Tubes Asylum

Questions about tubes and gear that glows. FAQ

Return to Tubes Asylum

Message Sort: Post Order or Asylum Reverse Threaded

45 Push/Pull

69.114.228.134
Posted on December 29, 2009 at 07:15:43
glenz10183@aol.com
Distributor or Rep

Posts: 84
Location: New York
Joined: September 27, 2003



Got the chance to wrestle Ed Duda's 45 Push/Pull amp from him. It has adjustable bias. Mr. Duda was the head engineer for Lafayette Radio for many years, and was responsible for many of their innovative ideas. Note the new "Globe" 45's from Emission Labs in the background. The amplifier is built on a custom made "perspex" chassis. The filament and intestage transformers are custom wound by Ed himself. The tube compliment consists of (4)76 tubes, (4)45 tubes and (1)80 rectifier tube.

 

Hide full thread outline!
    ...
Nice..........nt, posted on December 29, 2009 at 08:45:39
Neff


 
.

 

RE: 45 Push/Pull ......... Man you're talking my language.., posted on December 29, 2009 at 09:08:17
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003






I've built at least 4 45PP amps and completely rebuilt a pair of Wurlitzer 45PP amps.

This is a picture of my reference 45PP. It's 417A (E-P)IT coupled to 45PP with Electra-Print OPT's with solid Silver secondaries. As pictured with 45 Globes. This amp can run 2A3's cause of 4amp 2.5 volt filament transformers. I would really like to try EML's, but for now that not possible.

Have fun!
Willie

 

RE: 45 Push/Pull .........and another, posted on December 29, 2009 at 09:10:44
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003






Gone to a good home!

 

RE: 45 Push/Pull .........a pair ., posted on December 29, 2009 at 09:14:06
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003







These are keepers!

 

RE: 45 Push/Pull .........a different one., posted on December 29, 2009 at 09:18:16
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003








Gone to another home!

Have fun!
Willie

 

RE: 45 Push/Pull .........a different one., posted on December 29, 2009 at 09:25:54
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003












This one used E-P Autoformer as IT.

Willie

 

RE: 45 Push/Pull .........and another, posted on December 29, 2009 at 09:32:10
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 I like that semi modern version of an Atwater Kent. That would be a retro version of course..Anyway,nice amplifier.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

Nice stuff Drummerwill !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, posted on December 29, 2009 at 12:00:09
Interstage Tranny
Audiophile

Posts: 3063
Location: Eastern
Joined: October 4, 2006



Yes, Wurlitzer amp chassis are excellent platforms. I love the 771s, the first red ones. I've used the 660s as prototypes. Their back bias is a very good scheme, just like so many prewar amps, as well as the later Brook 10 watters, floating the B+ center tap. It's a great self regulating bias method, actually closer to cathode/self bias than fixed bias supplies. If the bias R opens, there will be no B+, which is a great way to save those precious tubes.

Do you still use the stock interstage trannies ? I could use a few more of them...Nice work on your amps; real nice work...

 

RE: 45 Push/Pull ......... Man you're talking my language.., posted on December 29, 2009 at 13:03:32
glenz10183@aol.com
Distributor or Rep

Posts: 84
Location: New York
Joined: September 27, 2003
 Willie,
Ed's amp runs 2A3's too!

 

OT Reply, posted on December 29, 2009 at 20:12:45
Eli Duttman
Audiophile

Posts: 10455
Location: Monroe Township, NJ
Joined: March 31, 2000
 Since you are in contact with Mr. Duda, would you ask him if Bob Murray is still among the living. Mr. Murray was Lafayette's engineer at the 100 6th Ave. location. That man taught me a thing or 2 back when I was a snot nosed kid.


Eli D.

 

RE: OT Reply, posted on December 29, 2009 at 20:59:09
glenz10183@aol.com
Distributor or Rep

Posts: 84
Location: New York
Joined: September 27, 2003
 Will do Eli!

Best,

George

 

RE: OT Reply, posted on December 30, 2009 at 06:39:01
glenz10183@aol.com
Distributor or Rep

Posts: 84
Location: New York
Joined: September 27, 2003
 Hi Eli,
I spoke with Ed regarding Bob Murray. He remembers Bob, but has no idea where he is these days. Ed told me that Bob Murray partnered with Frank Lester(who also worked at Lafayette). They both worked together on many projects.

Best,

George

 

Thanks for trying! (nt), posted on December 30, 2009 at 16:57:46
Eli Duttman
Audiophile

Posts: 10455
Location: Monroe Township, NJ
Joined: March 31, 2000


Eli D.

 

RE: Nice stuff Drummerwill !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, posted on February 17, 2010 at 17:16:40
rockdoc


 
Very cool! I've got a box of 45's; I need to know more about these Wurlitzer amps!

Steve

 

RE: 45 Push/Pull, posted on May 20, 2017 at 13:31:15
llassoff
Audiophile

Posts: 3
Location: Philadelphia, PA
Joined: April 27, 2014
 I recently picked up 2 compact little 45 SET amps made by Mr. Duda off of CL. They were just too cute not to buy! I wish I had the schematics. They sound terrific but have a little bit of hum to them, not at all objectionable when the musics playing though. I also bought a 3rd amp, a 3E29 SE amp that came out his workshop also.

 

RE: 45 Push/Pull, posted on May 21, 2017 at 14:45:06
glenz10183@aol.com
Distributor or Rep

Posts: 84
Location: New York
Joined: September 27, 2003
 He had some interesting designs that were conceived in his basement. I have an unfinished 7C(total redo) that he was working on that needs to be completed.

 

RE: 45 Push/Pull, posted on May 21, 2017 at 19:24:29
llassoff
Audiophile

Posts: 3
Location: Philadelphia, PA
Joined: April 27, 2014



I also have a very interesting and wild looking 3E29 single ended amp that was from his workshop as well.

I'm new to posting on this site, I wonder if I can upload pictures from my phone onto this sits?

 

Page processed in 0.035 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]