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Best Sounding Output Tube

With a view to economics, there's no point buying a Rolls R and using it at tick-over.. i.e no point heading into KT88's prices unless your circuit B+ warrants it. The 6550 series can deliver the goods at a lower B+ and price with equal sound quality and I use'm more and more.
Drop-in sound quality differences between the two tubes in many o/p stages are hard to tell which easily fool audiophile soothsayers.

EL34's are reliable good sounding tubes, but again these are cheaper simply because they are commercially attractive in MI equipment. They don't need a jock-strap to keep'em upright whereas KT88's can easily come out of IO holders and break the spigot as in pic.

You might be dissapointed swapping an EL34 into a circuit designed for KT88's, the Load Z may be loo low, bias changes, signal drive, thd changes, heater juice, screen +, are all a raft of considerations.


richj
 

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Here's the result of a load of posts asking for favourite tubes. Seems the EL34 has more fans (9) than the KT88 (4). Nevertheless, the preference for DHTs is clear.

45 15
300B 14 WE, Full Music Mesh Anode
2a3 10 TJ mesh plate
EL34 9 Mullard, old Tesla
10Y,VT25 9 RCA/Cunningham globe, Cunningham 310
EL84 8
7591A 7 Westinghouse or Sylvania 7591A, class A
6550 6 Tungsol
845 5 Amperex brass plate
KT-90 5
811A 4
KT88 4 Original Tesla, Golden Dragon
50 4 ST, globe
PX-25 3
RE604, PX4 3 Telefunken (RE604)
WE VT-52 3
6L6GC 3
KT66 3 GEC
71a 3 Cunningham 371A
801a 2
KT77 2
EL38 2 Mullard (sound wonderful but cheap)
6146 2 ubiquitous, cheap, and bulletproof – 2
6B4G 2 Sovtek
6V6/7408 2 RCA 7408
483 2 Globe 183/483's
SV811-3a 1
211 1
GM70 1 Copper plate
 
I couldnt say what the "best" sounding output tube is out there, but I can say on my extreme budget that the PCL82 in parallel single ended triode sounds pretty damn good. Sure, it's not a beauty (its butt-freakin'-ugly in my opinion), but it does what it needs to do, and that's make music. No defining characteristics come to mind on how it affects the music other than a slight warmth and slightly smoother highs than my other rig (Marantz 2270, moderately restored). The fact that I don't hear any glaring qualities of the tube makes it one I'll love for a while, at least until I get around to building a better SE amp.

I'd mention other tubes, but I have yet to hear any others yet. I'm still living up my tube newbness :)

-Jared
 
Wavebourn said:
order to get end results
It is great!
What I love in DIY?
I love share of information, of ideas, of findings.
Lot of things we studied in TIASUR now are rediscovered; people cry" Eureka!" and share what they found.
It it amazing!!!
Hold on fellows; continue to torture tubes; continue to make mistakes; continue to experiment and find best optimal designs!
You may take a magic eye and use it as a plain triode; you may take a fat tube designed for destructive military transmitters and use it for a peaceful audio reproduction; you are free to experiment: if somebody tells you that it is out of fashion you may ignore and go on...
You are free. You are DIYer. So take your tubes and make what you want. It is easy!
:smash:

100% RIGHT and 100% agreed with.
 
Boy I love this post! I've never used outputs other than the mainstream types and these are my faves (IMHO):

1) KT88. Best tube for hi fi. Deep powerful bass and shimmering highs. Not good for guitar amps due to a very late break up. (Unless it's for bass guitar).

2) 6L6GC/KT66. Not as powerful as a KT88, but wonderfully detailed mids and highs, more than satisfactory bass. Great for both hi fi and guitar amps.

3) EL84. Not a power monger, but a flat freq resp and awesome detail. What would the Dyna ST-35/SCA-35 and the early Scott 222/299 sound like w/o them? Also perfect for a low powered guitar amp for late night jamming.

4) EL34. Not my favorite for hi fi, although it's got beautiful midrange clarity. To me it seems to lack deep bass, but it may be a perfect mid/high powered guitar amp tube...somewhat early break up with awesome harmonics.

~~~Johnny~~~
 
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I have this top of the line BAT VK150SE thing for bias tracking inspection in my system lately. It uses 6C33s. Those tubes are very different to each other in production regarding emission matching, and they need to be hand matched. They tend to drift a lot, and auto tracking systems are usual among ready made amps using this type. Their sound lacks bass sustain IMHO. I have listened to them in many different expensive machines, OTL or not, and always I feel this 'cold' signature. But I reserve judgment since I haven't developed a project of my own with 6C33s so to know what else is at play in circuits around them for sure.
 

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6C33 (the correct writing is 6S33 ) is a very powerful and very robust russian tube. It is actually double triode within one glass bulb, therefore some people are connecting only one triode within 6S33 claiming of getting more stable functioning of this tube although the power is lower - I never heard it in this configuration.

It can sound extraordinary well but it is not so easy to achieve that 6S33 sounds at its best. You have to find the best B+ (some say that ~280V for SET configuration gives the best result) and to take special care about heating. In addition, the output transformer is a bit of a problem beacause there are no many output transformers on the market, which are build especially for this output tube.

I have heard some SET 6S33 sounding thin, lacking obviously bass competency, but I was told that the reason for that is the output transformer (it was DIY one) and not appropriate B+ (it was too high).

Some 6S33 OTL designs that I heard (Einstein, Graaf, ...) sound realy very good and the sound is very dynamic and not at all lean or cold.

So I guess, if you want to go after SET 6S33 (or OTL) you should first search internet carefully in order to find appropriate information and above all appropriate output transformers. Also take a look (if you can) in Armarro amps using 6S33 - they sound really great, according to all people that had the opportunity to hear them.

By the way, the nickname for this tube is: Babushka, because of its shape ...