Tube DIY Asylum

interstage tranny / load resistor=Padding Resistor

68.39.179.254

In Reply to: RE: interstage tranny / load resistor question posted by frankn on June 19, 2008 at 18:53:26

Sometimes, the tranny gain is very high, or the tranny has some high frequency rising response, leading to a bright sonic character, or even harsh. By "padding" the tranny secondary, with a suitable loading resistor, we can tame this effect. Start with a 500K Ohm, which will have minimum effect. Then, work your way down in R value, until the highs start to sound rolled off, or, at least more mellow.

In severe cases, when the sound can be described as fuzzy, there is certainly something wrong. Sometimes, there are "parasitic oscillations" occurring, causing the fuzz and intermittently affecting the output tube's bias. Besides the padding resistors, sometimes the fix requires small values of capacitance, also in parallel with the secondary/grid, to bypass those parasitics. Without a sig generator and scope, experimentation with these methods can save the day, er, sound...

Follow Ups:

RE: interstage tranny / load resistor=Padding Resistor - frankn 20:36:21 06/19/08 (0)

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.