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Best SE output transformer for 300B - shootout

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Hello Ciro,
I wonder whether you would mind using the Hashimoto split secondary winding schematic, without asking you to give away too many of your winding secrets, to show the direction and connections of your split windings?
many thanks
Ciao
tim
No problem sharing the basics of my winding insights ;)
but remember, I use a winding inspired to Hashimoto, but I do not know if it works exactly the same.

Hashimoto splits secondaries within the same slot, while leaving primary sections full width.
I do the contrary: splitted primary winding, full width secondary.
I guess the advantages are very similar.
Since I use series connected secondary sections I maximize the advantages splitting the primary.
I have never unwound an Hashimoto OPT, but I guess they use a parallel or maybe series/parallel secondary configuration.

I use the Hashimoto style winding in 2-4 slots windings or in 4-8 slots windings.
To the best of my knowledge Hashimoto uses only 1-2 slots windings.

within the same slot, and within tha same section my splitted primary windings have the same direction and are series connected, practically is almost like a standard single slot winding.
Lets say you would have a primary section with 4 layers with 100 turns x layer,
now you will have two sections of 4 layers, 50 turns x layer series connected. Last turn of the 4th layer of first section will go on with the first turn of the 1st layer of the second section.

Compared with a standard single slot winding, this will give a better distribution of stray capacitances, but not as good as a full 2 slots winding.
 
Dude, let me refresh your mind. In post 54 you say you made transformers profen to be superiour to the best of Tango and Tamura.

You give till so far no proof at all, just give incompleet measurements. Some of you measurements look nice but.... Some could be not truth at all!
Your last measument of an transformer has a frequency response of 11Hz-320kHz? No way, i not believe that! Not with 2 slots 10 sections as you say. And maybe not with more complicated winding techniques too.
Look at brand as Sowter and Lundahl who use 2 slots technique too, or Hashimoto. Even on toroids we not see such performance.
Did we see the last 100 years any transformer with this performance! No!
Come on, who dos believe your story?
The most easy way is to tell us that's it all about sound.........pfffffff
Mate, I see you do not get the point (or may be you do not want to get it).
I am not interested in playing "my triode is longer, my triode is stiffer" game.
(The same applies to "my OPT is longer, my OPT is stiffer" :D )
<snip>
 
EL509

Thank you Ciro,
You are very generous.
I need to draw out what I think you have written so I can get my mind around it. Though it's purely academic as I have no ability to wind OPT. Though I would like to build a second EAR859 amp at some stage.
My venerable and much modified EAR859 amp has EL509 output tubes. Tim de P wrote that it has a 4.8K OPT, and I'm sure (at a hifi show in Buxton UK many years ago) said it had 13 winding sections.
best regards
tim
 

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I just built a 4P1L SE which I posted on the "One more 4P1L SE" thread". Up to now I've been using a LL1660/80mA with two 4P1L outputs in parallel. This version with a single 4P1L output sounds a touch better to me. OPT is a LL1682/50mA. Much cheaper and smaller! Looks like a subtle improvement, though the circuit is slightly different so could be other things. But I'm definitely not losing any quality here.

The LL1682/50ma is one of a family which includes the LL1663 and LL1664 which probably sound similar. Does anyone have any feedback on these models? What I'm hearing is good.
 
I use the Hashimoto H507S for my 45 monoblock amps along with their PT-100F power transformer and C60-50W choke. They are very good units and the amp is flat to 50KHz within a dB or so. I've been using the amps regularly since 2008 and the performance has been excellent. I can highly recommend the Hashimoto products, I have a decent sized collection of them. All are top notch fit/finish and performance, but not inexpensive.

Regards, KM
 
guys, this is my short list, after I read a couple of forums and based on other mates subjective comments, to replace my AN 152 OPT (AN Kit One):

Hashimoto H-30-3,5
Tamura F-2007 (as far as I know, 7001 and 7002 were discontinued)
Monolith Magnetics Summit S-9

All of this trafos can be new and not at speculative prices as some Tango and Tamura.
The idea is to get something equally good to the Audio Note double C core Improved HiB core, the less expensive of the AN C core line, but costing either way something like the double than the ones on the list. So that is a very good reason to look for alternatives. Btw, I have no information about the new wavac tango.
Any comment will be welcomed.
 
Why look for exotic, expensive irons when we have top quality, reasonably priced, manufacturer right here in the US? I mean Electra Print Audio located in Las Vegas, NV. A bonus point is that every time I do business with Jack Eliano, the owner, I get tons of audio info thrown in for free.
 
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