My low watts projects

the thermionic watercooler

Re: My low watts projects

Postby azazello » Wed Feb 19, 2014 1:46 am

Great tube in SE E236L Telefunken with little cosmetics adjusting: https://picasaweb.google.com/1095707775 ... 5944848034
Output power in triod mode about 5 W.
Last edited by azazello on Wed Feb 19, 2014 11:48 am, edited 2 times in total.
Projects: OTL 6AS7 Gen, Electric, SEs 2A3 RCA, 300B JJ, 6S4S, 4P1L, EL11 Telefunken, 6AS7 RCA, 6S33S, 6S41S, 6S19P, headphone ampl. OTL Loftin White 6AS7 RCA....SE E84L&E80CC Siemens&Tel-n.
User avatar
azazello
KT88
 
Posts: 285
Joined: Tue Nov 10, 2009 8:24 am
Location: Bulgaria - EU

Re: My low watts projects

Postby Geek » Wed Feb 19, 2014 4:58 am

That's like an EL36. BEAUTIFUL sounding tube in triode :))
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
User avatar
Geek
KT88
 
Posts: 3585
Joined: Sun Oct 21, 2007 3:01 am
Location: Chilliwack, British Columbia

Re: My low watts projects

Postby azazello » Wed Feb 19, 2014 9:13 am

Geek wrote:That's like an EL36. BEAUTIFUL sounding tube in triode :))

Not....EL36 is like E236L.... ;) (lol) (b)
Projects: OTL 6AS7 Gen, Electric, SEs 2A3 RCA, 300B JJ, 6S4S, 4P1L, EL11 Telefunken, 6AS7 RCA, 6S33S, 6S41S, 6S19P, headphone ampl. OTL Loftin White 6AS7 RCA....SE E84L&E80CC Siemens&Tel-n.
User avatar
azazello
KT88
 
Posts: 285
Joined: Tue Nov 10, 2009 8:24 am
Location: Bulgaria - EU

Re: My low watts projects

Postby soundbrigade » Wed Feb 19, 2014 11:18 am

I recently got two more 5902 and a pair of 5719 to make up a submin 2W PP-amp. I will use Hammond 125B PP trannies and propably have Frag Jan Zuerst to wind med 150V HV- transformer - propably a toroid. In myc stores I have dug up an old nice and heavy external HDD-bay that will house all parts perfectly (I hope :/ ).
Will share some photos later.

I have seriously fallen in love with the tiny tubes, ofen called submin tubes or pensize tubes and would like to have a go at the compactron tubes (like the heap of 50CA10 I have collected for a comin project).
Magnus

"It is always more difficult to fight against faith than against knowledge."
User avatar
soundbrigade
KT88
 
Posts: 1760
Joined: Mon Jan 28, 2008 4:57 am
Location: Little Paris, Sweden

Re: My low watts projects

Postby EWBrown » Fri Feb 21, 2014 6:28 pm

And, not to forget to include this in your new circuit ;) (lol)

Image
Last edited by EWBrown on Mon Feb 24, 2014 10:23 am, edited 1 time in total.
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !

Re: My low watts projects

Postby soundbrigade » Sun Feb 23, 2014 7:16 am

Magnus

"It is always more difficult to fight against faith than against knowledge."
User avatar
soundbrigade
KT88
 
Posts: 1760
Joined: Mon Jan 28, 2008 4:57 am
Location: Little Paris, Sweden

Re: My low watts projects

Postby EWBrown » Wed Jun 04, 2014 7:39 pm

So, I now have a quantity of ten 4P1Ltubes newly arrived.... Not from Russia, but from Malaga, Spain. And a lot of questions to ask (???)

So far I haven't found any detailed operating characteristics of these tubes, just two different very "generic" and not-too-informative mini-data sheets, both of which are from Russia, though in English language. .

It appears that VA = 150VDC, IA = 50 mA and approx. -8.5V control grid bias, is nominal operation, into a 4.5K plate load.

What is the specification for triode strapped operation, as far as internal plate resistance, transconductance and voltage gain?

If I were to triode strap these, I presume that the usual G2 connected through a 100 ohm resistor to the plate would be good. Should the 3rd grid be connected to the filament CT or ground, or directly to the plate? Update- it connects to the plate trough a resistor, same as for the screen grid.

Plan B would be to operate these in Class AB1 Push-pull, not sure of the best OPT A-A impedance to use for this application, I would SWAG 8K A-A, or should it be lower, perhaps 4.3K A-A, or even 3.3K A-A, or perhaps higher - 9 to 10K A-A ? Just considering OPTs that I already have available...

Just pondering another "weird tube" amp project...

Image
УНИВЕРСАЛ ТЕХНО-КОНТРОЛЬ

/ed B
Last edited by EWBrown on Thu Oct 09, 2014 5:37 pm, edited 3 times in total.
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !

Re: My low watts projects

Postby EWBrown » Mon Jun 09, 2014 11:10 am

Just stumbled across some new 4P1L information, including triode strapped operation, from the UK:

http://www.bartola.co.uk/valves/2013/09 ... -improved/

Image

More 4P1L information and experimentation: http://www.bartola.co.uk/valves/tag/4p1l/


Image

Image

Image

/ed B
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !

Re: My low watts projects

Postby Shannon Parks » Fri Jun 13, 2014 5:34 am

Those curves look great, Ed: very linear and a nice low impedance. Only negative I see is their low dissipation. Kinda like a 6BX7.

Shannon
User avatar
Shannon Parks
Site Admin
 
Posts: 3764
Joined: Tue Mar 18, 2003 5:40 pm
Location: Poulsbo, Washington

Re: My low watts projects

Postby soundbrigade » Thu Oct 09, 2014 5:47 am

Have sort of different problem. Got a small box ith 12 6S19P and decided to build something smallish to test the tube. However I need a 2K5 SE-tranny but right now I have just 3K5 trannies to spare. That's OK, but I also have some 5K transformers (maybe 3 pairs) and have really no clue what tubes to mate them with. I guess they are Ok for amsp <5W.
Ideas?? (???)

I have tubes like 4P1L, 6L6, 6V6, ECL82/85 and some more.
Magnus

"It is always more difficult to fight against faith than against knowledge."
User avatar
soundbrigade
KT88
 
Posts: 1760
Joined: Mon Jan 28, 2008 4:57 am
Location: Little Paris, Sweden

Re: My low watts projects

Postby Geek » Thu Oct 09, 2014 11:35 am

650mA on that driver tube, eh? ;)
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
User avatar
Geek
KT88
 
Posts: 3585
Joined: Sun Oct 21, 2007 3:01 am
Location: Chilliwack, British Columbia

Re: My low watts projects

Postby EWBrown » Thu Oct 09, 2014 5:27 pm

Filament current is 650 mA parallel connection (2.1V) or 325mA series connected (4.2V) .

The 25 ohm resistor in series with the driver stage filament drops the filament to 4.2VDC, and also applies 16.7V "cathode" bias on the filament, referenced to signal ground.

He is (mis)using the term "CCS" for a current-regulated power source, for filament and for grid bias for the two paralleled output tubes.

/ed B
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !

Re: My low watts projects

Postby Geek » Thu Oct 09, 2014 8:19 pm

Oh geez! I shouldd'a seen that :$
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
User avatar
Geek
KT88
 
Posts: 3585
Joined: Sun Oct 21, 2007 3:01 am
Location: Chilliwack, British Columbia

Re: My low watts projects

Postby EWBrown » Fri Oct 10, 2014 6:47 am

Image
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !

Re: My low watts projects

Postby azazello » Wed Apr 15, 2015 12:48 pm

https://picasaweb.google.com/1095707775 ... 7091783346
PP unknown great tube 815 - two penthodes in tube. I recommend You to try..../PS - in black box in left side/. I added gas stabilitron СГ4 for 150 VDC for second grids - not shown near to 815.
Projects: OTL 6AS7 Gen, Electric, SEs 2A3 RCA, 300B JJ, 6S4S, 4P1L, EL11 Telefunken, 6AS7 RCA, 6S33S, 6S41S, 6S19P, headphone ampl. OTL Loftin White 6AS7 RCA....SE E84L&E80CC Siemens&Tel-n.
User avatar
azazello
KT88
 
Posts: 285
Joined: Tue Nov 10, 2009 8:24 am
Location: Bulgaria - EU

PreviousNext

Return to diy hifi

Who is online

Users browsing this forum: No registered users and 13 guests

cron