Post by GroovySauce on 04/03/24 at 18:17:25
I want to bring your attention to this Kamran posted in another thread.
A few years ago I was curious about this and eventually placed the idea into long term storage.
He kindly repaid the favor and started watering the seed I stored away.
There was another thread started about the STR… it quickly turned into a dumpster fire, so starting fresh. I didn’t relook at the entire thread, I don’t think anyone actual owned one to tried one so it was all speculation anyway.
Well I’m not speculating anymore! I have a STR-1002 Super.
These tube really are JUMBO!
When I first held a EML 5u4g I was giggling how big it was... now it looks like a small guy.
There is almost no information about these so I’ll explain how it works to the best of my understanding.
The STR requires a power cord. This power, powers the heaters of the tubes.
There is an umbilical cable that fits into the rectifier socket on the component you want to use the STR with. The component “sends” AC down the umbilical cable to the STR for rectification. Then the STR sends DC back to the component.
The STR has a few different modes of operation. It can use 1 or 2, 4-pin jumbo tubes as diodes. So running two tubes you get full wave rectification and 1 tube half wave rectification. It also includes a SS rectifier so you can run 100% no tube rectification. You can blend the SS and tube rectification. It’s also possible to run different tubes and “blend the sound like blending two different juices”
I’ll speculate a bit here. By offloading the high current heater from the rectifier the component power supply isn’t working as hard. It also reduces electromagnetic fields inside the component. By separating and spacing apart the two diode-tubes there is less interference between them resulting in a cleaner signal. Look at a standard rectifier everything is jammed in there really close.
The 4 pin jumbo tubes are amazing. Al from Space Tech said that when using DHT as a rectifier people cannot wrap their heads around how much they copy the same sound when used as a power tube. I’ve only listened to 4 pin jumbo tubes in show settings so I don’t know what their sound is. Based on others reports of how the jumbo tube amps sound, when used as a rectifier they do impart their sound signature.
What is that sound signature? It’s the most involving reach out and touch the music sound I’ve ever heard. Music flows through out the room in a magical way.
The thing that is really hard to wrap my head around is how it really adds everything.
In the Lampi TRP I was running a Sophia 274b Aqua II and then the EML 274b Mesh. The Sophia is bold and juicy with plenty of density. The EML is more extended and faster, much better attack and space.
Running 1x PSVANE 805A Classic—half wave rectification—It’s better than both at the same time. I’ll say it again, it takes the best of both tubes increases the goodness and blends them together.
The first thing that I noticed was how everything was more vivid. My old definition and understanding of density has entered a new paradigm.
I’m hesitant to start talking about how much more detail there is. Often for me when someone starts raving about detail bright, harsh and fatiguing come to mind. None of that exists.
Details like cymbals being lightly activated when the kick drum is struck. Not since I added all the room treatment have I been so blown away with now much things have changed.
Another thing that caught me by surprise. Having the STR-1002 plugged into the TRP the entire system sounds like it has unlimited power. Which is something that I would think would be in the domain of the amplifier.
I received a pair of Linlai 845s, I bought the internally coated ones specifically because the 4 pin jumbo tubes are as bright as light bulbs. At night they offer a nice amount of illumination without being too bright.
The first few hours I was not impressed with them preferring the single PSVane 805a Classic. The 805As had been burned in for a day or two at STL before shipping and the Linlai 845s are fresh. After 5 hours the 845s started to sound better. As of right now I have 10 hours on the 845s. I’ll comment on the sound difference once I have more time on the 845s.
I did elect to have the choke option. The choke smooths everything out, reducing dynamic impact and some speed. It offers a more euphoric dreamy sound. I only have a few hours with the choke engaged, I want to get some more hours on it before I really did into the differences with and without the choke.
I can see the choke being a nice option for the nights I’m tired and want to float off to sleep.
I'm still trying to wrap my head around how much of an impact this has. It's really giving me everything I've wanted. All the mythical things that seem out out reach this is providing. I do want to offer a bit of a context. I have a dedicated room with literally 3+ tons of treatment.
Sometime in the near future I'm going to bring it over to my brothers place and try it on his UFO25th. This should be a more "real world" experience.
I'm talking to Al about making a custom 4 tube version for my amp.
, they don't have voltage regulators.
