One more 4P1L SE - Page 30 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd December 2012, 02:16 AM   #291
diyAudio Member
 
Join Date: Nov 2007
Quote:
Originally Posted by Pano View Post
I'm still waiting for my 4P1L tubes to show up. Been over 2 weeks and I was hoping to build an amp during the Christmas break.
I can top that. I have been waiting for over 1 month for mine......
Fortunately seller has offered to send replacements.
  Reply With Quote
Old 23rd December 2012, 03:26 AM   #292
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by Pano View Post
I'm still waiting for my 4P1L tubes to show up. Been over 2 weeks and I was hoping to build an amp during the Christmas break.
How far are you from Pleasant Hill?
You can borrow mine.
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 23rd December 2012, 03:42 AM   #293
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
Quote:
Originally Posted by rotaspec View Post
I can top that. I have been waiting for over 1 month for mine......
Fortunately seller has offered to send replacements.
One day all the supply off all these fabulous inexpensive Russian tubes is going to come to a halt and we will all wish we had bought 100 of each. Tubes like this one are a deal of a lifetime right now.

Last edited by regal; 23rd December 2012 at 03:47 AM.
  Reply With Quote
Old 23rd December 2012, 03:52 AM   #294
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Thanks, but I'm on the other side of the continent. Guess it will be a project for next year. Rotaspec, I hope you get yours soon.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 23rd December 2012, 04:09 AM   #295
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by Pano View Post
Thanks, but I'm on the other side of the continent. Guess it will be a project for next year. Rotaspec, I hope you get yours soon.
Oops... I thought you are in North California.
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 23rd December 2012, 04:12 AM   #296
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by regal View Post
One day all the supply off all these fabulous inexpensive Russian tubes is going to come to a halt and we will all wish we had bought 100 of each. Tubes like this one are a deal of a lifetime right now.
I have at least hundred of them. And lifetime stock of 6S17K-V and 6N16B-V.
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 23rd December 2012, 12:07 PM   #297
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Sorry for my ignorance, can 4P1L be used as preamp? if yes what's the input & output impedance? what's the gain? for SS amp can be used without output transformers if not what are the specs of the output transformer?

Thanks for help, I wish you Merry Christmas & a Happy New Year for all people of this amazing thread.

Felipe
  Reply With Quote
Old 23rd December 2012, 03:27 PM   #298
diyAudio Member
 
Join Date: Sep 2003
Location: London
Yes, 4P1L in triode can be used as a preamp, and it sounds great. BUT - it is microphonic and if that bothers you in your system you will need to take steps to kill the microphonics. Basically you need to mount it on a solid and fairly heavy piece of metal (or mount two on the same piece) and then decouple that from the chassis. You also need to decouple the chassis from the stand it's on. I have been winding teflon plumber's tape around the bottle half way up as well - not sure how much that helps but it doesn't seem to do much harm.

I use a 1:1 OPT straight into my amp - Lundahl 1660/18mA. That's a gain of around 10 and output impedance of around 2k. You need at least 15mA. For a lot of SS amps you would need to step down, so you will lose some of the gain. You may be OK with others - depends what devices are on the input.

But, yes, 4P1L makes a great preamp and it's what I use myself - in filament bias.
  Reply With Quote
Old 23rd December 2012, 04:26 PM   #299
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Thanks Andy, I have on hand the Lundahl 1660/18mA for #26 tube preamp and wired as you: Alt Q SE Line Output 4.5 : 1 with that configuration have a gain x10 & and output impedance of 2K? could you link me to your schematic? can be enough gain for vynils?
  Reply With Quote
Old 23rd December 2012, 04:37 PM   #300
работник
diyAudio Member
 
Rod Coleman's Avatar
 
Join Date: Jul 2004
Location: Warwickshire UK
Quote:
Originally Posted by regal View Post
Yes I agree about the flexibility, it is such an interesting tube and I have a quartet I am dying to use. Using the 3a5 for a DAC output makes sense, and it adds more flexibility for a wide range of DAC's/preamps. But for my case with a solid 2Vrms DAC (SS) do you think a 4P1L would have enough gain to push a 6C4C 150V-180 Vp-p, maybe even even a GU-50 triode ? Worse case I would use an input transformer to use the DAC's balanced output and deliver 4Vrms to the 4P1l ?

Thanks your work with all DHT SET's is inspiring. I just figure if I'm doing an DHT oupt it really makes most sense to use all DHT.
Hi Dave,

The 4П1Л will drive the 6C4C into clipping easily.

It's very well behaved in pentode mode - there are no sharp rises in screen current, even with the anode down at 50V.

The only big demand is a B+ of 500V. But the current is low, so you can use a voltage doubler to get this high voltage. a tube (damper) rectifer is recommended, to give a slow rise to this level of HT.

Operating condition:

Va(b) = 500V, well filtered LCLC or shunt regulated
Va = 200V
Vg2 = 150V (eg DN2540 CCS into gas tube)
Ra = 10K 14W Welwyn W24
Ia = 30mA
Pa = 6W (7,5 max rating)

Gain is approx gm.RL: about 6 x 10 = 60
So to get 90V zero-to-peak, need 1.5V peak from DAC

IME a single pentode driver sounds much fresher and more articulate than 2-stage triode.

And if you like the sound in pentode, you can convert the stage to shunt cascode later, and get better supply rejection, more gain, and better sound.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
pentode in triode mode SE vs a DHT SE like 2a3/300b jarthel Tubes / Valves 67 8th July 2014 01:51 AM
Russian-English Translation of 4P1L datasheet 316a Tubes / Valves 16 6th September 2011 12:09 AM
Rare audiophile stereo tube SE amplifier DIY kit (6C2C + 4P1L). mik190 Swap Meet 7 1st November 2010 07:59 AM
Can the Golden Tube Audio SE-40 SE drive 16 ohm woofers? nelsondog Everything Else 1 11th November 2007 05:00 PM
Parallel SE vs. Single SE Output Question valveitude Tubes / Valves 19 4th May 2005 05:36 PM


New To Site? Need Help?

All times are GMT. The time now is 02:04 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2