so i did the bias mod on my 6505+

[Vrad]

Took all of 5 minutes. In fact it took that long because I had to wait for the soldering iron to heat up. I put a 10k resistor in parallel with the 12k that's there. I biased the amp to 39 mA or so and played it for about 10 mins. Initial impression is that it sounds beefier with less fuzz. I'll have to play it some more to see what I think.

 

[glpg80]

once you get the tubes out of crossover the resonance and presence controls wake up big time at band volumes. every 5150 should be biased correctly - makes a world of a difference in noticing the differences between tube types as well.

 

[Lord Toneking]

Come to Ohio and fix my amp fool!

 

[Vrad]

once you get the tubes out of crossover the resonance and presence controls wake up big time at band volumes. every 5150 should be biased correctly - makes a world of a difference in noticing the differences between tube types as well.

Yeah I gotta play it some more to figure out what I'm actually hearing.

 

[Vrad]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

 

[Lord Toneking]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

No, I suck ...but i did treat myself to 2 capt and cokes and a couple miller lites for my efforts

 

[Vrad]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

No, I suck ...but i did treat myself to 2 capt and cokes and a couple miller lites for my efforts

I suck at diagnosing too. Too new at this shit. U want to pm me. Maybe we can figure it out.

 

[Vrad]

Ok so I played it again. Pretty loud. It sounds really good. The tone is fatter/thicker. Just sounds a better. The rhythm channel with a boost sounds great! The lead channel on it's own sounds great... Maybe I'll make a clip at some point.

 

[Quickdraw]

What method did you use to bias? I'm thinking of finally doing this mod myself now. Thanks for sharing man.

 

[Mailman1971]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

No, I suck ...but i did treat myself to 2 capt and cokes and a couple miller lites for my efforts

There you Go Tom......and thats a good pat on the back!
We need to hook it up of these days for an amp fest!
Or hell......meet up at Cedar Point for some good old fashioned coaster stuff!@!

 

[Vrad]

What method did you use to bias? I'm thinking of finally doing this mod myself now. Thanks for sharing man.

I have a 6505+ which already has a bias pot but the sweep is very small. So I put a 10k resistor across the 12k resistor. 10k + 12k in parallel is about 5.6K which gives me plent of range to bias up the amp correctly.

I used my Biasrite and biased to 40mA.

For a 5150 you'd need to add a bias trim pot and a resistor.
Check out Psychodave's 5150 mod thread for pics and more info. It's really easy.

 

[Motorpud]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

No, I suck ...but i did treat myself to 2 capt and cokes and a couple miller lites for my efforts

There you Go Tom......and thats a good pat on the back!
We need to hook it up of these days for an amp fest!
Or hell......meet up at Cedar Point for some good old fashioned coaster stuff!@!

I just went there in August, those big coasters never get old

 

[Lord Toneking]

Come to Ohio and fix my amp fool!

Did u ever make any progress on diagnosing it?

No, I suck ...but i did treat myself to 2 capt and cokes and a couple miller lites for my efforts

There you Go Tom......and thats a good pat on the back!
We need to hook it up of these days for an amp fest!
Or hell......meet up at Cedar Point for some good old fashioned coaster stuff!@!

Coaster stuff? Heck us old guys would be gaulking at all the little chickies

Seriously though, an ampfest somehow somewhere would be cool