Forums - Pentode to Triode comparison

Brian Seasoned Member Posts: 903	Pentode to Triode comparison 10/26/15 at 02:50:32 I am wondering how single end Pentode compares sonically to single end Triode. Perhaps some of you Mini Torii owners who have also heard SET could compare them for me. I especially wonder if Pentode operation is a more dynamic sound. Thanks, Brian
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Fireblade

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wisdom lingers.
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Re: Pentode to Triode comparison
Reply #1 - 10/26/15 at 11:26:50

IMHO, both single-ended Pentodes (EL34, EL84, etc.) and Beam-Tetrodes (i.e., 6V6, KT88's, etc.) can sound great even if not strapped as Triodes. It depends on the design and implementation of that design.

I've tried both scenarios (Mini Torii and SET), and I'm satisfied with both performances. Again, IMHO it depends more on the design accomplishments than just the conceptual configuration differences.

I have never tried pure Triodes (i.e., 300B, 45, 2A3, etc.) so I could not comment on those, but other than the excessive tube prices, I would argue that the important difference again is in the design merits, IMHO

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Brian Seasoned Member Posts: 903	Re: Pentode to Triode comparison Reply #2 - 10/31/15 at 02:06:43 Does no one have a comparison of the sound? I understand that as Fireblade has said they can both sound great, but do they sound alike? Does Pentode operation have it's own unique sonic signature which is different from the sound of triode operation?
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Lord Soth

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Re: Pentode to Triode comparison
Reply #3 - 10/31/15 at 05:12:42

I have always wished ( still wishing) that Steve would get round to producing a 300B based tube amp.

IMHO, the golden age of tube audio was reached during the era of Pentodes.

But there is something Primordial about the simple 300B.
It comes with a kind of ancient intangible quality ( positive) just like a Dinosaur from Jurassic Park.
Yes ! I want a 300b amp which speaks, nay, sings to my soul.....

The legendary WE 300Bs may be too rare and expensive today but with the new production takatsuki 300b , sonic SET bliss is still possible.
As an audiophile, I just want to be able to enjoy some good old fashioned 300b SET sound for nostalgic reasons.

Please Audio Gods, send a message to Steve D so that an old audio fart like me can not just experience this myself but also let my grandkids know what a simple good "light bulb" can do.

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busterfree Seasoned Member Posts: 438	Re: Pentode to Triode comparison Reply #4 - 10/31/15 at 16:42:46 According the amp buying guide, "Because it [Mini Torii] has more gain than our other amplifiers, it can be driven by something as weak as an iPod or smartphone and come of[f] with surprising dynamics."
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busterfree

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Posts: 438

Re: Pentode to Triode comparison
Reply #5 - 10/31/15 at 17:56:12

I should say that I have owned the white top Mini Torii, SE34I.32, and SE84C+. I even upgraded Mini Torii to latest version, and I still sold it. Not because it is bad or anything. It just didn't fit my needs.

With a good source putting out 2V or more, the SE84CKCS with UFO transformers beats it in my room with my speakers. I just listened to a recording, and I cannot imagine something being more dynamic. I am sure there is, but I do not want to spend time and treasure at this point to find out.

I think it is an apples to oranges comparison because of the built in preamp stage, dual mono design, and the tube set. It is a great option if you want second output to drive another amp and can adjust the output voltage of your source. It is also a tube rollers dream. There are so many output tube choices.

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seikosha

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Posts: 124

Re: Pentode to Triode comparison
Reply #6 - 10/31/15 at 21:05:01

Kind of hard to compare the concepts because a well designed pentode with good parts could sound better than a SET with poor design/parts and vice versa. If you are looking for comparisons between the Mini Torri and an SE 84 or 34, there are threads with that and I can point you to some.

Generally speaking, my experience has been that you'll get more drive out of a pentode design. It might sound slightly fuller, denser and thicker than the SET. The SET characteristics are transparency and medium to low level dynamics and that "lit up from within" sound from instruments and vocals.

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Brian Seasoned Member Posts: 903	Re: Pentode to Triode comparison Reply #7 - 11/01/15 at 06:07:09 Thank you seikosha. That is the sort of comparison I am seeking. Brian
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Brian

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Posts: 903

Re: Pentode to Triode comparison
Reply #8 - 11/01/15 at 06:11:45

Lord Soth, Here is a link to a forum thread where Eddie Vaughn (who used to be a regular contributor here in the Decware forum) designed a 300B amp for me.
http://www.hawthorneaudio.us/forums/viewtopic.php?f=8&t=581
So far as I am concerned, you are welcome (as is anyone else reading this) to hire an amp builder to build it for you. I wish someone would. I don't know if I shall ever have the money to do it for myself, and I would like someone to get some good out of what seems like being just about the best 300B amp ever cooked up.
Eddie knew I was impoverished and so talked up the build cost as very high, but I don't think the original build cost need be prohibitive. You can see at the end of the thread that I worked up an estimate of $1800 parts cost at the time that was written. I don't know labor costs, but would guess an electrician would solder an amp together for parts cost plus 50%. I don't know how much optimisation of parts swapping will be necessary after the initial build to max it out, or how much that would add to the price.

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