Review: Tube Research Labs Dude Tube preamp


Category: Preamps

This review is on the Dude tube preamp made by Paul and Brian Weitzel of Tube Research Labs (TRL). I purchased this preamp some 7 months ago direct from TRL which is how they market and sell them. The price is $3500. The unit has 5 tubes total with one 6sn7 tube per channel.

I am not a technical person and can only comment that the unit is very heavy, all point to point wired and contains a forest of caps the size of Red Bull and Coke cans!

The Dude also benefits from TRL’s newly designed power supply which is something very special indeed. It comes with two sets of outputs and three inputs – all RCA. I think Paul can work out XLR’s if you desire, but you would have to ask him. My unit has special wooden knobs which I prefer over his high quality gold ones.

The unit is turned on by a breaker switch on the back on the unit. The Dude does not incorporate any fuses, simply the breaker, for improved sound. The chassis is well built and solid in terms of fit and finish. While it is not eye candy, the Dude offers a simple attractiveness.

I must have over 700 hours on my unit by now and it is fully burned it. I have found this preamp responds very well to tube rolling. This review is based on the use of RCA 6sn7 GT’s ,VT231 with smoked glass. I picked up 6 of these for $130 on Ebay and just love them in the Dude. Paul likes Raytheon NOS’s, but I have not tried them as yet.

I like female vocals, Christian contemporary, jazz, piano and acoustic guitar instrumentals as well as some small ensemble Classical. You can also read my review of the TRL Samson amps for more information of my musical tastes.

As you have noticed I have owned and heard many great preamps over the years. The Dude has far outclassed each of them in virtually every important performance area. I particularly liked the Audio Horizons and Tube Distinctions preamps on my list. The Dude simply recreates real music in my home well beyond these other fine units.

The level of transparency is utterly shocking. Details and musical lines previously hidden now come alive and my music sounds brand new to me. I was amazed at all the instruments and notes I was missing in my recordings. What a revelation and joy to me as one into this hobby for 30 years.

Right now I am listening to solo acoustic guitar by Phil Keaggy and am consistently astounded with the additional pic, string and guitar body sounds completely hidden before. The sting plucks are so much more distinctive with every molecule of nuance presented to my senses. This is true at even the lowest of volumes on my system. Magic my friends and I mean magic!

I have never known any preamp to dig as deep, taunt and powerful in the bass region as the Dude. Bass has incredible impact, drive and articulation. Easily the best bass I have yet to encounter in a preamp. This tube preamp will shatter your preconceptions of tube preamp bass performance. Bass is no longer this vague sort of deep running tone, but rather a distinct and articulate portion of the whole performance.

Tonality is so beautiful and right. Not a hint of listener fatigue to be found. The massive amount of detail is delivered with exquisite beauty, body and soul. Don’t we all want that? The Dude does both in a way I felt was not even attainable. Tonality is vitally important to me. Voices have weight when they should. Like the guitar work nuances mentioned above the human voice is rendered absolutely and completely naked before you. You will hear aspects of your favorite vocalist you have never heard before. More air, more texture, more nuance, more personality – just amazing.

The Dude sets the stage big, wide and deep. First time I have heard stage depth so profoundly obvious. I now get a sense of what some reviewers mean by 3D! Life sized performance is a consistent attribute of the music flowing from this preamp.

I like to listen to very loud music at times. I like the live scale it gives the recording. The Dude is always in control and supremely poised. Nothing, no part of the audio spectrum is ever out of balance or forced. I hear a new standard of performance in terms of effortless, uncompressed music.

My system seems to have infinite room filling abilities. This is very, very important to me. Even at very loud settings music must flow not attack! The Dude is a complete gentleman in this regard.

Highs seem to have no ceiling or cap as they extend smoothly and without any hint of hardness. I am very sensitive to bright or hard highs and will quickly box up a unit if I hear a trace of it. Yikes! The Dude is a smooth operator and does so without robbing music of the precious detail and air we desire.

Well, I could go on much longer as the Dude is a revelation to me. It is the heart and soul of my current system and really makes everything sound so real and right.

I hope my words were able to convey what I experience with The Dude.

Have fun!



Associated gear
Please see my member system.

PBN Montana EPX custom speakers
TRL Modified Sony CD player/battery
TRL Samson amps
Audio Horizons cable
TRL Cables
Star Sound Sistrum stands
Echo Buster room treatments
SVS PB 12 Plus/2

Similar products
I have owned or had these preamps in my home system.

Audio Horizons TP2.1 fully loaded
Joule LA100 MKIII
Conrad Johnson LS16 V2
Thor 1000 MK2
Tom Evans Vibe
Supratek Cortese
Supratek Syrah
Audio Note m5
Wavac PR-X1
Rowland Concerto
Cary SLP98
Aesthetix Calypso
Tube Distinctions SoulMate
Placette passive
Wright Sound WLA 12A
Aloia 11.01
Belles 21A
Rogue 99
128x128grannyring

Showing 16 responses by vett93

What are the differences, sonically and technically, bewteen the new Dude and the old Dude?
Thanks, Bill. I have tweaked my BAT preamp to its best. It is ready for a head-on shootout with the Dude!
I have received my Dude preamp and put about 170 hours on it. I have to say that I like its sound!

Bill, have you tried clear glass RCA 6SN7s? I am amazed that these inexpensive tubes sound better than other expensive tubes I own.

Have you tried maple platform as Paul suggested? I think this preamp is quite sensitive to the platform supporting it by looking at its design.
I have about 450 hours on the Dude. It is indeed a very nice preamp! The initial slight edginess is all gone. It is all music to my ears now.

I am thinking to send my Marantz SA11 player to TRL for mods. This shows how much I like the Dude preamp!
Bill,

I have been waiting for my Dude preamp to show up. It is exciting to read your review. I am going from a BAT tube preamp to Dude.

I see that you like cables from Audio Horizons. I may be looking for a longer IC soon. What other cables have you tried?

Thanks.
The Dude is more musical than my BAT VK-3iX. The Dude also has a larger sound stage and more details. Its midrange is also better.

The BAT does have its strength though. Its bass extends to lower and is more impactful. This is probably due to its higher capacitance in the B+ power supply.

Maybe I'll add more capacitors to the Dude preamp one day.....
Hi Bill,

You have tried quite a few preamps. I think you are right in picking the Dude as the best. Even though I have listened to many gears elsewhere, I only have owned 3 preamps so far; the Dude, BAT VK-3iX, and my DIY SST (simple single triode) preamp. To me, the Dude is the best of the three.

My BAT preamp uses 6922s. Even though I probably have used one of the very best 6922 variants, Telfunken 6DJ8s, but I like the sound of 6SN7s better. However, BAT preamps have balanced outputs and more capacitors in the B+ power supply, and I think they contribute to more powerful bass.

My DIY SST preamp is a reflection of my audio/electronic experience. I use premium parts throughout the SST preamp. It sounds pretty good but not finished yet. However, after listening to the Dude preamp, I am not very motivated to finish it up. LOL...

The Dude preamp is a time proven product after decades of continuous improvement from TRL. I have to say that it is very difficult for other companies to match that. I played violin when I was a kid and later on played trumpet in school band. I was an electronic DIYer/tweaker when I was a teenager and later on received my EE PhD degree from UCLA. I have to say that Paul really knows his stuff well.

IMHO, the Dude does have a couple of operational issues. But I can ignore them because it just sounds too good.
Strangely, I am okay with the 23 step attenuator. My BAT preamp has 99 steps as a comparison. I never thought 23 steps would be sufficient. But it works for me....
Long time no chat, Bill. Do your Marconi tubes have smoke glass or clear glass? Mine have smoke glass. They sound a bit too sweet and thick to my ears.

I still prefer RCA clear glass variants.
Bill,

Did you switch to TRL's IC's? How do you like it? I am thinking to upgrade the IC's between Dude and the amp. It needs to be 3M long. Other Dude owners, please chime in too. Thanks.

I sent my Dude back to TRL for power supply upgrade. It is exciting to know that it will sound even better.
I now have 6SN7 tubes in my source, preamp, and power amp. Beside my TRL modded Marantz SA11 CDP, I also have a ModWright Transporter, which uses a pair of 6SN7s in the signal path. Then the Dude preamp also uses a pair of 6SN7s in the signal path. My power amp is a hybrid power amp, a rebuilt Counterpoint NP100 by Mike Elliot. It, again, uses a pair of 6SN7s in the signal path.

I found tube rolling is quite interesting in this setup. For example, a pair of Russian 6H8Cs (metal base, round hole plates) may sound aggressive in the MWTP. But they make the NP100 more lively when used there.

For the Dude, I now use GE 6SN7GTBs. I have found that they are fast, neutral, and have nice harmonics in the Dude.
Has any Dude owner tried Mapleshade Heavy Footers on a maple block? Does Dude work well with Mapleshade products?