Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: kagliostro on May 03, 2015, 12:06:30 pm

Title: How to test an unknown OT - Video
Post by: kagliostro on May 03, 2015, 12:06:30 pm

https://www.youtube.com/watch?v=Yzo3A-NywSs (https://www.youtube.com/watch?v=Yzo3A-NywSs)


K

Title: Re: How to test an unknown OT - Video
Post by: dude on May 03, 2015, 03:06:04 pm

OK, I used a 7.3vac transformer and put that voltage on the primary of the single ended OT

Gave me .20 VAC on the secondary

That gave me a turns ratio of 36.5 to 1

Squaring the turns gave me 1332.

Now dividing that by the impedance I want to use:

I get 10,658 @ 8ohms  and 5328 @ 4ohms

The amp is a single ended 6V6, plates running at around 315/325vdc from memory (pretty close)

Not sure what that 6V6 wants to see at 8 ohms but looks like this OT is at 10,658 @ 8 and 5328 @4

Can I use an 8 ohm speaker?

al

Title: Re: How to test an unknown OT - Video
Post by: shooter on May 03, 2015, 03:25:46 pm

Quote

Can I use an 8 ohm speaker

From the data sheet I have it shows about 8.5k @ 315vdc so I think the 8 ohm will work best

Title: Re: How to test an unknown OT - Video
Post by: TIMBO on May 05, 2015, 04:07:18 am

K, That's GREAT. Thanks