Tube preamp test | D.W Fearn, Redd.47, AT-3 & WT-72

The Fearn sounds great. I don’t know if it sounds $2500/channel great…but that would be my choice were I making a bunch of money from music.

That said, matching these different pres to compliment the sources would lead to the best result.

Kind of hard when you’ve bought every one in Europe 😂

Ok, should be the same before the second gainstage hits though. I wouldn't mind a/b but I only have one friend that owns a pair of 1073 so we'll see and I'm not paying 10-15k for one preamp haha 😂

Really nice of you to do this Christian! Very subtle nuances..at least compared to what I usually do with equalizers when mixing. To me the REDD sounds most "like a record", closely followed by the WT. For more natural/flat I really liked the AT-3. To my surprise I liked the Fearn the least.

I agree. Thanks for doing this. My ear likes the REDD, then the Fearn, WT and AT-3. Frankly, I’d be happy with any of them, if somebody left one on my doorstep.

Thanks,

I recorded 12 tracks using a passive splitter, with Lundahl Transformers which to my knowledge is the best practice to split the signal without affecting the load. Then I levelel matched all individual channels, treated them exactly the same which basically was some super light eq:ing and in some cases room reverb.

What you hear on YT is the exact same loop/take/performance otherwise the test would be skewed.

Tracks:

2 muted acoustic guitar
2 strummed acoustic guitar
2 fingerpicked ac. Tracks
Snare
Hihat
Kick
Shaker
Basguitar
Vocals

What I would like to add in the feature is electric guitar and perhaps a Wurlitzer if I can get my hands on one, we'll see!

(I wrote my rant and after the fact wanted to make this abundantly clear: The discussion in this thread so far has been great/healthy, I'm not calling anyone out. I'm just trying to support someone that's doing this stuff the right way as inevitably, I think someone's going to start questioning the methodology and approach at some point. Hopefully this give them something to think about, because I've had to deal with it a few times and it's really frustrating)


I didn't run test tones or anything like that through my radial mic splitters, but I ran a lot of different stuff through them and didn't notice any differences. I'm not trying to start arguments here, but if people are hearing issues with them I want to hear more about it. First off, I think Christian did a great job and went about this the right way. Ultimately, there's just no "perfect" way to do something like this. I'm definitely not calling out anyone here, but "in general" I think a lot of people need to get their heads around that fact. I've literally had people message me on other forums and YouTube constantly calling me out for not doing things "the right way", as it seems some people are extremely opinionated about it, to a fault. I'm only saying that because I know there's going to be people reading this thread ready to pick apart these tests.

Christian went about this the correct way, AKA "the best way possible". Most people watching these videos just don't understand how much work goes into doing this right. I always love watching Christians stuff because he puts just as much effort and thought into doing it correctly as I do. I've done similar things and it's SO much work and investment (money and time wise). I don't know if it's the case for Christian, but it seems like the more effort I've put into trying to do these comparisons the right way, the more critical people get. I'm not saying that to call people out in this thread, everyones been awesome. All I'll say is that if you think there's fault in this methodology and approach, do a few of these tests at this thorough of a level a few times and then we can all have a conversation about it.

I don't mean to vent, but I know it's frustrating trying to do tests like this and then have people say "you should have done it X way, because XYZ...". When I was first thinking of doing some larger comparison videos for mics, I went out of my way to try a bunch of different approaches. I bent over backwards to try and find faults with using mic splitters and just couln't hear any differences no matter what I did. The only alternative was to do different takes, which I would hope everyone can agree is an inferior approach. The differences in takes will always be greater than anything a splitter is doing from a technical standpoint.

When I approached Coil Audio about reviewing their preamps, they were against the idea of using splitters like I had originally planned on doing to compare their 70 and 286 preamps. Understandably so, they've put a lot of effort into fine tuning the load and impedance relationship with what you're plugging into it. I was a little frustrated, but I'm not a gear builder or designer and wanted to respect what the smart people were telling me. I ended up using a stereo microphone as I could turn both capsules forward and send one of them to each of the preamps on each take. Still the same take, and allowed me to technically get the capsules as close as possible to each other in that compromise. The circuits were also as closely matched as you could ask for when dealing with two different mics. I started out feeding both of them to my AEA preamps so I could have a really clean test with the same set of preamps. I was able to get all my different instrument tests to phase out "almost" completely with each other, SO close. That was enough for me to say "ya this isn't an issue at all" and move forward with everything without wondering if I should have used splitters.

There's not a lot of different ways to pull this off correctly, but in my experience everyone seems super opinionated on these things for some reason and don't have any issues letting you know that "you did this wrong, you should have....". So I'll just say it for future prosterity of this thread, none of that theoretical crap matters in the greater context. If you can't turn that crazy technical part of your brain off long enough to take anything meaningful out of a comparison that's as well done as this, you need to tighten those loose screws in your noggin! 

As stated in my comments from a purple place, from whence most of us came. . .



If I had to pick one, it would be the AT3 .
And when challenged on the AT3 not sounding like the Grace by one of our colleagues, I offer this :

Just a small further point -- this is a snippet of a quote from Andersmv above:
"I started out feeding both of them to my AEA preamps so I could have a really clean test with the same set of preamps. I was able to get all my different instrument tests to phase out "almost" completely with each other, SO close. That was enough for me to say "ya this isn't an issue at all" and move forward with everything without wondering if I should have used splitters."

Just playing devils advocate here a little bit - and I largely in agreement with your findings - but your stereo mic (like Christian's mic) was a condenser (?). These require phantom power or some other power source for a reason -- the capacitive element needs a clean DC "bias" across it to function properly but circuitry is included that is sort of a pre-preamp built in (typically a JFET or vacuum tube).

Basically the capsule wants to see an incredibly high impedance but the external mic pre expects to look back and see a "low impedance" -- an active circuit like a JFET follower or similar tube circuit can do a pretty good job doing that, potentially with much less variation in impedance over the audio band compared to a completely passive dynamic mic or ribbon. In other words, ignoring the technical jargon: your experience might be mic specific or at least mic-type specific.

I should clarify - I haven't attempted any tests to the level of scrutiny both Andersmv and Christian have described/conducted - I am stuck with multiple mics, multiple pres, multiple tests -- subjective opinions. But on the EE side I've done very objective/repeatable electronics testing that surely shows circuit impedance matters in general.

Either way, please keep "moving forward with everything without wondering if I should have used splitters" and posting content for more lazy folks (myself) to check out :-)

....but maybe try to let us know if you used splitters or otherwise.


Thanks!
-Chris

ironinthepath Avatar
Oct 17, 2023 14:32:09 GMT -5 ironinthepath said:
Just playing devils advocate here a little bit - and I largely in agreement with your findings - but your stereo mic (like Christian's mic) was a condenser (?). These require phantom power or some other power source for a reason -- the capacitive element needs a clean DC "bias" across it to function properly but circuitry is included that is sort of a pre-preamp built in (typically a JFET or vacuum tube).

Basically the capsule wants to see an incredibly high impedance but the external mic pre expects to look back and see a "low impedance" -- an active circuit like a JFET follower or similar tube circuit can do a pretty good job doing that, potentially with much less variation in impedance over the audio band compared to a completely passive dynamic mic or ribbon. In other words, ignoring the technical jargon: your experience might be mic specific or at least mic-type specific.

I should clarify - I haven't attempted any tests to the level of scrutiny both Andersmv and Christian have described/conducted - I am stuck with multiple mics, multiple pres, multiple tests -- subjective opinions. But on the EE side I've done very objective/repeatable electronics testing that surely shows circuit impedance matters in general.

Either way, please keep "moving forward with everything without wondering if I should have used splitters" and posting content for more lazy folks (myself) to check out :-)

....but maybe try to let us know if you used splitters or otherwise.


Thanks!
-Chris


Yup, completely agree with what you've said. In my specific use case, I used a stereo tube microphone so phantom power wasn't coming into play. In instances where I would need to do it with condenser mics, I've got the Coil Audio external phantom power supply that I plan on using in the future so power requirements are taken care of before I have to split.



I've got some specific goals doing more reviews and putting in more effort on my YouTube channel this year, none of which are to try to be an "influencer". That's why I appreciate your videos, you seem very genuine and put in the effort. I know exactly how you feel though, it seems pointless at times trying to fight through the noise. We appreciate you!

I feel you.