Space-Tech Laboratory Super Rectifiers

[opnly bafld]

Not much information, but curious as to any possible benefit for some equipment (I have no interest in buying one). Any thoughts?

http://www.thebestamp.com/Accessories/Super_Rectifiers.php

 

[zackthedog]

Not much information, but curious as to any possible benefit for some equipment (I have no interest in buying one). Any thoughts?

http://www.thebestamp.com/Accessories/Super_Rectifiers.php

A friend of mine, something of a compulsive audioholic, was looking at his DACs and wanted to know about the "super-rectifiers." I didn't know what to say. Yes, I guess you could add more "tube goodness" to your power supply. Maybe the guy builds terrific-sounding stuff. Hard to say when he's got about seven hundred products. $4K for a rectifier? I don't know. Seems like a trap for guys like my friend. The shipping and return restrictions are a bit of a turn-off, too. I've seen some threads here or elsewhere were poeple in the area have visited his shop, think his stuff is good.

 

[Lavane]

My two parallel push pull KT-88 mono block amp kits cost about the same price.
I think I'll stick with my Copper Top rectifiers.

 

[maxhifi]

Benefits?

It looks cool. It lets you use more tubes, which adds to the apparant complexity of your sysrem. It might have a slightly lower impedance than the 5U4. It is something to talk about with your hifi buddies. More tubes to roll. It let's you spend money on your system and keep all your components. Hmmm I'm running out of ideas.

 

[gadget73]

Looks like a good way to cook the 5v filament winding to me. The 3B22 is 2.5v at 6.25 amps. In series that will be 5v at 6.25 amps. And this is meant to sub for something like a 5U4 that has a 3 amp filament?

 

[maxhifi]

Looks like a good way to cook the 5v filament winding to me. The 3B22 is 2.5v at 6.25 amps. In series that will be 5v at 6.25 amps. And this is meant to sub for something like a 5U4 that has a 3 amp filament?

It appears that at least some of these devices have their own external filament transformer built in.

 

[opnly bafld]

Thanks for the replies.
There is a discussion on another (small) forum, but they are not known for how this stuff works (or doesn't) like many here.

True his top of the line is $4k, but he has several models starting at $792 (usd).

 

[gadget73]

It appears that at least some of these devices have their own external filament transformer built in.

that would take care of that issue at least. Some of the pics I saw were basically just a project box with sockets and an umbilical cord, I didn't see any power cord.

personally I still wouldn't go for it, 800+ bucks for what is a fancy socket adapter is an absolute mint. I've knocked functional equivalents together using used tube bases and sockets but only when converting between equivalent tubes. One I have subs a 5Y3 for an 80. Same tube, different base. I didn't make that one, it was probably made decades ago, I found it in a box of random bits and pieces I ended up with from somewhere. There is more to consider than just popping in a rectifier. Some of them can't work into large capacitors, and the voltage drops will be different. Could result in shifting the operating points on the tubes enough to do not-great things.

 

[tonyg88]

expensive cell phone charger

 

[maxhifi]

that would take care of that issue at least. Some of the pics I saw were basically just a project box with sockets and an umbilical cord, I didn't see any power cord.

personally I still wouldn't go for it, 800+ bucks for what is a fancy socket adapter is an absolute mint. I've knocked functional equivalents together using used tube bases and sockets but only when converting between equivalent tubes. One I have subs a 5Y3 for an 80. Same tube, different base. I didn't make that one, it was probably made decades ago, I found it in a box of random bits and pieces I ended up with from somewhere. There is more to consider than just popping in a rectifier. Some of them can't work into large capacitors, and the voltage drops will be different. Could result in shifting the operating points on the tubes enough to do not-great things.

The way I would describe this device is a solution looking for a problem. It appears to be intended for people who want to fiddle with their gear but aren't comfortable actually getting inside it.

 

[trainbuftony]

The concept looks interesting.
They appear to (all) tap into the rectifier socket. That could be an easy way to make an amp with a limp power supply stiffen up, or if you're going the other way, it's an ideal way to Taylor your Rectifier sag in a musical instrument amp. Conceptually I like it, given just how many old amps come up short in the power supply.
Would I spend that kind of money on an extra box to fix something that was low to mid grade?
Personally I would not.
I'd be looking for solutions that fit in the existing chassis space. That and/or focus on acquiring amps with adequate power supplies. Rebuild the power supplies (obviously) and you're at the same end result.

Its neat in concept, and I could see how people addicted to audio tweaks could be parted from their dollars by these.
I admire the designer for coming up with something to do with tubes that nobody is doing and which hasn't already been done.
Not a lot of things that can be done with tubes and haven't.

 

[kyle]

One possible use / upside for these things; Some Western Electric theatre amps that used 211s or 845s could use the old worn power tubes as rectifiers. When the power tubes needed replacing, they put the old ones in the rectifier position. They don't have the emissions left to be a power tube but they'll work as a rectifier.
If you have an amp that uses one of the tubes in these Super Rectifiers, you could have a place for your old tubes other than the landfill. They have models with 300B, 211, 845, 872 etc.
They're still not going to be worth the price to me but if you've got em, smoke em.

 

[gadget73]

Usually when the emission is low its because the cathode can't boil off enough electrons to flow the required current. I don't really see how a weak power tube would work decently as a rectifier because it would still have limited current capacity.

 

[trainbuftony]

Usually when the emission is low its because the cathode can't boil off enough electrons to flow the required current. I don't really see how a weak power tube would work decently as a rectifier because it would still have limited current capacity.

It would provide sag.
People love the sound of Rectifier sag.

 

[kyle]

Both are likely correct. However, this photo is a Western Electric (corrected in the above post) 43A amplifier that uses 211s as amp tubes and rectifiers. I first read of this amp in Sound Practices magazine in the 1990s. Whether you approve or not, they did it and WE amps are usually pretty good sounding designs. There's a schematic below as well.
I was just trying to think of some justification for the Super Rectifiers and have some fun. I was in their shop when I lived In Vancouver. Most of their products look strictly DIY and many seemed to be one offs.

 

[FlaCharlie]

Is the supposed advantage here simply the fact that they use a pair of rectifier tubes instead of a single one?

I'd like to see a schematic. The deluxe version of the least expensive model has a choke which only costs an additional $225. So I assume the basic version is C-R-C.

And I hope your electric rates are low. Their cheapest model uses a pair of 3B22s whose heaters draw 6.25A each. The most expensive model uses a pair of 575As whose heaters draw 10A each. Best used in winter . . . you could turn your heater off as long as you're listening to music.

 

[Bill Ferris]

People love the sound of Rectifier sag.

, , , .

Only acceptable in tube guitar amps, at least in my wheel house ! , ,

 

[gadget73]

You can certainly use a triode as a diode. Wire the grid to the plate, voila! one diode. Its a single diode though, so you'd need a pair of them to make a full wave rectifier setup. I'm not questioning how good it may or may not sound, I just question whether the design truly allows for weak power tubes to be used in that spot with as-designed performance. Does that come from WE docs or is it from some other non-official source?

 

[Lavane]

I just don't see why they cost so much. The mark up must be huge. I'll stick with magic crystals and cryo treated speaker wire.

 

[zackthedog]

I just don't see why they cost so much. The mark up must be huge. I'll stick with magic crystals and cryo treated speaker wire.

Well, it depends. This is marketed for the well-heeled audiophile. He's clearly not manufacturing at scale. Hand built. He sells a few units a month. What should he charge for them?