• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Input transformer question

Status
Not open for further replies.

BHD

diyAudio Member
Joined 2004
I have a DAC that uses an output transformer and the output impedance of the DAC is listed as 600 ohms. If I wanted to put an input transformer on a single ended tube amplifier to work with this DAC, am I correct in assuming that I should use one with a 600 ohm primary? If so, what would be a good secondary impedance? 10K? 5K? The amp I'm considering is a 5842 transformer coupled 5K to 5K to a 45 or a 2A3. The interstage transformer will be a Hammond 126A and the output transformer will be a One Electron 3.5K if 2A3 or a 5K Edcor if a 45.

Any help would be greatly appreciated.

🙂
 
An input transformer (like all transformers) doesn't have an intrinsic "impedance," it just transforms the secondary impedance to the primary.

For a 600R output impedance, you want at least 10x greater load impedance- a nice 1:1 transformer like the Jensen JT11P-1 or a Cinemag 15/15B with an appropriate secondary terminating resistance will kick butt in this application.
 
Status
Not open for further replies.