@Chris Boswell paulears pcrecord Davedog dvdhawk Kurt Foster

No comments on the results?

This is a very neat piece of work, Donny. We owe you a great debt of thanks for your time and professional expertise in putting it all together. I particularly admired the consistency of your singing over the (at least 8) different combinations.

As I indicated previously, it's impressive how there are audible differences between all the op amps and all the transformers, but translating those diferences into better or worse is a difficult task with components of this level of quality. We all pretty much agreed that transformer 4A (ADK/Cinemag) was not as "good" as the others, but the fact that there were detectable differences between the other three while it not being easy to say which was the "best" is in itself interesting as a result that goes well beyond this test.

As a matter of interest, you give the turns ratios as 1:8 for the Jensen JT110K and the ADK Cinemag, and I assume that the Sowter is wired as a single 1:8, but is the Lundahl wired as 1:5? Do you know how the difference in voltage gain is managed inside the pre-amp? Also, one has to be a little careful when quoting "High ratio transformers generally don't perform as well as low-ratio transformers" (which I think was from a post by Ulysses on GS), as it is perfectly possible to design pre-amps that work well specifically with higher-ratio transformers, as I've been involved in that type of design myself. What is more difficult is to make a universal pre-amp design (as the ADK tries to be) that will work acceptably over a range of transformer types and turns ratios. The transformer is an integral part of the overall design of this type of pre-amp and its individual electrical and sonic characteristics have to be taken carefully into account when designing the following circuitry.

Great work, though! It's gems like this that make RO stand out above the crowd.

Boswell

Thanks, Bos. Coming from you, this means a great deal to me. ;)

As per your questions regarding the Lundhall, I don't know what the ratio is... I would expect your assumption of 1:5 to be correct... I did find out in my research that Lundhall makes several different transformers where the turn ratios are different from one to the other.

I don't know how the gain differential is handled within the preamp. This is a very nice mic pre, I think the majority of listeners here would agree that it would certainly do well for most professional level recording applications, but unfortunately, there's just so little information available on it. ADK made this model - along with the AP2 - 2 channel version - for only a short amount of time.

I've read that they couldn't turn enough of a profit with them to continue the production of them feasible. I read on another forum where a member - who also really liked this pre - said something like "it seems like everyone wants "Made In The USA Quality at Made In China Prices... "

Also, there was no digital I/O versions of these preamps. ADK said that they couldn't afford the extra support they would have needed to put that function into place, which would be required when you start also working with drivers, software, converters, etc.
Whether this was the reason that ADK discontinued making preamps or not (along with compressors and EQ's) is known only to the company. There are quite a few high end preamps that also come with digital connectivity, so I can see where this might have been a factor. In the end, business is business, and if your product isn't selling enough to turn a profit commensurate to cost, then it only makes sense that you need to reevaluate, and, unfortunately, even discontinue.

I don't have any idea of what something like this would cost to build in terms of materials and labor. As far as I know, every pre was hand-built ... I don't believe these ever saw any kind of "assembly line" type of production.

I have yet to speak to, or read about, anyone who doesn't like this pre. Some mentioned that they like "Pre X" or "Pre Y" better, but everyone I've talked to, or have read of, who has ever used this pre, still puts it comfortably on the same list as their other pro quality preamps.

There will always be some professional engineers who prefer a transformer-less preamp - like Chris, for example, just like there will always be pro engineers who like the character that certain transformers can add - like me.. LOL, but I personally don't believe that there is a "right" or "wrong" preference ... because it's just that - a preference, which is usually dependent on what you are doing song-wise, style-wise, mix-wise and performance-wise.

As a side note to the above... I think we also owe a little credit to Presonus as well, as the success of these tests was certainly partially dependent on the Presonus VSL1818 and its converters - because that's what I used to get the signal coming out of the API converted to digital.
I was pleasantly surprised at just how well - transparency-wise - the VSL handled the conversion... so I think these tests were perhaps also beneficial to those that own a lower priced I/O ( such as the VSL or a Focusrite), because it shows that they absolutely can successfully use their current converters with a preamp like the ADK... or, with any other high quality preamp that lacks a digital connection. I'm not saying that all cheap I/O's are the same with conversion quality... but I wasn't the least bit disappointed in the Presonus. I simply used one of the line-in's, adding no additional gain on the Presonus... but simply passing the audio to the converters in the VSL.

Might it have sounded better if I had used a professional level conversion system? Maybe. Probably. But as you mentioned, the tracks I posted sounded very good and would likely pass the criteria of any engineer working in a pro situation.
Just my opinion, of course.

:)

Kurt Foster, post: 425970, member: 7836 wrote: that's some great info Donny. you should sticky it. (just that post).

I'd be happy to, Kurt. Glad you liked the info. How do I sticky it?

Boswell, post: 426031, member: 29034 wrote: This is a very neat piece of work, Donny. We owe you a great debt of thanks for your time and professional expertise in putting it all together. I particularly admired the consistency of your singing over the (at least 8) different combinations.

As I indicated previously, it's impressive how there are audible differences between all the op amps and all the transformers, but translating those diferences into better or worse is a difficult task with components of this level of quality. We all pretty much agreed that transformer 4A (ADK/Cinemag) was not as "good" as the others, but the fact that there were detectable differences between the other three while it not being easy to say which was the "best" is in itself interesting as a result that goes well beyond this test.

As a matter of interest, you give the turns ratios as 1:8 for the Jensen JT110K and the ADK Cinemag, and I assume that the Sowter is wired as a single 1:8, but is the Lundahl wired as 1:5? Do you know how the difference in voltage gain is managed inside the pre-amp? Also, one has to be a little careful when quoting "High ratio transformers generally don't perform as well as low-ratio transformers" (which I think was from a post by Ulysses on GS), as it is perfectly possible to design pre-amps that work well specifically with higher-ratio transformers, as I've been involved in that type of design myself. What is more difficult is to make a universal pre-amp design (as the ADK tries to be) that will work acceptably over a range of transformer types and turns ratios. The transformer is an integral part of the overall design of this type of pre-amp and its individual electrical and sonic characteristics have to be taken carefully into account when designing the following circuitry.

Great work, though! It's gems like this that make RO stand out above the crowd.

Nicely put Bos. without question.

Donny, I'm an auditory learner so being able to discuss this to any scientific sense past saying I definitely didn't like D at all. Your example has that glassy, combing sound in the upper mids which I've heard before tells me to be cautious about Cinemag trannies.
What's interesting, I sold off a few product , all with that brand in them. I found them to all have noise and a week bottom and poor mid range in comparison to other products . I seem to prefer Lundalh across the board which may be why I love SPL products. My Premiums have Lundalhs.
Coincidence or not, example D is very interesting to me.

DonnyThompson, post: 425962, member: 46114 wrote: Here are the results:

Input Transformers were as follows:

Test 1A : Jenson JT110K
Test 2A: Lundhall 1538XL
Test 3A - Sowter 9820
Test 4A -ADK Cinemag

Stickys tend to over run the front pages of forums. I've disabled people from being able to create a thread into one. It's not uncommon to see 10 stickies in each forum over years. They have their pros and cons.
So, to avoid the cons,
I've created a sticky forum for the best of the best.
Copy paste this or any post for that matter and let's begin to build a sticky forum. I'm going to look for software that we can add to make this even better .

See the sticky forum Donny. Paste this in there.

Or, we can move parts of the entire thread into it as well. It's a very simple process of selecting boxes and moving the selected into a new location.

Let me know if you want help moving parts of it.?

@Chris Boswell pcrecord Davedog paulears dvdhawk kmetal

Feel free to put this, or any part of this, to anywhere that you think would be beneficial, Chris. You already know I don't mind you doing that. ;)

Before I go any further, if anyone who is tagged on this thread wished to be removed, just let me know. ;)

My personal observations:

I agree that 4A doesn't sound nearly as good as the other three. It sounds "glassy" to me... in a word, "unnatural"... at least with the JH990 as the OA, which, I find a bit strange, because this is the Stock IT that originally came with the pre to begin with.

I thought that the Jensen and the Lundhal sounded the most similar. Perhaps the Jensen was a bit more transparent, and the Lundhal had a little more coloration, but I think it's a real tossup between these two.
(I wish I had a Jensen JT-16B - this is John Hardy's self-proclaimed favorite IT for his 990c Op Amp).

But... that's not to say that I disliked the Sowter in this most recent test, either. It had a warmth and "richness" to it that, at least on this vocal sample, I found to be quite pleasing.

I realize that we've come to the conclusion that the sound is probably based more on the input transformer than it is the Op Amp, but in the first round of tests, where I used the Sowter as the IT and the OA's were the variable, I didn't care for the sound of the Sowter IT with any Op Amp other than the JH990C.

So, obviously, the OA does play some part in the equation, because so far, the most current combinations sound best to me.

I found that any one of those first three would have been completely useable in a pro application. I find it hard to believe that anyone would find any of those to be sub-standard in any way. With the understanding that some of us prefer a transformer-less design in a mic pre - for those who do like the sound, I think the AP-1 delivered beautifully. In short, I'd have been more than happy to receive any of those first three tracks; and if pressed, I'd say my favorite is probably the Lundhal, at least for that performance on that mic, and on my voice.

The other thing that I've noticed, is that those first three examples "took" EQ very nicely. I played around a little with a quick version that I threw together with an acoustic, bass and drums, and all three of those vocal takes that we liked sat in the mix in an "effortless" way. It's almost as if, the nicer the preamp, the less you end up having to do with the track you use it on.

And once again, hat's off to Presonus - because it was their converters in the 1818VSL I/O that got the AP-1 into my DAW in a very clean and uncolored way.

Okay, so... do you all want me to continue the tests?

If so, should I change the Op Amp to the Seventh Circle SC25, or, should I use the ADK - Vint -N, which is, from what I've read, similar to a Neve....

Or, I can continue with the current IT's, keep the JH990c as the OA, and this time change microphones. I can use a Neumann U89i, or, I can get my U87 back from my friend who is using it right now, or, I can use a 414 for the mic choice ... although it should be clear that the 414 I have is an older EB model - it has the original AKG CK12 brass capsule, and is not as common as the newer 414's with the Teflon capsule - that most people who own a 414 have.

You guys give me an indication of what you want to hear next...

And, if you've had enough and want me to discontinue, I can do that too. ;)

Let me know...

d.

As I said....My information about the "N" on the ADK vintage OpAmps comes from Larry in a conversation we had about these things. I think you should use the U89 and the ADK Op-Amp Vintage N and then run the transformer series. Also...run a DI test with a bass and the VintN opamp and all the transformers. The differences will be extremely obvious like that.

A voice has a lot of sub-harmonic content but I think to really understand what is being brought to the table with transformer differences, you have to listen to the voice in a mix to hear how it relates to filling up a sonic space with other sources' harmonics.
I find more and more on a voice, that the mic will make the 90% difference and the performance the last 5% above the preamp. Its not the same , however, with sources rich in low-end harmonics. Keeping those tightly compacted is THE #1 chore of a transformer in an audio circuit . They are certainly much more difficult to define than the highs and generate way way more energy than upper-mids and highs. Getting everything to arrive at the same time takes some thought as well.

Davedog, post: 426078, member: 4495 wrote: I think you should use the U89 and the ADK Op-Amp Vintage N and then run the transformer series.

Can do. :)

Davedog, post: 426078, member: 4495 wrote: I find more and more on a voice, that the mic will make the 90% difference and the performance the last 5% above the preamp.

Boy, I just don't think I can agree with you on that, Dave... and it's very rare that you and I don't see eye to eye (or hear ear to ear) on just about everything. Your posts are always on my "go-to first" list of what I read when I first log-on here every morning.

But, based on my own experience, I just can't agree with you on the 95%/5% thing. I can only go by personal experience, and that experience has shown me that the percentage of importance regarding the pre is much higher. I'm not saying the mic isn't important...of course it matters... a lot. I just don't believe that the ratio of responsibility relative to the pre amp's importance is as low as you feel it to be.

I have a pretty nice collection of mics, (most here on RO are familiar with what I have so I won't name them again), and I've always thought that they all sounded very "good" through the Presonus X-Max pre's... but ...when I heard my voice coming back at me after recording through the ADK - and on an SM57 no less - I felt as though my game had really been changed...( in an upwards direction, I mean) and, immediately so. ;)

I recall years ago, back when I was still doing a lot of hired-gun work as both a lead and assistant engineer, at studios both regional and national, having had the luck to work with some pretty sweet gear.
Some of the rooms that I had the privilege to work in were really nice, with awesome mic lockers, beautiful consoles, and racks of OB processing that would make even the most die-hard fan of DAW plug-ins salivate. LOL

What I discovered - although I didn't know it at the time - was that I was becoming accustomed to the "sound" of pro gear.

Those years were so formative for me, that everything I saw and worked on had my head spinning, so at the time, I guess I just didn't appreciate what I had access to - until the time came when I didn't have access to it anymore, and it was kinda like having withdrawal symptoms... I'm not talking about the "gear slutz" thing, or being impressed with everything just because of a high price tag; I worked on plenty of high priced gear that was considered to be "boutique" that I didn't care for - but when I was forced to scale back and "make do", I really had a hard time with it.

Fast forward many years, and I'm doing what a lot of veteran engineers have done... scaled back and working from home. And because I didn't have a sufficient budget to put a bunch of hi-caliber gear into my recording rig, I made the best with what I could afford. I think I did pretty well, considering.

And just like before, back when I became accustomed to the pro caliber sound, over time, I then started becoming accustomed to the sound of the lower level stuff... and it's not necessarily a bad level, but it's not what I consider to be a "pro sound". I always felt as if there was something missing. I would work hard on my vocal tracks to get a sound that I knew I used to get, but I just couldn't do it.

When I got this ADK from a friend, and started using it, it took me all of 10 seconds to immediately hear what I've been missing, the sound I used to hear when I was working in those pro rooms.
Nothing else had changed, I was using the exact same mics, same monitors, same room... but there was - at least to my ears - a HUGE difference in what I was hearing. And what I heard was way more than just "5%" of the sound, or 10%, or even 50%.
For me, after having worked on the budget gear for so long, the difference to me was, well, jaw-dropping.

I suppose it all comes down to reference, to context, and ultimately, to personal preference. I don't believe that the difference I am hearing is a placebo, either... that by power of suggestion, thinking that my tracks sound better just because I'm using a more expensive pre. I didn't purchase this ADK, it's being loaned to me, so it's not as if I'm subconsciously trying to justify an investment, either.

I do respect what you are saying, and I can't argue with your own frame of reference. I can only state my own. So, on this rare occasion, this time I think we're just gonna have to agree to disagree. ;)

-d.

I think the two key words here are difference and quality. Ignoring low-end mics and pre-amps, it's my experience that, for vocals, you get more difference between microphones than you get between pre-amps, but both are important. I have to take the view that you can't make a generalisation about how much depends on the microphone and how much on the pre-amp. It will depend on the voice, the room and the song. Some voices will swing more one way and some the other.

If I'm recording a singer who is new to me, I will listen to him/her first, select in my mind what microphones I will try, and then go through maybe two or three different ones, all with the same pre-amp (for vocals I usually start with an API3124+). Having selected which microphone sounds best in this first pass, I may then try that microphone through one or more different pre-amps. For example, my Neumann V476B pre-amps are extraordinarily different from the APIs, yet both are transformer-based and both exude quality of sound. If the different pre-amp seems to suit that voice better, I may go back to one of the other microphones. What I look for is one combination of microphone and pre-amp that captures that vocal in a way that lifts the song and fits well with whatever instruments are playing along at the same time. When recording an album, in the interests of consistency, I am always careful not to switch microphones, pre-amps and other gear around too much between tracks.

Boswell, post: 426081, member: 29034 wrote: When recording an album, in the interests of consistency, I am always careful not to switch microphones, pre-amps and other gear around too much between tracks.

indeed. Words of wisdom.

Each person's experience in this will be dependent on their individual needs and the surroundings. And my take on this is spoken from my set of experiences. I used to think the preamp had so much to do with a voices' character in a recording and I strived to have as best a piece of gear to help replicate that as possible. Then I began to consider my mic locker and build it out. This is when I began to really notice a lot of differences in mics. I have to agree with Bos that the words difference and quality are perhaps the reason for the changes I hear in the reproduction of a vocal source being more of a factor between mics than other points in the chain.

I can do the exact type of test as Donny has done here and the DIFFERENCES that would be evident between each of my preamp choices with the same mic with the same source voice is going to be subtle rather than extreme. And to clarify, its a VOICE I'm referring to not another source. And its different preamps I'm talking about not just the even more subtle difference in the architecture changes in a SINGLE preamp. BUT and this is a huge BUT.... These subtle differences in a mix will sometimes make or break the recording. But in solo context, these differences wouldn't be as apparent ON A VOICE as these differences would be to a BASS, for example, or a snare drum or some other sources.

If I put up the Cathedral Pipes U67 as my mic, I know I can use any of my 24 channels of outboard preamps and the QUALITY will be evident. The reaction of the preamps will be DIFFERENT based on their circuit design and this will effect what the voice source does in a recording where the voice is surrounded by other sounds...in short.."How It Sits In A Mix" ..but solo'd and compared in that way, the DIFFERENCES will not be earth-shatteringly different but rather quite comparable. Change the mic...same voice....same set of preamps....BIG differences in every way. Same 'quality'......

BUT...use a bass on the input. EVERY PREAMP is remarkably different in how it will handle the low-end. I think it says a lot about the architecture of each build and the circuitry.

I think that once Donny runs his test with a bass through this preamp with the different Op-amp and trans combo's the reason for what I'm saying will become evident. Don't mistake that what I suggest isn't possibly the MOST IMPORTANT part of capturing a voice, it's just not going to be the most extreme differences and in this way is the HARDEST to accomplish.

I felt that if I could establish a single vocal chain that would be my go-to, that the beauty of the mics in the locker for a vocal performance would become what they are intended to be. I very rarely if ever stray from my vocal chain. I will use all the mics according to what the voice brings to the mix, but the vocal chain doesn't change. In this also lies the other part of the equation and that is one of the performance. A really good vocalist who understands how to 'work' the mic in a recorded performance will be able to hear as well as feel the subtleties involved with the selection of a particular mic way before they will 'get' the differences in the preamp.

There is ONE thing where the preamp has its say in all of this and that is the gain-staging. A mic that is setup to feel and sound like it is a single wire going to the capture device is much easier to perform on as compared to one that feels 'choked'.

Until I used an M-2b, I thought a lot of pre-amps were pretty similar. Meaning, they all shared a similar bandwidth or size.
Regarding character pres: some have a bit more mids, a bit more grain, more or less top end, softer bottom...
Size is a big part of what I look for, so my opinion or needs are quite different today. . The M-2b is jaw dropping. It was even more jaw dropping when I added an LA2A/1176 combo through Lavry or Prism converters. So, it can be huge and true or huge and full of character depending on what you put in front of it. Pres like that make mixing , example, BFD drums super easy because those libraries are of the same caliber. As are analog synths and big bass.

Most pre's are more of another channel to greatness. The M-2b is in a class of its own. I would like to compare it to the Gordon.
Even the $100 dynamics sound impressive through it.

As I said many time, if i had a choice, I have 24 channels of M-2b. Its the sound HD Cinema with endless headroom. Until you hear rails like that, you cannot know pre-amp are this important. imho.

Boswell, post: 426081, member: 29034 wrote: When recording an album, in the interests of consistency, I am always careful not to switch microphones, pre-amps and other gear around too much between tracks

The only time I change up mics or preamps during the recording is if I'm doing the backing vocals by myself. I find that it helps to alter each interval a little bit. I don't make huge , dramatic changes from track to track - maybe I'll use a 414 on one take, a Neumann 89 on another, a U87 or RE20 on another... just to give the whole BV section a certain vibe that isn't always so "exact".

Davedog, post: 426087, member: 4495 wrote: A mic that is setup to feel and sound like it is a single wire going to the capture device is much easier to perform on as compared to one that feels 'choked'.

That's a great description, Dave, and one of the things I've had a hard time describing about cheaper preamps... "choked" says it very well. Chris's description of "small" is another that is accurate. I've often said "thin", but that doesn't necessarily fit the bill as well as "choked" does.

The other thing I've found is that most decent preamps of lower level don't really sound all that bad ...until you push them. This is one of the things I've noticed about higher end preamps... they can be pushed without adding noise or nasty artifacts. In fact, some sound better when they are pushed, depending of course on what you are after sonically, whereas lower caliber preamps generally don't sound as good when you gain them up to acceptable/optimal levels for moving coils/ribbons.

IMHO...
d.

I finally had a chance to listen to the new batch under the same conditions as the first set. Again, nicely done Donny. It's an interesting study in knowing the inherent tonal characteristics of your equipment.

Each take was probably quite usable, but I was least fond of the last one - tonally speaking. The first two had a more pleasing, more weighty tone (which I preferred, but there's no accounting for taste).

Thanks again Donny, for a job well done. I really appreciate the effort that went into it.

DonnyThompson, post: 426156, member: 46114 wrote: Chris's description of "small" is another that is accurate. I've often said "thin", but that doesn't necessarily fit the bill as well as "choked" does.

to me "choked" is what a maxing out pre sounds like when it is starving or slammed or hit the end of the rails. I haven't heard anything with big rails choke but I'm sure if I kept slamming it with everything I had it would eventually choke.
Don't you feel choking is starving? Dampening Factor comes to mind as well?

But the two levels of pre's would still have a smaller or difference in size no matter whether they choke faster than the other.

Maybe we're thinking of different ideas with the same word. To me, "choked" describes the way a lower level pre sounds in general... lacking a largeness, just kind of "thin" all the way around. I never disliked the Presonus, I think it's quite possibly the best pre in its price class - maybe neck and neck with a Focusrite of the same price range - but neither sounds as "big" to me, as "all encompassing" as the ADK does.

I always found that I had to do a lot of tonal work to get a vocal track to "sit" in the mix properly, or to tonally sound "right", when using the lower level Presonus and FR preamps I've used, whereas, with the ADK, the tracks kind of immediately "sat" in the mix just right, and I end up having to do far less tonal sculpting ( often, none at all ) to get it to sound like it's supposed to sound in relation to the other tracks in the mix... and when I do sculpt with slight EQ, the ADK tracks seem to "take" the EQ much nicer than tracks recorded with the lower caliber models...

Maybe I'm not describing it right...

The thing is... I'm working on a piece for a client that's a bit more contemporary sounding than the style that I normally work in - LOL... I know, right? Donny is working on a production style that is contemporary !
Yup. Go figure...
LOL... Hey, it's not that I can't work in a more modern style... it's that most of the time, I choose not to. hahaha... :D

Anyway, I need to scroll through some newer sounding percussion loops and samples to pick and choose what I need... right now, I have your basic "organic" samples.