My First Audio Project (Flesh and Blood mono blocks)

[tamra]

ISO TRANSFORMERS – 管球アンプ用トランス　　　 Audio Transformers for Tube Amplifiers

 

[Bigun]

A recommendation to consider the (FC-20S datasheet from ISO attached) XE-20S from another thread: Tango XE Output Iron (merged)

generally, i have never heard an amp with Tango OPTs that sounded like junk, it always was gorgeous sound. Tango sets the standard the other transformer manufactures have to tolerate to be compared with. (Some Japanese experts prefer certain certain but not all Tamura irons)
I have not yet listened to the Tango XE60-2.5S. If you have not yet bought the trannie, i would like to give an addititonal hint: The Tango XE-20S is a more flexible choice, I have listened to it in several set-ups, the sonics are just gorgeous, you do not pay sonically for the flexibility. Primary impedances are 2k5, 3k5, 5k.
....

However, it doesn't have a very high primary inductance at < 20H. A specification for the XE-60-5S is hard to find, the closest is shown in the attachment and we see > 20H. Another transformer maker I respect a lot is Sowter and their SE09 (datasheet attached) looks like an interesting option for 5k load: SE09 SINGLE ENDED OUTPUT TRANSFORMER