[me2621a]

Hey Guys,
I currently have two GE Red Base 5691's which sound great (I have been told the 5692's are kinda lousy).

I have a Tung Sol 6SU7 on its way (not black glass).

I am thinking about also trying out the Sylvania 6SL7 tube which I have been told are really good. I can choose for a reasonable price the 1950's black base, or the 1955 brown base (short bottle).

Can I get anyones thoughts on which tube is considered better or that people seem to like?

 

[55Powers]

Hey,

These are my 6sl7 tubes that i currently run in the Mogwai SE (from warmest to brightest):

- RCA - 6SL7GT - Grey Glass, black plates
- Tung Sol - 6188/6SU7WGT - Slim base, red print
- Brimar - CV1985/6SL7GTY - Brown base
- RCA - VT-229 - Black plates, bottom getter, pre WW2

I mostly do the Tung Sol (maybe the same one as you are getting?) and the Brimar these days. The Tung Sol (which is a dirt cheap tube btw) is an nice allrounder for me, good dynamics, slight sweetness, slight roll off. The Brimar is more of a vocals specialist tube (love me some of those vocals). If I do classical or instrumental, the RCA 229 gets some playtime, good treble extension and detail.
The grey glass is a bit too colored for me these days most of the time, but it a "fun" variation i suppose.

I really only want to get a 5691 now, but i am stalking for a Stockholm version (rare/pricey) to top it off.

 

[me2621a]

Hey,

These are my 6sl7 tubes that i currently run in the Mogwai SE (from warmest to brightest):

- RCA - 6SL7GT - Grey Glass, black plates
- Tung Sol - 6188/6SU7WGT - Slim base, red print
- Brimar - CV1985/6SL7GTY - Brown base
- RCA - VT-229 - Black plates, bottom getter, pre WW2

I mostly do the Tung Sol (maybe the same one as you are getting?) and the Brimar these days. The Tung Sol (which is a dirt cheap tube btw) is an nice allrounder for me, good dynamics, slight sweetness, slight roll off. The Brimar is more of a vocals specialist tube (love me some of those vocals). If I do classical or instrumental, the RCA 229 gets some playtime, good treble extension and detail.
The grey glass is a bit too colored for me these days most of the time, but it a "fun" variation i suppose.

I really only want to get a 5691 now, but i am stalking for a Stockholm version (rare/pricey) to top it off.

Thanks for the Reply, Yah that is the Tung-Sol I got, its great, been running it this week (probably have about 25ish hours on it) but I am a pretty big fan. Planning to have it go head to head with my Red Base, which has about the same amount of time on it this weekend. Not sure if I have heard of the "Stockholm" version, what makes that one so special? Might need to check out the Brimar in the next month of two.


Out of curiosity what are you running for power tubes/rectifier (Tung Sol 6550s/ and SED black plate or something else)?

 

[55Powers]

Thanks for the Reply, Yah that is the Tung-Sol I got, its great, been running it this week (probably have about 25ish hours on it) but I am a pretty big fan. Planning to have it go head to head with my Red Base, which has about the same amount of time on it this weekend. Not sure if I have heard of the "Stockholm" version, what makes that one so special? Might need to check out the Brimar in the next month of two.


Out of curiosity what are you running for power tubes/rectifier (Tung Sol 6550s/ and SED black plate or something else)?

Ohh sweet, will be very interested to see how they line up for you with the red base.

The Stockholm tubes are mostly a geographical/historical interest, as they were produced pretty close to home (Norway), with the added benefit that it seems like a really nice tube. Saw a pair on ebay recently for 750ish, so it's a bit of a waiting game.
http://www.nostubestore.com/2010/06/standard-33s29b5691-sweden.html

I run 6550s yes, i haven't really bothered rolling much on em tbh. Considering getting a pair of 6L6GCs or the 6384s, but i haven't gotten around to it yet (currently giving some love to my speaker amp pre stage as well).

For rectifiers i do GZ34 (X-coded), a 40s RCA 5u4g, or a Sylv 5931 (supersized 5u4gb i think).
5931 fun and cheap variant, not as techincally good as the other two.
I was really fixated on the GZ34 for a good while, but now the 5u4g is getting some time too... which has made me reeeeaally curious on a good GEC U52.

What are you running for power/rectifier?

 

[me2621a]

Ohh sweet, will be very interested to see how they line up for you with the red base.

The Stockholm tubes are mostly a geographical/historical interest, as they were produced pretty close to home (Norway), with the added benefit that it seems like a really nice tube. Saw a pair on ebay recently for 750ish, so it's a bit of a waiting game.
http://www.nostubestore.com/2010/06/standard-33s29b5691-sweden.html

I run 6550s yes, i haven't really bothered rolling much on em tbh. Considering getting a pair of 6L6GCs or the 6384s, but i haven't gotten around to it yet (currently giving some love to my speaker amp pre stage as well).

For rectifiers i do GZ34 (X-coded), a 40s RCA 5u4g, or a Sylv 5931 (supersized 5u4gb i think).
5931 fun and cheap variant, not as techincally good as the other two.
I was really fixated on the GZ34 for a good while, but now the 5u4g is getting some time too... which has made me reeeeaally curious on a good GEC U52.

What are you running for power/rectifier?

You and I should have a bunch of notes to compare then. Right now I am running Tung Sol (mid 60s) 3 whole grey plates for power, and a black plate SED Winged C 5u4g. I also have a GE 5ar4, I tried it for a short while but I noticed my noise floor pop up after an hour or so, and it was noticeable enough that it could be heard at lower listening volumes. My guess though is it is just a bad tube, or a bad tube combo (didn't investigate enough to figure it out). The winged C sounded great, so I ordered 2 more out of the Ukraine for under $30 shipped to have as backups.

On their way to me now though is a Mullard GZ34 (Four Notch) and an RCA 5u4g (I think its a early 1950s), I feel like based on the amount of money I have spent on the Tung Sol (I have two matched sets) I owed it to myself to try the Mullard GZ34 that people are so crazy about.

I do have a great pair of EL34's, east German Short Bases, and the Bendix 6384s, I will be rolling them in after I make the final call on the 6SU7 and the 5691 (which I hope to do this week), and then begin the process of comparing power tubes.

I am also considering trying out the Sophia Electrics KT88, 6SL7 combo, but I am skeptical based on their "like NOS" pricing.

I have found that when I get a new toy I massively suffer from fear of missing out (FOMO) and therefore must try all the recommended tube combos to find the best one....this is why I can't have nice things haha.

 

[me2621a]

Ohh sweet, will be very interested to see how they line up for you with the red base.

So I had a chance to finally sit down and compare the Tung Sol with the GE Red Base 5691. Long story short the Tung Sol will be staying, the red base, will go into my tube backup collection.

To start out with they actually sound reasonably similar, and the red base on its own is a very good sounding tube, however I find it quite compressed when compared with the Tung Sol, The Tung Sol, hits lower, and harder. The Red Base has slightly sharper lines during the initial impact, but caries not weight behind it. Honestly the only reason though I picked up on it, was I took notes when I listened to 6 songs with the Tung Sol, and then took notes listening to the same six songs with the GE Red Base, and reviewed the comparison. It was pretty clear with the exception of one song that the Tung Sol was preferred, and for the one song, it was because the detail the Tung Sol retrieved revealed recording weaknesses that the Red Base just didn't. Given that you have the Tung Sol, my suggestion would be to stick with it, and not bother with the 5691 (US versions at least), now who knows maybe if I let the 5691 break 150 hours it may loosen up more. I probably have about 50ish hours on each right now.

All this being said, I am not selling my two 5691's they are just going to be what I cycle in after my two Tung Sols eventually die (hopefully not for a good long time). The other thing to mention is that if I had not done as carful as a comparison I probably would have gotten used to the slightly more compressed 5691's sound and been very happy with it. They also may be a great choice for more base heavy power tubes as they would probably balance out nicely, but everything seemed light with the Tung Sol 6550s.

 

[55Powers]

You and I should have a bunch of notes to compare then. Right now I am running Tung Sol (mid 60s) 3 whole grey plates for power, and a black plate SED Winged C 5u4g. I also have a GE 5ar4, I tried it for a short while but I noticed my noise floor pop up after an hour or so, and it was noticeable enough that it could be heard at lower listening volumes. My guess though is it is just a bad tube, or a bad tube combo (didn't investigate enough to figure it out). The winged C sounded great, so I ordered 2 more out of the Ukraine for under $30 shipped to have as backups.

On their way to me now though is a Mullard GZ34 (Four Notch) and an RCA 5u4g (I think its a early 1950s), I feel like based on the amount of money I have spent on the Tung Sol (I have two matched sets) I owed it to myself to try the Mullard GZ34 that people are so crazy about.

I do have a great pair of EL34's, east German Short Bases, and the Bendix 6384s, I will be rolling them in after I make the final call on the 6SU7 and the 5691 (which I hope to do this week), and then begin the process of comparing power tubes.

I am also considering trying out the Sophia Electrics KT88, 6SL7 combo, but I am skeptical based on their "like NOS" pricing.

I have found that when I get a new toy I massively suffer from fear of missing out (FOMO) and therefore must try all the recommended tube combos to find the best one....this is why I can't have nice things haha.

Hold smokes, you have a lot going on here.

- Sounds like something wiers is indeed going on with the GE 5ar4, i don't think i've had tubes change noise floor during operation before. Although 5ar4 noise floor should be higher than the 5u4g.
- Speaking of 5u4g, will be like a cold war showdown once you get that RCA! $30 is insane if they match up.
- Powertubes, esp the 6384 I am very curious about, I'd rather not have adapters running, but Justin seems to really really like em. Could be worth running some adapters if they are a level above 6550s.
- Yeah, i've been looking at the Sophias too, not really sure about it. The dream would be NOS KT88s, but like...don't think its going to happen. Been looking at KT77s a bit too. But I am really unsure if there is much to gain above the 6550s.

Tube anxiety (FOMO) is definately real for me as well. But with NOS dreamroll prices I think one has to compromise at some point (close to 2k USD i think for my part: Stockholm 5691, GEC Gold Lion KT88, GEC U52)
I am really happy with the rolls i got now though, kinda relaxed to be honest.
Will definately be interested in your power tube rolls moving forward, I'll give some types a go as well some time.

We should move the rolling stuff back in the A&S thread moving forward I think, will probably be more productive.

 

[55Powers]

So I had a chance to finally sit down and compare the Tung Sol with the GE Red Base 5691. Long story short the Tung Sol will be staying, the red base, will go into my tube backup collection.

To start out with they actually sound reasonably similar, and the red base on its own is a very good sounding tube, however I find it quite compressed when compared with the Tung Sol, The Tung Sol, hits lower, and harder. The Red Base has slightly sharper lines during the initial impact, but caries not weight behind it. Honestly the only reason though I picked up on it, was I took notes when I listened to 6 songs with the Tung Sol, and then took notes listening to the same six songs with the GE Red Base, and reviewed the comparison. It was pretty clear with the exception of one song that the Tung Sol was preferred, and for the one song, it was because the detail the Tung Sol retrieved revealed recording weaknesses that the Red Base just didn't. Given that you have the Tung Sol, my suggestion would be to stick with it, and not bother with the 5691 (US versions at least), now who knows maybe if I let the 5691 break 150 hours it may loosen up more. I probably have about 50ish hours on each right now.

All this being said, I am not selling my two 5691's they are just going to be what I cycle in after my two Tung Sols eventually die (hopefully not for a good long time). The other thing to mention is that if I had not done as carful as a comparison I probably would have gotten used to the slightly more compressed 5691's sound and been very happy with it. They also may be a great choice for more base heavy power tubes as they would probably balance out nicely, but everything seemed light with the Tung Sol 6550s.

Those are some very interesting results. Thanks so much for sharing.
I have been very surprised of how well this humble bargain tube can do vs. the stuff i have (even though 5691, that i don't have, is held somewhat higher in regard than the CV1985 and the VT229 usually)

Might try another TS variant in the future, one of the fat bases with black glass looks interesting.

Not sure what the expected lifetime of these TS military tubes are like, but if you have two you should be fine for a good while, I am getting a backup now for sure! .

 

[Dipesh]

So I will be ordering Mogwai SE next week .I have heard the sound stage is less then desired. Is that true ..what are the best tubes you can get for these amps
Thanks

 

[me2621a]

So I will be ordering Mogwai SE next week .I have heard the sound stage is less then desired. Is that true ..what are the best tubes you can get for these amps
Thanks

Neither if my headphones are known for their sound stage (Utopia and Stella) so I cannot comment in the sound stage other then that I have no issues with it.

As for tubes, I believe I have tried most of the well known really good combos. My favorite are NOS TS 6550s (no hole or black plate, 3 holes are fine though) for power tubes, the RCA black plate 5u4g (late 40s early 50s), and the Tung Sol 6su7 for preamp duties.

Other tubes to consider:

6L6gc - RCA makes the black plates they are pricy but nice, and the bendix 6384 with adapters, this is a great tube but will require a ton of breakin time.

Tung Sol 6SL7 round plates (50s), great tubes but all of mine have been noisy so I like the su7 more.

All of this will depend on your equipment and headphones. It’s a great amp so enjoy it and you have so many choices for tube rolling.

 

[Dipesh]

Cool thanks mate.