Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: stingray_65 on September 12, 2010, 10:20:14 am

Title: Howl and Squeal on fire up
Post by: stingray_65 on September 12, 2010, 10:20:14 am

Hi fella's

Ok I know flip the brown and blue wires on the OT. (did that and no howl)

Heres the issue, in my haste for a neat lead dress I've cut the blue wire too short to"flip" to the other tube socket.

I don't want to splice in 3/4" of lead to make it reach.

Can I "flip" the leads  from my PI instead?

Ray

Title: Re: Howl and Squeal on fire up
Post by: sluckey on September 12, 2010, 10:30:28 am

yes

I never trim the OT leads for an amp that uses NFB until I know which way is correct.

Title: Re: Howl and Squeal on fire up
Post by: Fresh_Start on September 12, 2010, 11:12:18 am

+ I never connect the NFB at all until I'm getting good sound out of the amp during startup.

Potentially dumb question:  could you flip the leads on the primary side of the OT and get the same result?

Chip

Title: Re: Howl and Squeal on fire up
Post by: stingray_65 on September 12, 2010, 12:21:40 pm

Quote from: sluckey on September 12, 2010, 10:30:28 am

yes

I never trim the OT leads for an amp that uses NFB until I know which way is correct.

I only trim them when I want howl on start up  :angel

LOL thanks for the confirmation Steve.


Chip,
You can, I have BUT! you can't use the other taps

Thanks
Ray

Title: Re: Howl and Squeal on fire up
Post by: eleventeen on September 12, 2010, 01:50:44 pm

Quote

I never trim the OT leads for an amp that uses NFB until I know which way is correct.

They taught us that in the 1947 Airco Welding School Course.