Rectifier tubes, the hidden "sweetness" of electronic gear, vintage and new, guitar amps and stereo.

Modwright PS9.9 (for modded Oppo 105).

Stock rectifier: Ok...a bit flat
Philips 5R4GYS: better, warmer, a bit rolled off
Emission Labs 5U4G: like the Philips but tighter, deeper bass and better highs (it's now my defacto rectifier tube)

 

How is the EL tube holding up? I remember discussions of premature failure on the ModWright forum.

 

It's been running since last September and no problems with it at all. Mind you, 8 months isn't that long.

 

I have been rolling some 6X4's in my phono pre. One single FW rectifier tube. It came with an amperex from the 70's, I rolled in a GE from '52 NOS, everything just seemed better. The amperex had detail, but it was like being at a museum, no groove, didn't rock. The Ge's were spacious, just huge soundstage, slightly more noise than the amperexs, but damn quiet. Being shocked at the difference a rectifier tube( a****indiode!) had on the sound, I ordered a bunch more tubes, the ge was bought just to have a backup in house. I picked up a sylvania in a yellow box, cant find the date code, I rolled that in last week. Wow!! The difference was startling. The vocals are much more present and "thick", the bass is way deeper, and this is not hyperbole , I am talking resonances where there never were any at the same volume level. The sound stage is a bit smaller, but still big, it seems to be quieter than the GE. It really rocks though, it just presents music with more of that x-factor that keeps you engaged. I have 2 RCA's and another 2 GE's to try, it is really startling the difference in sound between these tubes. It seems when I changed 6922/7308's in my Chinook the differences were much more subtle, though I was comparing very high grade tubes and my system is much more revealing with the Lamm. Looking for comments, advice and recommendations.

 

As noted above, I found Sylvania Black Plate 1950's vintage to be my preference in a 6x4.

 

Can you tell me how to date them? didn't notice any codes on mine.

 

Mesa Boogie Maverick (guitar amplifier):

 

I'm the new-guy when it comes to rectifier Hi-Fi.
I have always used Fender guitar tube amps ('67 Deluxe Reverb!), and I've always assumed all integrated stereo tube amps use a rectified -- but maybe not?

But reading this thread confused me. Here are a few questions -- maybe you guys could shed some insight?
1. Do class A/B tube amps use rectifiers tubes?
2. Is the KT88 tube a rectifier, or power-0utput tube?
3. I'm really interested in the Jolida JD801BRC (http://jolida.com/product/jd-801-brc). Does this amp use a rectifier, or some kind of SS method?

Thanks for the help, guys! I'm considering going down the all-tube route, but want to be sure I'm making the best choices.

 

1. Yes. My own amplifier is class A/B, and uses a GZ37 rectifier tube.
2. KT88 is a power-output tube. Again, my amp can use KT88s, KT120s, or 6550s.
3. Probably is solid-state rectified.

EDIT: that Jolida amp doesn't have tube rectification. Higher-wattage amplification poses a challenge for tube rectifiers.

 

Wow, thanks for the quick response! This really makes me re-think the Jolida, then. All this gushing about rectifiers... I can't pass it up.

As a follow up, are there any well-regarded tube-rectified amps, over 50watts, and under $3k?
edit: I see you're using the Bob Latino kit. Very interesting, and matches exactly my criteria. Hmmmm...

 

There are quite a few, but within that cost, I'm not sure. Decware's Zen Torii is tube rectified, but is more than your stated budget, and isn't much more than 25 watts, I believe. My own amp, which is pretty modest, and which fits within your budget, is a VTA ST-120 (60 watts/channel; it's not a dual-mono amplifier). The builder (Bob Latino) includes a Weber solid-state rectifier, and upon request, a GZ37 for that particular build. Some people prefer a tube amp to have SS rectification, as it may favorably work with some speakers to control bass output capabilities.

Don't necessarily let whether an amp is tube-rectified drive your choice, though....just as one shouldn't dismiss an amp because it's not class A, or isn't single-ended, etc.

 

I don't know anything about a Jolida anything, at least by model number, but the answers to the rest of your questions are in a book called a tube manual. They can be downloaded free as .pdfs or purchased. Time spent reading them is never wasted. I bought my first one at Radio Shack when I was eleven and didn't understand 90% of what it said, but eventually figured it out.

 

Sylvania' s use ink that easily rubs off the glass. ( No etch codes either)It often has to be done by visual examination.. Comparing to a tube that either still has its date code ink. Or by someone that knows the tube so well, they can identify it just by looking.

Can you post a picture of your tube and the box it came in ?

Are you looking to find another one made in the 1950's.

I'll try and help and I'm sure other members can/ will do the same.

 

dont feel like moving the 40# beast right now to get the tube, but here is the box. The sound is getting much bigger over the past few sessions, really spectacular tube. I would definitely like to find a 50's sylvania to try.
actually can't figure out how to post pictures anymore.

 

Hurry ending soon

http://pages.ebay.com/link/?nav=item.view&id=331084987110&alt=web

 

Another pair

http://pages.ebay.com/link/?nav=item.view&id=360444062108&alt=web

 

http://pages.ebay.com/link/?nav=item.view&id=360707833461&alt=web

 

Snagged a pair, thanks!

 

6X4's at like $10 each!? Crazy! Those were in the dollar bins in the early 00's.

 

All it takes is for a few new pieces of high-end gear to be designed around this tube. And that's probably enough to create demand, which results in supporting prices.

 

For me it's Tube rectification all the way. Whether it's for the amp, pre, and phono.
The combination of tube rectifier, oil capacitor, and choke is magical.
A 300B amp rectified by a Bendix 5R4GY or a GE 6CJ3.
Pre amps are WE 407B tubes rectified with Bendix 6106
Phono stage is Siemens EC8010/WE 396A tubes with WE274B rectifier.

 

Any thoughts on the TV damper 6AX4?

 

Nothing wrong with damper diodes. A great option (and cheap) for diy'ers building their own power supplies, and no rolling required.

jeff

 

The literature (i.e., tube manuals, type notes for engineers) is pretty explicit. These types were designed for pulse service with a very low overall current in most cases. If you are rectifying sine wave power at any appreciable current, you are using the device for something it was not intended for or guaranteed for any amount of life at. It might work and might not, and that might vary not only with the specific type and even the manufacturer and run. If even one company decides to make a commercial product and roll the dice, damper diodes of the type they use will instantly skyrocket in value as hoarders buy them all up.

A power triode of low to medium mu, or even a beam power pentode would probably make a better rectifier than a damper diode. If you are gearing up for nuclear war and have a legitimate reason to use a vacuum or gas rectifier, that's the route I'd pursue, since they are still in production and at some volume.

 

I have a pair of Dynaco MKIIIs that use the GZ-34. I will have to look and see what brand they are.