Pantode and Tetrode What is the difference?

Don't worry about the forum thing too much. If in fact you are looking for advice that's that technical let me add something about pushpull and triode v. ultralinear. B/c of the suppressor grid on the EL34, you could say that usually it sounds better in ultralinear and as someone stated, peppier. It has to do with that supressor grid, electron cloud, maximum plate voltage thing; you can probably see how. The get up to a plate voltage, max out, and output constantly at that level (no overdriving like on guitar amps, as far as I know; someone correct me if I'm wrong on this one, but it's what I've been led to understand). This is why you see EL34 amps that are *specifically* balanced designs in ultralinear more of the time than with octals like KT88's; it's about creating a really super standardized power envelope for ultra-reliable bandwidth and no power spikes or dips base on load. The KT88/66/6550's sound better in triode for the most part because you kind of rev the plate voltage up as high as you can in Class A, with no cut off; not real efficient, and can lead to clipping, but that's why they sound purer. If you have transformers that can handle it, you get the benefits of Class A and the extra bit of bandwidth from a single ended design. Single ended like RCA plug vs. balannced plugs, where with balanced all the interconnects are grounded. Not single ended like a single ended tube design vs. a pushpull design; two totally different things. I'm surprised how often I see that particular confusion even in reviews. I've said this on another forum, but I'll say it here too: it's the difference between the sound of Sun Studios say (the EL34 camp) and like a great Verve recording (the KT88 camp), though not maybe as clear cut as rock vs. jazz.

Thanks
I am still a little confused about tube matching the Hurricane allows for each tube to be biased independently in this case is a matched pair still important.

In addition, I was going to buy a tube tester and had asked on THE AMP FORUM about which one would accommodate the KT88s and EL34s (for future experimentation).
One reply was that a small portable one would suffice but it would not "computer match" the tubes.
What makes a matched pair?

Punk--
1. When output tubes can be biased separately, 'matched' tubes are NOT required for excellent performance.
2. Are you sure your 'Canes can use '34s? I don't recall seeing that in my manual.
3. You do NOT need a tubetester. The WORST thing that will happen is one tube you install will be shorted or will arc and blow the high-Voltage fuse. (You DO have spare fuses--both kinds--don't you?)
4. Heed the instructions when replacing output tubes--the bias pot for that tube should be turned full down...CLOCKWISE, not counterclockwise...before you turn the amp back on. Turn the bias-selector switch to that tube, turn the bias meter on, and then adjust that tube's bias after the high-Voltage relay closes and the bias amount sort of settles. You probably already know that the tubes' bias draws vary considerably from cold to hot; if I've not moved my amp(s), I adjust mine before I turn the amps off for the evening.
5. 'Matched' output tubes are very close in bias draw, so that they'll work correctly in amps without separate bias adustments per tube.

Enjoy your 'Canes; I sure enjoy mine. I just finished my improvements; see my system.

Do you use yours in UL or triode? What do you drive with them?

PS. It's 'pentode'.
.

I am waiting on a pair of Merlin's as for the P/T I have only tested the amps with a Gallo Due to check if they are working.

The Merlin's should be here in about two or Three weeks I may well sell the Hurricanes and get a pair of Manly Snappers Bobby at Merlin said it is a great amp to drive his speakers.

As for the EL34 you are correct the Hurricane does not use them but if I do change amps for something smaller it will have the 34s.

I just won a Superior Instruments Co. TD-55 Tube Tester on ebay and hope it will accommodate my tubes as I found it difficult to find answers to which tube tester works with the KT88s I have a sinking feeling that this one does not.

There is a B&K CRT 465 coming up on ebay can anyone can tell me if this will test KT88s or if the TD-55 will work with 88s 34s and the other ones (That I cannot remember the name of)

Actually if you have an old mom & pop style radio shack place or seriously old school drug store, you may be able to find a tube tester locally - I happen to have a place like that around, and just like back in the 40's and '50's you can take your tubes in and get a reading by plugging them in to various sockets, turning a dial then pressing a button. I think computer match means "pay us extra for the same service; it will be on a computer plugged-in tube tester". Basically the difference between matched an unmatched is tubes used in tandem, or each tube on its own. Different topolgies is all. Personally I don't see one as inherently better than the other. Hurricanes and Merlins should sound great. If you get bored and want a sweeter sound, you can always try the EL34's. Merlins tend to be sweet. Should be a good balanced match with the KT88's.