Dude's 6SN7 replacements with Chinese CV-181/6SN7

After about 3 months of breaking in the Dude, I think it's time to do some 6SN7 tubes rolling. I know this topic has been discussed before but I missed the thread.

Instead of the NOS 6SN7 tubes, I am thinking of trying the Shuguang CV-181Z or the Sophia 6SN7. Both are very similar prices at about $200/pair.

Have anybody tried any of them before with your Dude preamp?

Any opinions or suggestions are welcome.
I have not tried those, but use 1940's RCA smoked glass and love them. Andy at Vintage Tube Services is the place to buy NOS RCA's.

Let us know if you try those CV181 tubes!
I've had both in my system. If you try the Sophia, you will love it. Very open and neutral. But when you try the BT CV181, you'll be selling the Sophia.
Just go to Grant Fidelity and get yourself a pair and you'll be glad you did. I have no affiliation with Grant Fidelity, I'm just a very satisfied customer.
While I can't speak to the "Dude" preamp, I have tried both the original BT tubes and the Sophias, (and many others) in my Modwright LS-100 preamp. I am using a Mullard GZ34/5AR4, (Blackburn) as the rectifier.

Each pair need a massive amount of burn-in/break-in. Grant Fidelity recommends 150-300 hours for the BTs. I have over 500 hours on each pair.

I find the BTs to be my "keeper" tube. In my system and for my tastes they throw a wider, deeper soundstage and are smoother and more open than the Sophias. I think that the Sophias are "a tad" more neutral, linear and have more detail, but that's not what I am looking for. I wanted a smoother, more open, more romantic sound and found that in the BTs. Had I started with the Sophias, (I didn't, I started with the BTs), I might have just stopped.

Bottom line, they are both excellent tubes and really need to be tried in one's system to match personal tastes and preferences. You really can't go wrong with either.
An alternative source is Audiogon member Trelja for great prices and service on the Shuguang line.

Any updates on the tubes? My Dude is on the way....
Paul told me that his preference are the RCA and the Raytheon short glass type. I happened to have some Raytheon VT-231 and they blew the Sylvania 6SN7s away that came with the Dude. He told me that some of his customers tried the Black Treasure and reported with good result.

I am planning to upgrade my Dude and working with Paul to build me an other Dude with some special features. So I am putting my Dude up for sale shortly. I will try the new BT CV-181 after I got the new Dude.
I like the RCA VT 231 smoked glass tubes as they have a nice rich tone in the Dude. The 1940's RCA clear glass are also quite good.

Can you share what new items the new Dude will have?
Guess not.
Jtwrace, mainly lower the output impedance. Paul suggested the balanced version.

Hope you will enjoy your Dude as much as I do!
Just used Shuguang treasure black bottle Z cv181 (6sn7) on my Viva Solista mkIi and couldn't believe the difference. Amazing tubes
I like Brimar 6ns7 tubes.
I did not care for the BT CV181's in the Dude. Found them to be way too soft and laid back. Am using Sylvania GTA's or GTB's and they are much more to my liking.
I'm trying the Sophia 6NS7 in my preamp/headphone amp and it's very nice, with air but not tipped up and very fine solid, transparent controlled bass.
I'm going to try some Pope Holland 6SN7's that I have in my Dude. It sounds so darn good with the tubes that it came with from Paul that I have no desire to change but I'm curious.
For 6NS7s, I find the nicest highs/upper mids (fleshed out, not piercing or aggressive, but still with lots of detail and extension) are the RCA VT231 and the Brimar Black base ones, but the bass is soft on both of these with systems that are not rock-solid in the bass to begin with. (the VT231s are especially loose in the bass to my ears, and I have tried 3 of them from different sources).
I've been using CV-181 Black Treasures in my Dude for about 3 weeks now. I agree they need some burn-in time before they open-up and "bloom". I'd say mine need some more playing time but even at this stage they are an excellent choice. Very extended on both ends of the spectrum yet natural sounding.
A top amp manufacturer loves the Brimar but where can I get some ? Ultra-rare, they seem.
My Dude is about a month running in my system now...theres a really lot

to like but tube rolling will be soon... Im assuming the 6sn7s are all i should be looking for...the others just keep in as per Paul
? Thanks
I like RCA tubes from the 40's. The other 6sn7's I like are the black base Marconi's.

The Dude is really amazing sounding and takes about 200-300 hours to fully open up and settle into the sweet music it is capable of. Congrats on your Dude purchase!
Well, I did my "default move" which is to call Andy at Vintage Tube Services again...he had helped me equip my trusty Sonic Frontiers Line 3 Custom Edition with some great sounding tubes so I figured I'd trust him again. I too have RCA 6sn7's coming from him now (they should be here in a day or two) as well as the other 2 too...(6080 and OD3)...they're all vintage NOS late 50's-early 60's which he assured me should sound fantastic and he's matching all 5 6sn7's so anyone can go anywhere (I too have the 2 per channel plus the pwr supply section for a total of 5). I also have the heavy duty transformer and all the accompanying "heavy duty" upgrades...). It IS coooool... What a beauty AND beast wrapped into one unit!
I let it stay ON for almost 30 days straight so it has its 500+ hrs on it but since then I've been turning it off when not in use then powering up when I want to have a dedicated listening session...this normally entails a half hour warm-up period for my [tube] amps anyway so it's easy and no problem. Paul said it will sound fine this way...
I told Andy I wanted rich but detailed sound...no glossy cover-ups, just natural, organic...wide & deep staging...(yes, we all want it all) and he said these RCA's were the ticket. I'll put a few hundred hours on them and hear what's what...
Thanks for the advice Bill and all...
I am curious about those Marconis though...I wonder if a pair swapped with/into the RCA's could be a satisfying combination?
I also purchased my tubes from Andy including the same od3 and 6080 tubes you have coming.

The first thing you must do is get a power cable from Paul. It will be the biggest improvement you will hear without a doubt. I use nothing but Paul wire.
Hi Bill, Thanks for your advice on the power cable. Yes, I know you had mentioned Andy from VTS, and as I said I had used him before too. I don't want to hijack this thread (I wish we could pm or somehow talk...) but I am a big believer in aftermarket power cables and am currently using one of my very favorites on the Dude, it's a Triode Wire Labs model "8G American" and quite a tremendous performer (reasonable too).
By coincidence I happened to have bought a CRL (Cable Research Labs ) power cable many years ago because I had heard of their reputation and thought I'd give it a try...It turned out to be extremely stiff and difficult to work with in my limited space behind my previous rack configuration so I set it aside at the time and never really pursued it since.
What a coincidence that I now end up with a Dude (CRL for those that didn't know, was originally a big part of Paul's domain for awhile, though I don't know the exact details...) Anyway, when I had mentioned the cable to him, Paul told me it was a very good match for the Dude and to give it a try. I sent it out for cryo treatment and just got it back recently so I'll be experimenting with it versus the TWL and hear how it goes... It should be interesting.
This is a great hobby if you have the time and patience for it...
As for the original post...I would like to know how the Sophia 6sn7 would sound in the Dude... I use Sophia Mesh Plate Ceramic Base Gold Pin 300B's in my Canary CA 301 MK2 amp in another system and I like them far better than the stock EH's it came with (but I guess that's to be expected)... they are much more open, articulate and expansive with surprising frequency extension at BOTH ends including remarkable potency and dynamics [in my particular application] (amp runs 2 pair per channel for 22wpc) into 95 db sensitive 8 ohm Silverline Sonata 2's [with a midrange on female vocals that is breathtaking...]
So, it makes me wonder how the Dude might like the Sophias, especially the two pair per channel version like ours...just maybe swapping out 1 pair split L/R...
Interesting. Good luck and keep us informed...
I owned your speakers for a couple of years as well as the Bolero's. I love
Silverline speakers.
I have a tube DAC that uses a single 6sn7 as output. I compared the shuguang black treasure and Sophia tubes in a direct comparison. The sophi has a slightly better dynamics overall, slightly better soundstaging/imaging, noticeably better bass slam and extension. However, its midrange is not fleshed out and natural like the black treasure. It is most apparent on female vocals. IMO, the latter is more enjoyable and less fatiguing in the long run.
How did the CRL compare to the TWL pc's

I'm also interested in hearing Lissnr's comparison. of the CRL and TWL cords on the DUDE. I owned a DUDE, sold it and now buying another more to my liking :)
Sorry for the delay folks, I've had my system in slight dis-array and didn't have the time to swap out the power cords as I had mentioned, but finally got to it today.
The best way to differentiate these 2 cables (CRL copper and TWL "7G") is the way most of us generalize the classic differences between solid state and tube amplifiers.
Please note my statements are based on "traditional" descriptions and do not mean to sound old-fashioned...I know advances have been made in both areas of amplifier development such that modern versions of both ss and tube are becoming more and more alike as they both seek the most musical/natural results their technologies can muster...that is: tube amps are becoming "faster", more extended, perhaps somewhat more "precise and articulate"...
while ss seeks to add more "lifelike tangibility, expansive 'density' to the sound-stage as well as 'natural/believable character'...(I know I'm opening myself up for using all these terms, because we all know there are as many exceptions to these sweeping stereotypes as there are manufacturers, but I'm making some points here...).
Enter the 2 cables. I have described the TWL on other posts and am personally convinced they are absolutely one of the best contributors I have ever found in my quest toward a natural, lifelike reproduction of the musical event in my listening room.
This latest cable swap only adds further to my assertions.
But first, the CRL. I like this cable too. And it absolutely has its place in a musical system. In fact, there are no shoes that fit all and where the TWL's don't quite integrate in your particular system, the CRL's will very possibly be an excellent match.
I'll simplify with the same generalities as before: the CRL cable will endow your system with the best attributes a ss amp will do. It is remarkably fast, extended, dynamic and articulate. It will effortlessly extend to both ends of the
frequency extremes and do so without fanfare save for the especially noteworthy grip and control it conveys in the bass. There is 3d space and dimensionality in "absolute" terms...and localization of instruments and performers is very good. If you already own tube equipment...especially a tube-based amp that already possess the generalized tube qualities outlined earlier, this cable may very well add that feeling of 'control and firm-handedness' that ss does so well...
I am fortunate that for the time being I have a few amps I am juggling at once...each with its own strengths and weaknesses. Putting this cable on either my Cary SA-280 V12R or my Dude [while using the Cary] results in just what the doctor ordered with this especially warm, rich but ever so involving [and 'pleasing'] sounding amp. It (the CRL) helps the Cary 'mind its manners'. It won't become TOO warm, rich, etc because that's already there and any more is too much. The bass has a nice firm grip, the top extension 'doesn't seem'to roll off and manages to stay clean and 'crisp enough', and the glorious mids remain glorious mids without getting overdone.It's an ideal match and in my experience a true synergy.
Do you have older style/classic sounding tube amps you'd like to tighten up a bit? try the CRL cables...you'll probably be surprised how much better control and definition your amp has in 'her'...not to mention the apparent increase in speed, definition and extension...
What about the Dude? keep reading.
Now those "other" cables...
The TWL cables mimic the best attributes of your favorite tube amp. And I mean a well-balance modern tube amp...not some traditional slow, syrup sounding rolled off...(though hopefully WITH seductive mid-range).
The TWL's are simply NATURAL. They present an organic, real, personal sense of "there"... The space between instruments has a tangible 'real-ness' to it that's a little hard to describe. I would almost liken it to an aroma in the air that adds believability to space and distances...sort of like catching a whiff of dinner from the other room and then walking towards the kitchen...you get a sense of "density in the empty air" in between the performers and the music coming from them (huh?? yes). These cables do much, and I do mean MUCH of what the CRL's can do but they do it with the most unassuming, un-"attention grabbing" way that you automatically stop analyzing facets of your system and just simply get lost in the beauty of the music.
Everything simply becomes part of an organic whole that is the performer(s) playing for you. You will "get lost", "be immersed", "lose track of time", you name it, it's what you have your system for (OK, it's what I have MY system for...).
Put it on your favorite ss amp and you'll never have to suppress the curiosity of whether those glass bottles could possibly be worth "changing over to" in your room. You will now have all of what you've known PLUS an absolute feeling of being more inside the musician's space. Being there with the performance.
On a modern tube amp you will also find it a true breath of fresh air.
But what about the Dude?
It works the same way. I've been running some hand picked early 1960's vintage NOS RCA 6sN7's in my Dude from Andy's VTS and they sound great. They sound really good with the CRL cable too but I had just the slightest itch about maybe swapping in another pair of another 6sn7???? a little warmer perhaps??? (I have a pair of them per channel, as discussed elsewhere and thought of swapping one per side) but with the TWL I am all done as is. perfect.
As for the Chinese tubes, maybe the power cable should come first before you start swapping tubes? Just a thought.
I can go on but I think I've made my point. The TWL's are 'all that' to me.

brimar is the ticket, or mullard.
Wow thanks for a great write up
Always a pleasure. BTW to clarify, I had mentioned that I started with the TWL "8G" but also inserted a "7G" (which is the latest/biggest version Pete is offering)...both are certainly more than needed,as his "10G" would be plenty...(I just can't resist going for the bigger ones...especially considering the nominal price differences). Performance results [above] are essentially comparable.
Have people experimented with the 6SN7 for the gain, OD3 or 6080? Do these tubes make much difference in the sound quality and is their synergy with the 6SN7 for the left and right channels? Thanks in advance for any responses.
Yes I have and I did find they made a difference. I had Andy at Vintage Tube Services supply me with strong nos rca's for the 6080 and od3. Nice inprovement for me. I also use a good strong nos RCA 6sn7 from Andy.

Well worth the investment. I keep the original tubes as backup now.

Biggest improvement in the Dude by the proverbial mile is upgrading the two coupling caps. No other improvement comes close. No power cord etc...

Get the Duelund CAST caps 630V from Parts Connextion. They have a 70 percent off sale. Any value .47 uf and above. They will take your Dude to a level that will blow your musical senses folks. An absolute must if you can afford it. The CAST cap is pure music and transformational my Dude loving friends. The Dude's circuit deserves the very best and the CAST's are the very best.
Sure would like to see if the dude bests mt Coincident Statement

Perhaps it would be a draw? Perhaps both are as good as it gets and it will come down to preferences? I do know the CAST cap upgrade mentioned above made my Dude all it could be.

I am in Southerm, MN if we wanted to compare.....
Are your RCA tubes from the 40's, 50's or 60's?
Gr I know we talked on the phone b4 I bought the Sampson
My rca tubes are a mix of the 40's and 50's. 6sn7's from the 50's? I am
pretty sure the 6080 and 0d3 is from the 40's.
09-02-12: Abruce
Sure would like to see if the dude bests mt Coincident Statement
Abruce (System | Threads | Answers | This Thread)
Showdown would be interesting since Coincident uses transformer coupling with no caps in signal path so will probably sound different.