Any info on this pair of Any info on TruTest TR117 Out-Put Transformer for Hi-Fi?
They look very similar to a pair of Sansui single ended HS-5 Output Transformer.
They also look very similar to some transformers I've seen installed in a Lafayette LA-240 (push pull EL84). The printouts on the power transformer of the Lafayette LA-240 were very similar to the ones of the power transformer of a Sansui Q-50.
Are the TruTest TR117 single ended as well?
They look very similar to a pair of Sansui single ended HS-5 Output Transformer.
They also look very similar to some transformers I've seen installed in a Lafayette LA-240 (push pull EL84). The printouts on the power transformer of the Lafayette LA-240 were very similar to the ones of the power transformer of a Sansui Q-50.
Are the TruTest TR117 single ended as well?
No, the TR-117 is a push-pull output transformer with, as you can see, 5K, 8K, and 10K primary impedance. It was also sold by itself by Lafayette in the early 1960s for about $20. I had 2 but built a mono amp (P-P 6BQ5) and gave it away for a good reason. I still have the other one. This is a really nice transformer and works great. I have the freq. response chart which came with the unit if you are interested. Or if you only have the one and are interested in getting rid of it, PM me and we can work something out depending on where you are. I would love to have another one of these and this is the first time I have seen it mentioned on DIY Audio in all the years I have been on this forum.
Ken
Ken
Thank you for the infos! If you could share the freq. response chart or any other original publication you have, that would be great!
I actually bought it not realizing it is push pull, I though maybe it was for single ended. I'm not planning to build any push pull amp, but I guess I'll hold onto the pair for now.
If I decide to sell it I'll PM you for sure.
I bought three of those circa 1960. The two 25W went into a pair of PPUL 6L6GC mono blocks.
They were used as daily drivers for 17 yrs. And still here on the shelf in working order.
The other is a 20W with UL taps, it is in an experimental PP 33s Class AB2 Amp. The Driver SE 33 IT
is a Hammond special. It too is on the shelf, I pull it out occasionally to try different measurement ides.
The OPTs came with a freq run printout.
They were used as daily drivers for 17 yrs. And still here on the shelf in working order.
The other is a 20W with UL taps, it is in an experimental PP 33s Class AB2 Amp. The Driver SE 33 IT
is a Hammond special. It too is on the shelf, I pull it out occasionally to try different measurement ides.
The OPTs came with a freq run printout.
