Best 7k output transformers for 46 triode SE amp

[carlos269]

Looking for opinion on the best 7k primary output transformers for a 46 strapped-in-triode for use in a Single Ended amplifier. I know that Hashimoto, Tamura, and Tango make or made 7k primary transformers but their low-end bass performance is curtailed to 30 to 45 Hz. Are there any 7K OPT that go down 20Hz or less? Did MagneQuest ever produce a 7K transformer? I know that they did a 6K FS-007.

Tribute Audio use to produce excellent 7K transformers. Are there any other high quality 7K OPT available today that deliver great bass from a 46 strapped for triode operation?

What is the best 7K OPT for this application in your opinion? Whether still produced or not, which OPT’s stand out with 7K primaries?

Thanks in advance. Your opinions and guidance is appreciated.

 

[rkoonce]

ISO FC-12S is a 7K 12 watt trans but -2dB @ 45Hz

 

[TG]

General Transformer (ex-Noguchi) makes a couple of models.
OHC-8WS-7K (Hi-B)
FM-14WS (Finemet)

 

[triode_al]

I have a Lundahl LL3720. It has special winding technique. 40mA available.

 

[fortyfive]

I have Hashimoto H-20-7U, excellent transformers. Like them more than ISO FC20S.

 

[carlos269]

Of the ones mentioned so far, the FM-14WS is inline with what I’m looking for. Let me know if there are others.

 

[fortyfive]

Hashimoto H-20-7U, 1 Watt, Straigth to 20hz. I dont understand what you mean curly bass performance.

 

[andyjevans]

My OPTs are made to order by Ogonowski in Poland. I'm very satisfied with them, and a good price too.

 

[carlos269]

“Curtailed” means rolled off. Most of the Japanese 7K transformers roll off the bass around 45 Hz. Some make it down to 30Hz but it is rare to find ones that make it into the 20’s at full power.

 

[carlos269]

I had heard that Monolith Magnetics were developing a line of lower power, 5W - 10W, transformers. Has anyone heard any details? Timing and if a 7K primary version is planned?

 

[Fuling]

I have a Lundahl LL3720. It has special winding technique. 40mA available.

Care to share your opinion about their sound quality? I'm about to order a pair for a 4P1L SET any day now.

 

[gupsta]

I had heard that Monolith Magnetics were developing a line of lower power, 5W - 10W, transformers. Has anyone heard any details? Timing and if a 7K primary version is planned?

I have one made for type 45 not listed on their website.

 

[gupsta]

Perhaps LL9202 would be a good candidate, 50mA 100H

https://www.lundahltransformers.com/wp-content/uploads/datasheets/1620_3_7_9202.pdf

 

[andyjevans]

Care to share your opinion about their sound quality? I'm about to order a pair for a 4P1L SET any day now.

My PSE 4P1L SET amp has Tomiko OPTs at the moment, but I'm going to rebuild my Ogonowski OPT amp as a PSE 4P1L SET with 26 driver. The Ogonowski OPTs are very nice - natural and detailed. Better than any Lundahls I've had in the past. For PSE 4P1L I'm using 3.5K in the Tomiko OPTs.