[RubyTiger]

What are those power tubes?

Indeed they are. http://en.psvane.com/info-11-285.html They're bigger than I thought they would be. I'm already hearing some great thing's from them and kudos to the KR RK rectifier too. It's all coming along great.

 

[claud W]

Well, RT, sounds like you are having a great Acme Christmas. For the final 24 hours of break in, I have returned my stratus to what I think will be my best tubes ond hand at the moment. I replaced the stock 2A3s with my new NOS RCA US Navy CRC 2A3s, 1942 and 1943 date codes. I returned the Ruby Tiger Select to its rightful place and of course kept the KR RK rectifier.

 

[RubyTiger]

I was having a good time until I decided to fiddle with the hum pot's. Now every thing sound's off. I'm not sure what to do about it and hope Donald will help. Anyone else have experience with them?

 

[claud W]

You are supposed to turn volume to zero. then turn hum pot until you hear noise. Then turn the other way until you hear noise, then back to about split the difference between the 2 noisy beginnings. I have been doing it when changing out the 2A3s. Had a bit of noise that I cleared by wiggling tube making noise.

 

[RubyTiger]

You are supposed to turn volume to zero. then turn hum pot until you hear noise. Then turn the other way until you hear noise, then back to about split the difference between the 2 noisy beginnings. I have been doing it when changing out the 2A3s. Had a bit of noise that I cleared by wiggling tube making noise.

That was what I did but they didn't sound right. Also, the temperature's of the tubes feel different. One is very hot and the other is not. Same goes for the rectifier.

Ok, I tried it again with the stock tubes and I think everything is good. May have had something to do with the all new tube's situation. I'm going to pretend so.

 

[m17xr2b]

Does the cool one have the heater filaments lit up? Does switching them make any differences?
Had this issue myself where due to excessive tube rolling the pins didn't make proper contact. Hopefully it's not the tubes at fault.

 

[RubyTiger]

Does the cool one have the heater filaments lit up? Does switching them make any differences?
Had this issue myself where due to excessive tube rolling the pins didn't make proper contact. Hopefully it's not the tubes at fault.

My rectifier and power tube socket's are still tight. My driver tube not so much. I installed the stock tubes and went back through the step's. Now it seems ok. Donald said he didn't think it would have harmed the tube's so I'm copasetic.

 

[adamaley]

There was a report on a failed tube on the whatsbestforum thead . Knock on wood, hopefully this isn't the same situation. hi

 

[RubyTiger]

Anyone with the KR whiskey barrel rectifier care to share impressions against the 422A?

I know it's a late reply but it's really early for evaluation's. I don't think the KR RK will ever have the "hauntingly beautiful tone" Dubstep Girl wrote about the 422a. The KR RK has a more natural tone.

The high's are not hyper extended and my ear's have not burned. In this regard it's more like my u52 than a new eml or pair of Sophia 300b 2.5v power tubes (I'm working with what I have here for impression's). My apology's to those who don't know these tubes. I think that the KR RK sound's more like an upper end U52. Like Dubstep girl's description found here: https://www.head-fi.org/threads/dub...mparison-rectifer-tube-rolling-thread.694525/ It's a good comparison to what I'm hearing. Unlike her description, it's not euphoric sounding. Not really. I do think one's choice of power tube's can make a difference though.

The bass is very much like the U52 or EML. A little warm, closer to a 50's 5u4g than the 40's type with hanging filaments. It has some weight and goes down deep. Again, power tubes may have a positive effect on this also. The Acme's for example have more weight and authority than the mesh plates. Regardless, I'm hearing good definition with both set's of tubes.

The soundstage is a little different than the 422a. With the Sophia mesh plate's and HD800's the sides are very wide. Deep as well. Imaging wraps around my head on some recording's and is nicely open. The Acme's have a different take. I get the feeling they want to come off as being more intimate sounding. But with only a few hour's on them I don't know.

If I failed at the initial analysis then I hope other KR owner's will post their own impression's. If one is considering a tube for their daily driver then consider the cost differences, reliability and warranty. New tube's can give one peace of mind buying from a reputable dealer. If I sound like I'm trying to sell the KR over the 422a it's because the KR fit's my need's better. They're both wonderful tubes and I have never regretted buying the 422a not once.

All subject to change as break in continues..

 

[UntilThen]

@RubyTiger thanks for the writeup. I'm still in the process of deciding on a pair of 2a3 and rectifier. I plan on using the stock tubes for a while then invariably will try some upgraded tubes but I won't go nuts with buying lots of tubes.

 

[P+D-MI]

I've had my Stratus for a month and plan on using the stock tubes for a while until I really get a good understanding of the sound. It sounds pretty good to me so far.

 

[P+D-MI]

I don't plan on spending money on a bunch of tubes either, been there before.

 

[RubyTiger]

I've had my Stratus for a month and plan on using the stock tubes for a while until I really get a good understanding of the sound. It sounds pretty good to me so far.

I think your right. I was going on what I think are the KR's stronger point's and less likely to change. The truth is a tube can change a lot during break in. For that reason I'm removing the recommendation to buy. I will come back after many hr's to see if I need to update my impression's.

One doesn't have to buy a bunch of tubes. You just have to buy the right tubes. The Stratus's performance can be greatly elevated with better tubes.

 

[m17xr2b]

I'm using the 422A as my main rectifier but I've asked Donald to mod my amp for it. I find it has the best balance and tone among the others.
Closest is U52, great mid range and extension, bass is not as controlled, slight warm tilt overall, smooth highs 422A is more neutral in tone but treble is not as relaxed.
MWT/RCA 5U4G top getter, got it for 10$, very thin glass, closer to 422A than to U52, nothing was wrong but the other two had X factor.
National Union VT244 foil getter, a great all rounders, blends smoothness and clarity really well, lacks ultimate extension but close overall
Ken Rad VT244, punchy and warm, a real nice hip hop tube but less air.
Fivre 5U4G, lean sounding and bright, might work well for some.
Sylvania VT244, sounded fine, a fine sounding valve, average, could do better.
Stock, worst of the bunch anything is an upgrade.

I've thought about getting the EML and old style KR but decided to stop trying rectifiers.

I'm not for one second suggesting the stock Stratus is not a fantastic sounding amp. Tube upgrades just enhance various areas.

 

[claud W]

I own most of those rectifiers and m17xr2b is spot on with his evaluations. Replaced WE 422a with KR RK 5U4G. I had put about 100 hours of break in on it. Sounds great now. Sounds about half way between WE 422a and U52. Great tone while listening to piano music. Nicely balanced tube SO FAR. I think I have about another 100 hours to put on it to complete break-in. Easier to do now that system sounds good with it.