Pentode sounds great

Cassiel · 29th August 2008, 03:16 PM

Hi, i have built a little amp with the ecl86.

My surprise is that it sounded better in pentode mode. Triode had a good tone (doesn't always) but the sound was a little opaque and too much laid off for my taste.
Try this with any pentode, el84 anyone?
Only requirement is no bypass caps,input and output stage, and a higher than normal primary impedance - 10.000 Ohms or maybe more if you can.

Lovely sound, clear and natural.

Jeb-D. · 29th August 2008, 04:35 PM

Quote:

Try this with any pentode, el84 anyone?

George (tubelab) did. He seemed happy with the result.

I've had good luck with other Pentodes as well.

Boris_The_Blade · 29th August 2008, 04:38 PM

Sometimes those extra two connections scare people, but there's nothing wrong with pentodes!

ray_moth · 29th August 2008, 08:51 PM

Stalker, did you use negative feedback (other than unbypassed cathode resistors)? It's common to use it to improve pentode harmonics and damping factor.

Cassiel · 30th August 2008, 01:14 PM

No Ray, only current feedback...but when i get used to the sound i'll try
a voltage feedback loop too. Thought i suspect i'll get an even cleaner sound but with less air and openness.

aletheian · 30th August 2008, 10:16 PM

You are not alone, I tend to like the sound of pentodes too--more bite and a more aggressive response typically-- but since I listen to heavier music it makes sense for me. They just seem so unpopular that I have never bothered posting about it.

ray_moth · 30th August 2008, 11:21 PM

Well, aletheian, I'll join you as a pentode fan.

My attraction to pentodes started over 40 years ago and hasn't abated yet. Expressions like pentode authority and pentode slam get the old pulses racing.

Of course, I know that triode sound is 'purer', but where's the fun in that?

JandG · 31st August 2008, 03:05 AM

I too am getting a high respect for Pentodes in SE as that is all the OT;s I have are SE, but in the last month or so I have ripped though many, many Pentodes & many sound excellent in the normal mode. Now I am off to learn NFB ways, I see there is many, many differnat ways to do it.I tried sceen dive this mourning on a 807 & couldn't get it to work, another day for that G2 drive thing. I like building sperate PS's & Pentodes in that mode give me a good reason to do g2 supplies & experiments. my top dog amp is a DIY PP 6l6 jobber from a very talented fella that used a Fisher 200 OT & adjustable NFB, it is a stunning sounding amp. Yep I like em..

azazello · 31st August 2008, 06:27 AM

Quote:

Originally posted by ray_moth
Well, aletheian, I'll join you as a pentode fan.

My attraction to pentodes started over 40 years ago and hasn't abated yet. Expressions like pentode authority and pentode slam get the old pulses racing. Of course, I know that triode sound is 'purer', but where's the fun in that?

What is better ? Pure, real sound .....or fun ?
/6C41C - 1/2 of 6C33C -.... sounds like pentod...compromise?/.

ray_moth · 31st August 2008, 07:29 AM

Quote:

What is better ? Pure, real sound .....or fun ?

I'm going to respond with the dreaded words "it depends", in this case on your reason for being in this hobby of ours. Good triode sound is well within reach for most people, whereas good pentode sound is more of a challenge (but also more rewarding when you get it right).

Maybe the best approach is to build a nice triode amp and keep it for listening, then build a pentode amp to use for experimenting.

29th August 2008, 03:16 PM	#1
Cassiel diyAudio Member Join Date: Sep 2004 Location: Madrid	Pentode sounds great Hi, i have built a little amp with the ecl86. My surprise is that it sounded better in pentode mode. Triode had a good tone (doesn't always) but the sound was a little opaque and too much laid off for my taste. Try this with any pentode, el84 anyone? Only requirement is no bypass caps,input and output stage, and a higher than normal primary impedance - 10.000 Ohms or maybe more if you can. Lovely sound, clear and natural.

30th August 2008, 10:16 PM	#6
aletheian diyAudio Member Join Date: Apr 2004 Location: Philly	You are not alone, I tend to like the sound of pentodes too--more bite and a more aggressive response typically-- but since I listen to heavier music it makes sense for me. They just seem so unpopular that I have never bothered posting about it. __________________ Heghlu'meH QaQ jajvam!

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Radio Sounds Great, CDs Sound Terrible	sdclc126	Car Audio	5	3rd August 2007 01:22 PM
FS Gainclone Great Chassis, Potted toroidal, great sound	PHilgeman	Swap Meet	4	2nd May 2006 01:20 PM
A small no-fuss pentode/pentode SE amp	Tubes4e4	Tubes / Valves	13	1st January 2006 05:16 AM
sounds great, thanks to everyone that helped.	Richie V6	Chip Amps	6	1st January 2005 03:06 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

29th August 2008, 04:38 PM	#3
Boris_The_Blade diyAudio Member Join Date: Mar 2007	Sometimes those extra two connections scare people, but there's nothing wrong with pentodes!

29th August 2008, 08:51 PM	#4
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	Stalker, did you use negative feedback (other than unbypassed cathode resistors)? It's common to use it to improve pentode harmonics and damping factor.

30th August 2008, 01:14 PM	#5
Cassiel diyAudio Member Join Date: Sep 2004 Location: Madrid	No Ray, only current feedback...but when i get used to the sound i'll try a voltage feedback loop too. Thought i suspect i'll get an even cleaner sound but with less air and openness.

30th August 2008, 11:21 PM	#7
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	Well, aletheian, I'll join you as a pentode fan. My attraction to pentodes started over 40 years ago and hasn't abated yet. Expressions like pentode authority and pentode slam get the old pulses racing. Of course, I know that triode sound is 'purer', but where's the fun in that?

31st August 2008, 03:05 AM	#8
JandG diyAudio Member Join Date: Jan 2005 Location: Washington State	I too am getting a high respect for Pentodes in SE as that is all the OT;s I have are SE, but in the last month or so I have ripped though many, many Pentodes & many sound excellent in the normal mode. Now I am off to learn NFB ways, I see there is many, many differnat ways to do it.I tried sceen dive this mourning on a 807 & couldn't get it to work, another day for that G2 drive thing. I like building sperate PS's & Pentodes in that mode give me a good reason to do g2 supplies & experiments. my top dog amp is a DIY PP 6l6 jobber from a very talented fella that used a Fisher 200 OT & adjustable NFB, it is a stunning sounding amp. Yep I like em..

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)