes good/solid state bad" comments. Nope. Just "Sounds great, built like a tank."

 

I believe that PreSonus was hoping the ADL 600 would update their image and show they could make boutique-type, pro-level gear more accessible but without compromise. Okay, $1,000 a channel still isn't exactly the budget zone, but when you look at the build quality it's clear that a lot of effort went in to designing and manufacturing this amp. And given what it does to a signal, there will be people willing to pay that grand per channel. If an image update was part of what PreSonus set out to do with the ADL 600, it was a good move because it has garnered the company a "buzz" ih pro audio circles it didn't really have before.

[Anderton]

When I started this Pro Review, I didn't really know what to expect. I've worked with enough "boutique" gear over the years to recognize that a lot of it does bring something special to the table - but some of it seems way overpriced, and more "emperor's new clothes" than anything else. Where would the ADL 600 fall?

 

Overall, it does indeed justify its price tag - not by being a "straight wire with gain," but by adding character to the overall sound. "Character" is always a dangerous concept, because it might be a character you like, but it also might not be. This is particularly the case with tube gear, where "character" may mean distortion or ringing from transformers: Fine for some signals, but not for others.

 

The ADL 600 has a character that really seems to flatter just about everything you put into it, from individual instruments to complete mixes. It does this by what appears to be a very gentle peak limiting/compression effect, and that's easy to see on the waveforms attached to some of these posts. There are also some frequency response things going on, as evidenced by the 3D spectrum analysis shots. Subjectively, I'd say there's more definition overall, and a very smooth bass range.

 

Those who expect these changes to leap out at them will be disappointed; the ADL 600 is much more about subtlety. It really comes into its own when you use it on multiple tracks and hear the cumulative difference, or use it to accentuate individual tracks. I also like what it does to mixes, and the surprisingly low noise level means yes, you can consider this a legitimate piece of mastering gear.

 

I really have only two complaints: Using XLR-only connectors in today's world, while "pro," isn't as practical as using combi jacks with XLR and 1/4" TRS connections. It's not a deal-breaker, but with so much gear using 1/4" TRS balanced connections, you'll find yourself looking for adapter cables perhaps more often than you'd like.

 

The other issue is the instrument input impedance. 100k is acceptable, but on the low side of acceptable. To squeeze every last bit of response out of a guitar or bass with standard pickups, the input impedance should be at least doubled...and I'd prefer something between 500K to 1M. This doesn't make a huge difference to the sound, but given the level of detail in the ADL 600's design, I'm surprised this detail was overlooked. (I also assume it would be relatively easy to mod the ADL 600 for a higher input impedance on the instrument input, although I haven't seen a schematic so this is speculation.)

 

Realistically, though, these complaints are minor considering the positives. Frankly, the idea of a box that just plain makes things sound a little better is hard to resist. Whether the improvement is enough to justify the ADL 600's expense is difficult to say; for example, if you don't have a really good mic, you're probably better off buying a really good mic than taking advantage of the fact that the ADL 600 can make okay mics sound better. On the other hand, if you do a lot of work with electronic sound sources and want something that can give them a more organic feel, then the ADL 600 might be an excellent investment. I've certainly enjoyed its visit (and so did the narration that used it instead of stock preamps).

 

Bottom line: This isn't an "emperor's new clothes" situation, but a solidly-engineered preamp that delivers what it promises. Some would say that it actually delivers more, because while it's billed as a tube preamp, it does a lot more than just make mics louder. Either way, it's a mighty fine piece of gear. Anthony DeMaria and PreSonus have every right to be proud of their new baby.

 

Thanks again for your participation, even if you just lurked . I've pretty much said all I have to say on the subject but feel free to carry on the discussion, particularly if you have any further questions.

[gsbe]

 

Originally posted by Anderton Frankly, the idea of a box that just plain makes things sound a little better is hard to resist.

This one comment was worth wading through the 6 pages for. I love it!

 

I'd like to see more direct comparisons to similarly-priced units in the future. You do a great job at quantifying what you're hearing with the various graphs. Having an A/B comparison such as the user posted with a Langevin or similar pre would have furthered these analyses. Adding in a third, popular less-expensive unit would have really helped, also. Some ideas for the future...

 

Thanks again for a great thread,

Graham Spice

[Anderton]

>

 

Well, it was worth doing the Pro Review just to be able to find a box that actually does that. Nice to know not everything is "emperor's new clothes."

 

>

 

That defeats the purpose of a Pro Review a bit, which zeroes in on one particular piece o' gear. You're asking for more of a shootout kinda thing, which is a little more daunting to pull off, what with having to deal with multiple pieces of gear. I don't mind throwing in some comparisons, but only if I already know the gear with which I'm comparing the unit.

 

>

 

The big problem there is the 102k limitation on attachments to posts. You can't really do great fidelity unless it's a very very short example. Hopefully I'll get some hard disk space on the server to which I can hot link examples in the very near future.

 

Thanks for the comments!

[Anderton]

Hey everybody, the ADL 600 is being shipped back to PreSonus tomorrow, so I won't have it to refer to if you have any further questions.

 

Great box, though. I was kinda hoping they'd forget they'd sent it here

[SteveE9C6]

I followed this and read everything I could about it. I don't have a huge budget and my mic pre's are currently limited to my Onyx 400F, Presonos Firepod, and my new Joe Meek TwinQ.

 

I now have one of these on order. I suggest folks look around for better deals. I saved several hundred dollars over the M.A.P. price. (After spending over $20k at that sweet place, they won't budge off of MAP... I ordered this and a new Neumann TLM49 form someone who would budge. With the money I saved, I can get some new software:D )

 

Regardless.. I appreciate the effort that went into this review.

 

My one dissapointment with the ADL600? No digital out. Any digital out would have been a real boon. I guess decent convertors would have upped the price though.

 

Steve

[Anderton]

>

 

Well, the ADL 600 has a 100% analog signal path. There's no digital in it from which you could derive a digital out, so you're better off just choosing the A/D of your choice and going from there.

[SteveE9C6]

I'm running the outs into channels 5 and 6 in the Onyx 400F. That way they don't go thru the Onyx preamps too. Works great. This really is a nice preamp.

 

Craig, I know it's all analog. What I meant was the cost of adding a A/D convertor inside the box would have been cost prohibitive. I suspect most folks who have this pre already have premier convertors in house.

 

Still.... 2 thumbs up for this preamp!

[Brittanylips]

Great review! I have heard similar praise about the ADL600 from other users who are putting this thing high up on their echelon of go-to preamps, and it is now high up on my wish list.

 

Also, I thought I might add that I have dealt with Presonus in the past and – with reference to the thread “are people more mean spirited?” – if anyone ever wants evidence that good-spirited people are out there as well, just give Presonus a call. Without exception, the guys at PreSonus are consistently friendly and helpful and if there is ever a problem, they go out of their way to make sure that it is quickly and entirely fixed. FWIW, in my experience, they really treat their customers right.

 

-blips

[mr. moon]

Hi folks,

 

I just want to make you aware of an issue with the ADL600 which was described in a review (by Paul J. Stamler) published in the October issue of Recording magazine.

 

Here's a quote from the article detailing the problem:

 

"The other anomaly I measured was the input impedances. These are marked on the selector switch as 1500, 900, 300 and 150 ohms, but when I measured them, what I found was quite different (see Below). The range of impedances available from the ADL 600 is considerably less than stated, and an input impedance >1 k (as recommended by most makers of condenser microphones) is only available with the 20 dB pad switched in. (Of course, condenser mics are hotter, so using the pad would probably be a reasonable choice.)

 

Impedence:

Listed-Measured-Measured(20dBPad)

1500-----785-----1256

900------526-----696

300------453-----560

150------177-----270

 

PreSonus confirmed my results; the discrepancy is due to a jumper resistor that was used in tests and was left on the first production run of these preamps, which can be easily removed if the user desires impedance settings that match the front panel specs. Concerned users should contact PreSonus about how to do this; my feeling is that the effect will be audible but small..."

 

 

I own an ADL600, so I contacted Presonus about this issue via an email to their technical support stff, and Presonus stood behind their product 100% and satisfactorily resolved this issue on my unit.

 

The difference to me between the before/after fix, was more dramatic than suggested in the review. I noticed that it REALLY opened up my Gefell 930 when recording an acoustic guitar; much larger and lusher image, to my ears anyways.

 

Hope this helps!

 

-mr moon

 

NOTE: I will also be posting this under it's own thread ("ADL600 input impedence issue") in the recording forum

[jahboo]

Greetings ... I use a Soundcraft Ghost 32 LE console and an Alesis HD24 as the basis of my home studio ... I was wondering if I would have any benefit from the ADL 600 during mixdown ... running the main outs of the soundcraft into the adl 600 or main inserts ... and then into my Alesis Masterlink ... I'm sure it would really come in handy for all kind of uses ... but that was my main plan for it ... between the console and masterlink during mixdown ... any thoughts ? thanks ... jahboo

[ricknaqvi]

 

I was wondering if I would have any benefit from the ADL 600 during mixdown

 

 

Absolutely. There are a lot of engineers running their final stereo mix through the LINE inputs of the ADL600 and hitting the tubes and transformers for a little extra 'love'.

 

We even have heard from some mastering guys that are using it in that way.

 

The ADL is not a 'low fi' sounding preamp. It has an extremely wide frequency response and headroom. So it lends itself to an overall mix in a really musical way without robbing the mix of any fidelity.

[Anderton]

I just noticed the new post (happened while I was in Frankfurt, I have an excuse!) and agree with Rick. As mentioned during the course of the review, the ADL 600 does "something" to the sound that makes it more defined and just, well, better-sounding. It's not exactly an inexpensive solution, but based on what I heard, there's a reason why it costs what it does.