The coke bottle tubes do add a nice aesthetic.
1 Like
I haven’t had issues with Ebay in terms of buying tubes so far. I also bought some 6922 tubes for my Sonic Frontiers DAC and runs fine without buzzing or hum. I also make sure there’s a good return policy just in case i get a bad batch of tubes.
1 Like
I’ve looked at a few options on eBay. Would only go with sellers who got good histories.
1 Like
Meh, not a fan of this tube. Sounds way too smooth and rolled off in the top end. Macrodynamics seem dialed down as well.
1 Like
That’s why I’m on the fence about changing out rectifiers. So many variables and no one can really tell you what a good tube is. Plus I’m not convinced it will do a great deal. I could go nuts, spend $$ on a NOS mullard and also go meh.
$30 Genalex new production seems to work well.
Gonna pick up a reasonably priced 5u4 first before I swap the 5ar4. I trust Donald wouldn’t throw in a junk rectifier. If I hear no real difference I’ll end the rectifier rolling and maybe look for some varied 6cg7 tubes, maybe try the GE you mentioned.
I’ll keep updating this thread whenever I try new tubes haha
Yeah no doubt stock tube configurations sound great already. I just want to see how far I can push the Starlett 
3 Likes
Yeah, Ive tried a few different preamp tubes but havent written much about them yet. I plan to, but just like listening right now as Im happy with the current set I have plugged in.
After seeing your post I now got a 5U4G coming, shipping is going to be more than the tube! Im gonna see if I can find a somewhat inexpensive Mullard or Amperex 5AR4, but I doubt it. Those might be a somewhat expensive experiment.
Plan is to buy a tube or 2 a month and slowly see what I can find out - if it becomes pointless then I’ll stop.
This is all just curiosity now, really dont need to roll anything.
2 Likes
I like this one a lot. Really slammy and excellent macrodynamics while maintaining starlett’s staging
2 Likes
Which power tube is that? Dont think Ive come across that brand.
Ive got a different set of matched power tubes that I haven’t listened too much yet. Now that I got the BF2 I have been slowly going through the tubes I have to see what I like. Gone through the preamp tubes and have noted some differences.
Swapping the power tubes is next.
Looking forward to trying out the 5U4 I got coming.
Im hoping to post later tonight on my preamp tube findings.
2 Likes
They’re Dumont 6DG6GT! I’ve never heard of this brand either. My other starlett butt buddy got these and told me I would like them, he was right. I would say the differences are slightly better macrodynamics and the mids are not as forward as stock tubes, which is closer to my preference.
Ooooh nice! Which 5U4 tube did you get?
3 Likes
RCA blackplate coke bottle. Did some cursory online searches and it was suggested that it may be a good value.
What Im trying to do is find a vendor who has a few different tubes I would like to try, not so much luck yet. Since these tubes are so cheap Im paying more for shipping than I am for even multiple tubes. Im in Canada so I get charged more for the border crossing. $5 tube with up to $30 shipping isnt always appealing.
Dumont, I dont think Ive even seen those on ebay. Will have to look them up.
3 Likes
that’s the best one for the price according to a friend who seems to be a tube expert (lol) I have one ordered as well. Apparently blackplates are the good ones.
“generally, black plates = brighter, grey plates = warmer”
2 Likes
IIRC, Dumont didn’t make their own tubes, and had other manufacturers rebrand their tubes for them. Depending on the model of tube, common rebrands were from Siemens, Mullards made in Blackburn, and Amprex from Holland. The Amprex ones almost always had “Made in Holland” printed on them somewhere, and the Mullard ones had the Mullard date code stamped in it.
3 Likes
Thats the rub in the tube game, what’s behind the mask!!
There is quite the added charge just for name brand tubes. Mullard branded Mullard 5AR4, good God! Mullard NOS anything, goodness me. Good thing there are manufacturer cheat codes to help figure out whats what.
Didnt Mullard make some for Amperex as well? Thinking about the 5AR4s… I remember someone trying to sell a “Mullard” made Amperex that said made in Holland. Conveniently wouldnt show a pic of the code - just claimed they were f32 - Ebay.
3 Likes
thank you for the tube history lesson Professor! 
4 Likes
It’s possible. That seems to have happened far more than people realize.
A really good tube I found for the Dragon Inspire was labeled IBM and had a blue tip. Come to find out, they were for an IBM government computer contract way back when, and the tubes had to be ultra clean and within a super tight tolerance electrically. They were made by Amprex.
Edit… Or was it Mazda? I forget.
4 Likes
Ive also read that anything JAN is also very good and very rugged as far as tubes go.
I have come across a few Mazda tubes here and there but my knowledge is limited there.
1 Like
JAN = Joint Army Navy.
Military tubes. Usually needed extra supports or mica, usually longer life too.
You probably knew that.
4 Likes
Lots of valuable tube insights shared here, thanks! I might need to make a couple special requests for my Starlett audition in a couple weeks.
For my small tube preamp, the Mullard and Voskhod have been nice.
1 Like
This is a novel length post so feel free to skip. If I surpass some kind of word count limit then the mods can scrap this post without bother from me. First part is tube impressions followed by me yammering.
The following impressions speak in generalities of how I found these tubes to act across two DACs: the Burr Brown of the micro iDSD BL and the BF2. However, having said that, the tube complement I favour with each DAC is different. Headphones were the ZMF Auteur (with perf Lambskin Auteur pads)
Stock tubes supplied with the Starlett:
- Genalex 5AR4 (new production) x 1
- Sylvania 6W6/6DG6T power tubes x 2
- Zenith labeled 6CG7 preamp x 1
For the comparison the preamp tubes were rolled while keeping the rest of the complement as stock.
The preamp tubes are an RCA blackplate, RCA clear top (grey plate) and the Zenith.
Im speaking on mainly tone, timbre and staging related issues. Didnt listen much for dynamics (Sorry TommyT)
Zenith Labelled 6CG7 (not sure original manufacturer, maybe Sylvania???). This tube had the narrowest soundstage of the three and obviously so. If I were to lateralize it in reference to my head its borders where between my eyes and my ears. Smallest three dimensional presentation of the three. Imaging was precise but instrument separation could sometimes get muddled in the narrowed staging.
Best treble performance of the three in terms of energy and clarity. Bass was well textured and tight but lacking in presence. Mids sounded appropriate. Best clarity of three and the sharpest transients. Created a natural timbre.
RCA Clear Top Grey Plate. Wide soundstage to my ears, Better representation of three dimensional space than the Zenith. Imaging and instrument separation where very good.
Most prominent bass response of the three. Nice mids. Treble energy was reduced compared to the Zenith. Clarity was reduced from the Zenith but still good. Transients were a touch rounded, compared to the Zenith, with a slightly blunted attack, also compared to the Zenith. I really liked the timbre it produced, probably the most natural with the Zenith a close second.
RCA Black Plate. Best soundstage of the three. Maybe a touch wider than the clear top but more 3 dimensional. Most holographic of the 3. Imaging was very good and instrument separation was improved over the other two simply due to the better use of the three dimensional stage.
Bass response was a bit less than the clear top but still obviously above that of the Zenith. Bass texture and control was very good, probably better than the clear top. Unfortunately the mids and treble timbre were off, thin sounding, nasally at times. Transients were similar to the clear top, a bit rounded and the attack was a touch blunted compared to the Zenith.
Overall, the black plate was my least favourite simply due to the timbre above the bass region. The strengths of the black plate (soundstage and bass) weren’t enough to overcome that for me.
The preference for the RCA clear top or the Zenith is dependent on other factors which I expand upon below.
Yammering About My Tube Rolling Story (stop reading now!)
I have found this initial foray into tube rolling to be a lot more interesting than I initially thought given that I had read reports that the Starlett didnt change much wth tube rolling and perhaps that is true relative to other tube amps. I can most assuredly say it has been a worthwhile experience with the Starlett.
Initial rolling was done with the Black Label as the DAC. With the BL I favoured the RCA clear top over the other two as preamp tubes, keeping everything else stock. Natural timbre with good tonality overall and a nice soundstage. I liked the balance. I would occasionally go back to the Zenith but the clear top spent heavy time in the Starlett with the BL as DAC.
I was quite interested in maybe getting some more tubes and seeing what it would get me; however, I knew I was acquiring a BF2 so I held off until that came in. All I purchased were tubes for back up, amounting to some power tubes and a backup rectifier. I was happy with how the current complement sounded.
BF2 arrives and I start listening to it. Clear top is still preamp. Improved detail retrieval and bass response is immediately noted. Natural sounding like the Burr Brown. Treble response wasnt what I had hoped. So while I would generally say the BF2 was better than the BL I wasnt swept off my feet with it.
I was also starting to note that the bass was perhaps a bit too much in some recordings, rolling over and obscuring the mids, too much bloom. Treble response still bothered me a touch. I still thought it a good DAC and good value so I accepted it as just the character of the audio chain I had. But then a light bulb went off! I have a tube amp and I have other tubes! Different DAC might need different tubes!!
So I roll again. Black plate has a bass response with the BF2 that is simply fantastic - texture and control with just a near perfect amount of presence, but, the timbre issues were still there and it was a no go for me. The Zenith… this was something different now. The treble was where I wanted it, the transient attack was there, the bass was improved (it was pretty anemic with the BL) and had excellent texture and control. Still lacked some presence. Timbre was very near if not identical to the clear top. Unfortunately the staging was still a fair bit behind the other two RCAs.
So Im in a quandary. I wanted to favour the Zenith but knew Id be giving up soundstage and certain bass performance elements. I was actually willing to accept that when another light bulb turned on: I have other power tubes.
Picked up the extra power tubes as a back up for the stock Sylvanias I had. Couldn’t find exact matches to the stock so I picked up a matched quartet of 6W6 Sylvania’s for something like $5 per tube, so having 4 extra was not a big expense. I installed them when I initially received them to make sure they worked. With the BL as DAC I just noted that they increased the bass level but not much else. I put back in my original stock Sylvania’s and put the extras away. I remembered that bass response though and thought that this might give a bit of a boost to the Zenith with the BF2. The result was a true sonic gift.
I installed them and I got bass plus some other things. I now have a soundstage! Width, height and depth along with improved instrument separation. I also got a surprising increase in detail retrieval. This was an overall jaw dropping improvement. The best thing is that I didnt seem to lose any of the treble performance or speed of the Zenith. This is the best, most balanced audio experience I have yet to hear from my audio chain.
I’ll stop there, because… word count, but holy expletive, synergy is a hell of thing.
10 Likes