How do you bias an amp that doesn't have a bias pot!!!

[Quencho092]

Peavey classic from '75-no bias pot! How do you bias this POS! It says that it's made for 6l6gc tubes-are they in the same range as kt66 tubes when it comes to biasing?

 

[texasguitarslinger]

Re: How do you bias an amp that doesn't have a bias pot!!!

If it doesn't have a bias pot it is probably self-biasing.

 

[mrid]

Re: How do you bias an amp that doesn't have a bias pot!!!

You install a bias trimmer! :laugh2:

 

[Vasshu the humanoid typhoon]

Re: How do you bias an amp that doesn't have a bias pot!!!

Bah
You are going to solder on some other values in components, but preferably you should get some tech to install one biastrimmer-pot.

 

[Lewguitar]

Re: How do you bias an amp that doesn't have a bias pot!!!

You install a bias trimmer! :laugh2:

That's the right answer. :laugh2:

Take it to a tech who knows his stuff and have a trim pot installed.

Cathode biased amps (like the AC30, 5E3 Deluxe, etc.) don't need one...fixed bias amps (isn't that a strange thing? Fixed biased amps are the ones that need to have the bias adjusted!) do!

Boogies should have that done too...had to have it done to my Mark I.

Lew

 

[y2stevo]

Re: How do you bias an amp that doesn't have a bias pot!!!

Would the tone of my DSL benefit from biasing??

 

[RiffRaff]

Re: How do you bias an amp that doesn't have a bias pot!!!

take it to a tech and have the bias adjusted or have a bias pot installed.

 

[Quencho092]

Re: How do you bias an amp that doesn't have a bias pot!!!

whats the usual bias value for a 6l6gc tube in a fender style amp? #mA's?
And just out of curiosity, which big amp companies have bias pots stock? I have a blackface bassman in mind and want to know if they have bias pots in em.

 

[proxy]

Re: How do you bias an amp that doesn't have a bias pot!!!

whats the usual bias value for a 6l6gc tube in a fender style amp? #mA's?
And just out of curiosity, which big amp companies have bias pots stock? I have a blackface bassman in mind and want to know if they have bias pots in em.

I can;t give you an answer, but I'd take it to get biased and tell them to install one if there isn't a bias adjuster.

 

[Quencho092]

Re: How do you bias an amp that doesn't have a bias pot!!!

I NEED CASH!!!! the brokeness...

 

[That90'sGuy]

Re: How do you bias an amp that doesn't have a bias pot!!!

Just get quality matched tubes if you're strapped on cash. I haven't gotten a bias trimpot installed yet on my H&K. The tubes have lasted for a while and they sound great... maybe I just got lucky.

 

[Gearjoneser]

Re: How do you bias an amp that doesn't have a bias pot!!!

With a mA bias tool, 6L6's usually operate best around 32-33 mA, and EL-34's operate best around 36-40mA.

 

[chcjunior]

Re: How do you bias an amp that doesn't have a bias pot!!!

Would the tone of my DSL benefit from biasing??

Depends upon your ear. You can tweak your tone by either running the bias hot or cold. Biasing the DSL is extremely simple and can be done with a $15 multi meter.