VM100 - how to prepare for TTL 5 Volt i/p?

Kits Audio Hi Fi Projects
1

Hi … I am trying to use a VM100 to drive square wave frequencies into an 8 ohm air coil. (This is for a pulsed magnetic therapy application and the wide bandwith of the VM100 would seem to make it attractive as a power amplifier).

Can anyone tell me how to safely condition 5 volt TTL signal, which I am using as my pulsed frequency source, so that it is safe for input to the VM100 amplifier?

I have already connected a 47k log pot between TTL signal and GND - with the tap connected direct to the VM100 input, and the TTL GND connected to VM100 GND … but this gave me SMOKE output from the amplifier… :oops: !!!

Do I need to add an additional a potential divider to limit the input to the the amp to some lower voltage? … any suggestions or ideas?

Thanks for any help … John

2

Don’t spam your question in three different categories ok

3

Please accept my Apology,
Spam was not intended. I thought I had probably selected a wrong forum area for my question, so I reposted. This is new for me - sorry again.
John

4

This circuit has been designed to handle MUSIC signals and to drive a SPEAKER. We cannot guarantee it is suited for your application. We strongly suggest to try it with music & speaker first, to make sure the amp is operating correct. If it has smoked, replace all semiconductors. Use a resistor divider to reduce your TLL level to 0.75V. Good luck.