Bloodlemons-  Nice now we know your real motivation for all your systems upgrades and tweaks💃🤣

With the addition of Mainstream and the EVS Speaker Music Purifiers I am not really missing much with  my STR 104 being sent off to Al for repair. That’s using a ‘50’s Sylvania 5U4GB USN tall straight bottle.  Surprisingly nice sounding inexpensive rectifier that I prefer to the pricey Phillips 5R4GYS everyone raves about.

Hi James. I have a few rectifiers and am currently using a very NICE Zenith labeled 5u4g tube. I am a Zenith nut. We currently own a Zenith antique 1940 radio. LOVE IT!)  and grew up with a Zenith tv,  a zenith record player, along with a zenith tube radio. Lots of memories and good luck with their stuff back then.  I also have that 1953 NOS RCA 5u4g that is also my favorite of the few rectifiers I have. I was told that the Zenith was probably an RCA.rebranded. Just curious if you know..or anyone. I am also test driving a 1974 Reflektor silver shield 6n23p input tube. Got that one on a very reasonable price. Very NICE so far. Our Zen is still working beautifully and almost ever evening too. Thanks! MIke  

Thought I would throw my 2 cents in here but James probably knows better.
Your rectifier looks more like a Westinghouse see link.  It’s hard to tell with the fuzzy pic.  Compare the plate construction and internal build.  The top is rectangular with rounded edges.  ST bottle RCA and Sylvanis’s that I have seen use round tops. Tung sol rectangular tops have square edges that I have seen.  its a crap shoot to say the least.  The 74 Refectors silver sheild with single wire getter are fabulous.  I have found the year doesn’t matter as long as they have that single wire getter support.  I have ‘73 and 75 ones that sound just as good.  They only made those single wire ones a few years.  The  Voskhod Rockets with single wire same years perform the same or really close.  Just my take.

https://www.ebay.com/itm/266925853219?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&s...

I have a couple of early RCA 5R4GY, same construction, and they sound entirely different.

The newly-upgraded 1004 is burning in and will be on its way to me this week...

CAJames -- That will be fun!

Ok finally sent my defective STR-104 into Al to fix after no progress could be made over email. Just wanted to share my frustrating experience for anyone interested in buying from Space Tech Labs so you know what you are getting in to. Love Al and he does stand behind his products.  It can be a challenge to work with Al if something goes wrongl…my experience below:
Space-Tech Lab components are an intriguing and the Super Rectifier (STR) was an amazing improvement but beware if something goes wrong it is a PITA as I am going through now.  It is really a leap of faith. Al is great and stands behind his products but it is a test in patience to trouble shoot haphazardly with Al through countless emails.  Additionally, you have to pay for shipping both ways to Canada no matter what goes wrong.  To return it’s 20% restocking fee plus shipping both ways.  Lastly he only takes Zelle or bank transfer so you really have no recourse.  I am not trying to bash Al as he is repairing my Super Rectifier which has a defective on/off switch, 2 defective sockets pulling apart at the base and it is costing me $160 in shipping.  Just be aware.

Holy @&$${!!

I both love and fear that.

We’re going out of town and off the grid for a couple weeks. Looking forward to getting caught up you guys when I get back.

🤯I hope you don’t blow a Sluggo!🤣

You haven't delved much into the big bottles until these Elrogs. How do they stack up?

That makes sense. It'll take some time for everything to settle in before you can parse what each brings to the party.

I'm looking to avoid the mercury vapor tubes due to a little one. Has anyone tried the 1616 tube that can share their thoughts on it?

My STR arrives next week so I'm doing my tube homework.

Are you referring to the USAF 596? I used one in my DAC years ago but ended up selling it. It had a bit of a narrow soundstage. With regards to that family of rectifiers, I find that the lower voltage variants sound significantly better. Of course, you'll need an adapter with resistors in place. My current favorite is a Valvo G2504, which I'm excited to try out in the STR.

Thanks for your generous offer to spare some tubes for me to try out. I'll probably take you up on that, and hopefully have some to send in your direction.

After some very fun, all-mercury, test-driving last night, I decided to revisit some of my "reference" audio to see how everything was really sitting in the  mix. I was disappointed (but maybe not surprised) to learn that I was sacrificing a ton of detail for the BIG SOUND EXPERIENCE I was having so much fun with.

After a prolonged period of swapping things in and out, not really getting anywhere with that, I effectively re-set back to my defaults this morning by taking the STR-104 out of the equation and just putting an Aqua II into the ZP3 for a while. I also took the Snubway and Mainstream out, to minimize the number of unknown factors.

After all of the subtraction, it was fairly easy to get back to an approximation of the sound in my head. Essentially, I was getting way too much big-and-gooey-and-sexy from the overabundance of mercury; too much of a good thing. Committing to the Elrog ER845 pair in the STR-1004 and just a single pair of 866As in the STR-104 is giving me the added heft I was expecting without drowning out all of that crucial midrange detail.

My reference songs sound "right" again, and I can recommence making smaller tweaks without losing the trees for the forest, hopefully.

I'm putting the Snubway and Mainstream back in next. I'm not expecting that to tip the balance for the worse, but sometimes you don't want to put a hat on a hat.

Current lineup pic:


imghost

It definitely appears to be all about hitting the sweet spot where you get the best qualities of all of the different types of tubes in play. I suspect I'll come to a more-nuanced lineup when it's all said and done. I have plenty to work with!

I have a pair of 1940s coke-bottle RCA 866As and they're great. The ones in the picture are older, globe-style, with engraved bases, one from United and one from Philco. They seem to sound about the same as the RCAs, really. The globe ones have a more pronounced glow, with a deeper blue. Maybe once the dust settles I'll try to decide if one is appreciably better than the other.

So far, what is everyone's favorite brand of the following:
3B28 and 836 rectifier tubes?

My STR arrived back from Al with his warranty repairs and all seems to working well. 🤞 I thought I was not missing the STR much since my system was sounding really good.  Woah…was I proven wrong. The music just filled the room in all directions with clearer highs and lower lows.  What’s next? 🤪

My STR arrived this week. I didn't have much time to play with it since I'm out of town this weekend. I've purchased a pair of 863s, two different 1616s (GE and RCA ), and a pair of VX-550. Should be a fun next couple of weeks.

I'll definitely keep you posted. I've been researching compatible tubes and inquired with Al about another tube - a 572B. Unfortunately, like the 575a, it can only be used in the STR-1004. It may be worth trying, @bloodlemons. It's a current production tube, and can be found for ~$100. It could end up being a gem. Just be sure to avoid the Svetlana variant (no top cap) because it is not electrically identical to the others.

Good to know. Although, now that my 1002 has been upgraded to 1004, I can run the 575As all day long.

However, after much swapping and auditioning, my current configuration is Amperex 872As in the 1004 and USAF-596s in the 104. I thought the 872As were a little harsh in the highs before but now, with Graphene Sluggos in everything, they are just right. The 596s are very nice, and clean, which i think balances out the mercury tone from the 872As.

I miss the more dramatic blue glow from the 866s, and will probably run them again eventually, but I'm very happy with what I am hearing with the current setup.

Photographic evidence:

Thanks! You have kids, right? I wouldn't have the mercury if I had kids. No way.

The USAF-596s aren't mercury, by the way. Woo Audio seems to have a corner on the market for these but, as you can see, I made my own adapters; about $5/piece rather than the $250 he charges for his (admittedly, much nicer-looking) adapter.

That applies to Al's anode leads too. I think he charges $60/pair or something and you can literally make one with a banana clip, any non-bare wire, and an alligator clip for like $3. I bought a ten-foot braided microphone cable and have been making my own. If I can do it, anyone can do it!

Back from vacay and getting caught up on the STR news.

Welcome to the club Adamaley, if you haven't ordered them already PM me and I'll sell you my 845 -> 300B adapters cheap, that goes for anyone else as well. I'm fully committed to mercury-free 10V tubes.

bloodlemons, you've moved on from the Elrogs? FWIW my RCA transmitting tube manual says the 8008 is electrically similar to 872, but with different base and physical dimensions so pretty much the same but not exactly. If you're still curious I feel like you could whip up an adapter from ebay parts for a lot less than what AL would charge.

Al says we can use the 4B32 tube as well. This doesn't require an adapter, however, his only caveat is to limit use to 3-4 hour periods.